A switchable single-band/multiband CMOS low nose amplifier

In this paper, a multi-band LNA using switching inductors is designed and measured. The switching inductors consist of three inductors in series and two MOSFET switches. The two MOSFETs are individually connected in parallel with one of the three inductors. The voltage supply is fed through the structure of switching inductors that forms three kinds of resonator according to on or off states of two MOSFET switches. There are four operation modes that generate a single-band, two dual-band, and a triple-band transfer characteristics. The presented circuit is a modified cascoded amplifier configuration with the common-gate input rather than the common-source input. The measured gains are more than 10dB at all operation frequency bands. The measured reflection coefficients are almost less than -10dB at all operation frequency bands. the noise figures are less than 5dB. The power consumption is 9mW. The chip size is 1.02 × 1.2 mm.