In a single-sideband transmitter, which stage normally includes a circuit providing protection from excessive SWR?

The final amplifier is the last active stage before the signal goes to the antenna system, meaning it handles the highest power levels in the transmitter. High Standing Wave Ratio (SWR) indicates that power is being reflected back from the antenna, creating high voltages and heat that can easily destroy the final amplifier's sensitive transistors or tubes. To prevent this damage, modern transceivers include an SWR protection or 'foldback' circuit directly associated with the final amplifier stage. When excessive SWR is detected, this circuit automatically reduces the output power to keep the final amplifier within safe operating limits.