This international application requirement is forwarded to the priority of the 2010-121186 Japanese patent application of Japan Office on May 27th, 2010, whole disclosures of this Japanese patent application are incorporated to herein by reference.
Summary of the invention
Technical problem
Because patent documentation 1 has been described, in the antenna assembly of discussing in the above, " about actual gain; gain declines slightly at high frequency band place; but gain improves at low-frequency band place; thereby on whole frequency band, obtain stable actual gain ", therefore, on the almost whole frequency band of service band, obtained favourable characteristic.Yet, because the actual gain at high frequency band place is low, need to further improve at this frequency band place.
Therefore, the duplicate test of being implemented by the present inventor has been found that in order to improve antenna assembly in the actual gain at high frequency band place, and the opening order of a group number that is formed at reflector place can increase.
Yet, in the antenna assembly of discussing, being similar to the whole shape of reflector in the above, the shape of the opening of reflector is longer in the vertical direction of the polarised direction with radio wave.Therefore, if opening order of a group number increases to improve the actual gain at high frequency band place, will cause the further increase of the whole length (length in the direction vertical with polarised direction) of reflector so, thereby have the problem that increases antenna assembly size.
Under this problem, target of the present invention is to improve the actual gain of high frequency band side in service band, and in the total of reflector that need to be in antenna assembly by forming a plurality of openings at tabular component place.
Technical scheme
The antenna assembly of the present invention of realizing this object is characterised in that, antenna assembly comprises: radiator, transmitting linearly polarized radio wave, and reflector, by conducting electricity and being similar to tetragonal tabular component, forming, the plate surface of described tabular component is arranged to towards described radiator, wherein, at the described tabular component place that forms described reflector, a plurality of openings at certain intervals conllinear arrange to be positioned at the direction identical with the polarised direction of the radio wave of launching from described radiator, opening group is along being arranged on a plurality of rank with the direction of described polarised direction quadrature, described a plurality of openings that wherein each opening group is arranged by conllinear form, wherein, form be arranged in the described opening group on a plurality of rank each of opening for approximate square shape and be formed and penetrate described tabular component, wherein, wavelength corresponding to the radio wave of peak frequency in the service band of described radiator, described tabular component is set in the length with described polarised direction equidirectional the length that the radio wave of minimum frequency can reflect, and wherein, described in each, the length on the limit of opening is set by the wavelength based on the radio wave of minimum frequency in described service band, make to form opening group's open amount described in a line and add the length that radio wave that length that the above tabular component obtains in the length with described polarised direction equidirectional is described minimum frequency can reflect by the length on the limit of opening described in each is multiplied by.
Antenna assembly of the present invention is characterised in that, the described tabular component that forms described reflector is all crooked towards described radiator on the limit, two ends of described polarised direction.
Antenna assembly of the present invention is characterised in that, in forming the described tabular component of described reflector, a plurality of protuberances of giving prominence to towards described reflector are arranged on towards the end margin place of the described tabular component of described radiator bending and have each other certain intervals.
And, antenna assembly of the present invention is characterised in that, in forming the described tabular component of described reflector, all described in each between opening group's adjacent apertures and along the direction layout vertical with described polarised direction with at least one in a plurality of bars of the row across opening group described in each by being provided with step and projecting to described radiator side being arranged in bar place between corresponding opening group along described polarised direction.
And antenna assembly is characterised in that, described antenna assembly is for receiving the reception antenna of the aerial electric wave of TV of UHF frequency band, and the service band of described radiator is set to the UHF frequency band for television broadcasting.
Technique effect
According to antenna assembly of the present invention, in the mode identical with above-mentioned traditional antenna device, reflector forms by conducting electricity and being similar to tetragonal tabular component, and a plurality of openings are formed and penetrate its plate surface.And, each opening be shaped as approximate square shape.
In the tabular component of structure reflector, a plurality of openings are in the identical direction conllinear arrangement at a certain distance of the polarised direction of the radio wave with from radiator transmitting, on a plurality of rank that the opening group that a plurality of openings of being arranged by conllinear form arranges along the direction with polarised direction quadrature.
Corresponding to the wavelength of the radio wave of the peak frequency of the service band of radiator, tabular component is set in the length of the direction identical with polarised direction the length that the radio wave of peak frequency can reflect.The wavelength of the radio wave of the length on the limit of each opening based on minimum frequency in service band is set, and the open amount that makes to form by the length on the limit of each opening is multiplied by a line opening group adds the length that radio wave that length that plate member obtains in the length with polarised direction equidirectional is minimum frequency can reflect.
That is to say, in the present invention, by forming opening group along the polarised direction of radio wave on a plurality of rank in the plate surface at tabular component, arrange reflector.Therefore, reflector is equal to and is provided with a plurality of reflecting elements that the opening group that is positioned on a plurality of rank is cut apart.
The wavelength that is known that traditionally this reflecting element is from half length (λ/2) of the wavelength X of the radio wave of radiator transmitting or is preferred less times greater than this length.For example, in the Yagi-Uda antenna consisting of radiator, reflector and wave guide, the length of radiator is λ/2, and the length of reflector is less times greater than λ/2, and the length of wave guide is slightly less than λ/2.
In the present invention, in order to there is the radio wave of the peak frequency of minimal wave length in can the service band of reflective radiator, the wavelength X min of the radio wave of the straight length of the reflecting element of being cut apart by opening group based on peak frequency is set (for example, being about λ min/2).
