3 ms·
I'm talking about the bandwidth of the individual signal. A 5 kHz wide signal uses a lot less electricity than a 50 kHz wide signal.
by RF_Enthusiast 3y ago
I'm talking about the bandwidth of the individual signal. A 5 kHz wide signal uses a lot less electricity than a 50 kHz wide signal.
- mlyle 3y agoThe same output power is the same output power. In general, the opposite of what you say is true: the more occupied bandwidth, the less power you need for equivalent information transfer. So, e.g. when the FCC made everyone doing VHF/UHF voice comms narrowband from 25KHz to 12.5KHz, you needed basically double the power for equivalent analog voice. Or for an extreme-- GPS uses 50MHz wide to send dozens of bits per second to allow much lower satellite output power and resilience to noise.
- RF_Enthusiast 3y agoAre you saying that a transmitter with an output of 20,000 watts and a bandwidth of 50 kHz using digital modulation uses the same amount of electricity as a transmitter with 20,000 watts and a bandwidth of 1 kHz using digital modulation?
- mlyle 3y agoYes. Watts are the unit of power. Either of them would probably use 22,000-35,000 watts of electrical input power to produce an output radio signal of 20,000 watts. The former could be expected to transfer much more information, or alternatively to go further. (Or the former you could use less than 20,000 watts to get the same data transfer rate and range as the latter).
- RF_Enthusiast 3y agoThank you.