A compact 24 GHz quadrature Doppler radar with front-end MMIC

Abstract

A compact 24GHz quadrature Doppler radar front-end monolithic microwave integrated circuit (MMIC) with Tx leakage canceller is developed. The chip is 3x2mm(2) and the front-end module is 3x3cm(2). The MMIC consists of a 24GHz voltage-controlled oscillator, a Tx leakage canceller and two mixers. The radar module can measure speeds as low as 2.5mm/s, which corresponds to a 0.41Hz Doppler shift. The quadrature topology enables the signs of a Doppler shift to be detected and obviates the null point problems.