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Quickly Optimize Antenna Designs for Ground Terminal Satellite Communication

A rendering of an Isotropic ground terminal

Satellite communication is a necessity of modern society. As global data transfer rates grow, so do the demands on satellite antennas.

To meet this demand, engineers need tools that can quickly and accurately optimize their antenna designs.

Isotropic Systems — an ANSYS Startup Program member — designs ground terminals for the satellite communications market. It has found that ANSYS HFSS’ derivatives feature speeds up its product development cycle.

How to Tune Variables in Real Time to Optimize Antenna Design

HFSS’ derivatives feature enables engineers to test how design variables affect the efficiency of an antenna.

“Without this feature, the number of variables needed to investigate an antenna could quickly become computationally prohibitive,” says Jeremy Turpin, CTO of Isotropic Systems. “In this case, nine design variables were included in Isotropic System’s example.”

Smith chart shows the performance of Isotropic Systems’ initial (red) and final (purple) designs. Engineers use the sliders to play with the variables to optimize the antenna’s performance.

A major component of antenna efficiency and performance is measured by the scattering parameter (S-parameter). The S-parameter equals the fraction of incident energy that is reflected by the antenna back to the source — rather than the energy that is accepted or radiated by the antenna.

HFSS graphs the S-parameter in polar coordinates with respect to frequency. This graph is called a Smith chart.

The values graphed in the chart can be changed in real time using a series of sliders that represent the design variables. This means engineers can tune the variables’ values until they achieve an antenna design that meets their needs. A small number of simulations are run sequentially, each time adjusting the variables’ values via the derivative tuning feature.

On the Smith chart, a good design is represented by an S-parameter curve that closely wraps around the center of the chart.

“Without rerunning the simulation, you can change the value of the variables and see the effects on the scattering response [Smith chart],” says Turpin. “In effect, the derivatives help you find if the variables that describe the design should increase or decrease in value.

“The alternative is to run a large sweep of simulations or an optimization process,” adds Turpin. “The number of additional simulations can increase the computational time by a factor of 10 to 100.” 

Turpin notes that fast-paced development, which HFSS supports, strengthens Isotropic Systems’ market position. The company was recognized as one of the 10 Hottest Companies in Satellite by Via Satellite magazine in its latest issue.

To learn how to access simulation technology to speed up product development, read up on the ANSYS Startup Program. To learn how to use the derivative feature in HFSS, watch the demo Analytic Derivatives in HFSS.