Opposite-Type FMCW Sensor Equipped with Interference Protection Measures via Use of Multi-Reflector

Masatoshi TSUJI 

Publication
C - Abstracts of IEICE TRANSACTIONS on Electronics (Japanese Edition)  Vol.J95-C  No.6  pp.123-126
Publication Date: 2012/06/01
Online ISSN: 1881-0217
Print ISSN: 1345-2827
Type of Manuscript: LETTER
Category: 
Keyword: 
FMCW,  micro wave sensor,  anti-false alarm,  multi reflect,  anti-interference, 

Full Text(in Japanese): PDF(309.8KB)

Summary: 
This study proposes measures against a reduction in the reception sensitivity of an opposing type MW sensor for security use that can result from interference between the direct wave and the wave reflected by the ground. The method involves the two reflectors being located at different distances from the sensor, with the passage of a person then being determined by the reflected signals from the reflectors both falling below their threshold values. 24 GHz band FMCW type sensors were used in experiments involving the proposed method. The results agreed well with the theoretical calculations; with a decrease in the reception intensity resulting in the height from the ground to the sensor being different. The proposed method was therefore proved to be of use in preventing any incorrect sensor detections resulting from waves reflected by the ground.