| 摘要 |
PURPOSE:To obtain a frequency converting circuit device which is less distortion to a large input signal, is operated up to a low voltage, and is ease of circuit integration, by applying the input signal to one base of the 1st and the 2nd transistors(TR) and extracting an intermediate frequency signal from one collector. CONSTITUTION:The 1st and the 2nd TRs 7, 8 perform frequency converting operation extracting an intermediate frequency signal from the collector of the TR7 to an intermediate frequency transformer 27, a voltage at a point (a) is applied to the base of the TR7 as a bias voltage and also to the base of the TR7 via a resistor 9. Then, the TRs 7, 8 and a local oscillation TR20 are operated to an arbitrary voltage up to about 1.5-1.8V of power supply. When the power supply is as high as 4-6V, since the voltage between the base and the collector of the TRs 7, 8 and 20 is +B-(about 1.4V), even if a large input signal is incoming, an output signal with less distortion is extracted at the collector. |
