Sub-nanosecond pulse-forming network on SiGe BiCMOS for UWB communications

A pulse-forming network (PFN) has been developed for ultra-wideband (UWB) communication systems. This PFN generates sub-nanosecond pulses at a pulse repetition frequency (PRF) of >500 MHz for high data-rate applications like wireless video streaming. To generate the pulses, the PFN performs two operations on an input data signal: it decreases the signal rise time, then it differentiates the signal. The differentiation circuit is a frequency-dependent negative-feedback system. The PFN is fabricated in SiGe BiCMOS with an active die size of less than 0.25 mm², and it requires 3.3-V 20-mA dc during operation. Measured performance is validated at 500-MHz PRF, achieving pulsewidth of 175 ps and pulse amplitude of 0.17 V. The PFN is also validated within a transmitter system that transmits Manchester coded pseudorandom bit sequence. Measured effective isotropic radiated power of the transmitter shows that the PFN output power is sufficient to meet the Federal Communications Commission´s emission limits, thus eliminating the need of amplification before transmission.