Design and Analysis of an LO Chain for an IQ Receiver in a 77~81 GHz Short-Range Radar System

Abstract

This paper presents the design and analysis of an LO chain implemented using the CMOS 65 nm bulk process. The LO chain was fabricated for driving the short-range radar IQ mixer in the 77∼81 GHz band. The LO chain comprised a poly phase filter (PPF), driver amplifiers to compensate for PPF losses, and a 3-bit 7-dB attenuator to ensure the appropriate power conditions. Measurement results indicated that the maximum gain within the target band was 8 dB, and the gain and phase difference between the IQ outputs were 0.5 dB and 74°, respectively. The LO chain consumed 74 mW of power at 1 V, and the size of the fabricated chip was 1.027×0.45 mm 2 , including RF and DC pads.