A 335–407-GHz SiGe-Based Subharmonic Mixer Using a Fully Integrated LO Generation

This letter introduces a silicon–germanium (SiGe)-based subharmonic mixer (SHM) optimized for THz radar applications, operating at a center frequency of 360 GHz with a 3-dB bandwidth of 72 GHz. This mixer is a key component in a fully integrated receiver, featuring a wideband 90-GHz voltage-controlled oscillator (VCO), a frequency doubler stage, and power amplifier (PA) stages. The mixer exhibits a conversion gain of −6.1 dB while maintaining an excellent input compression point of >4 dBm, accompanied by a simulated noise figure (NF) of 24.8 dB. Moreover, a current consumption of only 8.6 mA underlines the energy efficiency.