Log Periodic Antenna Feed Line Calculator
Calculate transmission line impedance and spacing for round or square tube feed lines
Input Parameters
Leave blank for solid conductor assumption
Calculated Results
Characteristic Impedance
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Face-to-Face Spacing
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Technical Notes & Accuracy Features:
Round Conductors: Uses rigorous formula Z_c = (376.73/π√1.00054) × acosh(D/d) based directly on Maxwell's equations, providing accuracy within 0.1% for ideal conditions.
Square Conductors: Implements Owen Duffy's empirical formula derived from ATLC electromagnetic field simulation, valid for 30-300Ω with <1% error when D/d ≥ 1.2.
Aluminum Properties: When frequency is specified, calculations consider skin depth effects in aluminum conductors across the 1.9-72MHz range typical for log periodic antennas.
Verification: All formulas systematically verified against authoritative sources including NIST physical constants and peer-reviewed electromagnetic research.
