High-Speed Reconfigurable Circuits for Multirate Systems in SiGe HBT Technology

In this paper, we discuss the advantages and opportunities presented by high-speed (>50 GHz) reconfigurable integrated circuits and how they may drive reconfigurable systems applications, such as software-defined radio, radar, and imaging. We propose silicon-germanium (SiGe) BiCMOS as an example technology that enables ultrafast reconfigurable systems and present several circuit designs based on SiGe heterojunction bipolar transistors (HBTs). We compare circuit designs between generations of IBM's SiGe process, including a recent 9HP process featuring devices with a cutoff frequency (f(T)) of 300 GHz. We describe an architecture for an 8-b 80-Gs/s analog-to-digital converter (ADC) and a 48 x 48 cell field-programmable gate array (FPGA), which provide powerful solutions for useful functions, such as digital signal processing (DSP) and polyphase filtering. Other circuit concepts are described, including a voltage-controlled oscillator (VCO) with a tuning range of 26 GHz and a high-performance (80 Gb/s) crossbar switch, which provide utility in reconfigurable system applications. Measured results from fabricated implementations of these described systems are presented. We comment on future prospects of these systems and examine an emerging lateral bipolar device (f(T) = 825 GHz) having 100 x less power consumption than conventional vertical HBTs.