Meanwhile, have the radio wave of long wavelength's minimum frequency in the service band about radiator, at reflector place, reflection can realize by the end margin of reflecting element.End margin is to form by cutting apart each opening group along the direction vertical with reflection direction at center position.
In this case, the length of reflecting element is by the length on one side of formation opening group's opening (length x opening number on one side) is added to the length that plate member obtains along the length (being about λ min/2) with polarised direction equidirectional.Therefore,, in order to reflect the radio wave of minimum frequency, wavelength X max that only need to be based on minimum frequency in service band, is about λ max/2 by the length setting of this part.
In the present invention, for have in can the service band of reflective radiator long wavelength minimum frequency radio wave (in other words, in order to reflect the radio wave in whole service band), the length of the radio wave of the length on the every limit of opening based on minimum frequency is set.
Especially, by half length of the wavelength of the radio wave of minimum frequency in service band (λ max/2) being deducted to the value that length that half length (λ max/2) of wavelength of the radio wave of peak frequency obtains obtains divided by the opening number that forms a line opening group, can be set to opening length on one side.
Therefore,, according to antenna assembly of the present invention, by reflector, radio wave can be reflected at the whole service band of radiator, and can improve directional characteristic and the antenna gain of antenna assembly.
And in antenna assembly of the present invention, in reflector, the opening consisting of each opening group is formed approximate square shape.Therefore,, with the comparison of above-described traditional antenna device, the length of reflector (length in the vertical direction of the radiation direction with radio wave particularly) can be shortened.
And, according to antenna assembly of the present invention, with the comparison of above-described traditional antenna device, can increase the opening order of a group number that can be disposed on reflector.Therefore, can increase by cutting apart the quantity of the reflecting element of each opening group formation, and can shorten the interval between each reflecting element.
Therefore,, according to antenna assembly of the present invention, with the comparison of above-described traditional antenna device, can improve the actual gain of high frequency band side in service band.
And in antenna assembly of the present invention, being shaped as of opening being formed in reflector is similar to square.This be because, if opening be shaped as rectangular shape longer on the transmit direction of radio wave, so in reflector, the opening number that can be arranged in the transmit direction of radio wave reduces, and can not guarantee to have in the service band of reflective radiator the required length of radio wave of long wavelength's minimum frequency.
That is to say, in the situation that reflector is configured with conduction tabular component and is formed with the opening matrix being positioned on tabular component, if the shape of each opening is if the present invention is for being similar to square shape, the reflection characteristic of reflector in whole service band be can guarantee so, and directional characteristic and the antenna gain of antenna assembly strengthened.
Yet opening needn't have for all limits the real square of equal length, the length on every limit can be slightly different.
Next, according to antenna assembly of the present invention, in forming the tabular component of reflector, two end limits of polarised direction are crooked towards radiator.Therefore, can shorten whole reflector in the length of polarised direction, and dwindle the size (finally dwindling the size of antenna assembly) of reflector, guarantee the length as reflecting element as above simultaneously.
And according to antenna assembly of the present invention, in forming the tabular component of reflector, a plurality of protuberances outstanding in radiator direction are arranged at the end margin at the tabular component of radiator direction bending at certain intervals.
Result, by protuberance, can extend reflector in the length of radio wave polarised direction, improve the reflection characteristic of low-frequency band side in service band, and strengthen the directional characteristic (front and back ratio) of antenna assembly, and can not affect actual gain or the VSWR characteristic of antenna assembly.
Simultaneously, according to antenna assembly of the present invention, in forming the tabular component of reflector, all described in each between opening group's adjacent apertures and along the direction layout vertical with described polarised direction with at least one in a plurality of bars of the row across opening group described in each by being provided with step and projecting to described radiator side being arranged in bar place between corresponding opening group along described polarised direction.
As a result, according to antenna assembly of the present invention, can shorten whole reflector along the length of polarised direction and the size (finally dwindling the size of antenna assembly) of dwindling reflector, guarantee by cutting apart the length of the reflecting element that each opening group forms simultaneously.
And, as mentioned above, in reflector, if a part that is formed at the direction vertical with the polarised direction of radio wave for bar is outstanding towards radiator, outstanding bar can be used as the supporting member of supporting reflex device or is used as the attachment of the housing that holds whole antenna assembly.
Next, according to antenna assembly of the present invention, service band is set to the UHF frequency band for television broadcasting.Therefore, can be by using radio wave in UHF frequency band and by using the reception dwindled with respect to antenna assembly size before for the radio wave of digital television broadcasting.
