On the design of waveguide devices using multiple propagating modes

Abstract

Ahtract -This paper presents B number of strategies which can be used when deigning waveguide devices with multiple propagating modes. Three types of devices are discussed by way of example, namely bsndstap filters lor microwave heating gpplicetions, narrow band coupled resonstor filters, and rectangular monopulse feeds. I. INTRODUC~IONMultiplemodes exist on all guiding structures, but dimensions are normally chosen in such a way that all except one of these modes are below cul-off, as most design algorithms are b a e d on single-mode tnnsmission line models. A number of applications where multiple propagating modes were not only allowed, but used to good effect, have however been proposed through the years. Ewamples of this include the use of dual and triple mode cavities to reduce the size of waveguide filters [1,2,3], the improvement of aperture distributions in antenna feeds for reflector Iype antennas [4,51, and more recently, the shaping of power diseihutions in waveguides for spatial amplifier applicelions [ 6 , 7 . Multiple propagating modes have also been utilized effectively to implement complicated designs elegantly, such as crosscoupled filters. Finally, the dimensions of agiven problem are not always under the control of the designer, forcing him to deal with these modes.The design of devices utilizing multiple propagating modes are complicated by a few problems. In general, a mid discontinuity separating two waveguides A and B is represented by an nxm port scaitering matrix, which can be implemented as the equivalent circuit shown in Fig. 1 [SI.

A new sensor-based self-configurable bandstop filter for reducing the energy leakage in industrial microwave ovens

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Analysis of reactive and resistive open waveguide filters for use in microwave‐heating applicators

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