A 212–224 GHz, 32-Element, λ /2-Spaced Phased-Array Transmitter With Joint Subharmonic Mixer and IF Beamformer Presenting 36-dBm Peak EIRP

This article presents a 220GHz, scalable planar phased array with precise $\lambda $ /2 antenna spacing based on 0.13- $\mu $ m SiGe BiCMOS technology. A novel joint design incorporating an image rejection subharmonic mixer (IRSHM) and a vector modulator (VM) is proposed based on the current reuse technique to effectively minimize power consumption and occupied area. And this architecture simultaneously enables image rejection, subharmonic up-conversion, and intermediate frequency (IF) phase and amplitude control. The proposed phased-array chip employs a splicing architecture with a $2\times 2$ array and on-chip antenna, where a ninth harmonic generator, a local oscillator (LO) signal distribution network, and four highly integrated transmitters (TXs) are integrated. Through the chip-edge wire bonding, a $4\times 8$ planar phased array is realized with an RF 3-dB bandwidth of 212–224GHz. In the measurement, the peak effective isotropic radiated power (EIRP) is 36dBm of a 32-element phased array at 221GHz, with about 2dBm output power per channel. A 3-dB beam widths of 10° (horizontal) and 17° (vertical), with beam steering capabilities of ±60° and ±40° in the respective planes are achieved. Furthermore, a wireless communication link using a 32-element phase array and a 40-dBi dish antenna is demonstrated, achieving data rates of 4 Gbps (QPSK) and 6 Gbps (16-QAM) with corresponding error vector magnitude (EVM) values of 9.5% and 9.2%, respectively. An inverse synthetic aperture radar (ISAR) imaging experiment involving two corner reflectors is also demonstrated. The measured azimuth resolution is 8mm, and two corner reflectors can be clearly distinguished.