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dB (Decibel)

Date: 2023-11-14Last modified: 2025-01-14

When use 10 and when use 20

Fig. 1 -

For power measurement the coeficiente is 10 But for voltage measurement the coeficiente should be 20

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Fig. 2 - {{./equation006.png?type=equation}}

replacing P by v²/R

Fig. 3 -
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Fig. 4 - {{./equation005.png?type=equation}}

What is the references values -3dB, -1dB

Fig. 5 -
dB Power Ratio Voltage Ratio
0dB 1 1
-1dB 0.794 0.891
-3dB 0.5 0.708

Voltage is the common measurement at osciloscope

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Fig. 6 -

dBV

Reference to 1V

===== dBm =====
Fig. 7 - ===== dBm =====

Reference to 1mW

Fig. 8 -

check planilha de linkbudget [autocalc] per MIL-HDBK-416; Eq. 4.2-22

330fceea 👉️ 1977-11-15 MIL-HDBK-416 Design Handbook for Line of Sight Microwave communication systems

path smoothness factor path humidity factor link connectiviry