Title :
Analog Signal Processing for Pulse Compression Radar in 90-nm CMOS
Author :
Parlak, Mehmet ; Matsuo, Michiaki ; Buckwalter, James F.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California at San Diego, La Jolla, CA, USA
Abstract :
This paper presents a pulse-compression radar baseband analog signal processing integrated in a silicon process for low cost and power dissipation. The analog signal-processing circuitry 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 analog-to-digital converter (ADC) via an analog correlator. The circuitry includes a two-stage variable gain amplifier (VGA) for high dynamic range, a correlator/integrator circuit, a comparator, and offset calibration circuits. The differential 6-bit VGA is designed to adaptively track the Friis path loss through rapid change of the VGA gain and offset calibration, relaxing the dynamic range requirements of the correlator. The measured performance shows a VGA gain variation of 52 dB and a VGA group-delay imbalance of 50 ps over 64 states. The high-speed pulse compression/correlation is performed in analog current domain and the speed requirement on the ADC is reduced by a factor equal to the duty cycle lowering the ADC power consumption. The chip is fabricated in a 90-nm process, wire bonded on the FR4 printed circuit board, and tested with a Stratix IV field-programmable gate-array board to evaluate the system performance for different radar polyphase codes.
Keywords :
CMOS analogue integrated circuits; analogue-digital conversion; comparators (circuits); correlators; elemental semiconductors; field programmable gate arrays; lead bonding; millimetre wave amplifiers; millimetre wave radar; printed circuits; pulse compression; silicon; CMOS integrated circuit; FR4 printed circuit board; Friis path loss; Si; Stratix IV field-programmable gate-array board; VGA group-delay imbalance; analog correlator; analog current domain; analog signal processing circuitry; analog-to-digital converter; autocorrelation properties; comparator; correlator/integrator circuit; high-speed pulse compression/correlation; offset calibration circuits; pulse compression radar; radar polyphase codes; silicon process; size 90 nm; two-stage variable gain amplifier; wire bonding; word length 6 bit; Bandwidth; Baseband; Correlators; Radar; Radar antennas; Signal resolution; Analog signal processing; CMOS; baseband; beamforming; comparator; correlator; high resolution; human sensing; millimeter wave; phased array; pulse compression; pulse compressor; radar; radar-on-chip; sensor; silicon integrated circuit (IC); variable gain amplifier (VGA);
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2012.2222433