Dual-band low-noise amplifier using Step-Impedance Resonator (SIR) technique for wireless system applications

A low-cost dual-band low-noise amplifier (LNA) is proposed and demonstrated for WLAN IEEE802.11b/g/a standards. A sufficient dual-band gain is achieved on the basis of cascaded two single-stage amplifiers. The LNA is realized in our standard Print Circuit Board (PCB) surface-mount technology with discrete components. Dual-band operating frequency ranges of the LNA are designed and obtained by using a quarter-wavelength microstrip line Step-Impedance Resonator (λ/4 SIR). The proposed LNA is biased with a supply voltage of 1.5 V. It exhibits 22 and 12 dB gain with noise figure of 1.5 and 1.6 dB at the pre-designated center-operation frequencies of 2.45 and 5.2 GHz, respectively. The LNA presents 7.5 mW (5 mA under 1.5V) power consumption at both frequency bands.