.. naslov: RF Fresnel Zone Calculator
.. polž: rf-fresnelova cona
.. datum: 2025-12-26 15:00:00 UTC
.. oznake: mreženje, kalkulator, orodje, RF, brezžično
.. kategorija: Kalkulatorji
.. povezava:
.. opis: Izračunajte radij Fresnelove cone za brezžične povezave RF, da zagotovite pravilno širjenje signala
.. vrsta: besedilo
<style>
    .calc-container {
        max-width: 900px;
        margin: 20px auto;
        padding: 20px;
    }

    .calc-header {
        margin-bottom: 30px;
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        margin-top: 0;
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</style>
<div class="calc-container">
<div class="calc-header">
<h2>RF fresnelov conski kalkulator</h2>
<p>Izračunajte radij Fresnelove cone za brezžične RF povezave. Fresnelovo območje je eliptično območje okoli vidne linije, v katero se razširijo radijski valovi, potem ko zapustijo anteno.</p>
<div class="input-grid">
<div class="input-group">
<label for="frequency">Pogostost:</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">Razdalja:</label>
<div class="input-row">
<input id="distance" placeholder="Enter distance" type="text" value="1"/>
<select id="unit">
<option value="feet">Miles</option>
<option value="meters">Kilometri</option>
</select>
</div>
</div>
</div>
<button class="calc-button" onclick="fresnelZone()">Izračunajte Fresnelovo cono</button>
</div>
<div class="result-section" id="results">
<div class="section-header">Rezultati izračuna</div>
<div class="section-content">
<div class="data-row">
<div class="data-label">Radij Fresnelove cone:</div>
<div class="data-value highlight" id="fnr">-</div>
</div>
<div class="data-row">
<div class="data-label">Lokacija osrednje točke:</div>
<div class="data-value" id="center">-</div>
</div>
</div>
</div>
<div class="info-box">
<h3>O Fresnelovih conah</h3>
<p>
<strong>Kaj je Fresnelova cona?</strong>Fresnelovo območje je eliptično območje okoli vidne linije med dvema antenama. Radijski valovi se širijo med potovanjem in to območje predstavlja območje, kjer lahko ti valovi motijo ​​konstruktivno ali destruktivno.</p>
<p>
<strong>Zakaj je pomembno?</strong>Za optimalno delovanje RF povezave mora biti vsaj 60 % prve Fresnelove cone brez ovir (zgradb, dreves, terena). Ta kalkulator vam pomaga določiti zahtevani radij prostora na sredini vaše brezžične povezave.</p>
<p>
<strong>Kako uporabljati:</strong>Vnesite svojo delovno frekvenco in skupno razdaljo med antenama. Kalkulator vam bo pokazal polmer Fresnelove cone na njeni najširši točki (središče povezave).</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>