Single-Antenna FMCW Radar CMOS Transceiver IC

This paper presents a CMOS transceiver IC for a single-antenna frequency-modulated continuous wave (FMCW) radar. Since transmitter (Tx) leakage is critical in a single antenna radar with CMOS technology, a comprehensive leakage canceling technique is proposed. It is able to cancel all the leakages caused by antenna reflection, asymmetry of a balanced structure, and lossy substrate without additional power or area. Even-order harmonic leakages from the power amplifier (PA) are also reduced by an even-harmonic filter, which is implemented simply by removing the real ground from the symmetrical point of the PA output transformer. Matching networks are simplified by using a modified coupler structure. A low-noise combining amplifier is used to make the combining circuit compact. As a result, the transceiver achieves the output power of -1.6 dBm, the phase noise of -105.44 dBc/Hz at 1MHz offset, the receiver (Rx) gain of 15.3 dB, and the noise figure of 11.6 dB. Tx leakages are canceled so that the isolation between Tx and Rx is 47.3 dB. The chip consumes 74.1 mA from a 1.5-V power supply. Despite the high integration level, the chip area including pads is 1.7 mm × 0.9 mm. A K- band FMCW radar module with a single antenna is implemented with this chip.