Accompanying drawing explanation
Figure 1A-1B is the explanatory of outward appearance of the antenna assembly of an execution mode, Figure 1A is the three-dimensional view of the antenna assembly seen from behind when receiving horizontal polarized wave, and Figure 1B is the three-dimensional view of the antenna assembly seen from behind when receiving vertically polarized wave;
Fig. 2 is the explanatory of the antenna body of antenna assembly and the assembled state of output of this execution mode;
Fig. 3 forms the radiator of antenna assembly of this execution mode and the exploded perspective view of the structure of reflector;
Fig. 4 A-4C is the shape of reflector of this execution mode and big or small explanatory, Fig. 4 A is the front view that a part for reflector is amplified, Fig. 4 B is the vertical view of the reflector seen along the line A-A in Fig. 4 A, and Fig. 4 C is the cutaway view of the reflector seen along the line B-B in Fig. 4 A;
Fig. 5 A-5B illustrates for count the reflector of the difference of researching antenna characteristic based on opening order of a group, Fig. 5 A is the front view for reflector relatively that is provided with the opening group of conventional art, Fig. 5 B be applied of the present invention for assessment of the front view of reflector;
Fig. 6 is the chart of the measurement data measured by the electrical characteristic of the antenna assembly of two types to relatively reflector and assessment reflector form;
Fig. 7 measures respectively the chart of measurement data to the electrical characteristic that is provided with the antenna assembly of protuberance at reflector place and is not provided with the antenna assembly of protuberance at reflector place;
Fig. 8 forms the radiator of antenna assembly of revision for execution example and the exploded perspective view of the structure of reflector;
Fig. 9 A-9B is the explanatory of shape of the reflector of the embodiment that revises, and Fig. 9 A is the front view that a part for reflector is amplified, and Fig. 9 B is the vertical view of the reflector seen along the line A-A in Fig. 9 A.
The explanation of reference number
1 ... antenna assembly, 2 ... antenna body,
3 ... coaxial cable, 3a ... support arm,
5 ... antenna element housing, 5a ... the back side,
6 ... support portion, 7 ... slotted hole,
8 ... antenna installation stent,
8a ... (for receiving horizontal polarized wave) mounting bracket fixed part,
8b ... (for receiving vertically polarized wave) mounting bracket fixed part,
9 ... the body of bolt, 9a ... fixed part,
10 ... output, 11 ... output end,
11a ... keep end, 11b ... center conductor,
11c ... outer conductor, 12 ... end housing body
18 ... inner space, 50 ... radiator,
50A, 50B ... skeleton slot antenna,
50C ... balanced circuit,
51a, 51b ... transmission line,
52,53 ... power feed portion,
52a, 53a, 52b, 53b ... connecting hole,
54a, 54b ... conveying member,
55a, 55b ... distributing point,
70 ... reflector, 70A, 70B ... reflecting plate,
70b, 70c ... bend, 70d ... upside,
70e ... downside, 71 ... the first reflecting plate,
72 ... the second reflecting plate, 72a ... protuberance,
73 ... opening, 75 ... opening group,
76,76a, 76b, 77 ... bar, 78 ... step,
79 ... attachment, 79a ... hole,
80 ... compare reflector,
83 ... compare opening,
85 ... compare opening group,
90 ... assessment reflector,
93 ... assessment opening,
95 ... assessment opening group,
100 ... antenna element.
Embodiment
To the execution mode of antenna assembly of the present invention be described below.
Figure 1A-1B is the explanatory of outward appearance of the antenna assembly 1 of this execution mode.Figure 1A is the explanatory of the outward appearance of the antenna assembly 1 seen from behind when receiving horizontal polarized wave.Figure 1B is the three-dimensional view of the antenna assembly 1 seen from behind when receiving vertically polarized wave.
The antenna assembly 1 of this execution mode is the UHF antenna for receiving television broadcasting radio wave.Antenna assembly of the present invention is not particularly limited in UHF antenna.
When by description direction indication given below, unless stated otherwise, the installation direction of antenna assembly 1 is called as basis, and the front surface side of antenna assembly 1 is described as positive side or front, and the rear surface side of antenna assembly 1 is described as dorsal part or the back side.That is to say, according to the layout of the antenna element shown in Fig. 3, lower-left, diagonal angle side (nearside) is positive side or front, and upper right side, diagonal angle (distally) is dorsal part or the back side.
As shown in Figure 1A-1B, the antenna assembly 1 of this execution mode is provided with: antenna body 2, consists of the antenna element housing 5 that holds the antenna element of describing subsequently; Output 10, is arranged on the 5a place, the back side of antenna body 2; And antenna installation stent 8, being removably mounted on mounting bracket fixed part 8a or 8b upper, mounting bracket fixed part 8a or 8b are formed at the back side 5a of antenna element housing 5.
Antenna element housing 5 is formed by the non-conductive synthetic resin of rectangular box shape.
As shown in Figure 2, output 10 consists of output end 11 and end housing body 12.As cylindrical socket, output end 11 have center conductor 11b and with the outer conductor 11c of the coaxial setting of center conductor 11b, and have and be positioned at the maintenance end 11a locating its one end and make the end of coaxial cable be attached and dismantle.End housing body 12 is set to the back side 5a along antenna element housing 5, and the maintenance end 11a that supports output end 11 is with outwards outstanding.End housing body 12 is formed by non-conductive synthetic resin.
Center conductor 11b and the outer conductor 11c of output end 11 are electrically connected to distributing point, and distributing point is arranged on the antenna element place in the space that is formed at housing 5,12.The signal receiving by antenna element is from 11 outputs of output end.
Next, antenna installation stent 8 is configured to be attached to mast, porch etc., can also be attached to various installation sites, such as the suspension bracket on metope.
As shown in Figure 1A, by antenna installation stent 8 being attached to mounting bracket fixed part 8a, the antenna assembly 1 of this execution mode is configured to as the antenna assembly that receives horizontal polarized wave.As shown in Figure 1B, by antenna installation stent 8 being attached to mounting bracket fixed part 8b, the antenna assembly 1 of this execution mode is configured to as the antenna assembly that receives vertically polarized wave.
