Hewlett-Packard 70620B MMS Microwave Preamplifier Module Module
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Replacement : 83006A
This module is an optional component within several Hewlett Packard spectrum analyzers configured using the 70K series Modular Measurement System (MMS).
“The Agilent 70620B Preamplifier boosts the sensitivity of any Agilent 70000 series spectrum analyzer by 15 to 25 dB. System noise figures can be better than 8 dB at 2.9 GHz, 11 dB at 12.8 GHz, and 14 dB up to 26.5 GHz. Spurious testing can be reduced from days to hours from the wider bandwidth that is useful due to the better sensitivity. Low-level signals from antennas will become visible as the noise floor is lowered. Broadband signal detection such as pulsed RF or electromagnetic interference is easier with a lower noise figure. Using the preamplifier is easy. Simply install the preamplifier into the mainframe and connect the cable. Whether in bypass mode or preamplifier mode, the system automatically calibrates the display of the analyzer.
HP/Agilent 70620B Features
The front-panel +28 V dc output provides a noise-source drive voltage. This allows the spectrum analyzer system to be used to make noise-figure measurements. Refer to Application Note 57-1, Fundamentals of RF and Microwave Noise Figure Measurements.
Adding a preamplifier to a system greatly reduces the system noise figure, resulting in an improvement in sensitivity. For example, when a preamplifier is added to an HP 71210C system, the resulting system noise figure is typically 6 or 11 dB. This corresponds to an improvement in sensitivity of approximately 20 dB. The improved sensitivity allows the use of wider bandwidths and shorter sweep times, resulting in faster measurement time.
The modular preamplifiers automatically calibrate the display of the spectrum analyzer, correcting for preamplifier gain and flatness. Gain and flatness correction data in the preamplifier's ROM is sent to the spectrum analyzer ensuring an adjusted and properly positioned display. Flatness data for the bypass mode is also corrected by the analyzer.
To compensate for the preamplifier's gain, the spectrum analyzer's IF step-gains may change when the preamplifier is switched on. This maintains a constant reference level. To ensure a safe level at the mixer input, the RF attenuation may even be changed if the maximum mixer level is exceeded.
(from Agilent website)