High Power 16-Way Compact Power Divider / Combiner and Power Amplifiers Design for S-Band Radar Transmitter Application

Abstract

In radar transmitter systems, high power amplifier design along with the high power divider/combiner for parallel amplification is one the most critical area. To design the high power divider/combiner, high power handling capability with low insertion loss and high isolation are necessarily required. In addition, impedance matching design of power amplifiers throughout the operating frequency band is also a great challenge in radar transmitter design. This research aims at designing and implementation of an equal split 16-way Wilkinson power divider/combiner at a frequency range of 2700 to 3000 MHz. Furthermore, transistor input and output impedance matching networks are designed and simulated using Advance Design System (ADS) software. The circuitry hardware is implemented on Rogers RT/Duroid 5870 substrate and simulated in ADS 2016. With simulations, 16-way divider/combiner exhibits insertion loss between -12.181 dB to -12.50 dB, Return loss better than -18.656 dB and Isolation more than -25 dB over the entire frequency band of 2700 MHz to 3000 MHz is achieved. In the next phase, 75W PH2731-75L is selected as RF transistor whose impedance matching networks are designed and simulated in ADS. In simulations, Return Loss better than -18dB for input matching and better than -16dB for output matching network is achieved in simulations. After achieving the desired results in simulations, layout is designed for fabrication. After fabrication, module is tested and the measured results are compared with the simulated results.