Common collector amplifier and amplitude modulation

dakupoto · 2019-04-13T03:19:00+00:00

Could some electronics guru here shed some light on this Could a single stage common collector amplifier exhibit amplitude modulation ? I have the SPICE model of a simple common collector amplifier consisting of two base bias resistors, a collector resistor and an input and a output DC blocking capacitor, as well as a source and a load resistor of 50.0 Ohm. The BJT collector is connected to Vcc via a RFC coil. I have tried input signal frequencies from 100 MHz to 750 MHz, with SPICE transient analysis. Each time, I have seen a output signal envelope, at the same spot on the time axis. I have tried several common RF|microwave transistors as BFR92A, BFS17, BFQ67W and HFA3134, but the bproblem is always there. All hints and suggestions are welcome - thanks in advance.