| 摘要 |
The microwave oscillation circuit provides a transistor having the collector electrode grounded, the base electrode connected to a resonator circuit determining the oscillation frequency, and the emitter electrode connected to an output open stub. An output transmission line is placed parallel to the output open stub for the output power supplied from the output open stub to be output via an end of the output transmission line to a buffer amplifier. A resistor having an impedance equal to a characteristic impedance of the output transmission line connects a stub circuit to an open end of the output transmission line. The stub circuit exhibits an infinite impedance at the oscillation frequency. At the oscillation frequency, the resistor floats due to the infinite impedance of the stub circuit so that all the oscillation power supplied from the output open stub is output to the buffer amplifier, without being consumed by the resistor. At frequencies other than the oscillation frequency, where the buffer amplifier is likely to be unstable, the output impedance of the output transmission line is damped enough to prevent the buffer amplifier from its unstable condition, because the resistor is grounded by a relatively low impedance of the stub circuit.
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