| 摘要 |
PURPOSE:To form a voltage controlled oscillator having a varactor bias supply circuit with high reproducibility and productivity and high microphonic resistivity by constituting a bias line on a microstrip base with a microstrip line and connecting directly an epoxy iron loading through-capacitor made of a radio wave absorbing member to the said bus line. CONSTITUTION:The varactor bias supply circuit is connected to a rand 10 on a microstrip base 9 one end of which is connected to a proper position of the varactor bias circuit and the other end of which is connected to a terminal of the epoxy iron (microwave band absorbing body) loading type through- capacitor 7 fitted to the lower part of the microstrip base 9 on a chassis 5 by solder 11. The capacitor 7 is arranged at a position of nearly 1/4 wavelength of the basic oscillation frequency, the impedance when viewing the bias circuit from the varactor circuit is higher than 50OMEGA and has some loss components. The epoxy iron loading type through-capacitor 7 gives more or less loss to harmonics generated in the varactor diode 1 and attenuates it. Thus, the modulation characteristic is improved and made stable.
|
