High Linearity, High-Power, Quadrature Balanced Amplifiers for Active Transmit Arrays

This proposal is intended to address the development of high linearity, high-power, quadrature balanced amplifiers for active transmit arrays supporting three different frequency bands from 5.5 to 18.5 GHz. We propose an innovative solution forimplementation in a commercial Silicon Germanium (SiGe) heterojunction bipolar transistor (HBT) process. This solution utilizes a differential topology combined with a broadband ft doubler circuit to enable a commercial SiGe HBT technology to achieve highoutput powers and wide bandwidths suitable for multi-function phased array applications. High linearity is achieved with the use of SiGe HBT NPN devices with relatively high Early voltages in a quadrature balanced structure minimizing third orderharmonics. VT Silicon's extensive experience in developing commercial SiGe power amplifiers will aid significantly in developing a practical solution. Commercialization is one of the major advantages of silicon-based technologies given its proven volumemanufacturing history, lower cost, greater availability, and ease of integration. In the first phase of this contract, VT Silicon intends to demonstrate the feasibility of a high performance, cost-effective and compact solution by extensive circuit andelectromagnetic modeling, simulations and thermal analysis. The proposed broadband SiGe PA solution will be integrated with state-of-the-art module technology developed by Lockheed Martin. VT Silicon intends to commercialize the work proposed for thisSTTR contract and develop silicon-based power amplifiers for variety of high-power and high linearity commercial applications. Mobile phones and IEEE 802.11 based Wireless Local Area Networks (WLAN) are some of the major applications targeted forcommercialization of this technology.