<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>

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

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For a rectangular patch antenna with an inset feed: