Method and Device for Protecting a High-Frequency Power Amplifier Against a Termination fault

A method for protecting a high frequency power amplifier having a high output power and a high efficiency against a termination fault, wherein a mismatch protection circuit is connected to the high frequency power amplifier on the output side, the method comprising:

• deriving a first voltage, which is proportional to a power level applied to a first detector diode, from the first detector diode of the mismatch protection circuit, wherein the first voltage corresponds to an effective power fed into the output;
• deriving a second voltage, which is proportional to a power level applied to a second detector diode, from the second detector diode of the mismatch protection circuit, wherein the second voltage corresponds to a reflected power;
• transmitting the first and second derived voltages are transmitted to a control circuit;
• and
• switching on or off, by the control circuit, an output stage of the high frequency power amplifier depending on whether a specified reference voltage is exceeded or undershot by the second voltage derived from the second diode.

A circuit for protecting a high frequency power amplifier having a high output power and a high efficiency against a termination fault, the circuit comprising:

• a waveguide coupler, which is connected to an output of the high frequency power amplifier, wherein the waveguide coupler comprises
• a first detector diode configured to supply, according to a power level applied to the first detector diode, a first voltage corresponding to an effective power that is fed to the first detector diode;
• and
• a second detector diode configured so that an outputted second voltage of the second detector diode corresponds to power that is reflected due to a mismatch;
• a control circuit configured to determine an amount of the mismatch using a difference between the outputted voltage value of the second detector diode and a reference voltage, and the control circuit is configured to switch on or off an output stage of the high frequency power amplifier, depending on whether the amount of the mismatch drops below or exceeds a given reference value.