S-Parameter Simulations > S-Params, Gain, NF, Stability, Group Delay vs. Swept Parameters

Description

This schematic sweeps two parameters in a circuit to determine how gain, noise figure, matching impedances, stability and group delay depend on the two parameters. Often this sort of a simulation provides designers with more insight than an optimization. You must decide which two parameters to sweep, and you may modify the network to be simulated.

Needed to Use Schematic

Any linear or nonlinear model, including measured S-parameters

Main Schematic Settings

Network topology, two parameters to sweep and their sweep ranges, frequency range for S-parameter simulation

Data Display Outputs

SP_NF_GainMatchKsweep.dds, "Matching for Gain or NF" page:

• Minimum noise figure versus frequency
• dB(S21), maximum available gain, and associated gain (when the input is matched for NFmin and the output is then conjugately matched), versus frequency
• dB(S21), maximum available gain, and associated gain (when the input is matched for NFmin and the output is then conjugately matched), versus each swept parameter, with the other parameter held constant, at one frequency selected by a marker
• Stability factor versus frequency
• Smith chart with traces of the optimal source reflection coefficients for minimum noise figure, and the following reflection coefficients (gammas) at a frequency selected by moving a marker:
  • Gamma source for minimum noise figure
  • Gamma load for maximum power gain when input is terminated for minimum noise figure
  • Gamma source for simultaneous conjugate match (without regard to noise)
  • Gamma load for simultaneous conjugate match (without regard to noise)
• Listing columns of data corresponding to the frequency point selected by moving a marker:
  • S-parameters, dB
  • Maximum available power gain, dB
  • Minimum noise figure, dB
  • Sopt for minimum noise figure in polar coordinates and in magnitude and phase
  • Zopt for minimum noise figure
  • Associated power gain in dB, if the input is matched for minimum noise figure and then the output is matched for maximum power gain
  • Corresponding load impedance for associated power gain
  • Source and load impedances for simultaneous conjugate matching (without regard to noise)
  • Stability factor, K

SP_NF_GainMatchKsweep.dds, "Stability Factors and Minimum NF" page:

• Stability factor, K, versus both swept parameters and frequency
• Stability factor, K, versus both swept parameters, at one frequency selected by moving a marker
• Minimum noise figure versus both swept parameters and frequency
• Minimum noise figure versus both swept parameters, at one frequency selected by moving a marker

SP_NF_GainMatchKsweep.dds, "S Params and MAG at 1 Freq." page:

• S-parameters versus both parameters
• Minimum noise figure versus both swept parameters
• Maximum available gain versus both swept parameters

SP_NF_GainMatchKsweep.dds, "Group Delay" page:

• Group delay versus both swept parameters and frequency
• Group delay at one combination of the swept parameters, versus frequency

Schematic Name

SP_NF_GainMatchKsweep

Data Display Name

SP_NF_GainMatchKsweep.dds

Note

Some of the simulation results on these data displays can be obtained via the ADS tuning feature. However, these data displays show the results in a format that may make it easier for you to analyze the data and determine what the optimal parameter values are.