JP3877856B2

JP3877856B2 - Semi-coaxial cavity resonator

Info

Publication number: JP3877856B2
Application number: JP03292898A
Authority: JP
Inventors: 利誠矢野; 金見佐々木
Original assignee: Hitachi Kokusai Electric Inc
Current assignee: Hitachi Kokusai Electric Inc
Priority date: 1998-02-16
Filing date: 1998-02-16
Publication date: 2007-02-07
Anticipated expiration: 2018-02-16
Also published as: JPH11234005A

Description

【０００１】
【発明の属する技術分野】
この発明は、半同軸空洞共振器にかかわり、さらに詳しくは、無線通信の送受信器などにおいて、バンドパスフィルタとして好適な半同軸空洞共振器の改良に関している。
【０００２】
【従来の技術】
従来、無線通信機などにおいて、パンドパスフィルタとして用いられている半同軸空洞共振器は、たとえば図７および図８に示すように、外部導体ａと、短絡板ｂ，ｃと、内部導体ｄと、印刷配線板ｅとを具備している。外部導体ａは、両端が開放された中空角筒の形態をなすもので、外側面にコネクタｆを具備している。短絡板ｂ，ｃは、外部導体ａの開放端を閉塞するように配置されているとともに、外部導体ａに接続されている。内部導体ｄは、外部導体ａの中空孔における丸孔領域の中心軸上に位置して、丸孔領域に配置されているとともに、一端を短絡板ｃに接続されている。印刷配線板ｅは、負荷容量を変え、共振周波数を変化させる回路を具備するもので、外部導体ａの中空孔における角孔領域に配置されているとともに、四隅を外部導体ａの丸孔領域と角孔領域との間に形成された座にねじｈによって固定されているとともに、中央を内部導体ｄの自由端にねじｇによって固定され、ねじｇによって印刷配線板ｅにある前記回路と内部導体ｄとの電気接続をなされている。
【０００３】
【発明が解決しようとする課題】
このような空洞共振器では、しかしながら、内部導体ｄが外部導体ａよりも大きな線膨張率をもつ材料からなっていると、電流が印加されたときに、内部導体ｄは外部導体ａよりも大きく伸びる。内部導体ｄが伸びると、印刷配線板ｅは、たとえば図９に鎖線で示すようなフラットな初期状態から、実線で示すような椀状に反った状態になり、通電がとまると、反った状態からフラットな状態にもどる。印刷配線板ｅがこのような変形あるいは歪みを生じると、印刷配線板ｅに実装された共振周波数を変える回路を構成する配線導体の間隔が変化し、共振器の出力周波数特性に劣化を生じる。さらに、印刷配線板ｅがこのような変形あるいは歪みを繰り返すうちに、印刷配線板ｅに実装されている共振周波数を変える回路を構成する電子部品ｉが割れたり、配線導体が断線するおそれがある。
【０００４】
本発明の目的は、内部導体の線膨張率が外部導体のそれと異なっていても、回路の特性変化や故障を防止することができる、改良された半同軸空洞共振器を提供することにある。
【０００５】
【課題を解決するための手段】
上記目的を達成するために、本発明の半同軸空洞共振器は、両端を開放された中空の外部導体と、外部導体の開放端の各々に配置されかつ外部導体に接続された短絡板と、短絡板の一方に一端を接続され、短絡板の他方との間にすき間を形成して外部導体内部に配置された内部導体と、内部導体の自由端側に位置して外部導体の内部に配置されかつ内部導体に電気接続された印刷配線板とを具備しているが、印刷配線板と内部導体との電気接続は、印刷配線板に設けられた孔に内部導体を貫通させるとともに、弾性をもつ導電部材を印刷配線板と内部導体との間に架橋することによってなされている。
【０００６】
