| 摘要 |
PURPOSE:To eliminate the distortion due to harmonics of the 4th order or over in an output having a frequency twice the frequency of an input by constituting the circuit so that it includes at least a couple of active elements connected so as to cancel the harmonic of even number order being the 4th order or over. CONSTITUTION:An input signal A0 is impressed to the primary side of an input transformer T3 via a capacitor C1. In increasing the winding ratio of the transformer T3 more than that of a transformer T1, a signal spectrum led out to a collector common connecting point of transistors (TR) Q3, Q4 is as shown in Fig. B when a signal having a spectrum as shown in Fig. A is led out at a collector common connecting point of TRs Q1, Q2 and the ratio of the level of the even number order harmonic of the 4th or over, 4f and 6f to the level of the 2nd harmonic 2f is larger than the case in Fig. A. Thus, in setting the value of resistors R4, R6 properly, then only the magnetic flux due to the 4th harmonic produced in the magnetic core of a transformer T2 is cancelled, the 4th harmonic in an output B is erased and the spectrum in the output B is shown in Fig. C. |
