GAIN CONTROLLED FREQUENCY CONVERTER CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a frequency converter circuit capable of gain controlling by changing the base bias potential of a transistor and controlling the output gain of intermediate frequency signals. SOLUTION: A gain control NPN transistor 6 is connected parallelly to LF modulation NPN transistors 5 and 7 between the collector of an RF modulation NPN transistor 13 and a power source. Also, the gain control NPN transistor 9 is connected parallelly to the LF modulation NPN transistors 8 and 10 between the collector of the RF modulation NPN transistor 14 and the power source. The base potential of the gain control NPN transistors 6 and 9 is controlled by a variable bias power source 12. In such a manner, just by adding the gain control NPN transistors 6 and 9 to a conventional frequency converter circuit and controlling the bias potential, the output gain is lowered almost to zero and this simple frequency converter circuit of an extremely large gain control range is obtained.