What frequencies are present at the output of a mixer?

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Multiple Choice

What frequencies are present at the output of a mixer?

When a mixer works, it multiplies the two input signals. This nonlinear mixing creates new components at the sum and difference of the input frequencies, which is the primary purpose of heterodyning. In real devices, there’s not perfect isolation between ports, and some of the original RF and LO signals can leak through to the output. So you can observe the original frequencies (leakage) as well as the sum and difference frequencies. That combination is why listing both the original frequencies and the sum/difference frequencies best describes what appears at the mixer output.

When a mixer works, it multiplies the two input signals. This nonlinear mixing creates new components at the sum and difference of the input frequencies, which is the primary purpose of heterodyning. In real devices, there’s not perfect isolation between ports, and some of the original RF and LO signals can leak through to the output. So you can observe the original frequencies (leakage) as well as the sum and difference frequencies. That combination is why listing both the original frequencies and the sum/difference frequencies best describes what appears at the mixer output.

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