.. pealkiri: RF Fresneli tsooni kalkulaator
.. nälkjas: rf-fresnel-tsoon
.. kuupäev: 2025-12-26 15:00:00 UTC
.. sildid: võrgud, kalkulaator, tööriist, RF, traadita
.. kategooria: Kalkulaatorid
.. link:
.. kirjeldus: Arvutage traadita RF-linkide Fresneli tsooni raadius, et tagada signaali õige levimine
.. tüüp: tekst
<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);
    }

    .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;
    }

    .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);
    }

    .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);
    }

    .calc-button:active {
        background: #3d8b40;
        transform: translateY(0);
    }

    .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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    .section-header {
        background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
        color: white;
        padding: 15px 20px;
        font-size: 18px;
        font-weight: bold;
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    .section-content {
        padding: 20px;
        background: #fafafa;
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    .data-row {
        display: flex;
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        padding: 10px;
        background: white;
        border-radius: 4px;
        border-left: 3px solid #4CAF50;
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    .data-label {
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        color: #555;
        min-width: 220px;
        flex-shrink: 0;
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    .data-value {
        color: #333;
        font-family: 'Courier New', monospace;
        word-break: break-word;
    }

    .data-value.highlight {
        color: #4CAF50;
        font-weight: bold;
        font-size: 18px;
    }

    .info-box {
        margin-top: 30px;
        padding: 20px;
        background: white;
        border-radius: 8px;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        border-top: 3px solid #4CAF50;
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    .info-box h3 {
        margin-top: 0;
        color: #4CAF50;
        font-size: 20px;
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    .info-box p {
        line-height: 1.6;
        color: #555;
        margin: 10px 0;
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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>RF Fresneli tsooni kalkulaator</h2>
<p>Arvutage traadita RF-linkide Fresneli tsooni raadius. Fresneli tsoon on elliptiline ala visuaalse vaatevälja ümber, kuhu raadiolained pärast antennist lahkumist levivad.</p>
<div class="input-grid">
<div class="input-group">
<label for="frequency">Sagedus:</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">Kaugus:</label>
<div class="input-row">
<input id="distance" placeholder="Enter distance" type="text" value="1"/>
<select id="unit">
<option value="feet">Miilid</option>
<option value="meters">Kilomeetrid</option>
</select>
</div>
</div>
</div>
<button class="calc-button" onclick="fresnelZone()">Arvutage Fresneli tsoon</button>
</div>
<div class="result-section" id="results">
<div class="section-header">Arvutustulemused</div>
<div class="section-content">
<div class="data-row">
<div class="data-label">Fresneli tsooni raadius:</div>
<div class="data-value highlight" id="fnr">-</div>
</div>
<div class="data-row">
<div class="data-label">Keskpunkti asukoht:</div>
<div class="data-value" id="center">-</div>
</div>
</div>
</div>
<div class="info-box">
<h3>Fresneli tsoonide kohta</h3>
<p>
<strong>Mis on Fresneli tsoon?</strong>Fresneli tsoon on elliptiline ala, mis ümbritseb kahe antenni vahelist visuaalset vaatevälja. Raadiolained levivad levides ja see tsoon tähistab piirkonda, kus need lained võivad konstruktiivselt või hävitavalt sekkuda.</p>
<p>
<strong>Miks see oluline on?</strong>Optimaalse RF-lingi jõudluse tagamiseks peab vähemalt 60% esimesest Fresneli tsoonist olema takistustest vaba (hooned, puud, maastik). See kalkulaator aitab teil määrata vajaliku vaba raadiuse traadita ühenduse keskpunktis.</p>
<p>
<strong>Kuidas kasutada:</strong>Sisestage oma töösagedus ja antennide vaheline kogukaugus. Kalkulaator näitab Fresneli tsooni raadiust selle kõige laiemas kohas (lingi keskel).</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>