Ku波段锁式铁氧体移相器

我们利用双平板模型推导出了锁式铁氧体移相器的超越方程。根据超越方程和铁氧体的参数对Ｋｕ波段自动跟踪同步通信卫生电视接收系统中的锁式铁氧体移相器进行了数值分析，结果表明：差相移随温度的增加而减小，但随频率的增加而保持不变。     

Some Effects of Dielectric Loading on Ferrite Phase Shifters in Rectangular Waveguide

The use of dielectric loading with the ferrites in nonreciprocal transmission lines has becolme quite prevalent. The theoretical analysis of unloaded ferrite phase shifters in rectangular waveguide has been extended to the dielectrically loaded case by Soohoo. The boundary-value problem of ferrite phase shifters in dielectrically loaded coaxial lines, which possesses a transcendental equation similar to the waveguide case, has been throughly discussed by several authors. The present commumcation reports the solution of the boundary-value problem of a dielectrically loaded ferrite phase shifter in rectangular waveguide to yield values of the lossless propagation constant for various slab positions for both directions of propagation. The theoretical values of the differential phase shift for slab positions about the center of the waveguide were compared with the measured values for three different applied magnetic fields.     

Precise Control of Ferrite Phase Shifters

Hysteresis and thermal drifts can prevent accurate calibration of ferrite phase shifters. To provide a precise setting of phase in response to a control signal a servo system has been developed. This system utilizes a control frequency to determine uniquely the phase shift in a ferrite element. The desired phase shift is then a function only of control frequency and line length. Performance data are given for various operating conditions of the control system.     

Field Theory Design of Ferrite-Loaded Waveguide Nonreciprocal Phase Shifters with Multisection Ferrite Or Dielectric Slab Impedance Transformers

Impedance-matched ferrite-loaded waveguide nonreciprocal phase shifters are designed using the method of field expansion into eigenmodes, which includes higher order mode interaction between the step discontinuities. Computer-optimized Ku -band ferrite stepped design examples, of 45° and 90° nonreciprocal differential phase shifts, attain typically about 2° phase error and less than -25 dB input reflection within a bandwidth of about 5 percent. Compact designs are achieved by thicker uniform ferrite slabs with dielectric transformer sections at each end. The theory is verified by comparison with available results from measurements and other methods.     

Operating Dynamics and Performance Limitations of Ferrite Digital Phase Shifters

Performance capabilities and limitations of nonreciprocal waveguide ferrite digital phase shifters are discussed. A computer-aided solution of the boundary value problem facilitates the optimization of both device geometry and material properties. Experimental results are in excellent agreement with predicted loss and phase shift values. Maximum figures of merit of the order of 1000 deg/dB have been realized. When high peak powers must be accommodated, some sacrifice in low-power performance is necessary. Operating peak power levels can be increased by lowering the saturation magnetization of the ferrite or by raising its spinwave linewidth. Peak power levels above 150 kW at X band and 350 kW at C and S bands have been attained in laboratory models with less than 1 dB loss for a 360 degree differential phase shift. When high-average power levels must be handled, various material and geometric considerations can be incorporated to minimize loss per unit length and to increase heat dissipation capabilities. Units have been successfully operated at S-band frequencies with only a five percent decrease in phase shift when carrying 900 watts average power. The various tradeoffs necessary to achieve high peak and average power performance are discussed.     

Nonreciprocal Remanence Ferrite Phase Shifters Using the Grooved Waveguide

For the purpose of improving the performance charasteristics of the nonreciprocal remanence ferrite phase shifter, a new configuration with a grooved waveguide is proposed and analyzed. Some results calculated as functions of dielectric and ferrite thickness, waveguide dimensions, and frequency are shown and compared as being in good agreement with experiments at the X band. The figure of merit (differential phase shift per insertion loss) and the handling power of the proposed phase shifter are discussed in comparison with those of the conventional waveguide geometry.     

相控阵雷达铁氧体移相器设计

铁氧体移相器在相控阵雷达中得到了广泛应用.主要分析了设计铁氧体移相器时需考虑的指标和设计方法,主要内容包括峰值功率和平均功率、饱和磁化强度、剩磁比、插损、工作频率范围、温度特性、横截面尺寸、陶瓷材料、相移误差和驱动功率等,并对指标之间的相互影响进行了分析.     

The Application of Planar Anistropy to Millimeter-Wave Ferrite Phase Shifters

The torque produced by the planar anistropy that occurs in some hexagonal ferrites is included in the equation of motion of the magnetization. The elements of the permeability tensor, derived here for a lossless approximation, are affected by the planar anistropy in much the same way as by an increase in saturation magnetization. This modified permeability has been incorporated into a model for a planar ferrite loaded rectangular waveguide, and the calculated values for differential nonreciprocal phase shift are found to increase substantially over those for a conventional isotropic ferrite.     

Reciprocal Ferrite Phase Shifters in Rectangular Waveguide (Correspondence)

A recent article by Reggia and Spencer describes a reciprocal ferrite phase shifter for rectangular waveguide, This phase shifter consists of a pencil of ferrite suspended along the central axis of the waveguide by means of a dielectric. The phase is controlled by an applied longitudinal magnetic field. This geometry is shown in Fig. 1. Large amounts of phase shift are produced by this geometry with low insertion loss, and application to antenna beam scanning appears likely, as suggested by Reggia and Spencer.     

