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An electronic mixer is a device used for mixing two or more electronic signals.
Types of mixer
There are two basic types of mixer; namely, Additive mixers and multiplying mixer.
Additive mixers add two signals together while multiplying mixer multiply the signals together.
Additive mixers are used for applications, such as audio mixing. On the other hand, Multiplying mixers multiply the signals together, and produce an output containing both original signals, and new signals that have the sum and difference of the frequency of the original signals.
Generally, additive mixers are resistor networks, which are surrounded by impedance matching and amplification stages. Multiplying mixers are made in a wide variety of ways. The most popular are diode mixers, gilbert cell mixers, diode ring mixers and switching mixers.
Gilbert cell mixers are arrangement of transistors that multiplies the two signals. Surprisingly, the switching mixers (below) pass more power and usually insert less distortion.
Diode ring mixers are the switching mixers with two transformers and an array of diodes in a ring. Basically, the transformers are arranged in such a way that one signal switches the diodes to conduct in one direction, or the other direction. The other transformer pushes its signal through the diodes. Diode ring mixers are popular because the on/off mechanism injects less noise, and loses less signal power than other methods. In addition, the transformers can be wound to match the impedances into and out of the mixer stage to the rest of the electroic system.
Apart from this, switching mixers use an array of Field effect transistors as electronic switches, to permit the other signal to go one direction, then the other. They are controlled by the signal being mixed. They are especially popular with digitally controlled radios.
The various other kinds of electronic mixers are as follows:
* Frequency mixer: frequency mixer is a telecommunications device used for deriving useful signals from modulated carrier waves
* Audio mixing console: Audio mixing console is an electronic device for combining, routing, and changing the level, tone, and/or dynamics of two or more audio signals
* Vision mixer: Vision mixer is a European term for an electronic device for combining of two or more video signals; known in the US as a production switcher
* Mode mixer: Mode mixer is a telecommunications device for handling signals on optical fibers
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