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-3db equates to half of the original power.
if you had 1 watt input. and the output is 1/2 watt.
The power gain is calculated by 10 log (Pin/Pout)
( in bels its log(Pin/Pout) in decibels its 10 log (Pin/Pout) )
That is 10 log (1/ 1/2) = 10 log 2 = -3 that's -3db for you
It communications and in so many other fields. the 3db mark is taken as kind of datum for useful power. that is to say beyond this the magnitude will reduce below half.
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I guess some kind of power you gain.
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After Magna Carta English Kings no longer had absolute power
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Can you put a dual exhaust on a truck with a welded muffeler?
Yes, you can pipe them into one. Why would you want to?
What is the difference between 0db 3db 5db gain?
Each 3db doubles the apparent volume.
What is db gain?
DB (decibels) gain is the log based 2 times 3 relative power change measured from input to output of a circuit. For instance, +3db is twice the power, +6db is four times, +9db is eight times. Similarly, -3db is half the power, -6db is quarter the power, and -9 db is eighth the power.Keep in mind that DB is relative power, not voltage, so if you are measuring voltage, then +3db is square root of 2 (1.414) times the voltage, etc.
Why 3db line used in amplifiers?
its where the gain is max and stable
What is the output if the input is 1kw and gain of 3db?
3 db is double the power, so an input of 1 KW would yield an output of 2 KW for a 3 db gain.
Why consider only 3dB for bandwidth calculation?
3dB of gain rolloff is a linear reduction of gain by a factor of 2. That makes it a good reference point.
What is -3db bandwidth?
Bandwidth is typically measured from the two -3dB points on each end of the response curve. You find the two points where the response is -3dB (half power) and measure the distance between them. That is your bandwidth.
What do you mean by 3 dB cutoff frequency?
3db frequency is the frequency at which the value in the graph is reduced by 3db level It's also known as the half-power point.
What do means by 3 dB?
3 dB is a change in power by a factor of 2. If it is plus, i.e. +3dB, power is doubled. If it is minus, i.e. -3dB, power is halved. 6 dB, then is a factor of four, or quarter; 6 dB is a factor of eight, or eighth, etc. The actual equation is 3 log2 (POWER OUT / POWER IN).
What is a -3dB point in an inverting amplifier?
The -3dB point is the point of half power. In a filter, the -3dB point, more commonly called the half-power point, is the point where the output power is one half the input power. A bandpass filter has two half-power points, and the distance between them is called the bandwidth, whereas a low-pass or high-pass filter has one half-power point, which is called the cutoff frequency. In terms of voltage, the half-power point is where the voltage is 0.707 (1 / square root(2)) of the input voltage.
How do you calculate input power of system with amplifier of 6 dB with a filter loss of 9 dB and an output power of 200 mW?
+6db -9db = -3dbso 400 mW -3db = 200 mWDecibels simply add, and they are 3 times the log base 2 of the power change, i.e. 3db, 6db, 9db is 2, 4, 8 times, and -3db, -6db, -9db is 1/2, 1/4, 1/8 times.
What is relation between antenna gain and beamwidth?
bandwidth refers to the amount of the frequency spectrum that a signal resides in.example, the spacing between channels on radio are determined by their bandwidth. beamwidth is a physical characteristic of an antenna. they generally mark the point bore sight of a directional antenna that are at -3dB or half power
Why line is drawn at 0.707 AV or 3dB to find bandwidth?
The bandwidth of a circuit, amplifier etc has been chosen to be defined by the points when the power output falls to half its maximum. Log 0.5 is -0.3 which in the decibel notation is -3dB (-0.3 Bels= -3 decibels). When the output power is at 0.5 maximum, then since the power varies as the square of the voltage, the output voltage is 0.707 of the maximum output voltage.
