Yutaka Aoki

Design of detector circuit for layer structured imaging module

Simple configuration of RF module is proposed for passive millimeter-wave imaging system. The results of the detector design for the module are reported in this paper. A detector planar circuit and a waveguide horn antenna are connected by broadband microstrip-to-waveguide transition. A number of the antenna is arranged around the focal point of the lens, which results in the proposed RF module. Since the module forms a layer structure composed of substrate and machined flat metal plates, which contributes low-profile and easy manufacturing. Here, the structure of the proposed imaging module is described in detail. Next, the results of the detector design used in the proposed imaging module are described.

RF Performance of Layer-Structured Broadband Passive Millimeter-Wave Imaging System

Low profile and simple configuration are advantageous for RF module in passive millimeter-wave imaging system. High sensitivity over broad operation bandwidth is also necessary to detect right information from weak signal. We propose a broadband layer-structured module with low profile, simple structure, and ease of manufacture. This module is composed of a lens antenna and a detector module that consists of a detector circuit and a broadband microstrip-to-waveguide transition. The module forms a layer structure as a printed substrate with detector circuit is fixed between two metal plates with horn antennas and back-short waveguides. We developed a broadband passive millimeter-wave imaging module composed of a lens antenna and a detector module in this work. The gain and the antenna efficiency were measured, and the broadband operation was observed for the lens antenna. For the detector module, peak sensitivity was 8100u2009V/W. Furthermore, the detector module recognized a difference in the absorber’s temperature. The designs of the lens antenna and the detector module are presented and the RF performances of these components are reported. Finally, passive millimeter-wave imaging of a car, a human, and a metal plate in clothes is demonstrated in this paper.

Passive millimeter-wave imaging system for automobile applications

In this paper we describe the capability of passive millimeter-wave imaging in obstacle width and clearance measurement for automobile applications. To confirm the capabilities, a passive millimeter-wave imaging (PMMWI) test system has been developed. This test system employs the Dicke configuration, which includes a 150mm diameter antenna, a PIN switch, a reference terminator, a 50dB RF amplifier, a 76-77GHz BPF, a W-band detector, a lock-in-amplifier, an elevation and azimuth scanning stage, and a PC for scan control and data acquisition. A van and sedans are utilized as targets. The vehicle width and the clearance between two vehicles measured from PMMWIs show fairly good agreement with real values. Therefore, the capability of PMMWI in width and clearance measurement is confirmed. In addition, the experimentally obtained PMMWIs of vehicles represent the vehicle shapes. This result indicates that obstacle distinction is possible by PMMWI.