Assertion: antenna's frequency | /r/HasProperty | high
Facets:
Source sentences:
text: If the frequency is too high (that is, above the critical frequency of the ionospheric F layer), refraction fails to occur and if it is too low, absorption in the ionospheric D layer may reduce the signal strength.
text: The dish antenna occupies the high frequencies (typically 950 to 1450 MHz), and the TV antenna uses lower television channel frequencies (typically 50 to 870 MHz).
text: The rhombic antenna was designed in the 1931 by Edmond Bruce and Harald Friis, It was mostly commonly used in the high frequency (HF) or shortwave band as a broadband directional antenna.