Electromagnetic Radiation Spectrum FREQUENCY SPECTRUM Figure 1, which follows, depicts the electromagnetic radiation spectrum and some of the commonly used or known areas.. Figure 2 depi
Trang 18meter ' 3x108
f Hz ' 3x10
5
f kHz ' 300f MHz ' 0.3f GHz f Hz ' 3x10
8
8meter f kHz ' 3x105
8meter f MHz' 300
8meter f GHz' 0.3
8meter
2-3.1
Figure 1 Electromagnetic Radiation Spectrum
FREQUENCY SPECTRUM
Figure 1, which follows, depicts the electromagnetic radiation spectrum and some of the commonly used or known areas Figure 2 depicts the more common uses of the microwave spectrum Figure 3 shows areas of the spectrum which are frequently referred to by band designations rather than by frequency
Section 7-1 provides an additional breakdown of the EO/IR spectrum
To convert from frequency (f) to wavelength (8) and vice versa, recall that f = c/8, or 8 = c/f;
where c = speed of light
or
Some quick rules of thumb follow:
Metric:
Wavelength in cm = 30 / frequency in GHz For example: at 10 GHz, the wavelength = 30/10 = 3 cm English:
Wavelength in ft = 1 / frequency in GHz For example: at 10 GHz, the wavelength = 1/10 = 0.1 ft
Trang 20.3 0.4 0.5 0.6 0.8 1.0 2 3 4 5 6 8 10 20 30 40 50 60 80 100
FREQUENCY (MHz)
12 18 27 40 60 80 100
FREQUENCY (GHz)
MILITARY STANDARD BANDS INTERNATIONAL STANDARD BANDS
U.S INDUSTRY STANDARD BANDS (IEEE Radar Designation)
15
250
* "u" stands for unabsorbed or under K; "a" stands for absorption region or above K
200 300
400
Millimeter
12
110
2-3.2
Figure 2 The Microwave Spectrum
Figure 3 Frequency Band Designations