| 摘要 |
PURPOSE:To control delay time and to decrease the number of sections as well as to miniaturize a delay line by constituting a secondary all-pass type delay line of concentration constant inductors and variable capacity diodes. CONSTITUTION:The secondary all-pass type delay line 12 is constituted of the concentration constant inductors L and the variable capacity diodes VC1, VC2. The delay time is changed by changing control voltages V1, V2 and controlling the electrostatic capacities of the diodes VC1, VC2. The characteristic impedance of this delay line 12 varies with a change in the capacities of the diodes VC1, VC2 and, therefore, electron control variable resistors 13 are provided in the parts of the signal source resistance and terminal resistance of the delay line 12 and the gain of a variable gain amplifier 14 is changed by the control voltage Vcg, by which the input resistance of the resistors 13 are continuously changed and the impedance matching is executed. The smaller number of the sections required for obtaining equal frequency delay characteristics is thereby necessitat ed. |