【発明の実施の形態】
本発明の半同軸空洞共振器では、内部導体が外部導体よりも大きな線膨張率をもつ材料からなり、外部導体よりも大きく伸びても、内部導体は印刷配線板の孔を通り抜けて伸びて、印刷配線板を変形させたり、歪ませたりさせない。このときに、外部導体と印刷配線板との電気接続は導電部材によって維持されるが、導電部材は内部導体が伸びると撓んで、内部導体の伸びを吸収して、印刷配線板を変形させたり、歪ませたりさせない。このため、負荷容量を可変させて、共振周波数を変える回路を構成する配線導体の間隔が変化しなくなるとともに、この回路を構成する電子部品や配線導体の破損がない。逆に、外部導体が内部導体よりも大きな線膨張率をもつ材料からなり、内部導体よりも大きく伸びても、印刷配線板は内部導体に拘わりなく外部導体とともに移動し、変形したり、歪んだりしないばかりか、導電部材が印刷配線板の移動に応じて撓み、印刷配線板を変形させたり、歪ませたりさせずに、内部導体と印刷配線板との電気接続を維持するため、負荷容量を可変させて共振周波数を変える回路を構成する配線導体の間隔を変化させないとともに、この回路を構成する電子部品や配線導体の破損がない。
【０００７】
本発明において、導電部材は、一端を印刷配線板上の配線導体に固定され、他端を内部導体の自由端側側面に接触させられていても、また、一端を印刷配線板上の配線導体に固定されているが、他端を内部導体の自由端側端面に接触させられていてもよい。また、導電部材自体も、弾性特性のすぐれたベリリウム銅合金の薄板によって構成して、印刷配線板の変形や歪みをさらに小さくしてもよく、さらに、このような導電部材の表面に銀メッキを施して、内部導体との電気接続をさらに向上させるなどしてもよい。
【０００８】
本発明の半同軸空洞共振器の実施例は、以下に、図１ないし図６を参照して説明する。
【０００９】
この半同軸空洞共振器は、たとえば無線通信の送受信器にてバンドパスフィルタとして用いられるもので、図１および図２に示すように、外部導体１１、短絡板１２，１３、内部導体１４および印刷配線板１５を具備している。
【００１０】
外部導体１１は両端が開放された中空角筒の形態をなしている。この外部導体における中空孔１６は、一部が外部導体１１の外形に合わせて角孔に形成されているが、残余が丸孔に形成されている。コネクタ１７，１８が外部導体１１の側面に取り付けられている。
【００１１】
短絡板１２，１３は、外部導体１１の輪郭に対応する形状をもつ四角な板状をなすもので、外部導体１１の両端開口を閉塞するように配置され、外部導体１１に結合されている。
【００１２】
内部導体１４は、外部導体１１よりも大きな線膨張率をもつ材料からなる、一端が閉塞され、他端が開放された中空円筒の形態をなし、外部導体１１よりも短い全長をもつもので、閉塞端が短絡板１２に接続し、開放端が短絡板１３との間にすき間を形成するように、外部導体１１の中空孔１６におけ丸孔領域に、これと同軸に配置されている。
【００１３】
印刷配線板１５は、負荷容量を可変させ、共振周波数を変える回路が実装されている。この印刷配線板１５は、外部導体１１の中空孔１６における角孔領域にはまる形状とサイズをもつもので、中央に内部導体１４の直径よりも大きな内径をもつ孔２１が設けられている。外部導体１１への組み込みは、孔２１を内部導体１４にかん合させて、外部導体１１の中空孔１６における角孔領域にはめ込むとともに、外部導体１１における中空孔１６の丸孔領域と角孔領域との間に形成されている座に四隅をねじ１９によって締結することによって、あるいは半だ付けすることによってなされている。
【００１４】
印刷配線板１５の孔２１と内部導体１４の開放端あるいは自由端との間には多数の弾性をもつ導電部材２２が配置されている。各々の導電部材２２は、たとえば、表面に銀メッキを施したベリリウム銅合金の薄板を、ほぼ横に倒したＵ字形に曲げ加工したものからなっている。これらの導電部材２２は、図３に示すように、Ｕ字の一片あるいは一端２３が内部導体１４の自由端側側面に接触し、他片あるいは他端２４が印刷配線板１５に実装された前記回路を構成する配線導体に電気接続するように、印刷配線板１５の孔２１の周囲に配置されかつ印刷配線板１５に固定されている。そして、これらの導電部材２２の端部２３は、さらに内部導体１４の側面と反対方向に向かって浅いＵ字形に曲げられ、該Ｕ字の頂点を内部導体１４の側面に接触させられている。
