| 摘要 |
PURPOSE:To improve a cross modulation characteristic, by using in common a tuning circuit of the antenna side and a tuning circuit of the radio receiver side, and getting rid of a shift between the variable capacitors in case when two tuning circuits have been used, so that ''Q'' can be set high. CONSTITUTION:Induced voltage Ea of an input signal which has been received by an antenna is applied to a gate G of an FET11 constituting one main part of an antenna booster amplifying circuit through a capacity Ca. To the drain side D of the FET11 is applied supply voltage Vcc, and on the other hand, its source side is connected to one terminal of a coaxial cable 12. Also, it is a tuning circuit 13 constituting the other main part of the antenna booster amplifying circuit that is connected the other terminal of this coaxial cable 12. This tuning circuit 13 is also used as a tuning circuit which is incorporated in a radio receiver, and its output E is led to a mixer of the poststage. |
