.. judul: Kalkulator Zona Fresnel RF
.. siput: rf-fresnel-zone
.. tanggal: 26-12-2025 15:00:00 UTC
.. tag: jaringan, kalkulator, alat, RF, nirkabel
.. kategori: Kalkulator
..tautan:
.. deskripsi: Hitung radius Zona Fresnel untuk tautan RF nirkabel untuk memastikan propagasi sinyal yang tepat
.. ketik: teks
<style>
    .calc-container {
        max-width: 900px;
        margin: 20px auto;
        padding: 20px;
    }

    .calc-header {
        margin-bottom: 30px;
        padding: 25px;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        border-radius: 12px;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        color: white;
    }

    .calc-header h2 {
        margin-top: 0;
        color: white;
        font-size: 28px;
        margin-bottom: 10px;
    }

    .calc-header p {
        margin: 10px 0;
        opacity: 0.95;
        font-size: 15px;
    }

    .input-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 20px;
        margin-top: 20px;
    }

    .input-group {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }

    .input-group label {
        font-weight: bold;
        font-size: 14px;
        color: rgba(255,255,255,0.95);
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    .input-row {
        display: flex;
        gap: 10px;
    }

    .input-group input,
    .input-group select {
        padding: 12px;
        font-size: 16px;
        border: 2px solid rgba(255,255,255,0.3);
        border-radius: 6px;
        background: rgba(255,255,255,0.95);
        transition: all 0.3s ease;
        font-family: 'Courier New', monospace;
    }

    .input-group input {
        flex: 1;
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    .input-group select {
        min-width: 150px;
    }

    .input-group input:focus,
    .input-group select:focus {
        outline: none;
        border-color: #4CAF50;
        background: white;
        box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
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    .calc-button {
        margin-top: 20px;
        padding: 14px 35px;
        font-size: 16px;
        background: #4CAF50;
        color: white;
        border: none;
        border-radius: 6px;
        cursor: pointer;
        font-weight: bold;
        transition: all 0.3s ease;
        box-shadow: 0 2px 4px rgba(0,0,0,0.2);
        width: 100%;
    }

    .calc-button:hover {
        background: #45a049;
        transform: translateY(-1px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
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    .calc-button:active {
        background: #3d8b40;
        transform: translateY(0);
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    .result-section {
        background: white;
        border: 1px solid #e0e0e0;
        border-radius: 8px;
        margin-top: 30px;
        overflow: hidden;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        display: none;
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    .result-section.show {
        display: block;
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        color: white;
        padding: 15px 20px;
        font-size: 18px;
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    .info-box {
        margin-top: 30px;
        padding: 20px;
        background: white;
        border-radius: 8px;
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        border-top: 3px solid #4CAF50;
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    .info-box p {
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    /* Responsive design */
    @media (max-width: 768px) {
        .input-grid {
            grid-template-columns: 1fr;
        }

        .input-row {
            flex-direction: column;
        }

        .input-group select {
            width: 100%;
        }

        .data-row {
            flex-direction: column;
        }

        .data-label {
            margin-bottom: 5px;
            min-width: auto;
        }
    }
</style>
<div class="calc-container">
<div class="calc-header">
<h2>Kalkulator Zona Fresnel RF</h2>
<p>Hitung radius Zona Fresnel untuk tautan RF nirkabel. Zona Fresnel adalah area elips di sekitar jalur garis pandang visual tempat gelombang radio menyebar setelah meninggalkan antena.</p>
<div class="input-grid">
<div class="input-group">
<label for="frequency">Frekuensi:</label>
<div class="input-row">
<input id="frequency" placeholder="Enter frequency" type="text" value="2.4"/>
<select id="freunit">
<option value="ghz">GHz</option>
<option value="mhz">MHz</option>
<option value="khz">KHz</option>
<option value="hz">Hz</option>
</select>
</div>
</div>
<div class="input-group">
<label for="distance">Jarak:</label>
<div class="input-row">
<input id="distance" placeholder="Enter distance" type="text" value="1"/>
<select id="unit">
<option value="feet">mil</option>
<option value="meters">Kilometer</option>
</select>
</div>
</div>
</div>
<button class="calc-button" onclick="fresnelZone()">Hitung Zona Fresnel</button>
</div>
<div class="result-section" id="results">
<div class="section-header">Hasil Perhitungan</div>
<div class="section-content">
<div class="data-row">
<div class="data-label">Radius Zona Fresnel:</div>
<div class="data-value highlight" id="fnr">-</div>
</div>
<div class="data-row">
<div class="data-label">Lokasi Titik Pusat:</div>
<div class="data-value" id="center">-</div>
</div>
</div>
</div>
<div class="info-box">
<h3>Tentang Zona Fresnel</h3>
<p>
<strong>Apa itu Zona Fresnel?</strong>Zona Fresnel adalah area elips di sekitar jalur garis pandang visual antara dua antena. Gelombang radio menyebar saat merambat, dan zona ini mewakili area di mana gelombang tersebut dapat berinterferensi secara konstruktif atau destruktif.</p>
<p>
<strong>Mengapa ini penting?</strong>Untuk kinerja tautan RF yang optimal, setidaknya 60% Zona Fresnel pertama harus bebas dari penghalang (bangunan, pepohonan, medan). Kalkulator ini membantu Anda menentukan radius jarak yang diperlukan di titik tengah tautan nirkabel Anda.</p>
<p>
<strong>Cara menggunakan:</strong>Masukkan frekuensi pengoperasian Anda dan total jarak antar antena. Kalkulator akan menunjukkan radius Zona Fresnel pada titik terlebarnya (pusat tautan).</p>
</div>
</div>
<script>
function fresnelZone() {
    // Set variables from input
    var frequency = Number(document.getElementById("frequency").value);
    var freunit = document.getElementById("freunit").value;
    var distance = Number(document.getElementById("distance").value);
    var unit = document.getElementById("unit").value;

    if (freunit == "ghz") {
        var sf = frequency;
    } else if (freunit == "mhz") {
        var sf = frequency/1000;
    } else if (freunit == "khz") {
        var sf = frequency/1000000;
    } else {
        var sf = frequency/1000000000;
    }


    var d1 = distance / 2;
    var d2 = d1;
    if (unit == "feet") {
        //var radius = Math.round(72.05 * Math.sqrt((d1*d2/(sf))));
        var radius = Math.round(36.03 * Math.sqrt((distance/sf)))
        var distunit = "Miles"
    } else {
        //var radius = Math.round(17.32 * Math.sqrt((d1*d2/(sf))));
        var radius = Math.round(8.657 * Math.sqrt((distance/sf)))
        var distunit = "Kilometers"
    }

    document.getElementById("fnr").textContent = radius + " feet";
    document.getElementById("center").textContent = "Located " + d1 + " " + distunit + " from the first antenna";

    // Show results section
    document.getElementById("results").classList.add("show");

    // Scroll to results
    document.getElementById("results").scrollIntoView({ behavior: 'smooth', block: 'start' });
}

// Add enter key support
document.addEventListener('DOMContentLoaded', function() {
    document.getElementById("frequency").addEventListener('keypress', function(e) {
        if (e.key === 'Enter') {
            fresnelZone();
        }
    });

    document.getElementById("distance").addEventListener('keypress', function(e) {
        if (e.key === 'Enter') {
            fresnelZone();
        }
    });
});
</script>