Abstract: A CMOS RF (radio frequency) front-end for digital radio broadcasting applications is presented that contains a wideband LNA, I/Q-mixers and VGAs, supporting other various wireless communication standards in the ultrawide frequency band from 200 kHz to 2 GHz as well. Improvement of the NF (noise figure) and IP3 (third-order intermodulation distortion) is attained without significant degradation of other performances like voltage gain and power consumption. The NF is minimized by noise-canceling technology, and the IP3 is improved by using differential multiple gate transistors (DMGTR). The dB-in-linear VGA (variable gain amplifier) exploits a single PMOS to achieve exponential gain control. The circuit is fabricated in 0.18- m CMOS technology. The S11 of the RF front-end is lower than -11.4 dB over the whole band of 200 kHz–2 GHz. The variable gain range is 12–42 dB at 0.25 GHz and 4–36 dB at 2 GHz. The DSB NF at maximum gain is 3.1–6.1 dB. The IIP3 at middle gain is -4.7 to 0.2 dBm. It consumes a DC power of only 36 mW at 1.8 V supply.

Key words: RF front-end,  noise-canceling,  DMGTR,  dB-in-linear,  DRM/DAB/DVB-H,  CMOS