L波段高功率双结波导环行器

介绍了采用部分高度双铁氧体圆片和脊梁阻抗变换器设计L波段高功率压缩矩形波导结环行器的方法,结合传统设计方法和HFSS软件的仿真分析对环行器进行了仿真和优化,给出了仿真分析结果.同时采用λg/4变换波导与标准波导相连的方法,研制出L波段高功率双结波导环行器,给出实验结果.环行器的单结损耗小于0.25 dB,功率容量可达8 kW.     

Octave-Bandwidth UHF/L-Band Circulator

Test data are presented on two aluminum-substituted yttrium-iron-garnet (YIG) materials that have low-saturation magnetizations that permit the extension of ferrite devices well into the UHF/VHF region. In particular, one composition has a saturation magnetization of 300 gauss and a line width of 50 oersteds. Measurements are presented that compare the new materials with previously available higher-saturation magnetization materials. A broad-band UHF/L-band four-port circulator that operates over a 2-to-1 frequency band has been developed, using this 300 gauss material. Insertion loss is 1 db or less from 665 to 1320 Mc (with constant magnetic field) and 0.5 db or less from 800 to 1150 Mc. A compact and favorable circulator package design was obtained by using coaxial hybrids and dielectric-loaded strip transmission line. Data on the broad-band magic-tee used in the circulator are included. Isolator measurements down to 200 Mc are reported. Reverse-to-forward magnetic-loss ratios of 36 at 600 Mc and 12 at 300 Mc were obtained.     

Tunable Low-Loss UHF Circulator for Cryogenic Applications

A 600-MHz above-resonance circulator operating at 4.2 K has been constructed and successfully tested. Its high isolation (>30 dB), extremely low insertion loss (<0.1 dB), low VSWR (< 1.1), and acceptable instantaneous bandwidth (~6 percent) make it a promising device for utilization in narrow-band very low-noise systems.     

UHF大功率收发前端设计

射频收发前端电路是无线收发信机的重要电路之一,它对整个系统的噪声系数,动态范围等关键指标起决定性作用。文中具体分析了射频前端电路在无线通信系统中的重要性、射频收发前端的组成、工作原理、接收和发射部分的设计难点和重点。对关键技术指标进行了优化设计。设计了思维简洁、电路控制速度快的UHF大功率射频收发前端,并对方案进行试验改良。通过实验结果表明,该电路噪声系数达到3.2 dB,接收通道增益达到30 dB。发射通道输出功率≥40 dBm,三阶交调≤-18 dBc,试验结果达到预期目标。最后结合实际测试曲线,对实验结果进行进行了分析,并对现有方案提出了改进。     

Design of a High-Power CW Y-Junction Waveguide Circulator

A junction circulator appears inferior in average power-handling capability, although it is compact and light-weight and has good performance. A new type of 100-kW CW waveguide Y-junction circulator is realized by dividing the junction of the circulator into four equal unit junctions in a so-called "multilayer structure," which is water-cooled easily. This circulator has an insertion loss of 0.18 dB and an isolation of 20 dB, and it is compact and economical to build. The design of 30- and 100-kW CW waveguide Y-junction circulators is presented in this paper, which discusses determination of ferrite dimensions and air gap, considers heat generation in the ferrite, and the influence of dc magnetic-field distribution on its performance. The ferrite dimensions and air gap are determined very easily by using this design method, and these have been confirmed by experiment. It was found that a uniform distribution of internal dc magnetic fieId, obtained by considering the demagnetizing dc magnetic field, gives optimum performance. This is a significant design factor for high-power circulators which require minimum insertion loss.     

High-Power S-Band Junction Circulator (Short Papers)

The design of a high-power air-cooled microwave Y-junction circulator which is capable of operation at peak and average power levels of 800 kW and 800 W, respectively, is described. The unit is an H-plane waveguide circulator which is externally air cooled. The circulator design employs a full-height substituted YIG rod with a center metal pin together with boron nitride matching transformers. The circulator exhibits an insertion loss of less than 0.4 dB, isolation greater than 22 dB, and a VSWR <1.26:1 over a 400-MHz bandwidth centered at 3.3 GHz. At high-power levels, the device exhibits insertion loss of less than 0.9 dB, isolation greater than 20 dB, and VSWR <1.25:1 at an indicative frequency within the operating bandwidth.     

差相移式高功率铁氧体环行器的设计

介绍了一种用于高功率微波系统中的差相移式波导四端环行器,分析了环行器的工作原理,给出了实验结果及高功率讨论。     

Ferrite Shape Considerations for UHF High-Power Isolators (Correspondence)

Ferrite isolators deteriorate at high microwave power levels due to the gyromagnetic saturation phenomena described by Suhl. The onset of this deterioration is particularly detrimental to isolator performance when the main and subsidiary resonances coincide. At microwave frequencies the coincidence effect can generally be avoided if thin transversely magnetized ferrite slabs are used. However, at frequencies below 1 kMc, the finite slab thickness can con tribute to main-subsidiary resonance coincidence unless care is taken to choose the proper length and width dimensions of the slab. The following calculations specify the ferrite slab shape needed to avoid this coincidence in UHF ferrite isolators.     

