LAUSR

Passive millimeter-wave imaging systems (PMWIS) are employed for detecting concealed objects by mapping millimeter waves emitted from materials or living tissues. The emitted waves are measured by a receiver or radiometers without employing external wave sources. In this paper, a new super-heterodyne receiver front-end of a PMWIS at 35 GHz with an even order band pass filter is simulated and implemented. The receiver has a suitable temperature resolution for the use of hidden object imaging, is integrated and lightweight assembled on one-layer board. It has a bandwidth of 1.5 GHz, a noise figure (NF) of 2.2, and a temperature resolution of 0.126 K. The even order filter is implemented based on the substrate-integrated waveguide (SIW) technology, with Chebyshev response. The filters are designed at the central frequency of 35 GHz with the bandwidth of 1.5 GHz and one of them has controllable transmission zeroes. The filters are made by printed circuit board technology, employing SIW as resonators, having a high-quality factor of 23.33. Additionally, a triple-stage radio frequency (RF) low noise amplifier has been implemented having the specification of: RF 34.25–35.75 GHz; bandwidth 1.5 GHz; gain >60 dB; NF <2.3 dB, which are better indexes compared to some other works.