Economical HF diode demodulator - operates at very small HF voltages in order of demodulating diode's diffusion voltage

摘要

The HF demodulator demodulates very small h.f. voltages of the order of the diffusion voltage of the diode employed. This is achieved by establishing a radiation coupling between teh demodulating signal and the HF input signal. This coupling may be thermal or optical. If thermal, then the demodulating diode in the HF circuit is controlled by a variable heating element (RH). If optical, then the demodulating diode is controlled from a variable light source (S). The demodulating diode is in both cases connected into an LCR circuit.