Masamune Takeda

Passive millimeter-wave imaging for security and safety applications

77 GHz passive millimeter wave (PMMW) imaging camera for the purpose of security is developed. In order to detect concealed objects in clothes without hindrance to flow of people at airport security checks, video rate imaging is realized using one-dimensional imaging sensor array of 25 elements and a flapping reflector. As receiving antennas, novel antipodal Fermi antenna (APFA) having required characteristics for passive imaging such as broad bandwidth to obtain enough power, axially symmetric directivity with 10dB beam width of 35 degrees to obtain optimum coupling with dielectric lens, narrow width geometry for high spatial resolution of imaging is used. Real-time calibration (RTC) technique is introduced to eliminate the drift of receiving circuits. Interpolation technique to improve the quality of image and marking software for screening of suspicious objects are also developed. High spatial resolution of 20 mm is obtained by using developed imaging camera.

Development of 77 GHz millimeter wave passive imaging camera

77 GHz millimeter wave passive imaging camera for the purpose of security is developed. In order to detect concealed objects in clothes without hindrance to flow of people at airport security checks, video rate imaging is realized using one-dimensional imaging sensor array of 25 elements and a flapping reflector. As receiving antennas, novel antipodal Fermi antenna (APFA) having required characteristics for passive imaging such as broadband to obtain enough power, axially symmetric directivity with 10dB beam width of 35 degrees to obtain optimum coupling with dielectric lens, narrow width geometry for high spatial resolution of imaging is used. High spatial resolution of 20 mm (width of finger) is obtained by using developed passive imaging camera.