Varactor-tunable dual-band filtering low-noise amplifier

摘要

Design and development of a tunable dual-band filtering LNA has been presented in this paper. The center frequency of the lower band is continuously tuning with applied dc voltages. The center frequency of lower band has a tuning range of 2.0-2.5GHz; while that of upper band is fixed at 5GHz. Power consumption of our circuit is 28mW. Overall size of proposed device is 0.96g x 0.34g, where g is the guided wavelength at lower frequency. One ATF36163 GaAs HEMT is used as the active device in our circuit. Measured per stage gain of lower band is varying from 8 to 1.6dB; while that of upper band is 5.4dB. Measured noise figure of lower band is 2.4-3.4dB; while that of upper band is 2.5dB. Proposed filtering LNA has improved selectivity and spurious harmonic suppression with measured stopband attenuation of 45dB. To author's knowledge, the investigation of tunable multiband and multifunctional device for highly improving the level of integration of the multiband RF front-end design is reported for the first time.