Output 10 is fixed to the back side 5a of antenna body 2 via the body of bolt 9, thereby output 10 can be about the axis as its pivot center at least 90 degree or rotation (as shown in the arrow R in Figure 1A) in larger scope, and this axis is parallel to the center line of the fore-and-aft direction of antenna assembly 1.
This is for by change the projected direction of output end 11 according to the installment state of antenna assembly 1, allows output end 11 outstanding when receiving horizontal polarized wave or vertically polarized wave downwards.
To the concrete assembly program of antenna body 2 and output 10 be described below.
Fig. 2 is the antenna body 2 of antenna assembly 1 of this execution mode and the view of the concrete assembled state of output 10.
As shown in Figure 2, in output end 11, keep end 11a to be supported with outwards outstanding by end housing body 12, center conductor and the outer conductor of a side that is cut into the coaxial cable 3 of predetermined length waits center conductor 11b and the outer conductor 11c of the opposite side of the maintenance end 11a that is connected to 18 places, inner space that are positioned at end housing body 12 by welding.
The output 10 that is connected with coaxial cable 3 is assembled to the slotted hole 7 that antenna body 2 is arranged at antenna element housing 56 places, 5aChu support portion, the back side by the other end of coaxial cable 3 is inserted in form, then by can screwed mode the body of bolt 9 being installed on the fixed part 9a that the center position in support portion 6 forms and being realized.
Next, after output 10 is attached to support portion 6, support and be fixed on support arm 3a place with the centre position of a side interval preset distance of coaxial cable 3, support arm 3a is formed from the back side 5a of antenna element housing 5 and inwardly gives prominence to.
Now, centre position is determined, makes to be present in connecting portion and the gently bending of the coaxial cable between centre position 3 of exporting end 11.
And the other end of coaxial cable 3 is connected to unshowned match circuit, and by match circuit being connected to the current feed department of the antenna element of describing subsequently, assembling completes.
That is to say, by screwed mode, threaded body 9 is arranged on to fixed part 9a upper, the body of bolt 9 that the output 10 of antenna assembly 1 can make as pivot center rotates within the scope of at least 90 degree.And, once the position of output 10 determined, just can tightly the body of bolt 9 be arranged on to fixed part 9a by screwed mode, maintain securely the layout of output 11.When output 10 rotates, coaxial cable 3 swings (as shown in arrow r in Fig. 2) in response to its rotational motion along slotted hole 7.
Next, with reference to Fig. 3, describe the antenna element of the antenna assembly 1 that forms this execution mode in detail.Fig. 3 is the exploded perspective view of the structure of antenna element 100 when receiving horizontal polarized wave.
As shown in Figure 3, the antenna element 100 of this execution mode consists of radiator 50 and reflector 70.
Radiator 50 disposes two skeleton slot antenna 50A, 50B and balanced circuit 50C.Two skeleton slot antenna 50A, 50B are respectively such as by forming with the conductive plate that mould crush-cutting is made by metal etc.Balanced circuit 50C is connected to each other the power feed portion 52,53 of two skeleton slot antenna 50A, 50B.
Radiator 50 is by being arranged as skeleton slot antenna 50A, 50B with preset distance (D2 in Fig. 3) and being relatively configured up and down symmetrically, thereby radiator 50 is global approximation square shape, its minor face is positioned at the direction parallel with the polarised direction of radio wave, fully, its long limit is positioned at the direction vertical with the polarised direction of radio wave.
And radiator 50 is configured by be connected to each other the power feed portion 52,53 forming in each about center of the skeleton slot antenna 50A, the 50B that arrange as mentioned above by balanced circuit 50C.
Balanced circuit 50C consists of a pair of transmission line 51a, 51b, and a pair of transmission line 51a, 51b such as the mode by with identical with skeleton slot antenna 50A, 50B is carried out molded with the conductive plate that mould crush-cutting is made by metal etc.
The place, two ends of transmission line 51a one of therein, connecting hole 52a, the 53a to power feed portion 52,53 to be connected is formed at the position of facing with power feed portion 52,53 in skeleton slot antenna 50A, the formation of 50B place.Transmission line 51a is by constructing via conveying member 54a connection connecting hole 52a and connecting hole 53a.
Similarly, place, the two ends of transmission line 51b one of therein, connecting hole 53b, the 52b to power feed portion 53,52 to be connected is formed at the position of facing with power feed portion 53,52 in skeleton slot antenna 50A, the formation of 50B place.Transmission line 51b is by connecting connecting hole 53b and being connected 52b and constructing via conveying member 54b.
It is by power feed portion 52,53 is alignd with 53b, 52b with connecting hole 52a, the 53a of transmission line 51a, 51b with 53,52 and by being adhesively connected to realize such as known methods such as welding that two transmission line 51a, 51b are assembled to skeleton slot antenna 50A, 50B.
Here, the interval of the width of conveying member 54a, 54b and transmission line 51a, 51b is determined, thereby the impedance of the balanced circuit 50C consisting of two transmission line 51a, 51b is about 200 Ω.
Distributing point 55a, the 55b of radiator 50 is formed at the place, centre position of transmission line 51a, 51b.By balance cable, distributing point 55a, 55b are connected to unshowned match circuit, the signal being received by radiator 50 is exported from output end 11 via unshowned balanced cable, match circuit and coaxial cable 3 from distributing point 551,55b.
