Maxim Afanassiev, an Agilent Applications Engineer from Russia, wants to help a customer measure the quality of a linearly chirped pulse. The quality metrics are Side Lobe Level (SSL) and Pulse Compression Ratio (CPR). :?: [/b]

The 89601 Vector Signal Analyzer (VSA) software is a versatile tool that also featured User DSP Math which can be used for this measurement.

SSL is a quality metric and is the level of time side lobes in a compressed chirp after processing thru a matched filter. The matched filter can be made from an ideal version of the chirp made from Matlab. The VSA software's User Math then is used to cross-correlate the measured pulse against the ideal. The resulting compressed pulse is viewed in the logMag format and the time side lobes are measured.

The PCR is the ration of the uncompressed to compressed pulse width. The theoretical PCR is

PCR = pw * dev /k^2

where pw is the uncompressed pulse width in sec dev is the pp frequency deviation for a linear chirp k is the window shape factor used in the measurement k = 1.43 for a flat top window

See the enclosed Agilent Aerospace/Defense Symposium paper for the details of making this measurement.

SSL is a quality metric and is the level of time side lobes in a compressed chirp after processing thru a matched filter. The matched filter can be made from an ideal version of the chirp made from Matlab. The VSA software's User Math then is used to cross-correlate the measured pulse against the ideal. The resulting compressed pulse is viewed in the logMag format and the time side lobes are measured.

The PCR is the ration of the uncompressed to compressed pulse width. The theoretical PCR is

PCR = pw * dev /k^2

where

pw is the uncompressed pulse width in sec

dev is the pp frequency deviation for a linear chirp

k is the window shape factor used in the measurement

k = 1.43 for a flat top window

See the enclosed Agilent Aerospace/Defense Symposium paper for the details of making this measurement.