A WLAN transmitter that emits a 50 mW signal is connected to a cable with 3 dB loss. If the cable is connected to an antenna with 9dBi gain, what is the EIRP at the antenna element?

The correct answer is C. 23 dBm. To calculate the EIRP at the antenna element, we need to add the transmitter output power, subtract the cable loss, and add the antenna gain. All these values need to be converted to dBm first, if they are not already given in that unit. In this case, we have: Transmitter…

Radio Frequency (RF) Fundamentals

Question

Options

A26 dBm
B13 dBm
C23 dBm
D10 dBm

How the community answered

(35 responses)

A
6% (2)
B
17% (6)
C
74% (26)
D
3% (1)

Explanation

To calculate the EIRP at the antenna element, we need to add the transmitter output power, subtract the cable loss, and add the antenna gain. All these values need to be converted to dBm first, if they are not already given in that unit. In this case, we have: Transmitter output power = 50 mW = 10 log (50) dBm = 16.99 dBm Cable loss = 3 dB Antenna EIRP = Transmitter output power - Cable loss + Antenna gain EIRP = 16.99 - 3 + 9 EIRP = 22.99 dBm Rounding up to the nearest integer, we get 23 dBm as the EIRP at the antenna element.

Topics

#EIRP#dBm conversion#antenna gain#cable loss

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