【００１５】
この半同軸空洞共振器は、無線通信の送受信器に、コネクタ１７をＲＦ部に、コネクタ１８を制御部に接続することによって組み込まれ、内部導体１４の長さと印刷配線板１５にある回路の負荷容量とによって定まる波長を遮断周波数とするバンドパスフィルタとして作動する。
【００１６】
通電がなされ、内部導体１４が発熱すると、内部導体１４の長手方向中心軸に沿う長さが増大する。内部導体１４は、前述のように、外部導体１１よりも大きな線膨張率をもつ材料からなっているため、外部導体１１よりも大きく伸びる。しかし、内部導体１４は、印刷配線板１５の孔２１を貫通しているため、伸びによる荷重を印刷配線板１５に負荷させずに、自由に伸びることができ、印刷配線板１５を変形させ、歪ませたりしない。このときに、内部導体１４と印刷配線板１５との電気接続は導電部材２２によって維持されているが、導電部材２２は内部導体１４が伸びると、内部導体１４の側面と接触しつつ滑りかつ撓んで、内部導体１４の伸びを吸収することができるため、印刷配線板１５を変形させ、歪ませたりしない。そして、導電部材自体は前述のようにベリリウム銅合金の薄板からなっているため、内部導体１４の伸びにしたがってつねにスムーズに撓み、印刷配線板１５の変形や歪みをさらに少なくするとともに、表面に銀メッキを施されているため、印刷配線板１５と内部導体１４との電気接続を確実におこなわせる。
【００１７】
本発明による半同軸空洞共振器は、このように、外部導体１１と内部導体１４との間に線膨張率の差があっても、印刷配線板１５が変形したり、歪んだりしないため、印刷配線板１５にある共振周波数を変える回路を構成している配線導体の間隔が変化しなくなって、出力周波数特性がつねに安定しているばかりか、配線導体の断線や前記回路を構成している電子部品も曲げや捻れを受けなくなり、破損しない。
【００１８】
図４ないし図６はこのような半同軸空洞共振器の他の実施例を示している。
【００１９】
この半同軸空洞共振器も、無線通信の送受信器においてバンドパスフィルタとして使用されるもので、図４および図５に示すように、外部導体１１１、短絡板１１２，１１３、内部導体１１４および負荷容量を可変させ、共振周波数を変える回路が実装された印刷配線板１１５を具備している。
【００２０】
外部導体１１１は両端が開放された中空角筒の形態をなしている。この外部導体における中空孔１１６も、一部が外部導体１１１の外形に合わせて角孔に、残余が丸孔となっている。コネクタ１１７，１１８が外部導体１１１の側面に取り付けられている。
【００２１】
短絡板１１２，１１３は、外部導体１１１の輪郭に対応する形状をもつ四角な板状をなすもので、外部導体１１１の両端開口を閉塞するように配置され、外部導体１１１に結合されている。
【００２２】
内部導体１１４は外部導体１１１よりも大きな線膨張率をもつ材料からなる、外部導体１１１よりも短い全長をもつソリッドな中空円柱の形態をなすもので、一端が短絡板１１２に接続し、他端が短絡板１１３との間にすき間を形成するように、外部導体１１１の中空孔１１６におけ丸孔領域に、これと同軸に配置されている。
【００２３】
印刷配線板１１５は、負荷容量を可変させ、共振周波数を変える回路が実装されている。この印刷配線板１１５は、外部導体１１１の中空孔１１６における角孔領域にはまる形状とサイズをもつもので、中央に内部導体１１４の直径よりも大きな内径をもつ孔１２１を設けられている。組み込みは、孔１２１を内部導体１１４に貫通させて、外部導体１１１の中空孔１１６における角孔領域にはめ込むとともに、中空孔１１６の丸孔領域と角孔領域との間に形成されている座に、四隅をねじ１１９によって固定することでなされている。