About each size in skeleton slot antenna 50A, the 50B of this execution mode, size in accompanying drawing between both sides (W2 in Fig. 3) is 190mm, the size on limit (H2 of Fig. 3) is 260mm, and skeleton slot antenna 50A and 50B are arranged to each other the preliminary dimension (D2 in Fig. 3) at a distance of 110mm.Thus, the external dimensions of radiator 50 { the transverse width W2 in Fig. 3 * highly (H2+D2+H2) } is for being of a size of the global approximation square shape of 190x630mm.In this case, be formed at and be spaced apart 320mm (that is, the length of transmission line 51a, 51b) between the power feed portion 52 at skeleton slot antenna 50A and skeleton slot antenna 50B place and power feed portion 53.
Next, will the reflector 70 of this execution mode be described.
Reflector 70 consists of two reflecting plate 70A, 70B, and reflecting plate 70A, 70B form such as the conductive plate (that is, conductive plate linear element) by being made by metal etc. with mould crush-cutting.
Reflector 70 is by these two reflecting plate 70A, 70B are arranged as with preset distance (D22 in Fig. 3) and are relatively configured up and down symmetrically, thereby reflector 70 is global approximation quadrangle shape, its minor face is positioned at the direction parallel with the polarised direction of radio wave, and its long limit is positioned at the direction vertical with the polarised direction of radio wave.
The reflector 70 of this execution mode is to be configured by combining these two reflecting plate 70A, 70B, but reflecting plate 70A, 70B can be integrally moulded.
At this, describe the reflecting plate that forms reflector 70 in detail.
The description of reflecting plate 70A will be provided below.Because reflecting plate 70B has identical configuration, so will omit detailed description.
Reflecting plate 70A is arranged to towards skeleton slot antenna 50A and by following parts and forms: the first reflecting plate 71, present approximate quadrangle external structure, and its longitudinal direction is positioned at the direction vertical with the polarised direction of radio wave; The second reflecting plate 72,72, by two long limits at bend 70b, 70c place are bent to form towards radiator 50, the first reflecting plate 71 is between the second reflecting plate 72,72; And a plurality of openings 73, be formed and penetrate the first reflecting plate 71.
Opening group 75 is configured according to this execution mode, and as each opening group 75 of one group, have a plurality of openings (having 3 opening 73a, 73b, 73c according to this execution mode), a plurality of openings are arranged their central point are alignd on the parallel line of the polarised direction with radio wave with predetermined space.Opening group 75 be take and is similar to uniform interval and along the direction vertical with the polarised direction of radio wave, is formed at a plurality of rank (being 5 rank according to this execution mode) and locates.
The second reflecting plate 72,72 has been wholely set a plurality of protuberance 72a ... a plurality of protuberance 72a ... for be set to from they end (, end edge) sheet of outstanding intended size forward, and be arranged to along the leading section of the second reflecting plate 72,72 and there is predetermined space.
About the size of the first reflecting plate 70A, 70B, the size between the limit of reflecting plate (W22 in Fig. 3) is 220mm, and the size on limit (H22 in Fig. 3) is 302.5mm.The first reflecting plate 70A, 70B are arranged to the preliminary dimension (D22 in Fig. 3) of each interval 5mm.Thus, the overall outer dimensions { transverse width W22x height (H22+D22+H22) } in Fig. 3 that does not comprise the reflector 70 of the second reflecting plate 72,72 is 220x610mm.
A plurality of openings 73 that are formed at the first reflecting plate 70A, take-through plate surface, 70B place are all identical and be approximate foursquare shape in form.
Next, with reference to Fig. 4 A-4C, describe the reflector 70 of this execution mode in detail.
Fig. 4 A-4C is the explanatory view that describes the reflector 70 of this execution mode in detail.Fig. 4 A is the front view that a part of the reflector 70A shown in Fig. 3 is above amplified.Fig. 4 B is the vertical view of seeing along the line A-A in Fig. 4 A.Fig. 4 C is the cutaway view of seeing along the line B-B in Fig. 4 A.
The second reflecting plate 72 of reflecting plate 70A shown in Fig. 4 A along the direction of arrow in Fig. 4 B towards both sides in open state (that is, and crooked and be shaped before state), thereby the second reflecting plate 72 and the first reflecting plate 71 are coplanar so that being described clearly below.Open state dots.
The size Expressing of the minor face of the first reflecting plate 71 is the W22 in Fig. 4 A.Yet what the following describes is the size (that is, the size of the minor face of reflecting plate 70A) that comprises the minor face of the second reflecting plate 72, the second reflecting plate 72 is by making the bending two ends of the first reflecting plate 71 carry out molded.
The size of the minor face of the reflecting plate 70A of this execution mode is formed and meets two conditions that the following describes.
First condition is, the second reflection width (the route R2=W22+L16+L16 in Fig. 4 A) of minor face size (L16 in Fig. 4 A) overall size of the minor face size as the first reflecting plate 71 (W22 in Fig. 4 A) and the second reflecting plate 72 is configured to the approximately λ min/2 of wavelength X min of the radio wave of the peak frequency in the service band based on antenna assembly 1.When the second reflection width is λ min/2, radio wave can be reflected.
