Amplifier characterization

AmplifierTest determines small-signal gain, the 1 dB and 3 dB compression points, and permissible input levels. The script supports two measurement setups.

Measurement setups

rack

The amplifier is installed in a measurement rack. Directional couplers and power meters acquire forward and reverse power.

direct

The isolated amplifier output is connected to an output power sensor through a cable and attenuator. The DOT graph describes the path corrections.

Virtual runs

python script/amplifier-test.py \
    script/conf/amplifier-test-virtual/conf.py

python script/amplifier-test.py \
    script/conf/amplifier-test-direct-virtual/conf.py

The direct configuration is also used by the End-to-end developer tutorial. Start the Qt interface with amplifier-test-qt.py and the same configuration.

Evaluation

When evaluation is enabled, the class generates an amplifier INI with these channels:

S21

Gain as a function of frequency.

C1DB and C3DB

Input levels at the identified compression points. Compression points that were not found are not emitted as invalid numbers.

MAXIN

Selected maximum input level, using the 1 dB compression point by default.

Frequency, value, and complex interpolation are selected explicitly in evaluation_parameters. Typical logarithmic RF support points and gain values expressed in dB use LOG, DB, and POLAR.

Protection

Amplifier limits are enforced through AmplifierProtect from the MGraph. In the direct setup, the power meter may additionally provide a MAXIN channel. Before setting a new level, the workflow estimates the power at the sensor from the current path corrections.

Virtual tests do not replace measurement physics. They verify workflow, graph correction, protection, logging, pickle output, and resume behavior. Compression data become meaningful only with a suitable real or deliberately simulated characteristic.