【００２４】
導電部材１２２は、表面に銀メッキを施したベリリウム銅合金の薄板からなっているとともに、該薄板の一端１２３をほぼ円弧状に曲げ加工したものからなっている。これらの導電部材１２２は、図６に示すように、フラットな一端１２４が印刷配線板１１５に実装された前記回路を構成する配線導体に電気接続させて印刷配線板１１５の接合され、円弧に形成された他端あるいは自由端１２３が内部導体１１４の自由端側端面に接触するように、印刷配線板１１５の孔１２１のまわりに配置されている。
【００２５】
この半同軸空洞共振器も、バンドパスフィルタとして無線通信の送受信器に組み込まれ、コネクタ１７をＲＦ部に、コネクタ１８を制御部に接続される。
【００２６】
通電がなされると、内部導体１１４は外部導体１１１よりも大きな線膨張率をもつ材料からなっているため、発熱し、外部導体１１１よりも大きく伸びるが、内部導体１１４は印刷配線板１１５の孔１２１を貫通しているため、印刷配線板１１５に接触せずに自由に伸びることができ、印刷配線板１１５を変形させ、歪ませたりしない。内部導体１１４と印刷配線板１１５との電気接続を維持する導電部材１２２も、内部導体１１４が伸びると、導電部材１２２が内部導体１１４の端面と接触しつつ撓んで、内部導体１１４の伸びを吸収するため、印刷配線板１１５を変形させ、歪ませたりしない。そして、導電部材１２２は表面にメッキを施したベリリウム銅合金の薄板からなっているため、内部導体１１４の伸びに応じてスムーズに撓み、印刷配線板１１５の変形や歪みをさらに小さくさせるとともに、印刷配線板１１５と内部導体１１４との電気的接続を確実におこなわせる。
【００２７】
さらに、この半同軸空洞共振器では、導電部材１２２が広い面積で印刷配線板１１５に接触しかつ固定されているため、図１ないし図３に関連して説明した共振器よりも、印刷配線板１１５を内部導体１１４にしっかり支持させることができ、しかも、導電部材１２２の弾性が小さく、内部導体１１４の熱膨張に応じて容易に撓むことができるため、印刷配線板１１５の変形や歪みが前述の半同軸空洞共振器よりも小さく、そして、導電部材１２２の自由端が円弧に形成されているため、内部導体１１４がのびによって印刷配線板１１５との固定点を中心に撓んでも、内部導体１１４の端面との接触をつねに維持することができる。
【００２８】
【発明の効果】
本発明によれば、内部導体の線膨張率が外部導体とそれと異なっていても、印刷配線板を変形させたり、歪ませたりさせないため、印刷配線板上の回路を構成する配線導体の間隔が変化しなくなり、配線導体の断線および前記回路を構成する電子部品の破損もしなくなり、信頼性がたかくかつ周波数特性のすぐれた半同軸空洞共振器を得られる。
【図面の簡単な説明】
【図１】本発明の半同軸空洞共振器の一実施例を示す縦断面図である。
【図２】図１のＡ−Ａ線にそう横断面図である。
【図３】図２のＢ−Ｂ線にそう断面図である。
【図４】本発明の半同軸空洞共振器の他の実施例を示す縦断面図である。
【図５】図４のＣ−Ｃ線にそう横断面図である。
【図６】図２のＤ−Ｄ線にそう断面図である。
【図７】従来の半同軸空洞共振器を示す縦断面図である。
【図８】図７のＥ−Ｅ線にそう横断面図である。
【図９】図８のＦ−Ｆ線にそう断面図である。
【符号の説明】
１１，１１１…外部導体
１２，１１２…短絡板
１３，１１３…短絡板
１４，１１４…内部導体
１５，１１５…印刷配線板
２２，１２２…導電部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semi-coaxial cavity resonator, and more particularly to an improvement of a semi-coaxial cavity resonator suitable as a bandpass filter in a radio communication transceiver or the like.
