Bandwidth Extension, High Gain and High Isolation InP Distributed Amplifiers

We present the design and development of extended bandwidth, high-gain, and high-isolation InP distributed amplifiers in mm-wave and THz frequencies. We will review and discuss the input line loss, which is one of the primary causes that limit bandwidth. A novel Darlington transistor cell has been developed to improve the gain-bandwidth product and output power. To achieve a high gain, we will discuss several design techniques, including transistor stacking, gain peaking, and amplifier cascading. We will also demonstrate the development of high-isolation distributed amplifiers to 220GHz.