A 140 GHz heterodyne receiver chipset for passive millimeter wave imaging applications

A heterodyne receiver chipset for 140 GHz passive millimeter wave imaging applications is presented in this paper. The chipset consists of two different millimeter wave monolithic integrated circuits (MIMICs): a voltage controlled oscillator (VCO) working in the 35 GHz frequency range and a receiver chip hosting a low noise amplifier, a down-conversion mixer, a frequency multiplier and a local oscillator buffer amplifier together with a local oscillator distribution network. Both chips presented are realized using latest 100 nm gatelength metamorphic InAlAs / InGaAs HEMT (high electron mobility transistor) technology on 50 ?m thick and 4 inch diameter GaAs substrates. The chips are utilizing grounded coplanar waveguide (GCPW) technology. Within the frequency band of operation from 120 to 145 GHz the receiver is showing a noise figure of ~ 5 dB and a conversion gain between -1 and 2 dB. The voltage controlled oscillator can be tuned from 31 to 37 GHz with associated output power levels from -2 to +2 dBm. All building blocks are explained in detail and measured results are presented. Finally the overall receiver performance is given.