Miniature 0.25-μm CMOS distributed amplifier using on-chip inductors

A CMOS distributed amplifier incorporating on-chip patterned ground shield (PGS) spiral inductors has been developed using a standard low-cost 0.25-μm CMOS process. Measured results show that this distributed amplifier has an average gain of 7 dB, return loss of more than 10 dB, and noise figure between 4.1-6.1 dB across DC-11 GHz. The amplifier occupies a small chip area of only 1.2×0.8 mm² including RF pads. These represent the best results for 0.25-μm CMOS distributed amplifiers and demonstrate that miniaturization and high performance can be achieved for CMOS distributed amplifiers and other wideband RFICs by implementing on-chip PGS inductors.