发明名称 |
Voltage controlled oscillator presenting high impedance to parallel resonant tank circuit |
摘要 |
A variable-frequency oscillator includes an oscillator portion coupled to a phase shifter and a controllable gain device for controlling the amount of phase-shifted signal reintroduced to the oscillator. The oscillator includes first and second transistors coupled at their emitters to a current source. The emitters of third and fourth transistors are coupled to bases of the first and second transistors, respectively. The base of the third transistor is coupled to a voltage source, and the base of the fourth transistor couples to the collector of the first to form a regenerative loop capable of oscillation. A parallel-resonant circuit is coupled between the collector of the first transistor and the voltage source for establishing a frequency-sensitive phase characteristic in the loop by which the quiescent frequency is determined. The phase shifter is coupled to a point on the regenerative loop. The controllable gain device is coupled to the output of the phase shifter and reinjects a variable-amplitude version of the phase-shifted signal to a second point on the loop for establishing the oscillation frequency. |
申请公布号 |
US4243953(A) |
申请公布日期 |
1981.01.06 |
申请号 |
US19790012811 |
申请日期 |
1979.02.16 |
申请人 |
RCA CORPORATION |
发明人 |
BALABAN, ALVIN R.;STECKLER, STEVEN A. |
分类号 |
H03B5/00;H03B5/12;H03L7/099;(IPC1-7):H03B5/12;H03L7/08 |
主分类号 |
H03B5/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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