CN2085114U

CN2085114U - Waveguide type transistor medium oscillator

Info

Publication number: CN2085114U
Application number: CN 90220770
Authority: CN
Inventors: 苏凯雄; 林金清
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 1990-09-29
Filing date: 1990-09-29
Publication date: 1991-09-18

Abstract

The utility model relates to a waveguide type transistor medium oscillator which is taken as a signal source of the oscillating of centimeter wave band and millimeter wave band of the main body. The waveguide type transistor medium oscillator of the utility model adopts gate bias and grid leak bias wafers to achieve inputting of the off-set wafer of dc of fieldistor. Gate fins and gate waveguides are used to form gate circuits, and drain output waveguides and the gate fins are used to form drain circuits; meanwhile, cut-off waveguides and a dielectric resonant chamber which is arranged in the cut-off waveguide are used to form a frequency selection feedback loop, achieving high stable oscillation characteristics of the utility model. In addition, the utility model with the advantages of simple structure, low cost, simply debugging, reliable work, high index of performance, etc. can connect with waveguide components conveniently.

Description

Waveguide type transistor medium oscillator

The present invention relates to the waveguide type transistor dielectric oscillator (being waveguide type field-effect transistor or bipolar transistor dielectric oscillator) that a kind of microwave regime, particularly superhigh frequency band and millimere-wave band are used hereinafter to be referred as WTDO.

Be applied in the transistor oscillator of the employing dielectric resonant chamber frequency stabilization of superhigh frequency band and millimere-wave band in the prior art, mainly contain following three types: a kind of is a coaxial waveguide type, open clear 54-126450 as the spy of Japan, this oscillator is on coaxial-waveguide type fet oscillator basis, the dielectric resonant chamber that adopts exocoel frequency stabilization mode (as reflective, through type or absorption) to introduce high Q is realized the stability of frequency, but this oscillator debugging more complicated, but also be easy to generate the phenomenon of jumping film work.Second type is microstrip type, open clear 58-942057 as the spy of Japan, this oscillator is to utilize on microstrip circuit the feedback circuit of high Q medium vibration chamber as oscillator, has overcome the shortcoming of above-mentioned exocoel frequency stabilization mode oscillator, and it is little to have a volume, adjust simple, advantages such as reliable operation, but along with the further raising of operating efficiency, existing dielectric loss of microstrip circuit and radiation loss also will increase thereupon, thereby make the decreased performance of oscillator, even cisco unity malfunction.The third type is little band-waveguide type, opens clear 59-19412 and the disclosed 90414A of Europe Patent Office as the spy of Japan ₂Its principle is to realize the vibration of microstrip type field effect transistor medium earlier on low frequency, utilizes waveguide type frequency multiplier or cut-off waveguide to obtain higher harmonic components again and exports as oscillator signal.This type of oscillator has solved the deficiency that above-mentioned microwave-type field effect transistor dielectric oscillator exists, and has obtained the stable oscillation stationary vibration signal of high band, but it is difficult to finish and curbs useless fundamental frequency and other each harmonic component, causes the humorous purity difference of exporting of frequency.

The object of the invention provides a kind of waveguide type transistor dielectric oscillator that can overcome the prior art deficiency, and it is simple in structure, debugs easyly, has the oscillating characteristic of high-purity, high stability.

According to purpose of the present invention, the disclosed WTDO of inventor comprises grid waveguide, drain electrode output waveguide, grid, drain dias sheet, grid, leakage fin, field-effect transistor and source electrode thereof add ground strip, and the cut-off waveguide and the dielectric resonance of formation frequency-selecting feedback loop swing the chamber device.Its operation principle is: at first, utilize above-mentioned grid, drain dias sheet to realize the feed-in of Dc bias, utilize above-mentioned grid fin and grid waveguide to constitute grid return impedance zg, utilize above-mentioned drain electrode fin and drain electrode waveguide to constitute drain electrode impedance loop zd, utilize above-mentioned dielectric resonant chamber that places cut-off waveguide and cut-off waveguide to constitute frequency-selecting feedback loop impedance zf(and see Fig. 4).Simultaneously, the fin grids chip size of the present invention by selecting to adapt to makes oscillator satisfy starting condition for oscillation, by selecting the natural frequency of suitable dielectric resonant chamber D, oscillator is operated on the required frequency.Secondly, size by selecting suitable cut-off waveguide and dielectric resonance are placed in the position in the waveguide, regulate dielectric resonant chamber and field-effect transistor grid, the coupling coefficient K between draining ₁, K ₂, make oscillator keep high D value.At last, by selecting the temperature coefficient of suitable dielectric resonant chamber, make it to compensate mutually again, thereby the high stability that realizes WTDO of the present invention is vibrated with the frequency-temperature characteristic of field-effect transistor.In order to realize the effect of best power output, best wen-frequency characteristics, the present invention can also adjust the fine setting of screw and realizes by frequency trim screw and power are set on the wall of grid waveguide and drain electrode output waveguide.The present invention compared with prior art has following advantage: 1, simple in structure, cost is low; 2, debugging is easy; 3, do not jump the film functional reliability; 4, electrical performance indexes height; 5, be convenient to connect with waveguide elements.

Further describe the present invention below in conjunction with drawings and Examples.

