Agilent Technologies E4406A manual Auto

Making Measurements

Making the Spectrum (Frequency Domain) Measurement

❏Flat Top - Selects this filter for best amplitude accuracy by reducing scalloping error.

❏Uniform - Select this filter to have no window active by using the uniform setting.

❏Hanning - Press this key to activate the Hanning filter.

❏Hamming - Press this key to activate the Hamming filter.

❏Gaussian - Press this key to activate the Gaussian filter with the roll-off factor (alpha) of 3.5.

❏Blackman - Press this key to activate the Hamming filter.

❏Blackman Harris - Press this key to activate the Hamming filter.

❏K-B 70dB/90dB/110dB (Kaiser-Bessel) - Select one of the Kaiser-Bessel filters with sidelobes at −70, −90, or −110 dBc.

—FFT Size - Allows you to access the menu to change the following parameters:

❏Length Ctrl - Allows you to toggle the FFT and window length setting function between Auto and Man (manual).

❏Min Pts in RBW - Allows you to set the minimum number of data points that will be used inside the resolution bandwidth. The range is 0.10 to 100.00 points with 0.01 resolution. This key is grayed out if Length Ctrl is set to Man.

❏Window Length - Allows you to enter the FFT window length in the number of capture samples, ranging from 8 to 1048576. This length represents the actual quantity of I/Q samples that are captured for processing by the FFT (“Capture Time” is the associated parameter shown on the screen). This key is grayed out if Length Control is set to Auto.

❏FFT Length - Allows you to enter the FFT length in the number of captured samples, ranging from 8 to 1048576. The FFT length setting is automatically limited so that it is equal to or greater than the FFT window length setting. Any amount greater than the window length is implemented by zero-padding. This key is grayed out if Length Control is set to

Auto.

—ADC Range - Allows you to access the menu to define one of the following ADC ranging functions:

❏Auto - Select this to set the ADC range automatically. For most FFT spectrum measurements, the auto feature should not be selected. An exception is when measuring a signal which is “bursty”, in which case auto can maximize the time domain dynamic range, if FFT results are less important to you than time domain results.

Chapter 4 101