enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Superconducting radio frequency - Wikipedia

    en.wikipedia.org/.../Superconducting_radio_frequency

    The Geometry Factor is also independent of cavity size, it is constant as a cavity shape is scaled to change its frequency. As an example of the above parameters, a typical 9-cell SRF cavity for the International Linear Collider [ 5 ] (a.k.a. a TESLA cavity) would have G =270 Ω and R s = 10 nΩ, giving Q o =2.7×10 10 .

  3. Microwave cavity - Wikipedia

    en.wikipedia.org/wiki/Microwave_cavity

    A microwave cavity or radio frequency cavity (RF cavity) is a special type of resonator, consisting of a closed (or largely closed) metal structure that confines electromagnetic fields in the microwave or RF region of the spectrum. The structure is either hollow or filled with dielectric material. The microwaves bounce back and forth between ...

  4. Leaky feeder - Wikipedia

    en.wikipedia.org/wiki/Leaky_feeder

    Diagram of leaky feeder cable. A leaky feeder is a communications system used in underground mines and inside tunnels. [1] Manufacturers and cabling professionals use the term "radiating cable" [2] [3] [better source needed] [4] as this implies that the cable is designed to radiate: something that a typical coaxial cable is generally not intended to do.

  5. The Thing (listening device) - Wikipedia

    en.wikipedia.org/wiki/The_Thing_(listening_device)

    The device, a passive cavity resonator, became active only when a radio signal of the correct frequency was sent to the device from an external transmitter. This is referred to in NSA parlance as "illuminating" a passive device. Sound waves (from voices inside the ambassador's office) passed through the thin wood case, striking the membrane and ...

  6. Waveguide (radio frequency) - Wikipedia

    en.wikipedia.org/wiki/Waveguide_(radio_frequency)

    In radio-frequency engineering and communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. [1] This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave ...

  7. Cavity perturbation theory - Wikipedia

    en.wikipedia.org/wiki/Cavity_perturbation_theory

    It is convenient to denote cavity frequencies with a complex number ~ = /, where = (~) is the angular resonant frequency and = (~) is the inverse of the mode lifetime. Cavity perturbation theory has been initially proposed by Bethe-Schwinger in optics [1], and Waldron in the radio frequency domain. [2]

  8. Maser - Wikipedia

    en.wikipedia.org/wiki/Maser

    The resonant frequency of the microwave cavity is tuned to the frequency of the hyperfine energy transition of hydrogen: 1,420,405,752 hertz. [15] A small fraction of the signal in the microwave cavity is coupled into a coaxial cable and then sent to a coherent radio receiver. The microwave signal coming out of the maser is very weak, a few ...

  9. Resonator - Wikipedia

    en.wikipedia.org/wiki/Resonator

    A cavity resonator is a hollow closed conductor such as a metal box or a cavity within a metal block, containing electromagnetic waves (radio waves) reflecting back and forth between the cavity's walls. When a source of radio waves at one of the cavity's resonant frequencies is applied, the oppositely-moving waves form standing waves, and the ...