| 摘要 |
PURPOSE:To ensure the variation for the equivalent line length of the input gate circuit, by using the suspended-structure resonator for the input gate circuit of the FET oscillator of external feedback system and then varying the insertion length of the screw made of the dielectric substance or the like and inserted into the cavity of the resonator. CONSTITUTION:FET1 including drain terminal 2, source terminal 7 and gate terminal 4 each is formed on MIC substrate 10. The output side of terminal 2 is connected to feedback circuit 6 via matching circuit 3, and the output of circuit 6 is fed back to input side gate terminal circuit 8. Thus an oscillator circuit is formed. The suspended-structure resonator formed on substrate 10 is used for circuit 8, and circuit 8 is stored into housing 11. And cavity 12 is formed to metal excluded area 9 of housing 11, and then dielectric or metal screw 13 plus temperature compensating dielectric substance 14 are inserted into cavity 12. With variation of the insertion length of screw 13, the equivalent line length of circuit 8 can be varied. And thus the oscillation frequency can be varied mechanically to secure the tuning. |
