diff --git a/magloop.html b/magloop.html index 450d2f7..875a979 100644 --- a/magloop.html +++ b/magloop.html @@ -7,7 +7,7 @@ -
Miguel VK3CPU - Magloop Antenna Calculator V9
+
Miguel VK3CPU - Magloop Antenna Calculator V10
@@ -116,6 +116,7 @@
  • Q : The antenna Q (quality) factor.
  • Ia (A): The RMS loop current in amps.
  • Perimeter (λ): Antenna perimeter size relative to the wavelength.
    • +
  • Skin depth (μm): Conductor skin depth in micrometers.
    • Usage hints:
  • Tap on legend items to disable or enable an output parameter. This can be used to declutter the chart.
    • @@ -134,6 +135,8 @@ [2]: A. Boswell, A. J. Tyler and A. White, "Performance of a Small Loop Antenna in the 3 - 10 MHz Band" , IEEE Antennas and Propagation Magazine, 47, 2, April 2005, pp. 5 1 -56.

    Change history:
    + [8-May-23] - V10
    + * Added conductor skin depth as a new calculated parameter.
    [23-Apr-23] - V9
    * Changed the frequency list to include VHF (2m) and UHF (70cm) bands.
    * Reduced minimum loop diameter to 4 cm.
    @@ -208,6 +211,7 @@ var shape = "circle"; // Shape of the main loop var loop_turns = 1; // var loop_mode = "series"; // Series or parallel. When loop_turns_slider.value == 0, loop_turns is 2 and loop_mode is "parallel" + const mu0 = Math.PI * 4e-7; var inductance = 0.0; var area = 0.0; // Loop area in square meters. @@ -309,7 +313,6 @@ // Calculate the inductance of the coil. For single turn loops, use standard inductance equation. For multi-turn, use Nagaoka correction. function getInductance() { - const mu0 = Math.PI * 4e-7; const loop_diameter_meters = loop_diameter_slider.value; const cond_diameter_meters = conductor_diameter_slider.value * 1e-3; const spacing_ratio = loop_spacing_slider.value; @@ -480,7 +483,6 @@ const a_coil_radius = loop_diameter_slider.value * 0.5; const b_conductor_radius = conductor_diameter_slider.value * 0.0005; const loop_spacing_ratio = loop_spacing_slider.value; - const mu0 = 4.0 * Math.PI * 1e-7; // How much longer is the perimeter compared to the circumference if it were circular: const shape_factor = perimeter / (Math.PI * loop_diameter_slider.value); @@ -505,6 +507,16 @@ }); return retval; } + + // Returns skin-depth in micrometers: + function calculateSkinDepth() { + var retval = []; + frequencies.forEach(freq => { + const skin_depth = 1e6 * Math.sqrt(1e-6/(conductivity * Math.PI * freq * mu0)); + retval.push({x:freq, y:skin_depth}); + }); + return retval; + } function calculateEfficiencyFactor() { var retval = []; @@ -626,6 +638,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -646,6 +659,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -665,6 +679,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -684,6 +699,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -703,6 +719,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -722,6 +739,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -770,6 +788,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -809,6 +828,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -846,6 +866,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -885,6 +906,7 @@ myChart.data.datasets[7].data = calculateQualityFactor(); myChart.data.datasets[8].data = calculateCirculatingCurrent(); myChart.data.datasets[9].data = calculateAntennaSize(); + myChart.data.datasets[10].data = calculateSkinDepth(); myChart.update(); } @@ -1611,6 +1633,16 @@ borderWidth: 1, yAxisID: 'sizeID', tension: 0.3, + }, + { + label: 'Skin depth (\u03BCm)', + fill: false, + borderColor: 'rgb(75,75,75)', + backgroundColor: 'rgb(75,75,75)', + data: calculateSkinDepth(), + borderWidth: 1, + yAxisID: 'skinID', + tension: 0.3, }] }, options: { @@ -1781,6 +1813,24 @@ }, min: 0.0, position: 'right', + }, + 'skinID' : { + type: 'linear', + display: 'auto', + title: { + display: true, + text: '\u03B4 (\u03BCm)', + color: 'rgb(90,90,90)', + font: { + weight : 'bold' + } + }, + ticks: { + beginAtZero: true, + //max: 0.3, + }, + min: 0.0, + position: 'right', } }, plugins: { @@ -1848,6 +1898,10 @@ } else if(label[0] == 'P'){ label = justifyText("Perimeter: ", value.toFixed(3).toString() + ' ' + '\u03BB'); + } else + if(label[0] == 'S'){ + var num = getMetricPrefix(value * 1e-6); + label = justifyText("Skin depth: ", num.val.toPrecision(3).toString() + ' ' + num.pfx + 'm'); } else { label += value.toFixed(3).toString(); }