Second condition is that the opening size of opening 73 (L12 * L11) is arranged to the first reflection width (size of the route R1 in Fig. 4 A) is with respect to the approximately λ max/2 of the wavelength X max of the radio wave of the minimum frequency in service band.When the first reflection width is λ max/2, the radio wave of minimum frequency can be reflected.Here, the first reflection width (size of the route R1 in Fig. 4 A) is the size of opening group 75 place's opening 73 alignment direction, as the opening group 75 of a group, there is a plurality of opening 73a, 73b and the 73c aliging on the parallel line of the polarised direction with radio wave, and the first reflection width is following overall size: the summation of the end size of the second reflecting plate 72 (L16 in Fig. 4 A); Bend 70b, 70c and be arranged in the summation of the size (L13 of Fig. 4 A) between the limit of outermost opening (73a of Fig. 4 A, 4C, 73c) at place, limit of bend 70b, 70c of the opening 73 that forms opening group 75; The summation of the size between the edge-facing of adjacent apertures (L14 in Fig. 4 A); An and whole outer perimeter summation { half-size scale { (the L12+L11) * 3} of (L12+L11) * 2 * 3} that all forms the opening with transverse width L12 * height L11.
Here, in order to be described more specifically the size (route R1) of the first reflection width, this size is interpreted as to { L16 * 2+L13 * 2+L14 * 2+ (L12+L11) * 3}.By the way, (L16 * 2+L13 * 2+L14 * 2+L12 * 3) are the size of route R2, and each opening 73 is for being similar to square shape (that is, L11=L12).Thus, the size (route R1) of the first reflection width is for route R2 with by the length L 11 (=L12) at an edge of opening 73 being multiplied by the summation of the length that the quantity 3 (L11 * 3) of opening 73 obtains.
About forming reflecting plate 70A, the 70B of the reflector 70 of this execution mode, the minor face size W22 of the first reflecting plate 71 is 220mm, and the minor face size L16 of the second reflecting plate 72 is 20mm.Thus, the size of the second reflection width is that route R2 (W22+L16+L16) is 260mm.
The service band of supposing antenna assembly 1 is for example 470-770MHz of UHF frequency band, the size 260mm of the second reflection width is the approximately 0.67 λ max of peak frequency (770MHz) wavelength X max ≌ 0.39m, thereby the size 260mm of the second reflection width meets first condition, and wherein the radio wave of peak frequency is reflexible.
And the opening size of the opening 73 of this execution mode is 50 * 50mm (L12=L11).The size L13 being arranged between the edge at limit place of bend 70b, 70c of opening (73a of Fig. 4 A, 4C, 73c) is 20mm, and the size L14 between the edge-facing of adjacent apertures is 15mm.Thus, the size of the first reflection width is route R1{ route R2+ (L11 * 3) } be 410mm.
The service band of supposing antenna assembly 1 is for example the 470-770MHz of UHF frequency band, the size 410mm of the first reflection width is the approximately 0.64 λ min of the wavelength X min ≌ 0.64m of minimum frequency (470MHz), thereby the size 410mm of the first reflection width meets second condition.
Above-described specific embodiment is an embodiment of the invention.As long as can obtain required electrical characteristic, the size of the quantity of the opening size of opening 73, formed opening 73, reflecting plate 71,72 etc. is not specifically confined to this execution mode.
Be set to be configured such that from the outstanding size of the end of the second reflecting plate 72 (L15-L16 Fig. 4 A) and be about 21mm from the size of the outstanding protuberance 72a of the tip forward of the second reflecting plate 72, and its width (L17 in Fig. 4 A) is 13mm.
Limit since the upper end 71d of the second reflecting plate 72, as second reflecting plate 72 places that are shown in, Fig. 3 top are provided with 4 protuberances, 4 protuberances have the predetermined space (L18 in Fig. 4 A) with respect to the 0.08 λ min-1.02 λ min of the wavelength X min ≌ 0.64m of the minimum frequency in service band (470MHz) each other.Similarly, since the limit of the lower end 71e of the second reflecting plate 72, as shown in Fig. 3 below, 4 protuberances are arranged on the second reflecting plate 72 places, and 4 protuberances have the interval identical with interval as above.
And, form reflecting plate 70A, the 70B of reflector 70 of this execution mode all by the second reflecting plate 72,72 is formed towards radiator 50 is crooked at bend 70b, 70c, thereby the transverse width of the first reflecting plate 71 is W22, and between a protuberance 72a and another protuberance 72a, be spaced apart W24, as shown in Figure 4 B.
Therefore, the external dimensions of the reflector 70 of this execution mode (size on perspective plane) is minor face size (transverse width on the perspective plane of transverse width W22+ second reflecting plate of the first reflecting plate) * length limit size (H22+D22+H22).
Especially, according to this execution mode, protuberance 72a is 240mm by being bent to form the interval W24 making between a protuberance 72a and another protuberance 72a.Therefore the size (size on perspective plane) that, comprises the reflector 70 of the first reflecting plate and the second reflecting plate is 240mm * 610mm.Here, the size (D24 in Fig. 4 B) between the first reflecting plate 71 and the end of protuberance 72a is about 40mm.
Here, the reflector 60 of describing in patent documentation 1 and the reflector 70 of this execution mode are compared and discussed.
The size (minor face size * length limit size) that is formed in the first reflector 611 of the reflector 60 of describing in patent documentation 1 is about 100 * 560mm (size that comprises the second reflector is about 190 * 560mm).At the first reflector 61 places, a plurality of openings 63 are set, a plurality of openings 63 are formed the opening size (minor face size * length limit size) with 7 * 95mm, thereby longitudinal direction is the direction vertical with the polarised direction of radio wave.