[0002]
[Prior art]
Conventionally, a semi-coaxial cavity resonator used as a pan-pass filter in a wireless communication device or the like includes an outer conductor a, short-circuit plates b and c, an inner conductor d, as shown in FIGS. 7 and 8, for example. And a printed wiring board e. The outer conductor a is in the form of a hollow rectangular tube with both ends open, and has a connector f on the outer surface. The short-circuit plates b and c are arranged so as to close the open end of the external conductor a and are connected to the external conductor a. The inner conductor d is located on the central axis of the round hole region in the hollow hole of the outer conductor a, is disposed in the round hole region, and has one end connected to the short-circuit plate c. The printed wiring board e includes a circuit that changes the load capacity and changes the resonance frequency, and is disposed in the square hole region in the hollow hole of the outer conductor a, and the four corners are round hole regions of the outer conductor a. The circuit is fixed to a seat formed between the square hole region by a screw h and the center is fixed to the free end of the inner conductor d by a screw g, and the circuit and the inner conductor on the printed wiring board e are fixed by the screw g. Electrical connection with d is made.
[0003]
[Problems to be solved by the invention]
In such a cavity resonator, however, when the inner conductor d is made of a material having a larger linear expansion coefficient than the outer conductor a, the inner conductor d is larger than the outer conductor a when a current is applied. extend. When the internal conductor d extends, the printed wiring board e changes from a flat initial state as shown by a chain line in FIG. 9, for example, to a warped state as shown by a solid line. Return to a flat state. When the printed wiring board e is deformed or distorted, the interval between the wiring conductors constituting the circuit for changing the resonance frequency mounted on the printed wiring board e is changed, and the output frequency characteristics of the resonator are deteriorated. Furthermore, while the printed wiring board e repeats such deformation or distortion, the electronic component i constituting the circuit for changing the resonance frequency mounted on the printed wiring board e may be broken or the wiring conductor may be disconnected. .
[0004]
An object of the present invention is to provide an improved semi-coaxial cavity resonator that can prevent circuit characteristic changes and failures even if the linear expansion coefficient of the inner conductor is different from that of the outer conductor.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a semi-coaxial cavity resonator according to the present invention includes a hollow outer conductor open at both ends, a short-circuit plate disposed at each of the open ends of the outer conductor and connected to the outer conductor, One end is connected to one side of the short-circuit plate, a gap is formed between the other side of the short-circuit plate and the inner conductor is disposed inside the outer conductor, and the inner conductor is disposed on the free end side of the inner conductor. The printed wiring board is electrically connected to the internal conductor, and the electrical connection between the printed wiring board and the internal conductor allows the internal conductor to pass through a hole provided in the printed wiring board and has elasticity. It is made by bridging a conductive member having a printed wiring board and an internal conductor.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the semi-coaxial cavity resonator of the present invention, the inner conductor is made of a material having a larger linear expansion coefficient than the outer conductor, and even if the inner conductor extends larger than the outer conductor, the inner conductor extends through the hole of the printed wiring board, Do not deform or distort the printed wiring board. At this time, the electrical connection between the outer conductor and the printed wiring board is maintained by the conductive member. However, the conductive member bends when the inner conductor extends, absorbs the elongation of the inner conductor, and deforms the printed wiring board. Do not let it distort. For this reason, the distance between the wiring conductors constituting the circuit for changing the resonance frequency by changing the load capacitance is not changed, and the electronic components and the wiring conductors constituting the circuit are not damaged. Conversely, even if the outer conductor is made of a material having a larger linear expansion coefficient than the inner conductor, and the printed wiring board moves with the outer conductor regardless of the inner conductor, the printed wiring board may be deformed or distorted. In addition, the conductive member bends as the printed wiring board moves, and the load capacity is reduced to maintain the electrical connection between the internal conductor and the printed wiring board without causing the printed wiring board to be deformed or distorted. The distance between the wiring conductors constituting the circuit that varies and changes the resonance frequency is not changed, and the electronic components and the wiring conductors constituting the circuit are not damaged.
