0.2 dB Gain Ripple - 20W- WCDMA Silicon MMIC

The Silicon MMICs have entered the wireless base station arena a few years ago, because of their good and reliable power performances together with excellent thermal properties. The WCDMA base station manufacturers require amplifiers with very stringent gain flatness specification, because of the UMTS linearity specifications, the multi carrier amplification and the associated linearity enhancement techniques. This paper describes the different technical problems inherent to very flat gain multistage power amplifiers, the techniques used to circumvent them, and presents the performances of a 3 stages 20W peak power amplifier featuring 0.2dB gain ripple within 5 times the UMTS band (300 MHz).