What Are the Tasks of a Switching Mixer?

A diode can be used to create a simple unbalanced mixer. This type of mixer produces the original frequencies as well as their sum and their difference. Have you heard of the switching mixer?

Mixer is the use of mechanical force and gravity, will be two or more materialsuniformly mixed up machinery. Mechanical mixing is widely used in various industrialand daily life.

The drive is capable of supplying high torque when demanded. However, this torque must be limited if the demand is excessive. Excessive torque can be a sign of seizing or jamming, which can result in damage to the mixing equipment.

The importance of the diode is that it is non-linear (or non-Ohmic), which means its response (current) is not proportional to its input (voltage). The diode therefore does not reproduce the frequencies of its driving voltage in the current through it, which allows the desired frequency manipulation.

Mixtures may require the mixer to operate at various speeds throughout the mixing process. The properties of the mixed material are a primary consideration when defining mixing applications.

Another form of mixer operates by switching, with the smaller input signal being passed inverted or uninverted according to the phase of the local oscillator (LO). This would be typical of the normal operating mode of a packaged double balanced mixer. In the frequency domain the switching mixer operation leads to the usual sum and difference frequencies, but also to further terms e.g. +-3*fLO, +-5*fLO, etc. The advantage of a switching mixer is that it can achieve - with the same effort - a lower noise figure (NF) and larger conversion gain. This come because the switching diodes or transistors act either like a low resistor (switch closed) or large resistor (switch open) and in both cases only minimum noise is added.

What's more, the aim of a switching mixer is to achieve linear operation over the signal level, and hard switching driven by the local oscillator....