Agilent Technologies 53152A, 53150A, 53151A manual Increasing Profile Accuracy

Chapter 1 Getting Started

Operating the Counter

NOTE	As the graph shows, the Counter never computes power-correction values
	for loss above the zero axis. Conversely, corrections are never computed
	for gain below the zero axis. Once the correction value reaches the zero
	axis, no further corrections are applied.
	When the Counter interpolates for frequencies that are above or below the
	range of frequencies specified in the currently selected profile, it never
	computes a value that would fall on the opposite side of the zero axis from
	the closest specified frequency. In other words, if there are two or more
	data points that contain loss values, the Counter never computes or
	applies a correction that would be indicative of gain. Conversely, if there
	are two or more data points that contain gain values (negative loss values),
	the Counter never applies a correction that would be indicative of loss.
	Since there can be no further change in the loss or gain values once the
	zero axis is reached, no power corrections are applied when the input
	frequency reaches or passes a point in the profile that intersects the zero
	axis. Effectively, the Counter computes only loss-correction values or
	gain-correction values—never both within the same profile.
	When you enter values in power-correction data points and then exit the
	data-point display (using either the left-arrow key or the Enter key), the
	Counter immediately sorts all of the data-points into order by the
	frequency values. Therefore, if you enter a pair of values in a data point,
	exit the data-point display, and then immediately return to the display for
	that data point, you may see different values than the ones you just
	entered. The values you entered may now be contained in a differently
	numbered data point in the same profile, if they were previously entered
	out of order by frequency.
	Increasing Profile Accuracy
	To increase the accuracy of a power-correction profile, you can add data
	points between the existing data points in the profile (if less than 10 data
	points are in use), thus bringing the data points closer together and
	shortening the straight-line segments. If all ten data points are in use,
	you can add data points by using two or more profiles for a single test
	configuration. If you do this, you must select the profile you need (from the
	Menu) for the range of frequencies being measured. This means that you
	must select a different profile whenever the measured frequency moves
	outside the range of frequencies defined by the data points in the
	currently selected profile.

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Operating Guide 1-27