RF Field Guide ยท reviewed reference
How radio works
A radio link carries information by deliberately changing a carrier and recovering those changes at the receiver.
Question
What has to happen between a transmitter and a receiver for useful data to arrive?
Inputs
- Carrier frequency and occupied bandwidth
- Transmit power, antennas, path, and receiver noise
Answer
Working
A link is not a pipe. Signal energy spreads, is absorbed or scattered, and arrives with noise and interference added. The receiver can recover symbols only while its signal-to-noise-and-interference ratio supports the selected modulation and coding.
Visual explanation
- Bits
- Modulation
- RF carrier
- Path
- Receiver
- Decoded bits
Interpretation
Treat frequency, bandwidth, antennas, path clearance, and receiver requirements as one system. Improving one term can expose a different constraint.