Adjustable stacked multi-arm dual-frequency helical antenna deviceTechnical Field
The invention belongs to the technical field of antennas, and particularly relates to an adjustable stacked multi-arm double-frequency helical antenna device.
Background
The antenna plays an important role in a communication system as a front-end component of radio frequency communication. Aiming at the design requirements of the current high-precision multi-system GNSS measurement type antenna, on the aspect of satellite signal receiving performance, the antenna is required to be ensured to have the characteristics of high positioning precision and stable and reliable performance, meanwhile, the satellite navigation multi-satellite multi-frequency signal resources are also required to be fully utilized, in order to meet the application requirements of compatible multi-system multi-frequency point GNSS terminal equipment, the antenna is required to have the characteristics of wide working bandwidth, strong anti-interference capability, excellent circular polarization performance, phase center stability and the like, and the antenna system is required to have stronger compatibility and more compact structural design, and is portable, light, small, strong in compatibility and the like. Especially to present wearable, hand-held type, unmanned aerial vehicle high accuracy navigation positioning terminal module and the supporting antenna application demand of equipment, not only need satisfy high performance, high efficiency, the stable receipt of many gestures to the requirement of antenna, the structure still needs to satisfy design demands such as light, little, nimble, portable moreover.
In the prior art, a substrate design with a medium support body with a higher dielectric constant (generally more than 5) is adopted, so that the antenna gain is low and the performance is poor under the condition of high-frequency signals; moreover, the existing antenna is mostly carved (etched) on ceramic or plastic, so that the error is large and the reliability is low; the general antenna double-frequency spiral passive signal is combined output, the gain is low, and if pre-filtering is carried out, the noise coefficient is large.
Therefore, it is considered to apply the flexible circuit board to the flexibility of the high-precision multi-system measurement type antenna. The circuit board fpc (flexible Printed circuit) is used more and more widely in the antenna industry, from the original flexible circuit to the present flexible antenna. The FPC has good flexibility, is convenient to form and paste, and is beneficial to manufacturing antennas with different shapes, so that the FPC is increasingly widely applied to the field of antennas. The existing antenna units, such as a satellite navigation helical antenna and a helical antenna for satellite communication, all use FPC technology. In order to wind the antenna into a rod shape, a cylinder (dielectric rod or engineering foam) or a round tube (plastic tube) is generally adopted in the middle, although the structure can be well supported, the manufacturing tolerance and the material consistency of the structure are difficult to guarantee, the working frequency deviation of an antenna product is easy to cause, and the product consistency is further influenced.
In addition, once the working frequency of the antenna is processed, the working frequency of the antenna is difficult to adjust, and the fine adjustment cannot be performed in time when the working frequency of the antenna deviates in use and the like.
Disclosure of Invention
In order to solve the problems, the invention provides a multi-arm dual-frequency helical antenna device which adopts a movable laminated structure, L1 and L2 signals are independently output, the working frequency of an L2 antenna unit can be finely adjusted, and the signal processing is convenient.
Another object of the present invention is to provide a small-sized and light-weight stacked antenna suitable for application scenarios such as unmanned aerial vehicles.
In order to solve the above technical problem, the present invention discloses an adjustable stacked multi-arm dual-frequency helical antenna device, comprising: the antenna comprises an L1 antenna unit, an L2 antenna unit and a coaxial cable, wherein the L1 antenna unit is arranged above the L2 antenna unit;
the L1 antenna unit comprises an L1 FPC circuit board, an L1 dielectric support body and an L1 grounding plate, wherein the L1 FPC circuit board is rolled into a cylinder shape around the L1 dielectric support body, and the L1 dielectric support body plays a role in supporting and shaping the L1 FPC circuit board;
the L2 antenna unit comprises an L2 FPC circuit board, an L2 dielectric ring group and an L2 grounding plate, wherein the L2 FPC circuit board is coiled into a cylinder shape around an L2 dielectric ring group, and the L2 dielectric ring group plays a role in supporting and shaping the L2 FPC circuit board;
the L1 medium support body can slide up and down in the cylindrical L2 FPC board.
