Compact and Wide Stopband E-Plane Waveguide Diplexer Design

Abstract

Abstract-This paper presents the design of a compact E-plane waveguide diplexer with wide stopband characteristics of high rejection level. This is achieved by utilizing a unique E-plane waveguide filter comprising rectangular apertures located along the waveguide's E-plane. The upper and lower sections of the aperture in the septum insert have periodic comb-like ridges. The effect of the septum is (i) to slow the propagating wave that helps to reduce the filter's size, and (ii) widens its stopband property. Dimensions of the periodic ridges of the aperture enable the center frequency of the filter to be controlled without compromising its bandwidth. In addition, the proposed E-plane waveguide filter provides a high isolation between the two diplexer channels, which is necessary to prevent significant cross-talk between the channels. The performance of the proposed design was verified through measurements. There is excellent agreement between the simulated and experimental results.

Simulation and Design of a Bandpass Filter Based on Substrate Integrated E-Plane Waveguide

“…Meanwhile, the E-plane waveguide technology has been studied by many researchers and used in microwaves and millimeter waves applications [4]- [8], mainly because of the low losses and the possibility of selectivity of signals observed in their circuits using horizontal polarization. In particular, the use of such technology has enabled the development of many components such as stopband filters [8], bandpass filters [9], diplexers [10], [11] and multiplexers [6] on front-ends of transmitters and receivers of communications systems [12], [13]. However, because they are developed in waveguide structures, these components are heavy and large size.…”