A Linear Q-Band Balanced Power Amplifier in a 130nm SiGe BiCMOS Technology Using Two-tone Load-pull Optimization

This paper presents a $Q$-band power amplifier (PA) in a 130nm silicon germanium (SiGe) BiCMOS technology envisioned for future space applications. To optimize linear efficiency a two-tone load-pull technique is used. As a metric for linearity the third order intermodulation distortion (IMD3) is used with a target value of -25 dBc. Leveraging this technique, the PA achieves a saturated output power of 24.2 dBm and a peak power-added efficiency (PAE) of 33\% at 40 GHz. The PAE at IMD3 = -25 dBc is measured to be 15\%, and 13.2\% for a 400 MBd 64-QAM signal for an EVM$_\text{rms}$ of -25.3 dB. A balanced architecture is used for good input and output return loss response.