This converter allows you to calculate the main dimensions of a microstrip patch antenna from the dielectric constant of the substrate, its thickness and the desired resonance frequency. It provides the width of the patch as well as its corrected effective length, which helps to design antennas adapted to the transmission and reception needs.
Formula
Width: W = (c / (2 × f₀)) × √(2 / (εr + 1))
Effective dielectric constant: ε_eff = (εr + 1) / 2 + ((εr – 1) / 2) × (1 + 12 × h/W)^(-0.5)
Effective length: L_eff = c / (2 × f₀ × √ε_eff)
Length correction: ΔL = 0.412 × h × ((ε_eff + 0.3)(W/h + 0.264)) / ((ε_eff – 0.258)(W/h + 0.8))
Actual length: L = L_eff − 2 × ΔL
Explanation of the formula
The width W is calculated to obtain a matched impedance based on the dielectric constant of the substrate. The effective dielectric constant ε_eff takes into account the effect of the fringes of the electromagnetic field around the patch. The effective length L_eff corresponds to the physical length necessary to reach the resonance frequency f₀. The term ΔL adjusts the length to compensate for edge effects, thus giving the actual length L to be manufactured.
Uses
- Sizing micro-strip patch antennas for Wi-Fi, Bluetooth or RFID applications.
- Evaluate the effect of the substrate and its thickness on the resonance frequency.
- Optimize the design of integrated RF circuits or on-board antenna modules.
- Prepare accurate prototypes with corrected width and length measurements for optimal performance.