A Broad-Band Microwave Circulator

The discovery of a simple, low loss way to hold Faraday rotation constant over a broad-band (coupled with the development of wide-band, high return loss, circular-to-rectangular waveguide transformers, and polarization couplers) has made it possible to design and build a high quality circulator for use in the 10.7 kmc to 11.7 kmc band. The essential characteristics of the described unit include a more than 30-db return loss at each terminal, an isolation of 30 db or greater between "isolated" terminals, and a 0.35-db insertion loss between transmission terminals.     

A Y-Junction Strip-Line Circulator

Summary--The theoretical approach to the three-port symmetrical circulator is reviewed and presented in a form valid for the most general waveguide case. A strip-line Y-junction circulator is described and the performance of different units in the band 800-1600 mc is illustrated. The new type of device described offers, for the low-frequency region of the microwave spectrum, advantages of simple design, light weight, and great compactness with respect to the classical types. When operated with a permanent magnet it gives--in a bandwidth of about 4 per cent--isolation greater than 20 db, insertion loss /spl les/0.4 db, and input VSWR/spl les/1.20.     

C波段单片有源环行器

报道了一种源耦合反馈单片有源环行器的研究结果、该单片电路采用实测ＦＥＴ的Ｓ参数进行微波ＣＡＤ优化设计，内部包含有３个３００μｍ栅宽的ＦＥＴ，芯片面积１．７ｍｍ×１．９ｍｍ。采用ＧａＡｓ的离子注入平面工艺，芯片电路具有良好的均匀性、一致性。在３．５～４．５ＧＨｚ内，电路插入损耗约７．５ｄＢ，隔离度为２１～２６ｄＢ，驻波比基本小于２。     

High-Power Pulsed UHF and L Band p+-n-n+ Silicon TRAPATT Diode Lasers

The design and performance of both the lumped-element TRAPATT oscillator circuit and deep-diffused p+-n-n+ silicon TRAPATT diodes designed primarily for pulsed RADAR applications in the UHF and L band frequency ranges are discussed. Circuit conditions for optimum performance are described. Methods of optimizing diodes are presented. Diode performance capability is shown to depend on the relative position of the junction in the device depletion region. Peak powers close to 900 W and maximum conversion efficiencies of 40 percent have been achieved from diodes with large p-region width to total depletion region width ratios. RF leading-edge jitter of less than 1 ns has been obtained under optimum circuit and diode operating conditions.     

A Latching Ring-And-Post Ferrite Waveguide Circulator

This paper presents the performance and normalized design parameters for a latching ring-and-post ferrite circulator in waveguide. A C-band circulator has provided an insertion loss of 0.35 dB and a 20-dB isolation bandwidth of 17 percent. When the circulator was matched for higher maximum isolation (50 dB) but narrower bandwidth (10 percent) at room temperature, the 20-dB isolation bandwidth was 7.8 percent across the -40/spl deg/ to +75/spl deg/C temperature range. Low-loss operation was obtained at pulsed powers up to 7.5 kilowatts, and at least 20 dB of isolation was maintained up to 100 kilowatts. This performance, in conjunction with a switching speed of a fraction of a microsecond, permits the use of these circulators for transmitting-receiving functions in high-reliability RADARs.     

A Proposed Lumped-Element Switching Circulator Principle

Two different analytical methods, the complex conjugate input admittance approach and the eigenvalue analysis, show the possibility of building a fast switching lumped-element circulator. In conventional switching circulators, switching is achieved by changing the required magnetic biasing field. The proposed principle, which is valid for circulators of all types, is especially interesting for lumped-element circulators where the switching may be accomplished by simply changing two capacitor values. The capacitors could be switched by varying voltages on semiconductors thus permitting very fast switching. The analysis has been experimentally verified. No attempt to obtain optimization of a specific design was made.     

Circulator Synthesis

A symmetrical three-port ring network composed of reciprocal T junctions and nonreciprocal phase shifters is analyzed theoretically to determine conditions under which it exhibits perfect circulation. All physically realizable T junctions are considered. It is found that many such junctions, combined with appropriate phase shifters specified by the theory, form perfect circulators. Among these are many cases for which the internal wave amplitudes are small and which require only very small amounts of nonreciprocal phase shift. Circulators designed in accordance with this model may offer appreciable advantages in insertion loss and bandwidth, as well as in mechanical characteristics such as size and weight, and in the possibility of adapting the design for special applications such as high-power capability, high-speed switching, etc. The nature of the model and the method of calculation are summarized.     

A Compact Broad-Band Thin-Film Lumped-Element L-Band Circulator

Impedance matrices including magnetic losses are developed for a number of lumped-element ferrite-loaded symmetrical three-port junctions. The scattering matrix eigenvalues corresponding to these matrices are determined as functions of frequency and circuit parameters and are used to analyze these three-ports with emphasis on their properties as circulators. A very compact broad-band thin-film lumped-element circulator is derived from the idealized equivalent circuit. An experimental model approximately represented by this circuit is shown to have a 20-dB isolation bandwidth of greater than 30 percent with an insertion loss of less than 0.6 decibel. A switchable circulator which requires no magnetic-field switching is treated using this same analytical approach. It is suggested that this type of analysis together with additional experimental refinement of equivalent circuits will lead eventually to a computerized design of lumped-element circulators.     

8毫米鳍线环行器的设计

本文给出了一种Y形结单面鳍线环行器的设计方法,实验结果表明,在Ka频段上,7％的带宽范围内,插损小于1.5dB,隔离度大于20dB,驻波系数小于1.3。