Ultra low power low noise amplifiers for wireless communications

The authors present the design and performance results of surface mount plastic packaged, ultra low power, GaAs monolithic low noise amplifiers, for cordless phone receivers at 1.9 GHz and spread spectrum receivers at 2.4 GHz. The results for the 1.9 GHz amplifier show a small-signal gain of 14.5 dB and noise figure of 1.5 dB with a 4 V supply while drawing only 3 mA. The LNA was also tested with a 3 V supply and with a current of 2 mA the measured gain and noise figure were 13.5 dB and 1.75 dB, respectively. Thus the LNA is compatible with the voltage requirements of the latest generation of 3 V CMOS logic circuits. The results for the 2.4 GHz LNA show a small-signal gain of 15 dB and a noise figure 1.8 dB drawing less than 5 mA from a single +5 volt supply. The LNAs are now being produced in volume in surface mount plastic packages for custom wireless communications applications.<
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