Coupled-Mode Analysis of Longitudinally Magnetized Ferrite Phase Shifters (Short Papers)

Application of a coupled-mode formalism to longitudinally magnetized ferrite phase shifters provides an explanation of the increase or decrease of insertion phase with increasing magnetization which is observed in different types of phase shifters. If the higher order mode is TM, the phase shift increases with magnetization while the reverse happens if the higher order mode is TE. The generalized telegraphists' equations are used to analyze the TEM phase shifter. The maximum phase shift that can be obtained is determined by the effective permeability of the ferrite. However, coupling to higher order cutoff modes reduces the phase shift significantly.     

Ferrite Microstrip Phase Shifters with Transverse and Longitudinal Magnetization (Correspondence)

Phase shifts of opposing sign are produced in a finear section of microstrip by transverse and longitudinal magnetization of the ferrite substrate. Nonreciprocal phase shift is also produced by the transverse magnetization. Theoretical calculations of phase shift that account for both the diamagnetic effects and the tensor properties of the ferrite permeability agree well with properly constructed experimental measurements. These measurements use closed magnetic circuits to remove the nonuniform demagnetization effects. A lightweight reciprocal phase shifter has been constructed that utilizes both transverse and longitudinal magnetization at low drive power with closed magnetic circuits to obtain a high figure of merit.     

Comments on the Design and Manufacture of Dual-Mode Reciprocal Latching Ferrite Phase Shifters

The design principles for dual-mode reciprocal latching ferrite phase shifters are relatively well understood at present. Discussions of a few selected topics not previously studied are presented in this paper. A tradeoff analysis is carried out for X-band units to show the interrelation between phase-shifter weight and insertion loss. An interesting consequence of this analysis is the theoretical prediction of an optimum range of values for the saturation moment of the ferrite material. Switching energy in the presence of shorted-turn damping is also analyzed and related to the geometry and hysteresis loss of the ferrite material. Finally, a discussion of manufacturing considerations and unit cost at high rates of production is carried out. The major conclusion is that unit cost levels approaching $10.00 are possible for a production run sufficiently large to justify the substantial cost of engineering and tooling for high rates of manufacture.     

A Peak Power Threshold Approximation for Remanent Ferrite Phase Shifters (Correspondence)

A parametric relationship is presented that permits an estimation of phase shifter peak power threshold level. The experimentally observed effect of a load mismatch on the peak power threshold is also reported.     

Ultra-Wideband Phase Shifters

A method with clear guidelines is presented to design compact planar phase shifters with ultra-wideband (UWB) characteristics. The proposed method exploits broadside coupling between top and bottom elliptical microstrip patches via an elliptical slot located in the mid layer, which forms the ground plane. A theoretical model is used to analyze performance of the proposed devices. The model shows that it is possible to design high-performance UWB phase shifters for the 25deg-48deg range using the proposed structure. The method is used to design 30deg and 45deg phase shifters that have compact size, i.e., 2.5 cm times 2 cm. The simulated and measured results show that the designed phase shifters achieve better than plusmn3deg differential phase stability, less than 1-dB insertion loss, and better than 10-dB return loss across the UWB, i.e., 3.1-10.6 GHz.     

Theoretical Considerations on the Use of Circularly Symmetric TE Modes for Digital Ferrite Phase Shifters

The effectiveness of using magnetized ferrite toroids in circularly cylindrical guides operating in the TE/sub 01/ mode as elements of a digital phase shifter is investigated. The phase of such a device is controlled by reversing the magnetization of individual ferrite toroids. An analysis of the circularly cylindrical guide containing, coaxially, a ferrite tube is presented for circularly symmetric modes. Some results of computations to determine the optimum tube thickness, mean radius, and effect of frequency and changes in the fundamental constants of the material are included.     

Investigations of Broad-Band, Linear Phase Shifters Using Optimum Varactor Diode Doping Profiles

The problem of obtaining linear phase shift of microwave signals over a broad frequency range and its dependence on varactor properties is addressed. An important application of the linear phase shifter, the microwave frequency translator, is investigated in detail and various circuit configurations and varactor doping profiles are examined relative to their performance including suppression of undesired frequency components and bandwidth. Hyperabrupt or Read-type varactor diodes are found to be very useful in this application     

Broad-Band Diode Phase Shifters

Design figures are presented for four types of diode phase shifters: switched line, reflection, loaded line, and a new type using lumped-element high-pass and low-pass circuits. Comparison of their bandwidths shows that most of them can work over an octave bandwidth.     

基于MEMS技术的射频移相器

微波与毫米波移相器是通讯和雷达应用上相控阵天线的基本单元，MEMS技术的引入提供了一个在移相器设计中用最小损耗的开关来大量减少移相器插入损耗的方法，该方法可以降低器件的功耗，改善插入损耗、隔离度、频带宽度等性能。相比于GaAs移相器，基于MEMS开关的射频移相器，无论是开关线型、分布式或是反射型，都有很好的RF性能。     

Theoretical Considerations on the Use of Circularly Symmetric TE Modes for Digital Ferrite Phase Shifters (Correction)

Recently, we have become aware of increased publication activity by authors who refer to the above early paper. We felt that it is particularly timely, therefore, to inform those concerned that in the above paper a few formulas, unfortunately, are in error.