屏蔽技术培训

+Q+Q+QAAABB1144)(1uZZCjZCjuSSS++=ωωgguZZCjZCju)(111111++=ωωgu1ZgZSZ„„„„„„„H0H1H0RsR0H1R0RsSE=1+R0/RSSlRSµ=151015µ0.010.11.010100kHzµr103BHµ=∆B/∆H„„„„„„„„„RSILSV1MISILjRMjISSSωω+=ILLKILMISSS==20406080100101001k10k„()„••„„„„–„–EiE0,:SE=20lg(Ei/E0)dBδteHH−=0δteEE−=0––0H02112HZZZHt+=02122EZZZEt+=AR1R2SER1R2ABRABB02121EZZZZEr+−=02112HZZZZHr+−=0022112122)(2)(HHZZZZZHr=+•−=0EE∝1/r3H∝1/r2H∝1/r3E∝1/r2E∝1/rH∝1/r377λ/2πrE/HΩtE0E1E1=E0e-t/δA20lg(E0/E1)=20lg(et/δ)dB0.37E0δA8.69(t/δ)dBA=3.34t√fµrσrdBR20lgZW4ZsZS=3.68×10-7√fµr/σr377Ω:R20lg3774Zs4500Zs=D=mf=MHz2DfDfZsZs:R20lg:R20lgdB1500.1k1k10k100k1M10M100M3×108/2πrfR(dB)r=30mr=1mr=30mr=1mB=20lg(1-e-2t/δ)•B••(0.5(0.5mmmm))15025000.1k1k10k100k1M10Mr=0.5mr=0.5mdB≡LLSE=100–20lgL–20lgf+20lg1+2.3lg(L/H))=0dBL≥λ/2HZC7.9/DfSE=48+20lgZC–20lgLf+20lg(1+2.3lg(L/H))ZC7.9/DfSE=20lg(πD/L)+20lg(1+2.3lg(L/H))•()•()•()•()•fc=+32t/d27.2t/lSEffcSE5f//360360