HIGH FREQUENCY CIRCUIT AND COMMUNICATION EQUIPMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a frequency multiplier for suppressing the output of third harmonic wave which is the spurious wave. SOLUTION: In this frequency multiplier provided with an HBT 4 for outputting, the fundamental wave of the same frequency as the signal outputted by a matching circuit 1 and the third harmonic wave from the collector and a stub 6b with the pint end opened for suppressing the fundamental wave outputted by the HBT 4, the stub 6a with the point end opened for reflecting the third harmonic wave to the HBT 4 is connected to the base of the HBT 4 through a transmission line 7a. The third harmonic wave outputted from the collector of the HBT 4 is suppressed by the third harmonic wave reflected by the stub 6a with the pint end opened by making the line length of the transmission line 7a within the range between 1/48 and 1/12 or between 3/12 and 1/4 times as long as the wavelength of the fundamental wave.