Portable Thermoacoustic Imaging for Biometric Authentication using a 37.3 dBm peak Psat 4.9 GHz Power Amplifier in 55nm BiCMOS

Handheld microwave thermoacoustic imaging (TA) can be used to image subcutaneous vasculature for biometric authentication and to monitor blood-vessel health, but the system requires a compact silicon microwave power amplifier (PA) with peak output power on the order of 10 W to be portable, affordable, and ubiquitous. This work presents a 55nm BiCMOS 4.9 GHz PA with 37.3 dBm peak output power that operates at a pulse width of 50 ns -
$2\ \mu\mathrm{s}$
for a duty cycle of 0.025 - 1%. The PA serves as the transmitter in a microwave TA system, which generates the first known TA images of tissue phantoms using a compact transmitter built on a silicon substrate.