UC San Diego

The power dissipation and cost of the next generation pulse radar beamforming systems needs to be reduced for the imaging and surveillance sensors. This research work aims at developing and innovating the next generation, mobile hand-held, high performance radar systems for outdoor surveillance applications, i.e. pedestrian detection sensor. Integrating the low cost millimeter-wave (mm-wave) imaging array platforms with advanced analog/ baseband signal processing on silicon is proposed for reducing the power dissipation, area, and cost of the next generation radar modules and for the wide deployment of the sensors that are capable of detecting the vehicles and humans with a good range/angle resolution and maximum detection range at the same time. The system concepts of a bidirectional beamforming pulse compression radar system, the design and measurement results of the bidirectional mm -wave front-end circuits at the front-end and the design and measurement results of a baseband/analog signal processing sub-system and its blocks are presented, although the pulse compression radar is not fully demonstrated. Low noise figure, low power consumption, high linearity and high bandwidth in circuit level is maintained to provide the maximum detection distance, good range and angle resolution for the overall system level. The analog signal processing system is demonstrated in 90 nm CMOS process. The baseband circuitry is designed as a pulse compression radar system that exhibits the autocorrelation properties of the polyphase codes, maximizes the sensitivity and resolution of a pulse radar system and alleviates speed and resolution requirements of the ADC via an analog correlator while minimizing the power consumption. The baseband circuitry includes a Friis loss tracking VGA for high dynamic range, a correlator / integrator circuit, a comparator, and offset calibration circuits. The different lengths of radar codes are given as inputs to the baseband circuitry chip to find the time of flight. Next, novel silicon millimeter-wave frequency circuits are implemented to reduce the number of elements in a beamforming front-end, although not specifically designed for the radar system front-end. Bidirectional circuits are motivated by the requirements of scalable microwave and millimeter-wave phased array transceivers. The first bidirectional amplifier in silicon/silicon- germanium is reported to date - a W-band bidirectional cascaded constructive wave amplifier (BCCWA) in a 0.13[mu]m SiGe BiCMOS technology which operates as either an LNA or PA one at a time. The first phase shifter/ variable gain amplifier at W-band in a 0.13 [mu]m SiGe BiCMOS technology is also reported to date. The circuit can operate both as a continuous variable gain amplifier and phase shifter one at a time. The first dual-channel distributed amplifier (DA) is reported to date. The DA is proposed for a highly linear multiple-input receiver front -end and can replace two LNAs at the same time. Next, millimeter-wave circuits in 45-nm CMOS SOI process are presented. The design and state-of-the-art measurement results of millimeter-wave (Q-band) balanced resistive ring mixer, LNA, and SPDT switch are demonstrated. The results indicate that 45-nm CMOS SOI demonstrates the lowest mixer conversion loss, lowest switch insertion loss, and lowest LNA noise figure compared to other CMOS processes