A CMOS 90nm 4-mW 15dBm-IIP3 base-band programmable gain amplifier for UWB Receivers

In this paper the design of a programmable gain amplifier (0 dBdivide15 dB, 3 dB per step) embedded in the analog base-band chain for UWB Receivers in a standard 90 nm CMOS technology is presented. The design has been realized using a proper Matlab procedure. Due to the large bandwidth required in the UWB Receivers, the procedure takes into account the second order effects related with the opamp parasitic capacitance and finite bandwidth. In this way the model guarantees to satisfy the IRN and transfer function accuracy requirements and to avoid linearity performance degradation. Thanks to the results obtained by the Matlab procedure, no capacitance are used in the PGA schematic. From a single 1.2 V supply voltage, the PGA total current consumption is 3.5 mA, the inband IIP3 is 15 dBm and out-of-band IIP3 is 23 dBm, the maximum IRN is 16nV/radicHz at 15 dB gain.