Downconversion uses a non-linear component, typically a mixer, to multiply an incoming high-frequency RF signal with a local oscillator signal. This produces a lower frequency signal that retains the original modulation and data. Engineers downconvert signals because lower frequencies are much easier to amplify, filter, and digitize with standard analog-to-digital converters.
Heard on the job
The receiver handles the downconversion right at the antenna to minimize signal loss in the coaxial cable.
Do not mix it up with
- Upconversion: Upconversion shifts a baseband signal to a higher frequency for transmission, while downconversion shifts an RF signal to a lower frequency for processing.