Quadrature Hybrid Design Summary

This repository contains MATLAB tooling for comparing measured and simulated S-parameters of a quadrature hybrid. The pipeline ingests VNA Touchstone files alongside simulator exports, aligns the data to global S-parameter labels, and produces side-by-side comparison plots suitable for documentation and verification.

Layout	Schematic

ADS Simulation

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Design Criteria

• Center frequency: 2.45 GHz
• Return loss at all ports: S11, S22, S33, S44 < -25 dB at 2.45 GHz
• Power division: S21 and S31 > -3.5 dB at 2.45 GHz
• Isolation: S41 < -30 dB at 2.45 GHz
• Phase balance: ∠S21 – ∠S31 = 90° at 2.45 GHz

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Substrate Properties

• Substrate thickness (h): 62 mil
• Relative permittivity (εᵣ): 4.4
• Relative permeability (μᵣ): 1
• Conductor conductivity (σ): 5.85 × 10⁷ S/m
• Clearance to upper reference (hᵤ): 3.93701 × 10³⁴ mil (effectively open)
• Copper thickness (t): 1.5 mil
• Dielectric loss tangent (tan δ): 0.02
• Surface roughness: 0 mil

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Repository Layout

• main.m — entry point that sets up paths, loads configuration, and launches the pipeline.
• run_sparam_project.m — orchestrates file discovery, measurement/simulation alignment, and plotting.
• +config/ — default configuration values (paths, plotting options, axis limits).
• +io/ — parsers for measurement (*.s2p) and simulation (*.txt / *.tab / *.dat) data.
• +plotting/ — routines that generate comparison figures and save them to output/.
• +util/ — helpers for path management and filename parsing.
• +data/ — sample measurement and simulation files for local runs.
• output/ — generated figures (Sij.png) for each available S-parameter.
• repo/ — supporting figures
• gerber/ — layout description, fabrication-ready.

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Running the Code

1. Open MATLAB and change into the repository folder.

2. Run the project entry point:

   >> main

The script will read measurement and simulation files from the configured directories, map the local two-port VNA data to the appropriate global S-parameter labels, and write comparison plots into the output/ directory for inspection and documentation.

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Measurement vs. Simulation

S11	S12

S13	S14

S21	S22

S23	S31

S32	S33

S41	S44