| 摘要 |
<p>PURPOSE:To stablize an oscillation frequency and to improve a C/N by eliminating one part of an inner ground potential layer corresponding to a semiconductor for oscillation and the lower layer of an electronic part, which is connected to this semiconductor for oscillation, to determine the oscillation frequency. CONSTITUTION:Fundamental constituting elements for the oscillation of a Colpitts oscillator are divided into an oscillation transistor 1, capacitors 2, 5 and 7, dielectric resonator 8, cholk coil 9, varactor diode 10 and capacitor 11. In an area A of a glass epoxy multilayer printed circuit board 12 shown by a broken line in a figure, the inner ground potential layer is eliminated and stray capacity is in inverse proportion to a distance between the electronic part and the ground potential layer. Therefore, concerning the parts on the inside of the area A, the influence of the stray capacity is reduced. Thus, the change of the oscillation frequency and the degradation of a Q value after mounting the dielectric resonator 8 or the oscillation transistor 1 can be released.</p> |
