Sky Wave Propagation

Sky Wave Propagation – The Ionosphere : The Sky Wave Propagation- the  ionosphere is the upper portion of the atmosphere, which absorbs large quantities of radiant energy from the sun, becoming heated and ionised. There are variations in the physical properties of the atmosphere, such as temperature, density and composition. Because of this and the different types […]

Electromagnetic Spectrum

Electromagnetic Spectrum: In an earth environment, electromagnetic waves propagate in ways that depend not only on their own properties but also on those of the environment itself; some of this was seen in the preceding section. Since the various methods of propagation depend largely on frequency, the complete electromagnetic spectrum is now shown for reference […]

Interference of Electromagnetic Waves

Interference of Electromagnetic Waves: Interference of Electromagnetic Waves occurs when two waves that left one source and travelled by different paths arrive at a point. This happens very often in high-frequency sky-wave propagation and in microwave space-wave propagation. It occurs when a microwave antenna is located near the ground, and waves reach the receiving point […]

Fundamentals of Electromagnetic Waves

Fundamentals of Electromagnetic Waves: Fundamentals of Electromagnetic Waves are energy propagated through free space at the velocity of light, which is approximately 300 meters per microsecond. As the object travelled downward, there would be a path of bubbles generated in the same direction (vertical) as the object, but there would also be a circular wave pattern […]

Reactance Properties of Transmission Lines

Reactance Properties of Transmission Lines: Reactance Properties of Transmission Lines : Just as a suitable piece of transmission line may be used as a transformer, so other chosen transmission-line configurations may be used as series or shunt inductive or capacitive reactances. This is very advantageous indeed. Not only can such circuits be employed at the […]

Quarter Wavelength Transmission Line

Quarter Wavelength Transmission Line: Sections of transmission lines that are exactly a Quarter Wavelength Transmission Line or Half Wavelength Transmission Line long have important impedance-transforming properties, and are often used for this purpose at radio frequencies. Impedance inversion by Quarter Wavelength lines: Consider Figure 7-8, which shows a load of impedance ZL connected to a […]