What Is the Microstrip Ring Resonator Permittivity Calculator?
The Microstrip Ring Resonator Permittivity Calculator extracts high-frequency dielectric properties of microwave substrates from measured resonance peaks.
How Does the Microstrip Ring Resonator Permittivity Calculator Work?
It computes ring mean circumference, solves for guided wavelength at mode n, extracts effective permittivity, and de-embeds quasi-TEM microstrip fringe factors.
Microstrip Ring Resonator Permittivity Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Closed circular waveguide standing wave resonance condition eliminating open-end fringe capacitance corrections.
How to Use the Microstrip Ring Resonator Permittivity Calculator
- Input mean ring radius and observed peak S21 frequency in GHz.
- Specify resonance order (n = 1, 2, or 3).
- Enter substrate thickness and trace width in mm.
Step-by-Step Example Calculation
2.45 GHz Fundamental Ring on 0.8mm Laminate
Input Values:
Understanding Your Result
Relative Permittivity (ε_r): Bulk dielectric constant of the laminate under test.
Effective Permittivity (ε_eff): Composite quasi-TEM dielectric constant.
Guided Wavelength (λ_g): Wavelength propagating within the transmission structure.
Factors That Affect the Result
- Higher resonant frequencies yield shorter guided wavelengths, testing dielectric properties at operational GHz bands.
- Thicker substrates increase fringe field proportions, lowering effective permittivity.
When Should You Use This Calculator?
- High-frequency material characterization, PCB laminate batch QA/QC, RF circuit substrate verification, and antenna feed design.
Assumptions & Limitations
- Assumes loose coupling where feed gap capacitance does not perturb the intrinsic resonant peak.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Based on Chang Microwave Ring Circuits and Related Structures and Hammerstad-Jensen models.