图共 6个 表共 4个

    • 图  1  通信电台单频电磁辐射效应试验配置

      Figure 1. 

    • 图  2  受试通信电台单频阻塞临界干扰场强

      Figure 2. 

    • 图  3  通信电台双频电磁辐射效应试验配置

      Figure 3. 

    • 图  4  通信电台原理结构框图

      Figure 4. 

    • 图  5  受试通信电台低频干扰电平随互调频差的变化

      Figure 5. 

    • 图  6  受试通信电台2阶互调低频阻塞干扰因子随辐射频偏的变化

      Figure 6. 

    • 频率组合(kHz)Δf1=f1–f036487296144
      Δf2=f2–f07296144192288
      临界干扰场强比E1/E10–11.7–12.3–13.3–17.9–18.2
      E2/E20–13.2–22.5–24.8–32.3–27.1
      频率组合(kHz)Δf1=f1–f036487296144
      Δf2=f2–f04886154212268
      临界干扰场强比E1/E10–8.7–13.3–13.6–19.5–19.8
      E2/E20–10.8–17.0–24.1–19.9–22.9

      表 1  通信电台双频3阶互调阻塞临界干扰场强

    • 频率组合(kHz)Δf1=f1–f0100150200250300
      Δf2=f2–f0150200250300350
      临界干扰场强比E1/E10–25.6–26.3–28.7–28.4–30.6
      E2/E20–26.7–29.5–29.2–30.5–28.5
      频率组合(kHz)Δf1=f1–f0127150220240230
      Δf2=f2–f0177160330360390
      临界干扰场强比E1/E10–26.5–17.5–30.6–34.4–4.0
      E2/E20–27.7–17.7–30.5–34.4–4.1

      表 2  通信电台新型双频阻塞临界干扰场强

    • 结构频率
      天线接收f1, f2 (设f1<f2)
      一级放大f1, f2, f2±f1, 2f1±f2和2f2±f1, 3f1和3f2 (忽略高阶互调分量)
      上变频Fm+f0–f1, Fm+f0–f2, Fm+f0–f2±f1, Fm+f0–2f1±f2, Fm+f0–2f2±f1, Fm+f0–3f1, Fm+f0–3f2和
      Fm+f0+f1, Fm+f0+f2, Fm+f0+f2±f1, Fm+f0+2f1±f2, Fm+f0+2f2±f1, Fm+f0+3f1, Fm+f0+3f2
      窄带滤波Fm+f0–f1, Fm+f0–f2, Fm+f0–2f1+f2和Fm+f0–2f2+f1
      三级放大Fm+f0–f1, Fm+f0–f2, Fm+f0–2f1+f2, Fm+f0–2f2+f1和f2–f1, 2(f2–f1), 3(f2-f1), 2(Fm+f0)–f1–f2,
      2(Fm+f0–f1), 2(Fm+f0–f2), 2(Fm+f0)–3f1–f2, 2(Fm+f0)–3f2–f1 (忽略3阶互调)
      下变频与低通(带通)滤波FL+f0–f1, FL+f0–f2, FL+f0–2f1+f2, FL+f0–2f2+f1, FL+(f2–f1), FL+2(f2–f1), FL+3(f2–f1)

      表 3  干扰信号进入通信电台各结构后输出分量频率

    • 电台工作频率(MHz)506070506070
      频率组合(kHz)f1–f0200200200200200230
      f2–f0250250250300300330
      临界干扰场强比E1/E10–25.0–28.9–29.1–26.3–30.2–29.1
      E2/E20–23.7–30.9–22.0–28.7–30.1–28.9
      评估准确度R24.4–6.72.0–4.1–9.4–7.6

      表 4  2阶互调低频阻塞干扰效应评估准确度