| 摘要 |
A broadband, very low phase noise, temperature stable, sync loss free voltage controlled oscillator ("VCO circuit") is described. One use of the invention would be in a radio receiver for receiving phase modulated signals from a remote transmitter. In one embodiment of the invention, the VCO circuit is disposed on a printed wiring board ("PWB") spaced apart from the PWB on which the synthesizer circuit is disposed. The VCO circuit may comprise a resonator, a voltage controlled oscillator, a varactor, and one or more buffer amplifiers. Additionally, a positive temperature coefficient resistive heating element ("PTC") may be included. In a preferred embodiment, the resonator, voltage controlled oscillator, varactor, and buffer amplifiers may be disposed on one side of the PWB and the PTC may be disposed on the other side of the PWB. Blind vias in the PWB enhance heat transfer from the PTC to the circuit elements on the other side of the PWB. The PWB may be encased in a thermal insulator.
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