A 27-to-65-GHz CMOS Amplifier with Tunable Frequency Response.

A tunable-frequency-response IF amplifier, using 40-nm CMOS process, is realized for wireless communication in the 300-GHz band. The Q factor is adjusted by controlling the gate-source voltage of the PMOSFETs as variable resistors in the inter-stage circuit, so that the frequency response of a total of four amplifying stages can be adjusted separately. In addition, a variable gain of 9 dB is achieved by connecting the PMOSFETs that make up the variable resistors in parallel.