| 摘要 |
<p>An oscillator (10) includes an amplifier (12) having an input and an output and a feedback circuit (14) disposed between the input and the output of the amplifier (12). The feedback circuit (14) includes a plurality of resonators (34) and a pair of switches (32,38). Each switch (32,38) includes a first port and multiple connectable ports, the multiple connectable ports of each switch (32,38) connected to a corresponding one of the plurality of resonators (34). The feedback circuit (14) further includes a voltage-controlled phase shifter (22) disposed in series with the switches (32,38). The oscillator (10) further includes a discriminator circuit (16), responsive to signals from the feedback circuit (14), for providing a control signal (52) to the voltage-controlled phase shifter (22) for degenerating low frequency noise within the oscillator (10). With such an arrangement, high Q low noise resonators can be switched in and out of the circuit thus providing improved phase noise performance at high power levels with the desirable frequency agility required for a microwave oscillator. <IMAGE></p> |
