S820E Microwave Site Master™ User Guide : Vector Voltmeter
Vector Voltmeter
How the VVM Function Works
Example B/A Measurement
Relative Measurements
Table Display Format
VVM Calibration
VVM Calibration versus Save Reference
Absolute VVM Measurements
Relative VVM Measurements
A/B or B/A Ratio Measurements
Performing Calibrations
Vector Voltmeter Menus
Measurement Menu (1 of 2)
Measurement Menu (2 of 2)
Measurement Format
Single Display Format
Frequency Menu
Amplitude Menu
Calibration Menu
Step 1 Calibration Dialog Box
Sweep Menu
Source Power
IFBW Dialog Box
Preset Menu
Trace Menu
Limit Menu
File Menu
System Menu
Mode Menu
This chapter provides an overview of Vector Voltmeter or VVM Mode (Option 441). Vector Voltmeter Mode in the S820E provides a modern equivalent functionality to the classic analog Vector Voltmeter (VVM) instrument, which has been discontinued for many years. The classic analog VVM had 2 input channels (typically A and B), and both were capable of measuring voltage directly. The classic VVM, however, did not have any internal signal source or bridges or couplers needed to perform reflection or transmission measurements. Those items needed to be supplied externally.
With the proper addition and usage of those external items, the classic analog VVM could be configured to perform complex measurements (reflection or transmission) between the 2 inputs (A/B or B/A). Typically one of the input channels would be dedicated as the reference channel, and the remaining channel would be used to perform the desired measurements. The A/B and B/A ratio measurements were the predominant usage of the classic analog VVM.
The S820E VVM option provides equivalent A/B and B/A ratio capability, which means that it can be used as a drop‑in replacement for a classic analog VVM. Since it already has a source and couplers built-in, it can also measure reflection or transmission of a DUT directly without needing any additional external items.
The S820E VVM option also offers additional capabilities that the classic VVM did not offer, such as the table display, which allows you to measure up to 12 devices. All 12 DUT measurements can be simultaneously compared to a single reference DUT response. This is especially useful in complex phase array antenna systems where cable lengths that are feeding multiple antennas need to have a precise phase relationship to each other.
The function hard keys in Vector Voltmeter mode are:
Measurement, Frequency, Amplitude, Calibration, Sweep, [BLANK]
The sixth key is not used in this mode.