Uhf Band Saw Resonators And Vco

Low phase noise VCSO depends on the realization of low loss, high Q value SAW resonator and low-noise oscillator circuit. After calculating the effective dielectric constants of substrate materials, selection electrode material, computing reflection coefficient of reflectors, building coupling model (COM), extraction COM parameters and computing p matrix, a simulation program of resonator was achieved. After the validation by experiments, the simulation procedure had been improved. When the accuracy of simulation program had met requirement, this paper simulated and analyzed the performances of resonators with different resonator geometries.After comparing traditional lithography process, lift-off process with benzene and lift-off process with reverse photo resist, 2.5μm, 4μm width device production by lift-off process with reverse photo resist were realized. In the testing process, the influences of acoustic transmission modes, sound absorbing plastic, electrode thickness and parasitic influence on devices were analyzed. Eventually, high Q resonators were realized, 315MHz resonators performances are: single port SAWR with IL -1.745dB, loaded Q 1368.9, two ports SAWR with IL -12dB, loaded Q 8668.8, STWR with IL -12.6dB, loaded Q 7028.After the analyzing phase noise calculation model, designing Collpitz oscillator circuit and circle oscillator circuit for different type resonators, producing and debugging these circuits, and analyzing the resources of noise in real circumstance, these circuits were improved. In the end, the oscillators performance are: single port VCSO with operation frequency 314.85MHz, phase noise -73.75/Hz@100Hz, -97.7 dBc/Hz@1KHz, second harmonic suppression 13dB, output power 3.62dBm, frequency tuning range 54ppm; two ports VCSO with operation frequency 315.426MHz, phase noise -60.6/Hz@100Hz, -88.7 dBc/Hz@1KHz, second harmonic suppression 28.6dB, output power 1.85dBm, frequency tuning range 135.3ppm.