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  2. Radio spectrum - Wikipedia

    en.wikipedia.org/wiki/Radio_spectrum

    The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves , are widely used in modern technology, particularly in telecommunication .

  3. Log-spectral distance - Wikipedia

    en.wikipedia.org/wiki/Log-spectral_distance

    Unlike the Itakura–Saito distance, the log-spectral distance is symmetric. [ 2 ] In speech coding, log spectral distortion for a given frame is defined as the root mean square difference between the original LPC log power spectrum and the quantized or interpolated LPC log power spectrum.

  4. Log-periodic antenna - Wikipedia

    en.wikipedia.org/wiki/Log-periodic_antenna

    The log-periodic is commonly used as a transmitting antenna in high power shortwave broadcasting [15] stations because its broad bandwidth allows a single antenna to transmit on frequencies in multiple bands. The log-periodic zig-zag design with up to 16 sections has been used.

  5. Spectral index - Wikipedia

    en.wikipedia.org/wiki/Spectral_index

    Therefore, a spectral index of -0.1 to 2 at radio frequencies often indicates thermal emission, while a steep negative spectral index typically indicates synchrotron emission. The observed emission can be affected by several absorption processes that affect the low-frequency emission the most; the reduction in the observed emission at low ...

  6. Frequency allocation - Wikipedia

    en.wikipedia.org/wiki/Frequency_allocation

    US frequency allocations chart, 2016. Frequency allocation (or spectrum allocation) is the part of spectrum management dealing with the designation and regulation of the electromagnetic spectrum into frequency bands, normally done by governments in most countries. [1]

  7. PKS 1127-145 - Wikipedia

    en.wikipedia.org/wiki/PKS_1127-145

    PKS 1127-145 is a radio-loud quasar [1] located in the constellation of Crater. This is a Gigahertz Peaked Spectrum object [2] [3] with a redshift of (z) 1.187, [4] first discovered by astronomers in 1966. [5] Its radio spectrum appears to be flat making it a flat-spectrum radio quasar, or an FRSQ in short. [6] [7]

  8. Shortwave bands - Wikipedia

    en.wikipedia.org/wiki/Shortwave_bands

    Shortwave bands are frequency allocations for use within the shortwave radio spectrum (the upper medium frequency [MF] band and all of the high frequency [HF] band). Radio waves in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of charged particles in the ionosphere and return to Earth beyond the horizon, a ...

  9. 8-meter band - Wikipedia

    en.wikipedia.org/wiki/8-meter_band

    The 8–meter band (40 MHz) is at present the lowest portion of the very high frequency (VHF) radio spectrum available for national amateur radio use. The term refers to the average signal wavelength of 8 meters. The 8–meter band shares many characteristics with the neighboring 6–meter and 10–meter bands.