Frequency, signal multiplexing modulation and spread sprectrum
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3. EHF Extremely high frequency 1cm-1mm 30 - 300 GHz SHF Super high frequency 10cm-1cm 3 - 30 GHz UHF Ultra high frequency 1m-10cm 300 MHz - 3 GHz VHF Very high frequency 10m-1m 30 - 300 MHz HF High frequency 100m-10m 3 - 30 MHz MF Medium frequency 1km-100m 300 kHz - 3 MHz LF Low frequency 10km-1km 30 - 300 kHz VLF Very low frequency 100km-10km 3 - 30 kHz ULF Ultra low frequency 10^3km-100km 300 - 3000 Hz SLF Super low frequency 10^4km-10^3km 30 - 300 Hz ELF Extremely low frequency 10^5km-10^4km 3 - 30 Hz Abbreviation [2] Designation Wavelength Frequency
4. EM Spectrum S/W radio 902 – 928 Mhz 2.4 – 2.4835 Ghz 5.725 – 5.785 Ghz ISM band Propagation characteristics are different in each frequency band LF HF VHF UHF SHF EHF MF AM radio UV FM radio TV TV cellular 1 MHz 1 kHz 1 GHz 1 THz 1 PHz 1 EHz infrared visible X rays Gamma rays 30kHz 300kHz 3MHz 30MHz 300MHz 30GHz 300GHz 10km 1km 100m 10m 1m 10cm 1cm 100mm 3GHz