[0007]
In the present invention, the conductive member has one end fixed to the wiring conductor on the printed wiring board and the other end brought into contact with the free conductor side surface of the internal conductor. However, the other end may be brought into contact with the end surface on the free end side of the internal conductor. In addition, the conductive member itself may be formed of a thin plate of beryllium copper alloy having excellent elastic characteristics to further reduce the deformation and distortion of the printed wiring board. Further, silver plating is applied to the surface of such a conductive member. The electrical connection with the inner conductor may be further improved.
[0008]
An embodiment of the semi-coaxial cavity resonator of the present invention will be described below with reference to FIGS.
[0009]
This semi-coaxial cavity resonator is used, for example, as a bandpass filter in a radio communication transceiver. As shown in FIGS. 1 and 2, the outer conductor 11, the short-circuit plates 12, 13, the inner conductor 14, and the printing are used. A wiring board 15 is provided.
[0010]
The outer conductor 11 is in the form of a hollow square tube with both ends open. A part of the hollow hole 16 in the outer conductor is formed as a square hole in accordance with the outer shape of the outer conductor 11, but the remainder is formed as a round hole. Connectors 17 and 18 are attached to the side surfaces of the outer conductor 11.
[0011]
The short-circuit plates 12 and 13 are formed in a square plate shape having a shape corresponding to the outline of the external conductor 11, arranged so as to close both end openings of the external conductor 11, and coupled to the external conductor 11.
[0012]
The inner conductor 14 is made of a material having a larger linear expansion coefficient than that of the outer conductor 11, has a hollow cylindrical shape with one end closed and the other end opened, and has a shorter overall length than the outer conductor 11, The closed end is connected to the short-circuit plate 12, and the open end is arranged in the round hole region of the hollow hole 16 of the outer conductor 11 so as to be coaxial with the short-circuit plate 13.
[0013]
The printed wiring board 15 is mounted with a circuit that varies the load capacity and changes the resonance frequency. This printed wiring board 15 has a shape and size that fits into a square hole region in the hollow hole 16 of the outer conductor 11, and a hole 21 having an inner diameter larger than the diameter of the inner conductor 14 is provided at the center. For the incorporation into the outer conductor 11, the hole 21 is engaged with the inner conductor 14 and fitted into the square hole region in the hollow hole 16 of the outer conductor 11, and the round hole region and the square hole region of the hollow hole 16 in the outer conductor 11. The four corners are fastened to the seat formed between the two by screws 19 or half-attached.
[0014]
Between the hole 21 of the printed wiring board 15 and the open end or free end of the internal conductor 14, a large number of conductive members 22 having elasticity are arranged. Each conductive member 22 is formed, for example, by bending a thin plate of beryllium copper alloy whose surface is silver-plated into a U-shape that is tilted sideways. As shown in FIG. 3, the conductive member 22 has a U-shaped piece or one end 23 which is in contact with the free end side surface of the internal conductor 14 and the other piece or the other end 24 mounted on the printed wiring board 15. The printed wiring board 15 is disposed around the hole 21 and fixed to the printed wiring board 15 so as to be electrically connected to the wiring conductors constituting the circuit. The end portions 23 of these conductive members 22 are further bent into a shallow U shape in the direction opposite to the side surface of the internal conductor 14, and the apex of the U shape is brought into contact with the side surface of the internal conductor 14.
[0015]
This semi-coaxial cavity resonator is incorporated in a radio communication transceiver by connecting the connector 17 to the RF section and the connector 18 to the control section. The length of the inner conductor 14 and the load on the circuit on the printed wiring board 15 are as follows. It operates as a bandpass filter having a cutoff frequency at a wavelength determined by the capacitance.
