1. Design of a stable dielectric resonator oscillator inż. Andrzej Stefański mgr. inż. Krzysztof Czuba dr inż. Krzysztof Antoszkiewicz Instytut Systemów Elektronicznych PW

2. Outline • Objective and specifications • Dielectric resonator • Problems to solve • Current project status • Future plans Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

3. Objective • Low phase noise Dielectric Resonator Oscilator (DRO) is needed for the phase reference system for the UVFEL/XFEL projects • DRO will be synchronized with the Master Oscillator • DR based oscillators offer very high noise performance but generator design is very difficult Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

4. Specifications • Output freq. : 1299.9996 MHz • Voltage controlled input • Output power : 10 dBm • Harmonics : < -25 dBc • Sub-harmonics : < -60 dBc • Spurious : < -80 dBc • Extremely low phase noise – next page Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

5. Required phase noise level Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

6. Dielectric Resonator Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

7. Design issues/problems • Selection of low-noise transistor • Oscillator circuit design • Tuning method selection • Minimizing noise from tuning circuit • Selection of DR coupling method – oscillation and output signal • Mechanical design: oscillator cavity, DR fixture – significantly affect oscillator performance Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

8. Recent development Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

9. Current project status • Analysis of existing design, found ways for oscillator improvement • 3D electromagnetic field simulations in progress. Objective – find optimum coupling method, estimate quality factor and extract S-parameters for electronic circuit simulations • 3D model created and first simulation results obtained Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

10. Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

11. Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

12. Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

13. Future plans • Cavity optimization • 3D simulations • S-parameters extraction • Circuit optimization • Find transistor with best noise performance • Apply it to optimal circuit • Make project and build model • Measurements Design of a stable dielectric resonator oscillator A. Stefański, ISE, PW

14. Thank you