RF Performance of Layer-Structured Passive Millimeter-wave Imaging Module

Simple configuration and broadband characteristic are required for RF module in passive millimeter-wave imaging. We propose a layer-structured imaging module for simple structure, low profile and easy manufacturing [1]. This module is composed of lens antenna and detector module as shown in Fig.1. Lens and feeding horn antenna are designed to realize high-gain lens-antenna which operates over broad frequency bandwidth. Detector circuit and waveguide-to-microstrip (WGMS) transition are also designed to obtain highly-sensitive detector-module with waveguide input which can be connected with waveguide fed horn antenna of the lens antenna. Since a printed substrate with detector circuit is fixed between two metal plates, the module forms a layer structure, which contributes to low profile and easy manufacturing. Designs of the lens antenna and the detector module are indicated and RF performances of these components are reported in this paper.