Fully integrated wideband sub-10 GHz radio frequency front end with active matching

This article presents an integrated radio frequency (RF) front end for the use in frequency bands up to 10GHz. It consists of an actively matched low noise amplifier (LNA) and a single multi-tanh Gilbert cell mixer. Its applications include frequency-modulated continuous wave (FMCW) radar front ends or single down conversion communication systems. The circuit is completely inductor-less. Using a negative resistance bandwidth enhancement technique, a 1dB bandwidth of 11.2 GHz is reached. The input reflection coefficient is below -7 dB up to a frequency of 7GHz within a printed circuit board (PCB) test bed. The single-sideband (SSB) noise figure amounts to 7dB and the small-signal gain is 26dB. The complete circuit is implemented using an IBM 180 nm SiGe BiCMOS process, occupies an active area of only 0.078 mm² and consumes 57mW of DC power.