Single FET X-Band Pulsed Power DRO

The design of an 8.65 GHz solid state pulsed power Dielectric Resonator Oscillator (DRO), intended for use in harmonic radar or beacon application, is presented. The oscillator is realized in MIC thin-film technology, using a 10 Watts matched power FET and a high-Q dielectric resonator. The simulated behaviour of the active and passive devices is verified by measurements in an operational environment. A pulsed output power level of 7 Watts has been achieved with 20% efficiency. Phase noise level is less than ¿105 dBc/Hz at 10 kHz offset. The second and third harmonic power levels are less than ¿57 dBc. The oscillator is drain pulsed by an integrated hybrid circuit with a TTL-compatible input. The RF-pulse characteristics are: risetime < 50 ns, falltime < 100 ns and an average start delay of 300 ns.