Active Three Way Equal Phase Power Splitter with 7 dB Gain Based on a Transmission Line Circuit and a Medium Power RF Amplifier at 2.45 GHz

Abstract

This thesis report presents the design, analysis, and implementation of an active three-way equal-phase power splitter with a 7 dB power gain, operating at the Industrial, Scientific, and Medical (ISM) band frequency of 2.45 GHz. The proposed power splitter combines a transmission line-based circuit with a medium-power RF amplifier to achieve both equal power distribution and consistent phase alignment across three output ports. Key design considerations include impedance matching, phase balancing, and minimizing insertion loss, which are crucial for maintaining high performance in RF and microwave systems. Detailed simulations using ADS (advanced design system) software tools are performed to validate the circuit's theoretical performance in terms of gain, phase, input reflection coefficient, and output reflection coefficient. The design process included careful biasing and transmission line integration to achieve impedance matching. The amplifier compensates for power losses inherent in passive power dividers, providing an overall gain of 7 dB across each of the three output ports, after accounting for the 5 dB insertion loss typically encountered in the power splitting process. The power splitter is optimized for low return loss and high isolation between output ports, ensuring minimal signal degradation and interference. The prototyped amplifier has a gain of 8.1 dB with an input reflection coefficient of -7 dB and an output reflection coefficient of -38 dB available at the operating frequency of 2.45 GHz. This amplifier is unconditionally stable up to 10 GHz. The fabricated cascaded circuit provides an equal 2.7 dB power gain after subtracting 5 dB at each output port with an input reflection coefficient of -7 dB and an output reflection coefficient of -10 dB at 2.45 GHz. Overall, this design effectively meets the needs of reliable and consistent power splitting, making it suitable for modern wireless applications.