Realisation of an E-Plane Metal-Insert Filter at E-Band Based on Multi-Layer Waveguide With Pin Array Electromagnetic Band Gap

Abstract

In this paper, a multi-layer waveguide (MLW) bandpass filter is realised by stacking thin metal layers at E-band. In order to eliminate the leakage between layers, an electromagnetic band gap (EBG) pin array is utilised. The periodic pin texture is created by 3D chemical etching on the layers. The thickness of layers and height of pins are selected properly to provide a stopband at operating frequency band of interest. A thin metal layer at the middle of the waveguide channel is used to realise the cavities and coupling slits of the filter. A seventh order metal-insert E-plane filter with frequency pass band of 69.5–76 GHz is designed and fabricated. The designed MLW bandpass filter is fabricated in brass and copper metal sheets with insertion loss of around 1.5 and 1.1 dB, respectively. Several filter prototypes are fabricated and studied to verify the repeatability of the fabrication and assembly processes.