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  2. Antenna measurement - Wikipedia

    en.wikipedia.org/wiki/Antenna_measurement

    A Compact Antenna Test Range (CATR) is a facility which is used to provide convenient testing of antenna systems at frequencies where obtaining far-field spacing to the AUT would be infeasible using traditional free space methods. It was invented by Richard C. Johnson at the Georgia Tech Research Institute. [3]

  3. Antenna factor - Wikipedia

    en.wikipedia.org/wiki/Antenna_factor

    For the relationship between the electric and magnetic fields, see the impedance of free space. For a 50 Ω load, knowing that P D A e = P r = V 2 /R and E 2 = μ 0 ε 0 {\displaystyle {\sqrt {\frac {\mu _{0}}{\varepsilon _{0}}}}} P D ~ 377P D (E and V noted here are the RMS values averaged over time), the antenna factor is developed as:

  4. Gain (antenna) - Wikipedia

    en.wikipedia.org/wiki/Gain_(antenna)

    When actual measurements of an antenna's gain are made by a laboratory, the field strength of the test antenna is measured when supplied with, say, 1 watt of transmitter power, at a certain distance. That field strength is compared to the field strength found using a so-called reference antenna at the same distance receiving the same power in ...

  5. Reciprocity (electromagnetism) - Wikipedia

    en.wikipedia.org/wiki/Reciprocity_(electromagnetism)

    Forms of the reciprocity theorems are used in many electromagnetic applications, such as analyzing electrical networks and antenna systems. [1] For example, reciprocity implies that antennas work equally well as transmitters or receivers, and specifically that an antenna's radiation and receiving patterns are identical.

  6. Modulation error ratio - Wikipedia

    en.wikipedia.org/wiki/Modulation_error_ratio

    MER is defined as a percentage in a compatible (but reciprocal) ... ETSI technical report ETR 290: "Measurement guidelines for DVB systems", Errata 1, May 1997

  7. Antenna gain-to-noise-temperature - Wikipedia

    en.wikipedia.org/wiki/Antenna_gain-to-noise...

    G/T is the figure of merit for a satellite system. G is the Receive antenna gain. T is the system noise temperature. System noise temperature = antenna noise temperature + Receiver noise temperature (LNA) Antenna noise temperature is the noise power seen at the receive output of the antenna. (To LNA) If we are not measuring with an LNA or ...

  8. Standing wave ratio - Wikipedia

    en.wikipedia.org/wiki/Standing_wave_ratio

    SWR of a vertical HB9XBG Antenna for the 40m-band as a function of frequency. In radio engineering and telecommunications, standing wave ratio (SWR) is a measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide.

  9. Radio propagation - Wikipedia

    en.wikipedia.org/wiki/Radio_propagation

    Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]