[0016]
When energization is performed and the internal conductor 14 generates heat, the length along the longitudinal central axis of the internal conductor 14 increases. As described above, the inner conductor 14 is made of a material having a larger linear expansion coefficient than that of the outer conductor 11, and thus extends larger than the outer conductor 11. However, since the inner conductor 14 penetrates the hole 21 of the printed wiring board 15, the inner conductor 14 can be freely extended without applying a load due to elongation to the printed wiring board 15, and the printed wiring board 15 is deformed, Does not distort. At this time, the electrical connection between the inner conductor 14 and the printed wiring board 15 is maintained by the conductive member 22. When the inner conductor 14 extends, the conductive member 22 slides and flexes while contacting the side surface of the inner conductor 14. Therefore, since the elongation of the inner conductor 14 can be absorbed, the printed wiring board 15 is not deformed and distorted. Since the conductive member itself is made of a thin plate of beryllium copper alloy as described above, it always bends smoothly as the internal conductor 14 stretches, further reducing deformation and distortion of the printed wiring board 15, and silver on the surface. Since the plating is applied, electrical connection between the printed wiring board 15 and the inner conductor 14 can be reliably performed.
[0017]
Thus, the semi-coaxial cavity resonator according to the present invention does not deform or distort the printed wiring board 15 even if there is a difference in linear expansion coefficient between the outer conductor 11 and the inner conductor 14. The interval between the wiring conductors constituting the circuit for changing the resonance frequency on the wiring board 15 does not change, and the output frequency characteristics are always stable, as well as the disconnection of the wiring conductors and the electrons constituting the circuit. Parts will not be bent or twisted and will not be damaged.
[0018]
4 to 6 show another embodiment of such a semi-coaxial cavity resonator.
[0019]
This semi-coaxial cavity resonator is also used as a band-pass filter in a radio communication transceiver. As shown in FIGS. 4 and 5, the outer conductor 111, the short-circuit plates 112 and 113, the inner conductor 114, and the load capacitance And a printed wiring board 115 on which a circuit for changing the resonance frequency is mounted.
[0020]
The outer conductor 111 is in the form of a hollow rectangular tube with both ends open. A part of the hollow hole 116 in the outer conductor is also a square hole according to the outer shape of the outer conductor 111, and the remainder is a round hole. Connectors 117 and 118 are attached to the side surfaces of the outer conductor 111.
[0021]
The short-circuit plates 112 and 113 are formed in a square plate shape having a shape corresponding to the outline of the external conductor 111, arranged so as to close both end openings of the external conductor 111, and coupled to the external conductor 111.
[0022]
The inner conductor 114 is formed of a material having a linear expansion coefficient larger than that of the outer conductor 111 and is in the form of a solid hollow cylinder having an overall length shorter than that of the outer conductor 111. One end is connected to the short-circuit plate 112 and the other end Is arranged coaxially with the round hole region in the hollow hole 116 of the outer conductor 111 so as to form a gap with the short-circuit plate 113.
[0023]
The printed wiring board 115 is mounted with a circuit that varies the load capacity and changes the resonance frequency. This printed wiring board 115 has a shape and size that fits into a square hole region in the hollow hole 116 of the outer conductor 111, and a hole 121 having an inner diameter larger than the diameter of the inner conductor 114 is provided in the center. Assembling is performed by passing the hole 121 through the inner conductor 114 and fitting it into the square hole region in the hollow hole 116 of the outer conductor 111, and in the seat formed between the round hole region and the square hole region of the hollow hole 116. The four corners are fixed by screws 119.
[0024]
The conductive member 122 is made of a thin plate of beryllium copper alloy having a surface plated with silver, and is formed by bending one end 123 of the thin plate into a substantially arc shape. As shown in FIG. 6, these conductive members 122 are formed into an arc by joining the printed wiring board 115 with a flat end 124 electrically connected to the wiring conductor constituting the circuit mounted on the printed wiring board 115. The other end or the free end 123 is arranged around the hole 121 of the printed wiring board 115 so as to contact the end surface on the free end side of the internal conductor 114.
[0025]
This semi-coaxial cavity resonator is also incorporated in a wireless communication transceiver as a band-pass filter, and the connector 17 is connected to the RF unit and the connector 18 is connected to the control unit.
