Five FR4 patch antenna shapes designed for 2.45 GHz, simulated in CST, fabricated and measured with a VNA. Python checks the reported values and generates tables and plots.
Keywords: Microstrip antennas · S-parameters · CST simulation · VNA measurements
Full-size diagram · Edit in Figma
Results · Design · Gallery · Run · Limits · References
S11 minima are reported at each shape’s resonance. Circular has the deepest reported minimum and the only listed band covering 2.45 GHz.
| Shape | Simulated S11 (dB) | Measured S11 (dB) | Reported VSWR | VSWR from measured S11 |
|---|---|---|---|---|
| Circular | −53.08 | −31.99 | 1.125 | 1.052 |
| F-shaped | −30.02 | −16.98 | 1.167 | 1.330 |
| Triangular | −18.86 | −15.37 | 1.368 | 1.411 |
| Square | −16.38 | −14.46 | 1.536 | 1.467 |
| Hexagonal | −14.78 | −13.93 | 1.694 | 1.504 |
All five measured S11/VSWR pairs disagree under a shared frequency and port reference; those conditions are undocumented. The pairs remain unverified; calculated VSWR is a consistency check.
Reported S11 minima
| Shape | Reported band (GHz) | Reported BW (%) | BW from edges (%) |
|---|---|---|---|
| Circular | 2.3990 to 2.4735 | 3.12 | 3.06 |
| F-shaped | 2.2994 to 2.3735 | 2.98 | 3.17 |
| Triangular | 2.1380 to 2.2830 | 2.45 | 6.56 |
| Square | 2.0930 to 2.1732 | 2.41 | 3.76 |
| Hexagonal | 2.0945 to 2.2455 | 2.12 | 6.96 |
BW from edges uses 100 × (upper − lower) / midpoint. Triangular, square and hexagonal percentages disagree with their listed edges. The threshold and normalization frequency are undocumented; all bands remain unverified. Circular is 3.62% on p. 6 and 3.12% on p. 20.
Reported simulation bands
Circular patch · CST S11
Closed-form resonance estimates
Reconstruction inputs. Closed-form estimates use an equilateral approximation for the triangle, an equal-area circle for the hexagon and an enclosing rectangle for the F-shape.
| Parameter | Value |
|---|---|
| Substrate | FR4; εr 4.4; loss tangent 0.02 |
| Substrate thickness | 1.4 mm |
| Copper thickness | 0.036 mm |
| Ground plane | 75.20 × 58.76 mm |
| Feed width / gap | 2.7 / 1 mm |
| Shape | Dimensions (mm) |
|---|---|
| Circular | Radius 17 |
| F-shaped | 37.60 × 29.38; vertical 10; bars 8; gap 3; middle 25 |
| Triangular | Base 37.60; height 29.38 |
| Square | Side 29.38 |
| Hexagonal | Side 17 |
All five geometries |
Circular |
F-shaped |
Triangular |
Square |
Hexagonal |
FR4 substrate |
Laminator |
UV exposure · open |
UV exposure · closed |
NaOH bath |
Etching machine |
VNA setup · 4.1–4.4 GHz display
Python 3.9+; run from the repository root:
python -m pip install -r requirements.txt "pytest>=7"
export PYTHONPATH="$PWD/src"
python -m antenna check
python -m antenna tables --check --readme README.md
python -m pytest| Task | Command |
|---|---|
| Plot comparisons | python -m antenna plot --out outputs |
| Analyze a sweep | python -m antenna ingest path/to/trace.s1p |
| Update README tables | python -m antenna tables --write --readme README.md |
| Estimate resonance / dimension | python -m antenna design / python -m antenna synth |
Open cst/patch-antenna.bas in CST’s VBA editor, choose PatchShape, and run in a fresh project. Its gap-coupled feed differs from the reported inset feeds and requires CST validation.
| Tool | Use |
|---|---|
| Python 3.9+ | Report checks and derived tables |
| Matplotlib | S11, bandwidth and resonance plots |
| pytest | Analysis and command-line checks |
| CST / VBA | Simulation and model reconstruction |
| VNA | Measurements recorded in the source reports |
Source reports: Simulation and results · Fabrication and measurement · Methodology
- Original CAD/CST files, raw sweeps, reading/calibration records and repeat measurements are unavailable.
- Four radiation values are simulated directivity and one is simulated gain. No measured gain or common gain ranking is established.
- Keep new raw sweeps, reading frequencies and calibration records separate from these historical values.
Check status: 0 errors · 8 unresolved warnings · 3 informational estimates. Software checks do not validate hardware performance or 2.45 GHz suitability.
- Add original CAD/CST models, raw sweeps, calibration records and repeat measurements.
- Verify reported S11/VSWR pairs and bandwidth values at documented reading frequencies.
- Validate the reconstructed gap-coupled feed against the reported inset feeds.
- Balanis (2016). Antenna Theory, 4th ed..
- Garg et al. (2001). Microstrip Antenna Design Handbook.
- Pozar (1992). Microstrip Antennas.
- IBIS Open Forum (2024). Touchstone v2.1 specification.