The Frequency Response Measurement - HP 3563A Operating Manual

The Frequency Response Measurement

The frequency response measurement, often called the "transfer function," is the ratio of a system's
output to its input and yields both gain and phase as a function of frequency. (The phase response
can be viewed by pressing PHASE in the COORD menu.) In the HP 3563A, the signal on Channel !
is assumed to be the system's input, and the signal on Channel 2 is assumed to be its output.
To select the frequency response measurement, press SELECT MEAS, followed by the
FREQ RESP softkey (see figure 3-7).
To select a measurement display for the frequency response measurement, press MEAS DISP . The
softkeys that appear are shown in figure 3-8. Notice that a number of different measurement
displays are available for this measurement, such as:
FREQ
RESP
COHER
POWER
SPECl
POWER
SPEC2
CROSS
SPEC
I MPLS
RESP
AUTO
MATH
FILTRD
INPUT
Displays the frequency response. When default units and coordinates
are active, this displays frequency on the X-axis and gain on the Y-axis.
Displays the coherence of the frequency response. (This softkey does
not appear if time averaging is selected-see "Averaging In The Linear
Resolution Mode" later in this chapter.)
Displays the power spectrum measured on Channel 1.
Displays the power spectrum measured on Channel 2.
Displays the cross spectrum.
Displays the impulse response.
Selects the display calculated with the auto math table; see "Math &
Auto Math" in chapter 15. Note that this label might be replaced by a
user-defined label.
Displays the filtered input menu, which provides time record and linear
spectrum displays; see "Filtered-Input Displays" later in this chapter.
Using The Linear Resolution Mode
Selecting a Measurement and Display
3-35