Preferably, the L1 FPC circuit board is fixed at the bottom of the L1 ground board, and the L2 FPC circuit board is fixed at the top of the L2 ground board; the L1 medium support is a hollow hard support, and the coaxial cable passes through the middle of the L1 medium support and the L2 medium ring set to connect the L1 ground plate with the L2 ground plate.
Preferably, the L2 dielectric ring set includes a movable dielectric ring and at least one fixed dielectric ring with the same outer diameter, the fixed dielectric ring is fixedly connected with the inner wall of the cylindrical L2 FPC board, and the movable dielectric ring can slide up and down along the inner wall of the cylindrical L2 FPC board; the diameter of the L1 medium support body is adapted to the inner diameter of the medium ring group, the bottom of the L1 medium support body is fixedly connected with the movable medium ring, so that the L1 medium support body can drive the movable medium ring to slide up and down along the fixed medium ring to adjust the antenna frequency of the L2 FPC circuit board.
Preferably, the height of the L1 dielectric support is greater than the height of the cylindrical L1 FPC board, the upper part of the L1 dielectric support plate is connected and fixed to the L1 ground plate, and the lower part of the L1 dielectric support is exposed to the cylindrical L1 FPC board to form an exposed part.
Preferably, the range of the L1 medium support body sliding up and down in the cylindrical L2 FPC board is limited by the length of the exposed part, and the distance between the movable medium ring and the fixed medium ring closest to the movable medium ring is not less than the length of the exposed part.
Preferably, the L1 antenna element synthesizes or receives an L1 signal, and the L2 antenna element synthesizes or receives an L2 signal; the L1 signal is transmitted to the L2 ground plate through a coaxial cable; and the L1 signal and the L2 signal are processed respectively and then are combined for output.
Preferably, a multi-arm spiral radiator is respectively arranged on the L1 FPC circuit board and the L2 FPC circuit board, the multi-arm spiral radiator is an eight-arm radiation arm structure, and the eight-arm radiation arm structure comprises four symmetrical long arms and four short arms.
Preferably, the ground plates L1 and L2 are multilayer circuit boards, and are used for processing signals including filtering and amplifying.
Preferably, the L1 ground board and the L2 ground board are respectively integrated with a power feeding device, the L1 ground board feeds power to the L1 FPC board, and the L2 ground board feeds power to the L2 FPC board.
Preferably, the device also comprises a fixing device arranged at the top center of the L1 grounding plate or the bottom center of the L2 grounding plate, and the fixing device is used for being fixedly arranged on other equipment.
The adjustable stacked multi-arm dual-frequency helical antenna device at least has the following advantages:
1. the L2 antenna unit has the advantages of being flexible in design, simple in structure, good in antenna performance, wide in application and the like, the reasonable physical structure and the good antenna performance are not only guarantee for improving system performance, but also are beneficial to saving cost, the working frequency of the L2 antenna unit is finely adjusted by adjusting the position of the movable dielectric ring in the L2 FPC circuit board, and the L2 antenna unit is suitable for use occasions needing double frequency bands but occasionally or frequently needing to adjust one fixed frequency band.
2. By adopting the laminated structure, the L1 and L2 signals are independently output, so that the signal processing is convenient. The dual-frequency satellite signal receiving device can simultaneously receive GNSS (global navigation satellite system) L2 (1164 MHz-1300 MHz) and L1(1521 MHz-1616 MHz) dual-frequency satellite signals, wherein the bottom layer can receive L2 signals, the top layer can receive L1 signals, and the channels are independent and can conveniently perform signal processing.
