Design of a FET Dielectric Resonator Oscillator at 11 GHz
|School||Nanjing University of Posts and Telecommunications|
|Course||Electronics and Communication Engineering|
|Keywords||DR negative resistance Phase noise ADS S parameter model|
Dielectric resonator oscillator (DRO) has been widely applied in microwave communication,radar, electronic counter, microwave measurement and so on. Because of the important role ofDRO and huge application market, improving the DRO performance and efficiency is necessary,while the high frequency oscillator design has a long development cycle. We strive to obtain lowphase noise, pure spectrum, stable frequency and frequency accuracy. The dielectric resonatordesign theory, negative resistance theory and S parameters design theory has been studied. Thethesis choose the common-source mode feedback circuit with a FET ofATF-26884.First,modeling the DR and micro-strip-line coupling circle through the simulation byCST and ADS software. Then, searching the FET ’s S parameters, DC point, to modify thedevice S-parameters in the aim of making K less than one, design the resonant network, matchingnetwork, though ADS Harmonic balance simulation get the complete oscillating circuit tononlinear analysis and optimization design.Finally, the dielectric resonator oscillator have been made and measured on phase noise,harmonic ,spurious spectrum etc .At last, we get an 11 GHz dielectric resonator oscillator(DRO), with a high output power higher than 10dBm, low spurious spectrum less than-70dB,which met the requirement of the project and the improving step was also proposed.