Improved four-channel direct-conversion SiGe receiver IC for UMTS base stations

This work presents the design and measurement results of an improved four-channel, direct down conversion receiver (DCR) for the application in universal mobile telecommunications system base stations. The whole analog receiver functionality including low noise amplifier, variable gain amplifier, local oscillator frequency divider, in-phase and quadrature DCR mixers and seventh-order active lowpass filter is integrated using Atmel´s 50-GHz f_t, 50-GHz f_max SiGe foundry technology (Atmel, 1998). Important cascaded design parameters of the fully ESD-protected device are a noise figure 1.5 to 2 dB; IIP3 (third-order intercept point) -20.3 to -15.8 dBm and a voltage gain of 51 to 57 dB into a 1000-Ω || 2.5-pF differential load [analog to digital converter].