Co-Designed 138 GHz Compact CMOS Transmitter With Simplified Sub-Harmonic Mixer

This letter presents a 138 GHz transmitter front-end with a simplified sub-harmonic mixer (SHM) in a standard 40 nm CMOS process. To effectively reduce the chip area, the proposed transmitter co-designs SHM with a power amplifier (PA), rather than integrating conventional discrete blocks with matching networks. Moreover, a simplified SHM is proposed to further simplify the required passive structure. The transmitter exhibits a remarkable conversion gain of 24.1 dB and a saturated output power of 6.4 dBm with a power consumption of only 142 mW. The compactness of the proposed design is highlighted by its core size of only 0.13 mm2, representing a significant reduction of approximately 50% compared to prior works.