A 3 Gb/s bipolar phase shifter and AGC amplifier

Two multipurpose bipolar ICs for Gb/s systems fabricated in a 2- mu m standard silicon bipolar technology are presented. The first is a wideband clock phase shifter with continuously adjustable phase (0 to -2 pi ), operating from 300 MHz to 3 GHz, and the second is a single-chip AGC (automatic gain control) amplifier with large dynamic range (40 dB), high voltage gain (40 dB), and high cutoff frequency (2.5 GHz), operating up to 3 Gb/s. The insertion voltage gain versus frequency at the nominal output voltage swing of 400 mV is shown. Flat gain response and nearly constant 3-dB cutoff frequency of 2.55+or-0.05 GHz within the total dynamic range were achieved. The amplifier was driven by a pseudorandom pulse generator at bit rates up to 3 Gb/s. Output eye patterns with nominal voltage swing and wide opening were observed over the dynamic range, and the bit error rate was below the sensitivity of the measuring equipment, 5*10/sup -11/ up to 2.7 Gb/s and increasing to 3*10/sup -10/ at 2.9 Gb/s. Chip micrographs of both circuits are shown.<>