Reciprocal Ferrite Phase Shifter Research Articles

The first phased-array antennas in Russia: 1955-1960

The first phased-array antenna in the Soviet Union was developed under the supervision of Professor Yuri Yurov, at Leningrad Electrical Engineering Institute (Technical University), in 1955. It was a four-element array of dielectric-rod radiators, fed through reciprocal ferrite phase shifters. The array was intended for use in radar, for automatic aiming at the target. In Yurov's group, the theory of phased-array antennas was developed. In 1960, a 61-element array, in the form of a lens filled with ferrite phase shifters, was designed, manufactured, and investigated. Later, the investigations were moved from the university to industrial research centers.

Magnetostriction insensitive dual‐mode phase shifter

AbstractThe dual‐mode phase shifter is known as a reciprocal ferrite phase shifter. However, in the dual‐mode phase shifter made of ferrite with magnetostrictive effect such as YIG for high power and low insertion loss applications, the reciprocal characteristics of the insertion phase shift is degraded when an external force is applied. This paper shows theoretically and experimentally that this nonreciprocal insertion phase shift is caused by the circumferential magnetization in the Faraday rotator known as the inverse Wiedemann effect, one of the magnetostrictive effects. The paper describes a method for constructing a dual‐mode phase shifter in which the nonreciprocal insertion phase is cancelled and summarizes the results of the trial fabrication. In the dual‐mode phase shifter cancelling the non‐reciprocal insertion phase developed for the X band application, the nonreciprocal insertion phase shift is less than 2 degrees, that is, one‐tenth that in a conventional device made of identical material.

Propagation in Longitudinally Magnetized Ferrite-Loaded Waveguide

Longitudinally magnetized reciprocal ferrite phase shifters have shown anomalous behavior in that some devices show increasing phase shift with increasing applied field, while others show decreasing phase shift with increasing applied field. This anomaly has been investigated theoretically by using a ferrite-filled parallel plane guide model. It is shown that for electrically thin guides the phase shift decreases with applied magnetic field, whereas with increased thickness, the phase shift becomes an increasing function of the applied field. The microwave electric and magnetic fields were calculated for various applied field values and reduced guide thicknesses. This showed that there are two competing mechanisms which govern the type of phase shift. These can be termed /spl mu/-effective" and "Faraday rotation." The latter sets in when the guide is thick enough to support a cross-polarized electric field of the same order of magnitude as the incident electric field. Similar analysis of the quasi-TE/sub 1/ and TM/sub 1/ modes were made, showing similar behavior at higher frequencies for a given guide thickness. Experimented verification of the quasi-TM/sub 0/ mode was made by observing transmission resonances versus applied field of resonated sections of ferrite-loaded reduced height guide.

Theory of the Suppressed-Rotation Reciprocal Ferrite Phase Shifter

A theory for the Reggia-Spencer reciprocal ferrite phase shifter is presented which explains the characteristic behavior of this device in terms of a nonreciprocal coupling of cross-polarized waveguide modes. The dominant mode is a distorted TE/sub 10/-like mode similar to that of a dielectric slab-loaded waveguide. The cross-polarized mode is a hybrid mode which is below cutoff. If this mode propagates, Faraday rotation occurs. The boundary value problem for these modes, in a ferrite described by a scaIar, frequency-dependent permeability, is solved and theoretical design data is presented. The frequency-dependence of phase shift and the onset of Faraday rotation is predicted and compares well with experimental results.

The design of reciprocal ferrite phase shifters

The design of a reciprocal ferrite phase shifter in a rectangular waveguide, using perturbation theory with a quasi-stationary approximation for the field perturbation of the system is considered. The theoretical results are compared with experimental data and with a design carried out without using the quasi-stationary approximation [5], The simplicity of the proposed method and the good agreement between the theoretical and experimental results enable it to be used in solving engineering problems.

Temperature dependence of phase shift in ferrite phase shifters

Reciprocal ferrite phase shifters exhibit a pronounced dependence of phase shift upon temperature. In a sample of magnesium-copper-chromium ferrite it is shown that the temperature dependence of the phase shift is basically determined by the temperature dependence of the microwave magnetic permeability.

A novel ferrite quarter-wave plate

Coupled-wave theory is applied to make an adjustment to the length of an elliptical Faraday rotator to obtain a ferrite quarter-wave plate with non-reciprocal properties. A ferrite rotator can be interposed between two such quarter-wave plates and matrix algebra used to obtain a new reciprocal ferrite phase shifter. A pulsed 180 deg non-reciprocal phase shifter is also described.

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.

A New Technique in Ferrite Phase Shifting for Beam Scanning of Microwave Antennas

A reciprocal ferrite phase shifter for 3-cm wavelength has been developed which makes use of a new design technique for obtaining large phase changes per unit length by electrical means. The device consists essentially of a longitudinal magnetic field applied to a ferrite rod centrally located inside a rectangular waveguide excited in the TE10 mode. With a proper choice of rod diameter and impedance matching elements, phase shifts of greater than 250 ø per inch and variations in transmitted power of less than ±0.2 db have been obtained with external control fields as low as 60 oersteds. Zero-field insertion loss of less than 0.1 db per inch has been measured. These characteristics, along with its geometrical configuration and small size, make this electrically controlled ferrite device useful in the design of rapid-scanning antennas or any similar microwave system requiring phase modulation.