K-band FMCW radar transceiver CMOS IC

Abstract

This dissertation presents K-band FMCW radar transceiver CMOS ICs. Three improved FMCW radar systems are proposed and implemented using 0.13-$\mu$m CMOS technology. First, to extend the detection range, CMOS front-end ICs with 13.3 dBm output power for a K-band FMCW radar are presented in chapter II. The transmitter consists of a voltage controlled oscillator, divider chain, power amplifier, and additional buffers. The receiver consists of a low-noise amplifier, IQ mixers, an IQ generator, and buffers. The leakage problem can be mitigated by adopting differential topology and ground shielding. As a result, the receiver achieves a conversion gain of 35.7 dB, a P1dB of -31.6 dBm, and a DSB noise figure of 5.5 dB. The transmitter achieves the tuning range of 23.8~24.5 GHz and the phase noise of -104 dBc/Hz @ 1MHz offset. The receiver and transmitter chips consume 121.5 mW and 373.5 mW from a 1.5 V power supply, respectively. Using these two chips, the K-band FMCW radar module is implemented and verified by measuring the distance of an object. In chapter III, a fully integrated K-band CMOS transceiver IC is presented. This transceiver IC is capable of dual-mode FMCW and UWB radar operation, providing full road coverage. In the transmitter part, the transmit signal can be switched between linearly frequency-modulated signal and time-slotted pulse signal according to the selected mode. In cooperation with control signal generator, the dual-functional block is switched between the pulse former and differential amplifier in UWB and FMCW modes, respectively. In the proposed receiver, not only the gain but also the bandwidth of the overall receiver can be tailored by switching of the center frequencies of stages and without lowering the quality factor of each stage. Therefore, dual-mode radar operation can be achieved in the single-path transceiver. Dual-mode operation was verified by the implementation of a transceiver module with the chip. It showed performance comparable to that of previously reported tranceivers despite the fact that it operates in dual modes. Chapter IV presents a CMOS transceiver IC for a single-antenna FMCW radar. Since Tx leakage is critical in CMOS technology, a comprehensive leakage cancelling technique is proposed. The suggested tech-nique is able to cancel all the leakages caused by antenna reflection, asymmetry of balanced structure, and lossy substrate without additional power or area. Even-order harmonic leakage from the power amplifier is also reduced by an even harmonic filter, which is implemented simply by removing the real ground at a sym-metrical point. 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 output pow-er of -1.6 dBm, phase noise of -105.44 dBc/Hz at 1MHz offset, receiver gain of 15.3 dB, and a noise figure of 11.6 dB. Tx leakages are cancelled to have isolation between Tx and Rx of 47.3 dB. The chip consumes 74.1 mA from a 1.5 V power supply. The chip area including pads is 1.7 mm $\times$ 0.9 mm. Using this chip, a K-band FMCW radar module with a single antenna is implemented and verified.