Suppose as opening group, one group of a plurality of openings (7 opening 63a of this execution mode ... 63g) being arranged to the parallel central point of opening 63 that makes is positioned on the line parallel with the polarised direction of radio wave, in the first reflector 61 of conventional art, opening group is disposed on 5 rank to have predetermined space on the vertical axis of the polarised direction with radio wave.
If the long limit size 560mm of the first reflector 61 becomes the 610mm equating with the long limit size of the reflector 70 of present embodiment, opening group can add single order on mathematics again so, so the sum on rank can be 6.
Meanwhile, according to present embodiment, the size of the first reflecting plate (minor face size * length limit size) adds up to 220 * 610mm, and opening 73 is all formed the square with size 50 * 50mm.Thus, on the first reflecting plate, be furnished with 10 opening groups 75 that are positioned on 10 rank.Each opening group 75 has one group of 3 opening 73a, 73b and 73c.Pay close attention to stacked opening order of a group number, the opening group 75 with the opening 73 of this execution mode can be arranged in than the exponent number of conventional art and have more on the rank of 4.
At this, with reference to Fig. 5 A, 5B and 6, experiment and the result thereof of being implemented by applicant described aspect stacking opening order of a group number and the relation between electrical characteristic.
Fig. 5 A-5B is that explanation tests to study the schematic diagram of the reflector of relation between stacked opening order of a group number and electrical characteristic for this.Fig. 5 A is for relatively and be provided with the opening group's who consists of traditional opening reflector.Fig. 5 B be for assessment of and be provided with the opening group's that the opening by present embodiment forms reflector.
Fig. 6 is relatively provided with the characteristic and the characteristic of antenna assembly that is provided with the reflector (solid line) of Fig. 5 B of antenna assembly of the reflector (dotted line) of Fig. 5 A.
Reflector for this experiment is the reflector 80,90 of Fig. 5 A and Fig. 5 B, and each reflector 80,90 is for being formed the flat board (not being provided with the bend corresponding with the second reflecting plate at the reflector place for this experiment) of the size with 250 * 660mm.Minor face size 250mm (the second reflection width, that is, the length of route R200) be the approximately 0.64 λ max of the wavelength X max ≌ 0.39m of the peak frequency (770MHz) in service band.Therefore, in Fig. 5 A, 5B, reflector 80,90 all meets first condition.
As shown in Figure 5A, thering are reflector 80 places for comparing for traditional opening relatively that are formed the vertical length of being formed of longitudinal length (each is 10 * 90mm) according to conventional art, as one group of opening group 85 with 3 comparison openings (83a, 83b, 83c), be stacked on 5 rank.
According to this compared with reflector 80, based on (route R200+ (L11 * 3) } (supposing that L11 is for the size on the limit vertical with the polarised direction of radio wave), the size (that is, route R100) as shown in the figure of the first reflection width is 250+90 * 3=520mm.Therefore, the first reflection width is of a size of the approximately 0.81 λ min of the wavelength X min ≌ 0.64 of the minimum frequency (470MHz) in service band, thereby the first reflection width meets second condition.
As shown in Figure 5 B, assessment reflector 90 have according to this execution mode be formed square (each is 50 * 50mm) for assessment of opening, as one group have 3 assessment openings (93a, 93b, 93c) opening groups 95 be stacked on 10 rank.
According to the size (that is, route R110) of these assessment reflector 90, the first reflection width, be stacked on 3=400mm for 250+50.Therefore, the first reflection width is of a size of the approximately 0.63 λ min of the wavelength X min ≌ 0.64m of the minimum frequency (470MHz) in service band, thereby the first reflection width meets second condition.
Fig. 6 shows the experimental data (solid line) by the experimental data (dotted line) of the antenna assembly that relatively reflector 80 forms and the antenna assembly that consists of assessment reflector 90.Relatively reflector 80 is configured as shown in Figure 5A, and for this experiment and the radiator 50 of having described.Assessment reflector 90 is configured as shown in Figure 5 B, and for this experiment and the radiator 50 of having described.
Pay close attention to the actual gain of this experimental data, compare with the antenna assembly that is provided with as shown in Figure 5A the comparison reflector 80 of configuration, be provided with as shown in Figure 5 B the antenna assembly of the assessment reflector 90 of configuration and have and from the midband in service band to broadband, be increased at the most the actual gain of 2dB.
That is to say, experimental data proves, from the midband in service band to wide band actual gain, can improve by increasing stacked opening order of a group number, as long as meet following condition: form at least the minor face of the reflector of plane (transverse width in figure) and be formed and there is the size corresponding with first condition; Reflector is formed has opening, and the opening size of opening meets second condition; Reflector is formed has opening group, and this opening group has a plurality of openings (being 3 openings in this experiment) as one group, thereby a plurality of opening is made the central point of opening be positioned on the line parallel with the polarised direction of radio wave by being arranged in parallel.
Even if relatively reflector 80 and assessment reflector 90 are all configured to meet the first and second conditions, and the foursquare assessment opening 93 (50 * 50mm) that is formed this execution mode and the whole opening periphery that there is the comparison opening 83 (10 * 90mm) that is positioned at the longitudinal direction in the direction vertical with the polarised direction of radio wave and be all formed to have the same size (100mm), except the first and second conditions by increasing a restrictive condition " the measure-alike approximate square shape on the limit that the size that is shaped as the limit parallel with the polarised direction of radio wave of the opening 93 of conventional art is vertical with the polarised direction of radio wave ", the exponent number that can be placed in the assessment opening group 95 at reflector place can increase the comparison opening group 85 who consists of the comparison opening 83 that is formed rectangular shape according to conventional art.As a result, think that actual gain improves from the midband in service band to broadband.
