This paper presents a diversity integrated circuit (IC) for digital satellite radio (SDARS) at 2.3 GHz. The IC contains an RF circuit which enables fast adaptive processing of up to three antenna signals for maximum ratio combining in a fast fading scenario. The RF front-end of the diversity system is integrated using 150 nm CMOS technology. The phase of each of the three input paths can be adjusted in quantized steps of 45 degrees from 0 degrees to 360 degrees. If the input signal of one path suffers from fading, a single path can be completely turned off for reducing the power consumption. The diversity IC is evaluated by means of laboratory measurements as well as by tests where antenna signals of real fading scenarios are processed using the presented IC. The results show a typical improvement in radio reception of more than a factor of 4 compared to a conventional reception system.