'dBm' is a unit used to describe power. It's very very common in measurements
of signal levels in radio transmitting and receiving equipment, mainly because it's
a unit that can describe such an enormous range of low- to high- powers without
awkward numbers. But there's no reason that any power level encountered in any
physical system can't be expressed in units of dBm .
Definition:
'dBm' doesn't describe an amount of power that you can hold in your hand.
It describes how any amount of power compares to 1 milliwatt (0.001 watt).
Any power level, in dBm = 10 x log ( the power level/0.001 watt )
1 milliwatt = Zero dBm
2 milliwatts = +3 dBm
1/2 milliwatt = -3 dBm
10 milliwatts = +10 dBm
100 milliwatts = +20 dBm
Examples:
-- 1 millionth of a millionth of a watt = 1 'picowatt' = 0.000 000 000 001 watt = -90 dBm
-- 1 whole watt = 1.0 watt = +30 dBm
-- 1 'kilowatt' = 1,000 watts = +60 dBm
-- Maximum capacity of Braidwood Nuclear Generating Station,
serving Chicago and northeastern Illinois . . . . .
2,360 MegaWatts = 2,360,000,000 watts = +123.7 dBm
frequency modulation
1
Radio frequency (RF) is a rate of oscillation in the range of about 30 kHz to 300 GHz
Frequency Modulation must have a carrier whereby the frequency can be modulated by the signal
ultrasonic wave is sound frequency
frequency modulation
In relation to a/c mains electricity, or to audio frequencies, 400 kHz is very high. In relation to radio waves it is fairly low.
Use the relation: speed = frequency x wavelengthUse the relation: speed = frequency x wavelengthUse the relation: speed = frequency x wavelengthUse the relation: speed = frequency x wavelength
A transmitter sends a radio frequency to a robot.
dc does not have frequency only ac
the relation between frequency and time period is ''t=1/f''
Frequency = 1 / period
Time of period=1/frequency
I would very much like to see you with greater frequency. What frequency will you be on? I can switch to another radio station by adjusting the frequency of my radio receiver.
20 dbm
frequency = speed of light/wavelength
voltage and frequency both are different quantity.. don't mix it...