Search results
Results From The WOW.Com Content Network
The dBm is also dimensionless, [1] [2] but since it compares to a fixed reference value, the dBm rating is an absolute one. The dBm is not a part of the International System of Units (SI) and therefore is discouraged from use in documents or systems that adhere to SI units. (The corresponding SI unit is the watt.)
The decibel watt (dBW or dB W) is a unit for the measurement of the strength of a signal expressed in decibels relative to one watt.It is used because of its capability to express both very large and very small values of power in a short range of number; e.g., 1 milliwatt = −30 dBW, 1 watt = 0 dBW, 10 watts = 10 dBW, 100 watts = 20 dBW, and 1,000,000 W = 60 dBW.
A power level of 0 dBm corresponds to one milliwatt, and 1 dBm is one decibel greater (about 1.259 mW). In professional audio specifications, a popular unit is the dBu. This is relative to the root mean square voltage which delivers 1 mW (0 dBm) into a 600-ohm resistor, or √ 1 mW × 600 Ω ≈ 0.775 V RMS.
A mobile phone signal (also known as reception and service) is the signal strength (measured in dBm) received by a mobile phone from a cellular network (on the downlink). Depending on various factors, such as proximity to a tower , any obstructions such as buildings or trees, etc. this signal strength will vary.
−68 dBm biomed: power entering a human eye from a 100-watt lamp 1 km away 10 −9: nano-(nW) 2–15 × 10 −9: −57 dBm to −48 dBm tech: power consumption of 8-bit PIC microcontroller chips when in "sleep" mode 10 −6: micro-(μW) 1 × 10 −6: −30 dBm tech: approximate consumption of a quartz or mechanical wristwatch: 3 × 10 −6 ...
The electric field strength at a specific point can be determined from the power delivered to the transmitting antenna, its geometry and radiation resistance. Consider the case of a center-fed half-wave dipole antenna in free space, where the total length L is equal to one half wavelength (λ/2).
It is the total power in watts that would have to be radiated by a half-wave dipole antenna to give the same radiation intensity (signal strength or power flux density in watts per square meter) as the actual source antenna at a distant receiver located in the direction of the antenna's strongest beam . ERP measures the combination of the power ...
The conversion level is chosen as the best compromise for the typical headroom and signal-to-noise levels of the equipment in question. Examples: [ 32 ] [ 33 ] [ 34 ] EBU R68 is used in most European countries, specifying +18 dBu at 0 dBFS.