VPI Laboratories Calculators

Power Density (Antenna)

This equation calculates power density at a specified distance using power to the antenna and antenna gain.

Power to Antenna (mW)

Antenna Gain (Numeric)

Distance from Antenna (cm)

Power Density (mW/cm²):

Power Density (EIRP)

Used to calculate power density at a specified distance using EIRP.

EIRP (mW)

Distance from Antenna (cm)

Power Density (mW/cm²):

Antenna Gain Conversions

Calculate antenna numeric gain from dBi or numeric.

dBi

Numeric

Radiated Field Conversion

EIRP (W)

Distance for EIRP (m)

V/m:

dBuV/m:

EIRP and ERP from dBuV/m and distance

Calculate EIRP or ERP from field strength.

dBuV/m

Distance

EIRP (W):

EIRP (mW):

EIRP (dBm):

ERP (mW):

ERP (dBm):

Unit Conversion dBm/mW

dBm

mW

Unit Conversion dBuV/uV

dBuV

uV

Distance Corrections in dB

Used to calculate factor for adjusting limits or field strengths for frequencies below 30 MHz (40 dB/decade)

Distance 1

Distance 2

Delta dB:

Used to calculate factor for adjusting limits or field strengths for frequencies above 30 MHz (20 dB/decade)

Distance 1

Distance 2

Delta dB :

Linear Interpolation with Log of Frequency

Used to calculate a value when the limit changes with the logarithm of the frequency.

Low Frequency

Value at Low Frequency

High Frequency

Value at High Frequency

Frequency for Limit Determination

Determined Value

Antenna Gain Calculator

Calculates antenna gain from field strength, power to antenna, and distance.

Field Strength (dBuV/m)

Output power (dBm)

Distance (m)

Antenna Gain (Numeric)

Antenna Gain (dBi)