A 6 GHz digital receiver using COTS prototyping boards

We have designed and tested a digital receiver suitable for the reception of 6 GHz instantaneous baseband signals. It is based on a Tektronix TADC-1000 12.5-GS/s 8-bit digitiser module, a Tektronix TIPA-3100 HAPS Interposer board and a Synopsys HAPS62-Virtex6 Prototyping Motherboard. This motherboard is also employed for filtering and signal processing. The ADC module uses an external clock from the interposer board and can accept a range of input clock frequencies between 1.6 and 3.125 GHz, resulting in sample rates of between 8 and 12.5 GS/s in single-channel mode. The external clock and digital data are supplied to and processed via the HAPS62 board. A 2048-channel weighted overlap-add (WOLA) and FFT structure separate the input signal into approximately 5-MHz sub-bands to allow subsequent high-resolution processing to obtain continuous spectral information over the input bandwidth. This system meets present-day demands on high-resolution wideband digital back-ends for RF spectrum monitoring. This technology could be part of the next generation wideband signal intercept systems for the future detection, classification and location of modern complex RF signals.