[0026]
When energized, the inner conductor 114 is made of a material having a larger linear expansion coefficient than that of the outer conductor 111, and thus generates heat and extends larger than the outer conductor 111, but the inner conductor 114 is a hole in the printed wiring board 115. Since it penetrates 121, it can extend freely without contacting the printed wiring board 115, and the printed wiring board 115 is not deformed and distorted. The conductive member 122 that maintains the electrical connection between the internal conductor 114 and the printed wiring board 115 is also bent when the internal conductor 114 is extended, and the conductive member 122 is in contact with the end face of the internal conductor 114 to absorb the extension of the internal conductor 114. Therefore, the printed wiring board 115 is not deformed and distorted. Since the conductive member 122 is made of a thin plate of beryllium copper alloy whose surface is plated, the conductive member 122 bends smoothly according to the elongation of the internal conductor 114, further reducing deformation and distortion of the printed wiring board 115, and printing. The electrical connection between the wiring board 115 and the internal conductor 114 can be reliably performed.
[0027]
Further, in this semi-coaxial cavity resonator, since the conductive member 122 is in contact with and fixed to the printed wiring board 115 over a wide area, the printed wiring board is more than the resonator described with reference to FIGS. 115 can be firmly supported by the inner conductor 114, and the elasticity of the conductive member 122 is small and can be easily bent according to the thermal expansion of the inner conductor 114, so that the printed wiring board 115 is not deformed or distorted. Since it is smaller than the above-described semi-coaxial cavity resonator and the free end of the conductive member 122 is formed in a circular arc, even if the inner conductor 114 bends around a fixed point with the printed wiring board 115 by extension, Contact with the end face of the conductor 114 can always be maintained.
[0028]
【The invention's effect】
According to the present invention, even if the linear expansion coefficient of the inner conductor is different from that of the outer conductor, the printed wiring board is not deformed or distorted. The semi-coaxial cavity resonator with high reliability and excellent frequency characteristics can be obtained because the wiring conductor does not change, the wiring conductor is not broken, and the electronic components constituting the circuit are not damaged.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a semi-coaxial cavity resonator according to the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is a longitudinal sectional view showing another embodiment of the semi-coaxial cavity resonator of the present invention.
FIG. 5 is a cross-sectional view taken along the line CC of FIG.
6 is a cross-sectional view taken along line DD of FIG.
FIG. 7 is a longitudinal sectional view showing a conventional semi-coaxial cavity resonator.
8 is a cross-sectional view taken along the line EE of FIG.
9 is a cross-sectional view taken along line FF in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11, 111 ... External conductor 12, 112 ... Short circuit board 13, 113 ... Short circuit board 14, 114 ... Internal conductor 15, 115 ... Printed wiring board 22, 122 ... Conductive member

Claims

Between the hollow outer conductor open at both ends, the short-circuit plate arranged at each of the open ends of the outer conductor and connected to the outer conductor, one end connected to one of the short-circuit plates, and the other of the short-circuit plate Printed wiring board that forms a gap and is placed inside the outer conductor, a printed wiring board that is located on the free end side of the inner conductor and that is placed inside the outer conductor, and through which the inner conductor passes , and one end printed Fixed to the wiring board, the other end is in contact with the free end side of the inner conductor, and comprises a conductive member having elasticity ,
When the elongation of the inner conductor during thermal expansion is larger than the elongation of the outer conductor, the inner conductor penetrates the hole, and the other end of the conductive member slides and bends while contacting the inner conductor, so that the printed wiring A semi-coaxial cavity resonator characterized in that electrical connection between a plate and an inner conductor is made even if there is a difference in linear expansion coefficient between the outer conductor and the inner conductor .

The semi-coaxial cavity resonator according to claim 1, wherein the conductive member has one end fixed to a wiring conductor on a printed wiring board and the other end in contact with a free end side surface of the internal conductor.

The semi-coaxial cavity resonator according to claim 2 or 3, wherein the conductive member is made of a thin plate of beryllium copper alloy having a surface plated with silver.