Modelling and realization of a 10.5 GHz GPS disciplined high-performance frequency synthesizer (DRO)

In this thesis, modeling and realization of a frequency synthesizer using dielectric resonator (Dielectric Resonator Oscillator, DRO) operating around 10.5 GHz center frequency and with low phase noise feature is described. Dielectric resonator is an electronic element that resonates in a narrow frequency range. DRO is preferred in military systems due to its features such as high frequency stability, high operating frequencies, low temperature sensitivity and small size. It is used in communication systems and radar systems as well as electronic warfare systems. Oscillators with dielectric resonators can be designed in 3 different ways: Reaction type, conduction type and reflection – negative resistance type. As a result of the examination of the mentioned methods, the negative resistance method has been adopted as the method that will provide the highest performance at the desired frequency in our study. After modeling using this method, the design realization phase was started. Locking the oscillator frequency to an external reference frequency, which is obtained from the reference clock signal used in GPS systems, improves the phase noise performance of the realized oscillator and authenticates the originality of our study. Besides contributing to the literature about the "GPS Disciplined Oscillator" concept, the end product of our thesis work will be used in electronic warfare projects carried out by TÜBİTAK, and the foreign dependency of military devices will be reduced. According to the findings obtained in this study, it was concluded that the performance of DROs can be improved by using the concept of phase locked loop with GPS disciplined reference frequency. Moreover, we showed that it is possible for oscillators placed in different locations to operate frequency synchronously by using GPS structure. Finally, the effect of phase noise performance of oscillators on bit error ratio parameter in communication systems is analyzed.