..标题：射频自由空间路径损耗
.. slug：rf-freespacepathloss
.. 日期: 2025-12-26 15:00:00 世界标准时间
..标签：网络、计算器、工具
..类别：计算器
..链接：
.. 描述：使用频率和距离计算自由空间路径损耗 (FSPL)。用于点对点微波链路规划和室外WiFi覆盖分析。
..类型：文本
<style>
    .rf-calc-container {
        max-width: 1000px;
        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: 15px;
        margin-top: 20px;
    }

    .form-group {
        display: flex;
        flex-direction: column;
    }

    .form-group label {
        font-size: 14px;
        margin-bottom: 8px;
        color: white;
        font-weight: 500;
    }

    .form-group input {
        padding: 14px;
        font-size: 16px;
        border: 2px solid rgba(255,255,255,0.3);
        border-radius: 6px;
        font-family: 'Courier New', monospace;
        background: rgba(255,255,255,0.95);
        transition: all 0.3s ease;
    }

    .form-group input:focus {
        outline: none;
        border-color: #4CAF50;
        background: white;
        box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
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    .submit-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);
    }

    .submit-button:hover {
        background: #45a049;
        transform: translateY(-1px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    }

    .submit-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);
        transition: all 0.3s ease;
    }

    .result-section:hover {
        box-shadow: 0 4px 8px rgba(0,0,0,0.1);
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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;
    }

    .data-row {
        display: flex;
        margin: 12px 0;
        padding: 10px;
        background: white;
        border-radius: 4px;
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    .data-label {
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        color: #555;
        min-width: 300px;
        flex-shrink: 0;
    }

    .data-value {
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        font-family: 'Courier New', monospace;
        word-break: break-word;
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    .data-value.highlight {
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        font-size: 18px;
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    .help-text {
        margin-top: 15px;
        font-size: 14px;
        color: rgba(255,255,255,0.9);
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        padding: 10px 15px;
        border-radius: 4px;
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    /* Responsive design */
    @media (max-width: 768px) {
        .input-grid {
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        .data-row {
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        }

        .data-label {
            margin-bottom: 5px;
            min-width: auto;
        }

        .submit-button {
            width: 100%;
        }
    }
</style>
<div class="rf-calc-container">
<div class="calc-header">
<h2>RF 自由空间路径损耗计算器</h2>
<p>根据距离、频率和天线增益计算射频传输的自由空间路径损耗。</p>
<div class="input-grid">
<div class="form-group">
<label for="distance">距离（公里）：</label>
<input id="distance" placeholder="e.g., 5" type="text" value="5"/>
</div>
<div class="form-group">
<label for="frequency">频率（兆赫）：</label>
<input id="frequency" placeholder="e.g., 2400" type="text" value="2400"/>
</div>
<div class="form-group">
<label for="txGain">发射天线增益（dBi）：</label>
<input id="txGain" placeholder="e.g., 0" type="text" value="0"/>
</div>
<div class="form-group">
<label for="rxGain">接收天线增益（dBi）：</label>
<input id="rxGain" placeholder="e.g., 0" type="text" value="0"/>
</div>
</div>
<button class="submit-button" onclick="freeSpacePathLoss()" type="submit">计算</button>
<div class="help-text">
<strong>笔记：</strong>自由空间路径损耗表示在没有障碍物的理想环境下发射机和接收机之间的信号衰减。添加天线增益以补偿路径损耗。</div>
</div>
<div class="result-section" id="results" style="display: none;">
<div class="section-header">结果</div>
<div class="section-content">
<div class="data-row">
<div class="data-label">自由空间路径损耗（线性）：</div>
<div class="data-value highlight" id="fsplResult">-</div>
</div>
<div class="data-row">
<div class="data-label">接收功率强度（dB）：</div>
<div class="data-value highlight" id="fsplResultindB">-</div>
</div>
</div>
</div>
</div>
<script>
function freeSpacePathLoss() {
    // Set variables from input
    var distance = Number(document.getElementById("distance").value);
    var frequency = Number(document.getElementById("frequency").value);
    var pi = Math.PI;

    var txGain = Number(document.getElementById("txGain").value);
    var rxGain = Number(document.getElementById("rxGain").value);

    // Free Space Path Loss
    var fspl = (Math.pow((4*pi*distance*frequency)/299792458,2))-txGain-rxGain;

    // Free Space Path Loss in dB
    var fsplResultindB = (20*Math.log10(distance)+20*Math.log10(frequency)+32.44)-txGain-rxGain;

    // Print results
    document.getElementById("fsplResult").innerHTML = fspl.toFixed(6);
    document.getElementById("fsplResultindB").innerHTML = fsplResultindB.toFixed(2) + " dB";

    // Show results section
    document.getElementById("results").style.display = "block";

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

// Add enter key support for all input fields
document.addEventListener('DOMContentLoaded', function() {
    const inputs = ['distance', 'frequency', 'txGain', 'rxGain'];
    inputs.forEach(function(id) {
        document.getElementById(id).addEventListener('keypress', function(e) {
            if (e.key === 'Enter') {
                freeSpacePathLoss();
            }
        });
    });

    // Auto-focus first input field
    document.getElementById('distance').focus();
});
</script>