Introduction: The Current drive LHCD System generates power of 2 MW CW at 3.7 GHz and delivers to the SST- 1 tokamak via a grill antenna through a phased array of waveguides. The existing system incorporates 4 Klystrons, amplifies the input power provided by a solid state driver, each Klystron generating 500 kW CW power. As such there is a requirement of a compact, low cost solid state source which can give an output of 50W to 200W at 3.7 GHz with a very narrow bandwidth. This paper proposes a modular design comprising of multiple solid state power amplifiers in parallel, with power combiner/divider and couplers operating at 3.7 GHz. System Analysis: The modular design represents 4:1 / 8:1 way power divider/ combiner approach. The system level computer simulation based on behavioral model is performed using Virtual system simulator software[2]. The system efficiency and power distribution considering the losses incurred, is analyzed. The analysis helps to determine the power handling capacity of individual stage, prior to system integration. Pre-driver stage design: Based on system analysis, the paper presents the design of an oscillator to drive an amplifier at 3.7 GHz. Linear and non-linear analysis[1] has been performed on the design to ascertain its performance. The oscillator delivered a power of 10dBm at 3.7 GHz. The pre-driver amplifier design is implemented using QPD1010 GaN transistor biased in Class AB mode. The simulated results are verified using non-linear model[3] of the transistor. The amplifier provides a gain of 14 dB at 3.7 GHz. The system analysis results and individual stage results helps to decide the architecture of complete solid state driver module.