Adaptive Sweep (ABS)

This is one of the sweep types which may be selected in the Frequency Sweep Entry dialog box or in the Optimization Goal Entry dialog box.

Adaptive Sweep (ABS): An Adaptive sweep uses the Adaptive Band Synthesis (ABS) technique to perform a fine resolution analysis of a specified frequency band. You enter the desired frequency band by entering the beginning frequency in the Start text entry box and the ending frequency in the Stop text entry box. Em analyzes the circuit at the beginning and end frequencies. Using an iterative process, em then analyzes at other discrete frequencies and determines a rational polynomial fit to the S-parameter data within a frequency band. Once a rational polynomial fit is achieved with an acceptable error, the frequency response across the specified bandwidth is calculated.

Note If you select None for the ABS caching level, and an ABS sweep is stopped before the adaptive data has been calculated, you will have to start the analysis over from the beginning. Any processing time invested in the analysis is lost.

Please note that when the value of the S-parameters approaches 1 (0 dB) you may have small ripples or oscillations in the S-parameter values. This is due to the rational fitting model having too many degrees of freedom when trying to fit a straight line. It is recommended that you analyze the frequency band in which this occurs with another type of sweep.