| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent occurrence of a disturbing signal made by higher harmonic waves in spite of the use of a double balanced type mixing circuit as an unbalanced input type. <P>SOLUTION: This television tuner is provided with: a multiple-tuned circuit 3 for selecting a television signal to be received; and a mixing circuit 5 connected to the multiple-tuned circuit 3 for converting the television signal to an intermediate frequency signal. The mixing circuit 5 comprises a multiple- balanced mixing circuit with respective bases of two transistors 5a and 5b as balanced input terminals. The base of one of the transistors 5a is connected to the multiple-tuned circuit 3, and the base of the other transistor 5b is terminated by an impedance element 8 having infinite impedance. <P>COPYRIGHT: (C)2004,JPO |