3. The radiator of the eight-arm helical antenna adopts the symmetrical design of four long arms and four short arms, and the circular polarization performance of the antenna is good; two eight-arm helical antennas are stacked to realize double-frequency operation, and can receive satellite signals of multiple frequency points such as L1, L2 and L5 of GPS, B1, B2 and B3 of Beidou, G1 and G2 of GLONASS and the like.
4. The antenna is fixed by a new manufacturing method, the performance of the antenna is improved, and the antenna is particularly suitable for equipment with high requirements on gain and anti-interference capability.
5. The eight-arm spiral radiator takes a flexible FPC circuit board as a carrier and is fixed on the medium support body in a winding mode, machining precision is high, consistency is good, different polarization modes can be conveniently formed leftwards or rightwards, and satellite signals of different polarization modes can be received.
The L1 medium support body adopts a hollow or tubular hard support body, and the L2 medium ring group adopts a medium ring with lighter gravity, so that the weight of the antenna can be greatly reduced; the antenna has a light and small structure and a good directional diagram performance, takes advantages of two types of the laminated microstrip antenna and the spiral antenna into account, and is particularly suitable for portable equipment or equipment (such as unmanned aerial vehicles and the like) with harsh requirements on weight.
7. The FPC antenna performance can be better played, the antenna operating frequency is conveniently tuned in production, the dielectric rings made of different materials, different heights, different inner diameters and different dielectric constants can be selected to be arranged at different positions, the antenna operating frequency is finely tuned, and the product consistency is better.
Drawings
Fig. 1 is a schematic structural diagram of an adjustable stacked multi-arm dual-frequency helical antenna device.
Fig. 2 is a schematic perspective view of the multi-arm spiral radiator of fig. 1.
Fig. 3 and 4 are schematic perspective views of the fixing device in fig. 1.
Fig. 5 is a schematic flow chart of the combination of the signals L1 and L2.
The reference numbers in the figures are: 1-L1 antenna unit, 110-L1 FPC circuit board, 120-L1 dielectric support, 121-exposed part, 130-L1 ground plate, 2-L2 antenna unit, 210-L2 FPC circuit board, 220-L2 dielectric ring group, 221-movable dielectric ring, 222-fixed dielectric ring, 230-L2 ground plate, 3-coaxial cable, 4-multi-arm spiral radiator, 410-long arm, 420-short arm, 5-fixing device, 510-fixing foot and 520-threaded hole.
Detailed Description
The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," when used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
Example 1
As shown in fig. 1-4, an adjustable stacked multi-arm dual-frequency helical antenna device comprises: the antenna comprises anL1 antenna unit 1, anL2 antenna unit 2 and acoaxial cable 3, wherein an L1 antenna unit is arranged above an L2 antenna unit;
the L1 antenna unit comprises an L1FPC circuit board 110, an L1dielectric support 120 and anL1 grounding plate 130, wherein the L1 FPC circuit board is rolled into a cylinder shape around an L1 dielectric support, and the L1 dielectric support plays a role in supporting and shaping the L1 FPC circuit board; by adopting the laminated structure, the L1 and L2 signals are independently output, so that the signal processing is convenient.
The L2 antenna unit comprises an L2FPC circuit board 210, an L2dielectric ring group 220 and anL2 grounding plate 230, wherein the L2 FPC circuit board is coiled into a cylinder shape around an L2 dielectric ring, and the L2 dielectric ring group plays a role in supporting and shaping the L2 FPC circuit board;
the L1 medium support body can slide up and down in the cylindrical L2 FPC board.
The L1 FPC circuit board is fixed at the bottom of the L1 ground plate, and the L2 FPC circuit board is fixed at the top of the L2 ground plate; the L1 medium support is a hollow hard support, and the coaxial cable passes through the middle of the L1 medium support and the L2 medium ring set to connect the L1 ground plate with the L2 ground plate.
