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 <tex-math notation="LaTeX">360</tex-math> GHz with a <tex-math notation="LaTeX">3</tex-math> -dB bandwidth of <tex-math notation="LaTeX">72</tex-math> GHz. This mixer is a key component in a fully integrated receiver, featuring a wideband <tex-math notation="LaTeX">90</tex-math> -GHz voltage-controlled oscillator (VCO), a frequency doubler stage, and power amplifier (PA) stages. The mixer exhibits a conversion gain of <tex-math notation="LaTeX">-6.1</tex-math> dB while maintaining an excellent input compression point of <tex-math notation="LaTeX">>4</tex-math> dBm, accompanied by a simulated noise figure (NF) of <tex-math notation="LaTeX">24.8</tex-math> dB. Moreover, a current consumption of only <tex-math notation="LaTeX">8.6</tex-math> mA underlines the energy efficiency.