18-06-2012, 03:30 PM
Mixing signals at different frequencies is common practice in many areas of electronics
Mixing signals at different frequencies is common practice in many areas of electronics.docx (Size: 175.4 KB / Downloads: 33)
Mixing signals at different frequencies is common practice in many areas of electronics. Audio systems, communications systems and radio systems are typical application areas. With conventional frequency mixers, feedback capacitance can cause the signal sources to be affected by the output signal, thus making supplementary filter circuits necessary. The signals from the individual signal sources can also affect each other. In an optical mixer, LEDs or laser diodes are used to first convert the signals to be mixed into optical signals. The light beams are then aimed at a shared photo-sensor (a light-sensitive resistor, photo-diode, photo-transistor, or photovoltaic cell). The current in the output circuit is thus controlled by the mixed input signals, so signal from the photo-sensor is the sum of the input signals.