Search results
Results From The WOW.Com Content Network
A gain greater than one (greater than zero dB), that is, amplification, is the defining property of an active device or circuit, while a passive circuit will have a gain of less than one. [4] The term gain alone is ambiguous, and can refer to the ratio of output to input voltage (voltage gain), current (current gain) or electric power (power ...
The gain of an amplifier is the ratio of output to input power or amplitude, and is usually measured in decibels.When measured in decibels it is logarithmically related to the power ratio: G(dB)=10 log(P out /P in).
In electromagnetics, an antenna's gain is a key performance parameter which combines the antenna's directivity and radiation efficiency. The term power gain has been deprecated by IEEE. [1] In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. In a receiving ...
The decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. Until the mid-1920s, the unit for loss was miles of standard cable (MSC). 1 MSC corresponded to the loss of power over one mile (approximately 1.6 km) of standard telephone cable at a frequency of 5000 radians per second (795.8 Hz), and matched closely the smallest attenuation detectable to a ...
The transmitter power output (TPO) of such a station typically may be 10,000–20,000 watts, with a gain factor of 5–10× (5–10×, or 7–10 dB). In most antenna designs, gain is realized primarily by concentrating power toward the horizontal plane and suppressing it at upward and downward angles, through the use of phased arrays of antenna ...
Received power (dBm) = transmitted power (dBm) + gains (dB) − losses (dB) Power levels are expressed in ( dBm ), Power gains and losses are expressed in decibels (dB), which is a logarithmic measurement, so adding decibels is equivalent to multiplying the actual power ratios.
The operating power gain of a two-port network, G P, is defined as: = where P L is the maximum time-averaged power delivered to the load, where the maximization is over the load impedance, i.e., we desire the load impedance which maximizes the time-averaged power delivered to the load.
A change of one bel in the level corresponds to a 10× change in power, so when comparing power quantities x and y, the difference is defined to be 10×log 10 (y/x) decibel. With root-power quantities, however the difference is defined as 20×log 10 (y/x) dB. [3]