In this thesis, a low phase noise local oscillator operating at 2210 MHz is designed and implemented to be used in X-Band transmitter of a LEO satellite. Designed local oscillator is a PLL (Phase Locked Loop) based frequency synthesizer which is implemented using discrete commercial components including ultra low noise voltage controlled oscillator and high resolution, low noise fractional-N synthesizer. Operational settings of the synthesizer are done using three wire serial interface of a microcontroller. Although there are some imperfections in the implementation, phase noise of the prototype system is pretty good which is measured as -123.2 dBc/Hz at 100 kHz offset and less than -141.3 dBc/Hz at 1 MHz offset. Made up of discrete compone...