A low current GaAs monolithic image rejection downconverter for X-band broadcast satellite applications

The design, fabrication, and performance of a fully integrated X-band monolithic image rejection downconverter are described. The downconverter consists of a low-noise amplifier, an image rejection mixer, and an IF amplifier. The downconverter receives RF signals between 11.7 and 12.3 GHz and converts them down to IF frequency between 1.0 and 1.6 GHz. A conversion gain of 46±1 dB, a noise figure of less than 3.3 dB, and an image rejection of 30 dB have been achieved over the RF frequency range. The chip size of the downconverter is 1.9 mm×2.2 mm, and its current dissipation is only 43 mA. Since the downconverter has sufficient image rejection due to an on-chip bandstop filter, it requires no off-chip circuits. Therefore, the use of this downconverter in X-band broadcast satellite applications will lead to a great reduction in size and current dissipation