Mixing two signals creates power at dc?

1. What is mixing signal?
2. How a switching mixer works?
3. How do you mix two signals?

What is mixing signal?

In the context of relationships, mixed signals are when a person is expressing interest in someone while also simultaneously expressing a lack of interest or a desire to keep their distance, causing confusion for the other person.

How a switching mixer works?

The aim of a switching mixer is to achieve the linear operation by means of hard switching, driven by the local oscillator. In the frequency domain, the switching mixer operation leads to the usual sum and difference frequencies, but also to further terms e.g. ±3f_LO, ±5f_LO, etc.

How do you mix two signals?

The simplest way to combine two signals is with two resistors as shown in the circuit diagram below. The ground connecton is shared between both inputs and output. The quality can be improved by adding an output buffer (opamp), but that complicates things in requiring an IC, power supply, (de)coupling caps, ...