Modern radar systems require low phase noise and long term phase-stable radar carrier signals for high-resolution imaging, micro-Doppler signatures applications. High stable signal generation through conventional crystal followed by frequency multiplier techniques are limited phase noise performance under vibration conditions. Optoelectronic oscillators (OEOs) offer low phase noise and long-term phase stability compared to the conventional oscillators. In this design of the Radar Exciter unit based on microwave photonics components viz., OEOs, frequency dividers, optical filters, optical delay lines, optical arbitrary waveform generators are discussed. The microwave photonics offers frequency-independent Exciter design with tunable filters and tunable laser sources. In this paper the performance comparison of microwave photonic-based exciter unit also discussed.