CN101312263A - Cavity filter and duplex device - Google Patents

Abstract

The invention provides a cavity filter and a duplexer, which is adaptable to filters in the field of wireless communication. The cavity filter comprises a case, a resonance rod and tuning screw rods, wherein the resonance rod is disposed inside the case and connected with the case, the tuning screw rods penetrate the case, and medium of the tuning screw rods is insulators. By utilizing a group of insulated tuning screw rods to replace metal tuning screw rods employed in the prior art, influences caused by discontinuity of metal to filters and duplexers are avoided.

Description

A kind of cavity body filter and duplexer

Technical field

The invention belongs to the filter in the wireless communication field, relate in particular to a kind of cavity body filter and duplexer.

Background technology

At present, in existing coaxial cavity filter, as shown in Figure 1, generally adopt the tuning screw rod of a kind of metal to realize adjusting to the resonant cavity frequency.Change the size of loading capacitance amount on each resonator by regulating the tuning screw rod of metal, thereby make resonance frequency obtain changing.Yet this traditional tuning manner requires the tuning screw rod ground connection of metal well (being that the tuning screw rod of metal must be locked on the metal cover board), otherwise just can produce bigger influence to electric index.Secondly, during the designing high-power filter, the tuning screw rod of traditional metal must and metal resonators between maintain the voltage breakdown of certain spacing when avoiding high-power.

Summary of the invention

Embodiment of the invention technical problem to be solved be to provide a kind of overcome adopt the tuning screw rod of conventional metals carry out tuning bring electric index is produced the cavity body filter and the duplexer of the defective of considerable influence.

For solving the problems of the technologies described above, the embodiment of the invention provides a kind of cavity body filter, comprises box body and resonant rod, and described resonant rod is built in the described box body, and links to each other with described box body; Described cavity body filter also comprises tuning screw rod, and described tuning screw rod is arranged on the described box body; The medium of described tuning screw rod is an insulator.

The embodiment of the invention also provides a kind of duplexer that comprises a plurality of cavity body filters recited above.

In embodiments of the present invention, adopt one group of tuning screw rod of insulator to replace the tuning screw rod of metal that prior art adopts, thereby avoided of the influence of metal discontinuity filter, duplexer electrical property.

Description of drawings

Fig. 1 is the structural representation of the coaxial cavity filter that provides of prior art.

Fig. 2 to Fig. 5 is the structural representation of the cavity body filter that provides of the embodiment of the invention.

Fig. 6 and Fig. 7 are another structural representations of the cavity body filter that provides of the embodiment of the invention.

Embodiment

In order to make technical problem to be solved by this invention, technical scheme and beneficial effect clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.

See also Fig. 2 to Fig. 5, the cavity body filter that the embodiment of the invention provides, this cavity body filter comprises:box body 10,resonant rod 20 and tuning screw rod 30.Form aresonant cavity 40 in the describedbox body 10, describedbox body 10 adopts metal material to make.Describedresonant rod 20 is built in theresonant cavity 40 of describedbox body 10, and thisresonant rod 20 links to each other withbox body 10; Be provided withshrinkage pool 50 at the top of describedresonant rod 20, the purpose that thisshrinkage pool 50 is set is in order to regulate the length range that tuningscrew rod 30 stretches into resonant cavity 40.See also Fig. 6 and Fig. 7 for the structural representation of shrinkage pool is not set at the top of describedresonant rod 20, at the top of describedresonant rod 20 shrinkage pool is not set and also is fine.Describedtuning screw rod 30 is arranged on thebox body 10, and thesetuning screw rod 30 parts are positioned at outside thebox body 10, and another part is positioned at theresonant cavity 40 of box body 10.As one embodiment of the invention, as shown in Figure 2, the lower end of describedtuning screw rod 30 is stretched in theshrinkage pool 50, and tuningscrew rod 30 is adjusted up and down, thereby regulates resonance frequency.As another embodiment of the present invention, describedtuning screw rod 30 is positioned at outside the describedshrinkage pool 50, as shown in Figure 3.As yet another embodiment of the invention, as shown in Figure 4, describedresonant rod 20 has through hole, and describedtuning screw rod 30 passes described through hole.The medium of describedtuning screw rod 30 is an insulator, and the medium of thistuning screw rod 30 can be the medium of high breakdown voltage: as mica, and breakdown strength 2200KV/cm; Quartz, breakdown strength 10000KV/cm; Aluminium oxide, breakdown strength 4000KV/cm; The medium of thistuning screw rod 30 also can be the higher medium of dielectric constant: as aluminium oxide, anddielectric constant 10; Ferrogarnet, dielectric constant 16; Pottery: dielectric constant 45.

In embodiments of the present invention, can also can change the resonance frequency ofresonant cavity 40 by the dielectric constant that changes tuningscrew rod 30 by changing how much the change resonance frequency oftuning screw rod 30 atresonant cavity 40 internal volumes.

In embodiments of the present invention, adopt one group of tuning screw rod of insulator to replace the tuning screw rod of metal that prior art adopts, thereby avoided of the influence of metal discontinuity filter, duplexer electrical property.By the tuning screw rod that selection has high breakdown voltage, can improve the withstand voltage of resonant cavity effectively, thereby improve the power capacity of filter, duplexer.Increase the regulated quantity of tuning screw rod by the dielectric constant that improves tuning screw rod, thereby realize the miniaturization of filter, duplexer.

The embodiment of the invention also provides the duplexer that adopts the cavity body filter that a plurality of embodiment of the invention provide.

The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1, a kind of cavity body filter comprises box body and resonant rod, and described resonant rod is built in the described box body, and links to each other with described box body; It is characterized in that described cavity body filter also comprises tuning screw rod, described tuning screw rod is arranged on the described box body; The medium of described tuning screw rod is an insulator.

2, cavity body filter as claimed in claim 1 is characterized in that, forms a resonant cavity in the described box body, and a described tuning screw rod part is positioned at outside the described box body, and another part is positioned at the resonant cavity of described box body.

3, cavity body filter as claimed in claim 1 is characterized in that, is provided with shrinkage pool at the top of described resonant rod, and the lower end of described tuning screw rod is stretched in the described shrinkage pool.

4, cavity body filter as claimed in claim 1 is characterized in that, described resonant rod has through hole, and described tuning screw rod passes described through hole.

5, cavity body filter as claimed in claim 1 is characterized in that, is provided with shrinkage pool at the top of described resonant rod, and described tuning screw rod is positioned at outside the described shrinkage pool.

6, cavity body filter as claimed in claim 1 is characterized in that, the medium of described tuning screw rod is the medium of high breakdown voltage.

7, cavity body filter as claimed in claim 6 is characterized in that, the medium of described high breakdown voltage is mica, quartz or aluminium oxide.

8, cavity body filter as claimed in claim 1 is characterized in that, the medium of described tuning screw rod is the higher medium of dielectric constant.

9, cavity body filter as claimed in claim 8 is characterized in that, the higher medium of described dielectric constant is aluminium oxide, ferrogarnet or pottery.

10, a kind of duplexer that comprises the described cavity body filter of a plurality of claims 1.

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