A Monolithic Dual-Band 77/94 GHz Transceiver Front-End With Shared Frequency Multiplier

Abstract

This paper presents a monolithic dual-band 77/94 GHz transceiver front-end with shared frequency multiplier. The transceiver front-end consists of two transmitters and receivers, operating at 77 GHz and 94 GHz respectively to support dual-band operation. In order to reduce the dc power consumption and save chip area, a shared frequency multiplier between the two bands is adopted in this work. We employ a frequency tripler cascaded with a doubler as the frequency multiplier to generate the desired 77 GHz signal and to lower down the frequency and phase noise of the local-oscillator (LO). The 94 GHz signal is produced by the generated 77 GHz signal up-mixing with the LO input to share the frequency multiplier for low power and low cost. The conversion gain of the multiplier is boosted by the efficiency enhancement technique in frequency tripler and the proposed gain boosting unit in the output power buffer. Besides, a frequency shunt network at the mixer output is utilized to short the unwanted mixed signal and improve the linearity of the 94 GHz transmitter. The measured saturated output power P sat and 3-dB bandwidth of the 77/94 GHz band transmitter are 14.2/12.35 dBm and 7.5/6 GHz, respectively. A 37.05/27.7 dB receiver conversion gain, 8.8/14.8 dB double side band noise figure are measured in the 77/94 GHz band receiver. The transceiver occupies a core area of 1.12 mm × 2.46 mm and draws 450 mA from a 1.2 V supply voltage. INDEX TERMS Automotive radar, dual-band, frequency tripler, frequency doubler, gain boosting unit, imaging radar, receiver, transmitter.