An 18-GHz continuous-time /spl Sigma/-/spl Delta/ analog-digital converter implemented in InP-transferred substrate HBT technology

We report an 18-GHz clock-rate second-order continuous-time /spl Sigma/-/spl Delta/ analog-digital converter (ADC) implemented using InP-transferred substrate HBTs. Under two-tone test conditions, the ADC achieved 43 dB and 33 dB SNR at signal frequencies of 500 MHz and 990 MHz, respectively. The IC occupied 1.95 mm/sup 2/ die area and dissipated /spl sim/1.5 W.