Power PHEMT with compact device layout for low voltage CDMA application

Abstract

A high efficiency low voltage operation dual delta-doped AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) for low voltage code division multiple access (CDMA) application has been developed. When tested at 2.4 V and 1.9 GHz under IS-95 CDMA modulation, the 20.16 mm PHEMT device was found to have a linear output power of 28 dBm with a power added efficiency of 30.2%. The device also has a saturation power of 30.0 dBm with a power added efficiency of 61.5%. The high efficiency and linearity of the PHEMT at low bias voltage is attributed to the use of the dual delta-doped PHEMT structure and to the reduction of the size of the device layout. The device is suitable for low voltage CDMA applications.