Agilent / HP 8555A

This unit is the top end tuning section for HP high performance modular Spectrum Analyzer family.

When this is added to a system package, it will offer absolute amplitude calibration capabilities from -125dBm to +10dBm over a frequency range of 10MHz to 18GHz with fundamental and harmonic mixing.

It has optional mixers that can extend its frequency coverage to 40GHz.

These high resolution measurements are made possible in part this automatic tuning stabilization (phase-lock) feature, which allows for narrow frequency range scanning with a minimum of display jitter.