Radio frequency and Microwave (RFM) infrastructure test facility is under development at RRCAT for evaluating and powering, subsystems of particle accelerator. As a part of this facility, design of 20-30 kW UHF solid state power amplifiers is in progress. For this work, design procedure has been formulated for the development of solid state amplifier modules, radial combiner, divider and directional coupler; with specifications suited to RFM power system for particle accelerator. Methodology has been demonstrated by developing two different compact amplifiers with power output of 2 kW each, operating at 352 MHz and 505.8 MHz, respectively. This paper describes underlying design principles and indigenous development of these amplifiers, consisting of 270-300 W amplifier modules, 8-way 2 kW radial combiner/divider and directional couplers. Design methodology for power combiner has been extended by physically realizing higher power (4 kW) 16-way power combiner and 2-way combiner (8 kW) for higher power (8 kW) amplifier configuration planned. Simple design, indigenous technology, high efficiency and ease of fabrication, are the main features of this design.