Calculate
Power Ratio of RF Transmitter

Animation using gif, by Chetvorno, via Wikimedia Common

Shown above is a good visualization of transmitting Radio Frequency (RF). This animation does not represent the real time travel speed of RF which is 30 kHz to 3 GHz. It was slowed down for visualization. Memory recall knowledge we acquired about all electromagnetic waves including RF that their travel speed in vacuum or outer space is the same as the speed of light, meaning 300,000 km/sec. We can use this knowledge to estimate the speed of a webpage that can be downloaded anywhere in the world.

Application of RF speed and Optical speed in fiber optics in relation to internet webpage access time. Assuming you are in Philippines which is about 13,215 km from US datacenter that manages INVBAT.COM web server and you click the webpage www.invbat.com, what is the estimated return time of the signal to your internet device? Answer total return time is 0.0881 sec. Assuming another 0.0881 time delay, INVBAT.COM webpage should be loaded in 0.1762 seconds. This calculation is valid if your data travels using RF and Fiber Optic Networks. But if you are using satellite with approximately 35,786 km from anywhere on the earth. The return time is 0.2386 seconds. Again assuming another 0.2386 seconds time delay, INVBAT.COM webpage should be loaded in 0.4772 seconds. This webpage access time is still very fast less than 1 second. So if it is taking more than 1 second, you need to remember that data signal travels several hundreds of router switches around the world and also your internet devices are storing data in memory cache to speed up your next access time. Soon you will have a faster download speed as more cloud technology web servers are becoming widespread, fiber optics cables, RF transmitter/receiver, and satellite transmission path are becoming common worldwide.

Given P_o in W and P_i in mW

Given power output of RF amplifier is 10 W and the power input is 1 mW.

Solve for the Power Gain in dB.

Pr in dB ANSWER

=

10 *Log 10

Po in Watts Pi in milliWatts

Here mW ( milliWatts ) is converted to 0.001 W in the program. Hence no need to write 0.001 just enter 1 for 1 mW.

But in manual computation use 1 mW = 0.001 W the reason is the Power ratio has no unit. Meaning the Watts unit in numerator must be divided by Watts unit in denominator in order to cancel out the unit.

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Given power gain of RF amplifier is 40 db and the input power is 1 mW.

Solve for the power output in watts.

dB

=

10 *Log 10

Po in Watts Pi in mW

Power output, M_p = Watts ; ANSWER