High linearity-wideband PHEMT darlington amplifier

The paper reports the new E-PHEMT Darlington feedback amplifier with a active self-biased topology. Compared with the conventional InGaP Darlington amplifier, the new amplifier has two prominent advantages. Firstly, there is a great improvement on linearity performance. We can achieve of P1dB no less than 21.5 dBm at 5 V of supply voltage and no less than 23.5 dBm at 8 V of supply voltage between 0.5~3 GHz. Secondly, the new amplifier eliminates the need for the external biased resistor of conventional case and operates directly from the supply voltage after employing active self-biased topology. The amplifier overall efficiency may be improved as much as 40%. The new amplifier has the much lower Idd, gain, IP3 and P1dB sensitivity with temperature variation.