A 200-GHz Signal Source in 40-nm CMOS for Sub-THz Biomedical Imaging Applications

This work proposes a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$200-\text{GHz}$</tex> signal source for sub-THz biomedical imaging applications. The signal source integrates a fundamental voltage-controlled oscillator (VCO), a power amplifier (PA), and a frequency doubler. Its architecture is optimized for a wide tuning range and high output power. The PA amplifies the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$100-\text{GHz}$</tex> signal generated by the VCO, providing sufficient power to drive the frequency doubler, which then multiplies the input frequency to produce the desired <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2 0 0 - G H z}$</tex> output. Implemented in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$40-\text{nm}$</tex> CMOS technology, the proposed signal source delivers an output power of -0.3 dBm at 181.4 GHz with a tuning range of 8.5 %. The signal source only consumes 172 mW from a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.9-\mathrm{V}$</tex> supply.