Inset Feed Calculator May 2026

// Calculate inset depth y0 (same unit as L) let ratio = Zfeed / Redge; let sqrtRatio = Math.sqrt(ratio); // arccos input must be <=1 (already ensured by Zfeed ≤ Redge) let acosVal = Math.acos(sqrtRatio); let y0 = (L / Math.PI) * acosVal;

<hr> <div class="note"> <strong>Formula:</strong> y₀ = (L/π) · arccos(√(Z_feed / R_edge))<br> Valid when Z_feed ≤ R_edge. Typical matching range: 50Ω feed to 150–250Ω edge. </div> </div> inset feed calculator

[ R_in(y=y_0) = R_in(y=0) \cdot \cos^2\left(\frac\pi y_0L\right) ] // Calculate inset depth y0 (same unit as

For a rectangular patch antenna with an inset feed: Inset matching requires Z_feed ≤ R_edge

[ y_0 = \fracL\pi \cdot \cos^-1\left( \sqrt \fracZ_feedR_edge \right) ]

Solving for inset depth (y_0) from the edge:

<script> function calculateInset() Zfeed <= 0) showError("Resistances must be positive."); return; if (Zfeed > Redge) showError(`Z_feed ($ZfeedΩ) cannot exceed R_edge ($RedgeΩ). Inset matching requires Z_feed ≤ R_edge.`); return;