An ISM band CMOS integrated wireless telemetry transceiver (in A 0.18 μm copper CMOS process)

A 900 MHz CMOS BFSK transceiver is used as a test vehicle to evaluate the impact of copper interconnect on CMOS RF circuit performance. The RF front-end contains spiral inductors and fractal capacitors, whose parasitics degrade the receiver sensitivity. It is shown that spiral inductor quality factors (Qs) are on average 70% higher when copper interconnect is used in place of aluminum, while capacitor Qs are also improved significantly. As a result, the front-end receiver gain is increased by nearly 4 dB and the receiver noise figure is reduced by more than 1 dB when copper is used instead of aluminum. The 20 mW transceiver fabricated in the 0.18 μm copper UMC process can achieve a 0.1% BER for a - 98 dBm input, while operating at 200 kb/s data. The maximum power output of transmit section is +10 dBm.