Nonreciprocal Remanence Phase Shifters in Rectangular Waveguide

Three types of nonreciprocal remanent phase shifters in rectangular waveguide are described which are approximated by a simple model consisting of twin ferrite slabs symmetrically placed in rectangular waveguide and separated by a dielectric rib. The model has been analyzed with the assumption that a fundamental TE mode wave propagates in the structure. Simultaneous solution of Maxwell's equations in the three regions of dielectric, ferrite, and air within the waveguide enables the characteristic equation to be formed. The characteristics of the model have been obtained with the aid of a computer as a function of dimensions, dielectric and magnetic constants, frequency, and power. The theoretical results are compared with experimental data obtained on a double toroid structure. Correction factors applied to the experimental data, which are necessary to account for differences between the practical structure and the ideal model, are discussed.     

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.     

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.     

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.     

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。     

铁氧体槽波导移相器的理论计算与实验研究

利用铁氧体矩形波导中的场方程,导出了铁氧体传输段的输入阻抗表达式,结合横向谐振技术和等效导纳概念,导出了铁氧体槽波导移相器计算模型的特征方程。在对计算模型进行了新的修正后,我们编程进行了计算,修正后的计算值与实验结果较吻合。     

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.     

Nonreciprocal Attenuation of Ferrite in Single-Ridge Waveguide (Correspondence)

The nonreciprocal transmission characteristics of rectangular and cylindrical waveguides containing ferrites have been extensively studied and utilized in the construction of microwave phase shifters, gyrators, circulators, and isolators. This note concerns the measurement of the nonreciprocal attenuation produced by ferrite in single-ridge waveguide transmitting dominant mode. In particular, three types of isolators in ridge waveguide are investigated including resonance-absorption isolators, field-displacement isolators, and isolators operating at low-biasing magnetic fields. Fig. 1 shows the dimensions of the single-ridge waveguide used in the measurement.     

Design of Multisection Impedance-Matched Dielectric-Slab Filled Waveguide Phase Shifters

Optimum-matched dielectric-slab filled waveguide phase shifters are designed with the method of field expansion into eigenmodes, which includes higher order mode interaction between the step discontinuities. The relative phase shift is mechanically adjustable between 0° and about 360° at midband frequency by lateral displacement of the dielectric slab. Computer-optimized design data are given for Ku-, K-, and Ka-band prototypes which achieve return losses of better than 40 dB, both as a function of displacement at midband frequency and as a function of frequency at fixed displacements. Measurements verify the theory.     

铁氧体非互易移相器的高功率容量分析

通过计算铁氧体波导移相器的微波磁场和功率分布,给出了一种分析该类器件峰值功率容量的有效方法,取得了与工程试验相一致的结果,从而使得铁氧体非互易移相器的峰值功率容量大小能够在设计阶段得以较准确计算。     

Theoretical Analysis of Twin-Slab Phase Shifters in Rectangular Waveguide

The differential phase shift and the losses to be expected in phase shifters using two oppositely magnetized ferrite slabs located symmetrically in a rectangular waveguide have been calculated for various locations and thicknesses of the ferrite slabs. For small thicknesses of the ferrite slabs, the differential phase shift increases rapidly with increasing thickness reaching a maximum when the thickness is approximately 1/10 of the free space wavelength. The calculated insertion loss of a 360-degree phase shifter decreases with increasing slab thickness for small thickness, reaching a minimum when the thickness is approximately 1/25 of the free space wavelength. The minimum insertion loss calculated with the assumption that the imaginary part of the diagonal component of the permeability tensor is 0.01 and that dielectric loss can be neglected is approximately 0.85 dB. The peak power handling capability has also been analyzed. It can conveniently be summarized in terms of a high-power figure of merit. For reasonably high values of this figure of merit, a peak power capability of the order of 100 kW is anticipated.     

Optimum Filling of Ferrite Phase Shifters of Uniform Dielectric Constant

Approximation methods are used to calculate the phase shift and loss for phase shifters containing ferrite and dielectric, with a uniform dielectric constant throughout the waveguide. If the RF magnetic loss in the ferrite is a significant fraction of the total loss, the overall performance of a phase shifter that is partially filled with ferrite may be superior to the fully filled case. Theoretical results relating performance to the amount of partial filling are presented for Faraday rotators in square and circular waveguides and a twin-slab phase shifter. Experimental results were obtained for a circular Faraday rotator.     

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.     

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.     

A Method of Fabrication for Waveguide Nonreciprocal Toroidal Ferrite Phasers (Short Papers)

An improved technique for latching ferrite-phaser construction is described. It is particularly attractive when magnetostrictive ferrites or garnets are employed and for configurations utilizing high-dielectric-constant loading. The technique is capable of yielding phasers with very uniform characteristics, large figures of merit, low loss, and excellent average power capability.     

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.     

矩形波导铁氧体移相器的有限元分析

本文从麦克斯韦方程推出适合于解决导磁率为张量形式的各向异性介质加载波导本征值问题的全电场有限元方程,讨论识别主模的方法和如何把两种不同媒质界面上的边界条件引入有限元方程。通过所建立的有限元方程,分析了双板铁氧体加载矩形波导的传播特性,并同解析解作比较,两者所得结果吻合得很好。     

A 20 GHz Steerable Array Antenna Using 3-bit Dielectric Slab Phase Shifters on a Coplanar Waveguide

A simple steerable array antenna is designed and developed using a movable dielectric phase shifter. The change of effective dielectric constant at different dielectric slab positions on a coplanar waveguide is used as the phase shifter. The impedance matching and desired phase shift conditions are satisfied at two slab heights, and the reflection is designed to be minimized at these slab positions. The low-loss dielectric material is used as the dielectric slab and is placed close to a coplanar transmission line with airgap. The 4times4 steerable array antenna with the phase shifters is designed and fabricated at 20 GHz. The H-plane radiation patterns are measured at different phase shift positions and compared with the expected results