| 摘要 |
PURPOSE:To stabilize an oscillation and to obtain a satisfactory degree of coupling with a mixer by constituting a fixed side oscillator and a mixer for injecting its oscillating power, of an element and a printed board contained in the same shielding cavity, and also connecting all ground wires of the oscillator directly to the shielding cavity. CONSTITUTION:An oscillation-mixer stage of a fixed side contains an FET transistor 32 of an oscillating element assembled on a printed board 31, a fixed oscillator 34 containing an elastic surface wave resonator 33 of a resonance element, a diode 35 and a mixing circuit 36 consisting of its lead wire, in the same shielding cavity 37. Also, as for the fixed oscillator 34, DC driving circuit parts are also incorporated in the printed board 31. Each ground side of capacitors 38, 39 and a shielding case 40 of the surface acoustic wave resonator 33 is connected by solder as ground points 41-33 directly to the shielding cavity 37. In this way, an oscillating power is coupled effectively with a mixer use diode 35, and a rectifying current of the diode can be increased to four- five times comparing with a conventional one. |