Fig. 1 is a structure cutaway view of the present invention, and wherein, Fig. 1 a is an elevation cross-sectional view, and Fig. 1 b is a side cutaway view, and Fig. 1 c is a top plan view

Fig. 2 is the gate bias sheet that Fig. 1 is integral structure, the structure chart of grid fin, drain dias sheet, drain electrode fin

Fig. 3 is the field-effect transistor among Fig. 1 and the structure enlarged drawing of ground strip

Fig. 4 is an equivalent circuit diagram of the present invention

With reference to accompanying drawing, grid waveguide 1, drain electrode output waveguide 2, cut-off waveguide 3 are towering font structure, and wherein lattice wave leads 1 and leak between the output waveguide 2 and be separated with a common wall 4, cut-off waveguide 3 respectively with lattice wave lead 1 and sieve waveguide 2 link up mutually.Common wall 4 is provided with waveguide window 41, gate bias cutting 42 and drain dias cutting 43 and gate bias input hole 44 and drain dias input hole 45, gate bias sheet 5, grid fin 7, just put sheet 6, drain electrode fin 8 is integral structure, gate bias sheet 5 and drain dias sheet 6 place the gate bias cutting 42 of common wall and leakage to put cutting 43 (should note having each other good electric insulation during placement) respectively, and grid fin 7 and drain electrode fin 8 then stretch into grid waveguide 1 respectively and leak among the output waveguide 2.To have the field-effect transistor 10 of metal ground strip 11 to be installed in the waveguide window 41 of common wall 4 in source electrode 101 attachings, the ground strip 11 of the grid 102 of field-effect transistor 10, drain electrode 103 and source electrode 101 constitutes good electrical contact respectively and between corresponding grid fin 7, drain electrode fin 8 and the common wall 4.The support 13 that dielectric resonant chamber 12 usefulness low loss dielectric materials (as polytetrafluoroethylene) are made is supporting, and places in the sub-cut-off waveguide 3.Frequency trim screw 13 and power adjustment screw 14 are contained in grid waveguide 1 respectively and leak on the wall of output waveguide 2.Grid is put sheet 5 and drain electrode and is put the length of sheet 6 in cutting 42,43 and should equal 1/4th operation wavelengths.Grid fin 7 and drain electrode fin 8 stretch into lattice wave lead 1 and the length of leaking output waveguide 2 should satisfy the starting condition for oscillation of oscillator.The natural resonance frequency of dielectric resonant chamber 12 should be a little less than operating frequency, and dielectric resonant chamber 12 is selected at the position and the placement direction of cut-off waveguide 3, should make oscillator be in best operating state, and best frequency stability and enough power outputs are promptly arranged.

The waveguide body of present embodiment is selected good electric conductor for use, for example the silver-plated material of copper.Gate bias sheet 5, grid fin 7, drain dias sheet 6, drain electrode fin 8 are made integral structure, and its manufacturing materials adopts the two-sided conductive plate of low loss dielectric, scribes as the little band plate of polytetrafluoroethylene to form.Field-effect transistor 10 adopts the WE71084 model to realize the vibration of X frequency range.Present embodiment is applied in the high-frequency head that X leaks frequency range direct broadcasting satellite receiving system (being outdoor unit), and as first local vibration source, it is as follows to record its typical electrical performance characteristics:

Operating frequency: 10.75GHz

Power output: 5mw

Frequency temperature stability: ± 230KHz (temperature :-20 ℃～+ 60 ℃)

Frequency long-time stability: ± 200KHz (8 hours)

The frequency pushing coefficient: 150KHz/v(grid voltage Q～-4V)

Claims

1, a kind of waveguide type transistor dielectric oscillator, comprise grid waveguide (1), drain electrode output waveguide (2), cut-off waveguide (3), gate bias sheet (5), grid fin (7), drain dias sheet (6), drain electrode fin (8), field-effect transistor (10), dielectric resonant chamber (12), it is characterized in that above-mentioned grid waveguide (1), drain electrode output waveguide (2), cut-off waveguide (3) is the π font structure, wherein: be separated with a common wall (4) between grid waveguide (1) and the drain electrode output waveguide (2), cut-off waveguide (3) is linked up mutually with grid waveguide (1) and drain electrode output waveguide (2) respectively, common wall (4) is provided with waveguide window (41), gate bias cutting (42) and drain dias cutting (43) and gate bias input hole (44) and drain bias input hole (45), above-mentioned gate bias sheet (5) and drain dias sheet (6) place the gate bias cutting (42) and the drain dias cutting (43) of common wall respectively, above-mentioned grid fin (7) and drain electrode fin (8) stretch into respectively among grid waveguide (1) and the drain electrode output waveguide (2), the source electrode (101) of above-mentioned field-effect transistor (10) is gone up attaching metal ground strip (11), field-effect transistor (10) is installed in the waveguide window (41) of common wall (4), dielectric resonant chamber (12) is supported by support (13), is placed in the cut-off waveguide (3).

2, oscillator according to claim 1 is characterized in that above-mentioned gate bias sheet (5), drain dias sheet (6), grid fin (7), drain electrode fin (8) make integral structure.

3, oscillator according to claim 1 and 2 is characterized in that on grid waveguide (1) and drain electrode output waveguide (2) wall frequency trim screw (13) being housed and power is adjusted screw (14).