5-6 GHz monolithically integrated calibratable low-noise downconverter for smart antenna arrays

An integrated downconverter for active antenna arrays is presented. From 5.125 GHz to 5.875 GHz the downconverter shows more than 20 dB conversion gain and a noise figure of less than 3.8 dB with a minimum of 3.3 dB. Input 1 dB compression point is -18 dBm. Image rejection better than 35 dB is achieved using an integrated lumped-element bandpass filter. A switchable symmetric input amplifier is proposed to calibrate amplitude and phase errors without degrading the noise figure.