| 摘要 |
PURPOSE:To improve the ratio of intermodulation interference, by connecting an impedance element consisting of resistors, a Zener diode, and capacitors in series with a mixer diode and applying a reverse bias voltage to the mixer diode via other resistors. CONSTITUTION:A high frequency signal enters a balun 5 from a terminal 7 and a local oscillation signal enters the balun 5 from a terminal 8. The high frequency signal and the local oscillation signal are given to terminals (a), (b) of a mixer circuit 13 through capacitors (C) 11, 12 for DC blocking. In the circuit 13, a diode (D) 14 and a resistor (R) 15 are connected in series between terminals (a) and (c), a D16 is connected between terminals (c) and (b), a D17 and an R18 are connected in series between the terminals (b) and (d), a D19 is between the terminals (d) and (a), Cs 20, 21 for high frequency signal passing are connected in parallel with the Rs 15, 18 and Rs 22, 23 are connected in series between a connecting point (e) between the D14 and the R15 and a connecting point (f) between the D17 and the R18. The connecting point between the R22 and R23 is connected to a reverse bias voltage supply terminal 24. An intermediate frequency signal is obtained betwen the terminals (c) and (d) and picked up at a terminal 9 via a balun 6. |
