| 摘要 |
PURPOSE:To extend the frequency range, by inserting and connecting the first and the second varactor diodes in series and in parallel to the tuning coil of a tuning circuit, respectively. CONSTITUTION:A varactor diode CD1 is inserted and connected in series to a tuning coil L, and a varactor diode CD2 is inserted and connected in parallel to the tuning coil L. If CT=7PF, CDIL=CD2L=33PF, and CD1H=CD2H=2PF are true when the maximum receiving frequency, the minimum receiving frequency, (the external additional capacity+ the stray capacity), the varicap capacity in tuning voltage 1V, and the varicap capacity in tuning voltage 25V are denoted as fH, fL, CT, CDL, and CDH, respectively, (fH/fL)=3.32 is true, and frequencies from 120MHz to 216MHz and frequencies from 216MHz to 470MHz can be received. |