Below with reference to Fig. 7, describe the assessment of protuberance 72a and result thereof.
What be used for this assessment is: antenna assembly, consists of the radiator 50 of having described as the first execution mode of this execution mode and the reflector 70 with protuberance 72a; And for antenna assembly relatively, there is radiator 50 and obtain reflector by remove protuberance 72a from reflector 70.
That is to say, although having protuberance 72a and lacking between protuberance 72a distinctly, be the reflector 70 of having described in this embodiment for the reflector of each antenna assembly of this assessment.Except being arranged to and being deposited on 10 rank on the axis vertical with radio wave polarised direction in the first reflecting plate towards the first reflecting plate of radiator 50 and opening group 75, reflector is provided with the second reflecting plate, and the second reflecting plate is clipped in the middle the first reflecting plate and forms on crooked two long limits respectively at bend by the direction along radiator 50.Thus, reflector is optimized to obtain the predetermined electrical characteristic as antenna assembly together with radiator 50.Use the reflector 70 of optimizing to carry out the assessment of protuberance 72a.Therefore, as relatively seeing between the experimental data of the experimental data in Fig. 6 (being provided with the antenna assembly of flat shape reflector) and Fig. 7 (being provided with the antenna assembly of the reflector 70 of the optimization being formed by the first plane-reflector and the second reflecting plate), no matter whether protuberance 72a exists, the antenna assembly 1 of this execution mode, be provided with the antenna assembly 1 of the reflector 70 of optimization, can there is the actual gain improving to broadband from the midband of service band.And the antenna assembly 1 of this execution mode can have good voltage standing wave ratio (VSWR) on the whole frequency band of service band.Thus, do not need to increase the external dimensions of antenna assembly, see that electrical characteristic can low cost easily further improve.
According to this execution mode, protuberance 72a is formed thin and elongated, and is arranged to and has predetermined space, while making the existence of protuberance 72a can not approach radiator 50 at the leading section of protuberance 72a, actual gain and VSWR characteristic is exerted an influence.As long as obtain predetermined properties, the size of protuberance 72a and position are not limited to execution mode above.
The protuberance 72a that is arranged on as mentioned above reflector 70 places that optimize is described below and whether has the assessment in situation.
In the data shown in Fig. 7, electrical characteristic when dotted line represents not have protuberance 72a, electrical characteristic when solid line represents to have protuberance 72a.
These digital proofs, whether the existence of protuberance 72a can appreciable impact actual gain or VSWR.
Yet, when about front and back than time, see that situation about existing at protuberance 72a and the non-existent situation of protuberance 72a are relatively, the low-frequency band side that compare at service band front and back improves several dB (2-5dB).
That is to say, as mentioned above, by layout, to be formed length be 21mm, the width thin and elongated protuberance 72a that is 13mm with the leading section along reflecting plate 72,72 respectively, has predetermined space, the further raising of specific characteristic before and after can realizing in the low-frequency band side of service band, and do not affect actual gain and VSWR characteristic.
And, by making to be provided with by the antenna assembly 1 of the reflector 70 configuring as mentioned above, be suitable for use in and receive the ground digital television broadcast that uses UHF frequency band to realize, can easily improve electrical characteristic and preferably receive ground digital television broadcast with low cost, and not need to increase the external dimensions of antenna assembly 1.
Although described embodiments of the present invention above, the invention is not restricted to execution mode above and can adopt various forms in technical scope of the present invention.
For example, according to this execution mode, reflector 70 consists of two reflecting plate 70A and 70B, and reflecting plate 70A and 70B are arranged to towards a pair of skeleton slot antenna 50A and 50B.Yet, as long as antenna assembly comprises the radiator consisting of skeleton slot antenna etc., as the reflector against radiator, provide a reflecting plate 70A or 70B just enough.
And, for example, in the first reflecting plate 71 being formed by reflecting plate 70A, 70B, by bar 77 places being arranged in along polarised direction between each opening group 75, provide step 78, between the opening 73 that forms each opening group 75 and along the vertical direction of the polarised direction with radio wave, arrange that take can outstanding towards radiator (particularly, outstanding towards skeleton slot antenna 50A, 50B) across at least one of a plurality of bars 76 (being two bar 76a, 76b in accompanying drawing) of each opening group 75 row.
By this way, can shorten physical size (W22 in Fig. 8) and without the electric size changing between the limit of the first reflecting plate 71, and the size (thereby the size of finally dwindling antenna assembly 1) that can dwindle reflector 70.
By this way, in the first reflecting plate 71, by making a part for being formed at of bar 76 direction vertical with the polarised direction of radio wave outstanding, can use outstanding bar 76 as the standing part for antenna element housing 5.
In this case, as shown in Fig. 9 A-9B, only need to be integrally formed attachment 79, each attachment 79 has hole 79a to be arranged on the support portion of antenna element housing 5 by screwed mode towards the outstanding bar 76a of radiator, 76b place, or needs directly to form by screwed mode and be arranged on the hole 79a on the support portion of antenna element housing 5.