This 3.50 GHz microstrip patch array project started with a single inset-fed rectangular patch on FR-4, then scaled into a 2x2 corporate-fed planar array in Ansys HFSS to evaluate matching, feed network behavior, and radiation performance.
A single microstrip patch is straightforward to design, but scaling into an array introduces practical issues in impedance matching, feed distribution, spacing, and performance tuning. The goal here was to design a single patch around a standard 50-ohm interface, then expand the concept into a compact 2x2 planar array with a corporate feed network and evaluate how the system behaved in simulation.
The development flow is split into clear engineering phases from baseline geometry to full array integration.
The baseline rectangular patch was sized for 3.50 GHz on FR-4, producing a patch length of 20.06 mm and a width of 25.83 mm. That gave the project a grounded starting point before feed optimization and array expansion.
Because the patch edge impedance was about 199.1 ohms, the feed point was moved inward using an inset feed to make the patch behave closer to a 50-ohm load. The calculated inset depth was 6.68 mm, with a near optimal total inset gap around 3 mm.
Four patch elements were then combined into a 2x2 topology using quarter-wave transformers and T-junction power dividers to distribute power evenly from a 50-ohm input while keeping element spacing within practical array constraints.
This project demonstrates the full engineering loop: define a target, choose a practical architecture, build the model, and use simulation results to guide design decisions.
These results combine model views, S-parameters, and field behavior to show both performance and diagnostic depth.
The initial single element model showed the intended resonance region and served as the baseline before introducing the array feed network.
Radiation behavior was reviewed in both 2D and 3D to evaluate directional performance and co-polar versus cross-polar behavior.
The 3D gain view adds immediate context on radiation shape and helps quickly communicate directional behavior.
In the corporate-fed array, the S-parameter minimum shifted to roughly 3.1 GHz, making the feed geometry and line tuning one of the biggest next step optimization targets.
Surface current views help explain why a design behaves differently from the original target and give a clear path for feed line refinement.
This comparison highlights diagnosis and root-cause analysis, not just a final curve.
The single patch behaved close to target, but the full array showed how strongly feed-network geometry can shift the final frequency response. That insight directly informs the next optimization cycle before fabrication.
If you need support with RF design, simulation, or validation, use the contact form to share your project goals, constraints, and timeline. We will review and follow up with next step recommendations.
