摘要 |
<p>A double-balanced modulator in which the bias voltages do not become different by a buffer amplifier or the like connected to the front stage and a carrier wave is not leaked is provided. This modulator comprises a pair of input terminals 2, 3, a pair of preamplifiers 4 for amplifying balance signals supplied to the input terminals 2 and 3, and a double-balanced differential amplifier 23 to which balance carrier signals are supplied and which further amplifies the balance signals that have been amplified by the pair of preamplifiers 4, wherein capacitors 12 are connected in series between the base of a first transistor 7 and one of the input terminals 2, 3 and between the base of a second transistor 8 and the other one of the input terminals 2, 3, respectively. <IMAGE></p> |