Waveguide Y-junction Circulator Research Articles

W Band Circular Waveguide Y-Junction Circulator

In this paper, a new type of W band circular waveguide Y-junction circulator is presented. The structure of this type of Y-junction is a cylindrical cavity connecting with three circular waveguides. The performances of the type of circulator are analyzed by the edge-based vector finite element method hybridized with the modal expansion. The numerical results show that this type of waveguide Y junction circulator has good circulation performance.

Investigation of Waveguide Y-Junction Circulator with a Triangular Ferrite Post

An H-plane waveguide Y-junction circulator with a triangular ferrite post is investigated by a modified analysis of jointly resonance theory and simple field theory. Good agreement between the theoretical obtained performances and experimental results is observed. The circulator exhibits a very low insertion loss and a wide bandwidth.

FDTD analysis of scattering by a magnetized ferrite sphere

The scattering of a plane wave by a magnetized ferrite sphere is rigorously analyzed by a finite-difference time-domain technique with a perfectly matched layer. The field components in the sphere and power–density distribution on the surface of the sphere are obtained. The circulating characteristics of the scattered field due to the magnetized ferrite sphere are observed. The insertion loss and isolation coefficient of the scattering of a magnetized ferrite sphere are presented and compared with the experimental results of a waveguide Y-junction circulator with a ferrite sphere. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 297–300, 1998.

Analysis and development of millimeter-wave waveguide-junction circulator with a ferrite sphere

This paper presents a class of new easy-to-fabricate ferrite-sphere-based waveguide Y-junction circulators for potentially low-cost millimeter-wave applications. A new three-dimensional modeling strategy using a self-inconsistent mixed-coordinates-based modal field-matching procedure is developed to characterize electrical performance of the proposed circulator. It is found that the circulating mechanism of the ferrite-sphere post is different from its full-height ferrite counterpart in that the new structure operates in a turnstile fashion with resonant characteristics, while the conventional device operates on a transmission cavity model. Extensive comparable studies between the new and conventional circulators are made to show that the electrical behaviors of the new structure are also distinct and radial power-density profiles are not stationary, as in the case of the full-height ferrite post circulator for different geometrical parameters. Results obtained by the analysis technique are compared with the available results for a full/partial-height ferrite circulator, showing an excellent agreement. Our calculated and measured results are also presented for W-band circulators with the proposed ferrite-sphere technique, indicating some interesting characteristics such as the frequency offset behavior of the isolation and reflection curves. In addition, radial power-density profiles are plotted inside and outside the ferrite sphere to illustrate its intrinsic circulating mechanism, as well as its difference, as compared to its full-height ferrite structure.

A compound high power millimeter wave waveguide circulator

In this paper, a high power millimeter wave waveguide Y-junction circulator, which is compound in structure, has been analyzed and developed. Its enduring power attains 60 W CW-power and the temperature of the waveguide surface does not exceed 25 degree centigrade under natural coolness.

A novel waveguide Y-junction circulator with a ferrite sphere for millimeter waves

A novel waveguide Y-junction circulator with a ferrite sphere is developed for uses at millimeter-wave frequencies. Sphere is preferred because the production cost of a pertinent circulator is lower. Performance of the new circulator is comparable to the conventional one with a cylindrical ferrite. A simple formula is derived for determining the center frequency of a circulator. Good agreement between analytical results and measurements is observed. An extremely fast method is developed to analyze the circulator. Various properties of the circulator can be predicted with reasonable accuracy.

Analysis and experiments of the 3mm-band higher order modes waveguide Y-junction circulators

Based on the boundary value solution of electromagnetic fields, a calculated results of the 3mm-band higher order modes waveguide Y-junction cirulators, which are given with the frequency dependence of the eigenvalues of the junction scattering matrix, are presented for the first time. It has been verified exactly by the experiments. Using the higher order modes. the bandwidth of the circulators can be expanded.

Analysis of Unsymmetrical WaveguideY-junction circulators

This article analyzes unsymmetrical waveguide Y-junction circulators whose two arms are connected with H-plane bends according to the electromagnetic field solutions given in [1, 2]. The scattering matrix and numerical results are given. The results show that the H-plane waveguide bend has an influence on the performance of the waveguide Y-junction circulators.

Exact calculation of partial-height waveguide Y-junction circulator using mode-matching technique

The mode-matching technique is used to solve the entire field theory problem of the widely used partial height ferrite circulator. Calculation and measurement of an X-band circulator gives 29% and 31.6%, respectively, for relative bandwidth at an isolation of 20 dB.

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.

A 100 kW Waveguide Y-Junction Circulator for Microwave Power Systems at 915 MHz

A 100 kW CW Y-junction circulator at 915 MHz has been developed. The circulator has three metal discs and two protruding metal cylinders in the conventional waveguide junction. A thin ferrite disc ...

Design of broadband microwave circuits

The relation between the scattering-matrix eigenvalue phase/frequency responses and the energy stored in a general microwave junction filled with an anisotropic material can be used to facilitate the design of broadband microwave circuits. The technique of this approach is illustrated for a waveguide Y-junction circulator.