Pin Feeding vs Coaxial (Cable) Feeding for Microstrip Patch Antenna

Jaehoon

This document shows the compared simulation results of the rectangular patch antenna by using two different feeding methods: Pin-fed and Coaxial-fed.

Overview of the Simulated Antenna

1) Original model: A.8 Microstrip Patch Antenna from Feko’s example guide

2) Antenna dimensions: Unit = mm, Radiator/Ground = PEC

3) Simulation frequency: 2.7 ~ 3.3 GHz

4) Simulation solver: MoM

Two Feeding Methods

1) Pin feeding

• • How to construct: Vertical line (length = substrate height, 2.87 mm)
    • Port setting: Wire port
    • Source setting: Voltage source (Reference impedance = 50 Ohm)

2) Coaxial (cable) feeding

• • • How to construct: Two cylinders (length = 10 mm)
      • Inner conductor: 0.65 mm in radius, 12.87 mm in length, PEC
      • Outer conductor: 2.1 mm in radius, 10 mm in length, PEC
      • Dielectric: Teflon (er= 2.1)
      • Characteristic impedance: 48.5 Ohm from https://www.pasternack.com/t-calculator-coax-cutoff.aspx
    • Port setting: Waveguide port
    • Source setting: Waveguide source
    • Watch the following video for the details.

Comparison of two Reflection Coefficients

 

Conclusion: Simple Pin feeding can replace Realistic Coaxial feeding for microstrip patch antenna simulations.

Patch_antenna_Coax.cfx

Patch_antenna_Pin.cfx

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