Design of combined power amplifier using 0.35micron SIGe HBT technology for IEEE 802.11a standard

In this thesis, a 5GHz Radio Frequency (RF) Power Amplifier (PA) design approach will be specified for IEEE 802.11a Wireless Local Area Network (WLAN) standard, and performance of Class-A PA will be specified in terms of power gain, Power Added Efficiency (PAE), linearity, gain, and output power. The amplifier design is based on AustriaMicroSystems (AMS) 0.35um SiGe BiCMOS HBT technology which has an ft of 100 GHz. IEEE 802.11a standard specifies the maximum power that can be transmitted in the Unlicensed National Information Infrastructure (UNII) band. These specifications are also the output power of the amplifier for frequency band of 5.18-5.8 GHz and specified as follows: 40mW (5.18- 5.24GHz), 200mW (5.26-5.32GHz) and 800mW (5.74-5.8GHz). The power amplifier is designed to operate in Class A to achieve high linearity and the bias points are chosen accordingly in order to preserve linearity. After the design of a single stage power amplifier, to reach higher output power and improve linearity, Wilkinson power combining technique is used in a new design. The behaviours of two kinds of circuits are compared and layouts are drawn. All the simulations are performed in Agilent Design System (ADS) and Cadence environments.