A wide-band RF front-end for multi-standard application

A multi-standard transceiver requires a wide-band radio frequency front-end in order to process RF signals of any frequency included by all the standards concerned. A noise cancellation technology is utilized in the low noise amplifier (LNA) to cancel the noise introduced by the source resistance matching segment. An active balun is embedded in the input stage of the mixer, which connect the single-end output LNA with the double-balanced mixer. To reduce the flicker noise introduced by the switching transistors, a current injection technology is utilized in the mixer. The present front-end*, integrated in a 0.18 ¿m CMOS process, can cover the bands over 0.8~2.5 GHz and exhibits NF below 6 dB at intermediate frequency (IF) which is higher than 1 MHz. Since the present front-end has no inductor, it occupies only 0.35 mm² on the chip. The total current consumption is 10 mA from a 1.8 V supply.