A Modular Design Approach for Ka-Band Front-End Receiver of Synthetic Aperture Interferometric Passive Imager

Electromagnetic Laboratory of Beihang University is engaged in the development of Ka-band synthetic aperture interferometric based passive imager named as BHU-2D-U. The imager is intended for detection of concealed weapons on human body. Noise figure of front-end receiver dictates the dynamic range and consequently the imaging performance of the imager. A modular design approach is presented to obtain improved noise figure as compared to the previous work. Additionally, the modular design gives a flexibility to adopt any desired receiver gain, instantaneous bandwidth, and noise figure and image rejection suppression. The measured gain, noise figure and image rejection is 42 dB, 4.1 dB and 60 dB respectively with 80 dB excellent spurious free spectral response. The reconstructed image performance of the imager is found satisfactory