| 摘要 |
<p>PURPOSE: To obtain a burst signal generating circuit to generate a continuous burst signal through the use of a phase locked loop by generating a continuous burst signal while operating the phase locked loop in response to a detected discontinuous burst signal, etc. CONSTITUTION: When a burst detecting circuit 20 detects a discontinuous burst signal through an input terminal P2, a switch 22 is controlled in response to a burst gate pulse, selects the signal, and outputs the signal to a phase detecting section 24. The section 24 compares the phase of the discontinuous burst signal with that of a predetermined continuous burst signal from a phase shifter 30, and outputs to a loop filter 26 the error signal corresponding to the phase difference. A voltage-controlled oscillator 28 changes its output oscillation frequency by inputting an integrated signal from the filter 26. A continuous burst signal is obtained by the repetitive operations of a phase locked loop composed of the detecting section 24, filter 26, and oscillator 28. In a section where no burst signal exists, the phase locked loop is operated by using a phase shifting signal from the phase shifter 30 through the switch 22.</p> |
