How to calculate erp program?

How to calculate erp program?

The effective radiated power (ERP) of an RF transmission system is the actual power of a signal when it leaves the system's antenna. It is defined as the sum of transmitter power output (TPO) and transmission system gains and the difference with system losses. The units for the ERP are expressed in Watts.

The basic equation for ERP is TPO + dBd = ERP which is based on use of isotropic antennas with a value of 0dBi. Further, there are other equations and additional factors which will the change the ERP output.

How to calculate ERP:

1.  Go to database of coaxial cable losses at various levels of signal frequency and check the resources for a direct link.

 2. Locate the model number of the coaxial cable used by the antenna and scan down till you get through to the signal frequency.

3. The labels of each frequency will be found in the far left column which is measured in megahertz (MHz). The value in the cell represents the decibel (dB) loss per 100 feet of cable for that particular signal frequency.

4. Now, divide the total length of the transmission's system cable (in feet) by 100 and multiply the result obtained from the step 3 to determine the loss caused.

5. Take the standard logarithm for the electric power level, in watts (i.e., log base 10) to get the power output from the transmitter and after the result, multiply it by 10 to give you the TPO for the transmission system, in decibels (dB).

6. Now , add the antenna’s gain to the TPO result obtained above and then subtract the  result obtained in step 4 for the loss caused, to give you the effective radiated power (ERP) of the system in decibels.

7.Divide the result obtained above by numeral 10 and take the inverse logarithm (i.e., log^-1) of the result to convert the units from decibels to watts.

Hope this information helps you better.