The L2 medium ring group comprises amovable medium ring 221 and at least onefixed medium ring 222 with the same outer diameter, the fixed medium ring is fixedly connected with the inner wall of the cylindrical L2 FPC board, and the movable medium ring can slide up and down along the inner wall of the cylindrical L2 FPC board; the diameter of the L1 medium support body is adapted to the inner diameter of the medium ring group, the bottom of the L1 medium support body is fixedly connected with the movable medium ring, so that the L1 medium support body can drive the movable medium ring to slide up and down along the fixed medium ring to adjust the antenna frequency of the L2 FPC circuit board. The L2 antenna unit adopts the dielectric ring group as the supporting body, and has higher manufacturability because the dielectric ring has small thickness and higher processing precision than the columnar or tubular supporting body; in addition, the traditional columnar or tubular support body usually needs to be opened during production, so that the cost is increased to a certain extent; the processing cost and the material cost of the medium ring are lower than those of the traditional columnar or tubular support body.
In this embodiment, each dielectric ring is made of FR4 hard circuit board material; the thickness (difference between the inner diameter and the outer diameter) of the movable medium ring and the fixed medium ring is 2mm (generally between 0.5mm and 10 mm), and the height is 8mm (generally between 1mm and 20 mm); the two fixed medium rings are respectively arranged at the upper part and the lower part of the inner wall of the cylindrical L2 FPC circuit board, the movable medium ring is arranged between the two fixed medium rings, the L1 medium support body penetrates through the fixed medium ring at the upper part, the outer diameter of the L1 medium support body is slightly smaller than the inner diameter of the fixed medium ring at the upper part, so that the L1 medium support body can slide along with the fixed medium ring at the upper part, the movable medium ring is driven to move, and the position of the movable medium ring can have certain influence on the working frequency of the L2 antenna unit.
The height of the L1 medium support body is larger than that of the cylindrical L1 FPC board, the upper part of the L1 medium support body plate is fixedly connected with the L1 grounding plate, and the lower part of the L1 medium support body is exposed out of the cylindrical L1 FPC board to form anexposed part 121.
The range of the L1 medium supporting body sliding up and down in the cylindrical L2 FPC board is limited by the length of the exposed part, and the distance between the movable medium ring and the fixed medium ring closest to the movable medium ring is not less than the length of the exposed part.
The L1 antenna unit synthesizes or receives an L1 signal, and the L2 antenna unit synthesizes or receives an L2 signal; the L1 signal is transmitted to the L2 ground plate through a coaxial cable; and the L1 signal and the L2 signal are processed respectively and then are combined for output.
The L1 FPC circuit board and the L2 FPC circuit board are respectively provided with amulti-arm spiral radiator 4, the multi-arm spiral radiator is of an eight-arm radiation arm structure, and the eight-arm radiation arm structure comprises four symmetricallong arms 410 and fourshort arms 420. The eight-arm spiral radiator takes the FPC circuit board as a carrier and is fixed on the medium support body in a winding mode, so that different polarization modes can be conveniently formed to receive satellite signals in different polarization modes.
The L1 ground plate and the L2 ground plate are multilayer circuit boards and are used for processing signals including filtering and amplifying.
And the L1 ground plate and the L2 ground plate are respectively integrated with a feeding device, the L1 ground plate feeds the L1 FPC circuit board, and the L2 ground plate feeds the L2 FPC circuit board.
The fixingdevice 5 is arranged at the center of the bottom of the L2 ground plate, aconvex fixing foot 510 is arranged at the top of the fixing device, the fixing foot is inserted into the L2 ground plate, and a threadedhole 520 is machined in the bottom of the fixing device. Carry out the thread tightening through fixing device, can be convenient install on unmanned aerial vehicle.
Example 2
As shown in fig. 5, the L1 signal and the L2 signal are processed separately and then combined for output. In this embodiment, the L1 signal and the L2 signal are processed by a pre-filter, an amplifier, and a filter, respectively, and then are combined and output by the amplifier; the signal channels L1 and L2 respectively adopt pre-filtering to improve the anti-interference capability of signals; amplifiers with low noise figure are used.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.