A digital ΔΣ RF signal generator for mobile communication transmitters in 90nm CMOS

Abstract

The presented digital RF signal generator in 90 nm CMOS uses 1-bit DeltaSigma modulation and targets mobile communication terminals. A 50 MHz bandwidth centered on 1 GHz can be achieved when the circuit is clocked at 4 GHz. Signals up to 3 GHz can be synthesized when using the first image band. The peak output power into a 100 Omega diff. load is 3.1 dBm with 53.6 dB SNDR. The digital core employs redundant arithmetic, precomputed non-exact quantization and differential dynamic logic. The digital core consumes 49 mW at maximum clock frequency. Active area is 0.15 mm2.