Electromagnetic Radiation Waves

According to DIN 5031, section 7, the radiation in the wavelength ranging from 380 nm to 100 nm is called UV radiation. Electromagnetic waves have a double nature They could be described either as a wave or a photon. It is well known that each radiation has a certain quanmm of energy. 

Maxwell in 1873 who postulated that an oscillating electrical circuit should radiate electromagnetic waves... 

When heated, a blackbody radiates electromagnetic waves. Under some conditions, a blackbody isn t black at all. When the radiation emitted by a blackbody has wavelengths in the visible region of the electromagnetic spectrum, we see them as light. 

C. Antenna. The antenna is used to make a transition from a guided wave (from the transmission line) to a radiated electromagnetic wave. The design of the antenna is influenced by many factors such as size, frequency, and electrical impedance. Antennas are normally of two types - omnidirectional and directional. The omnidirectional antennas are element type antennas such as monopoles or dipoles. The directional are horn-type antennas, parabolic dish type antennas such as a satellite communications antenna (SATCOM), or a phased-array antenna which can emit many beams at once. The characteristics of the antenna are a very important aspect of hazard evaluation. 

From Maxwell s equations, the fundamental difference between static near fields (electromagnetic fields) and radiation (electromagnetic waves) is demonstrated. In Section 6.2, we treated the dipole. Consider that the dipole moment varies as a sine function with time. Now if the frequency is very high, the time delay will be noticeable if we are at a distance much longer than the wavelength X = c/f from the dipole. 

RFID systems are classified as radio systems because they generate and radiate electromagnetic waves. Hence the RFID systems should operate within certain frequency limits like the LF, HF, or UHF. Since some of the frequencies are already in use by police, security services, industry, medical, or scientific operations, there is a limited number of frequencies available for RFID systems to operate. Figure 2 shows the radio... 

Some crystals polarize radiation electromagnetic waves transmitted through the crystal have electric field vectors that aU he in the same plane. What property of these crystals permits this ... 

This book concentrates on the interaction of electromagnetic waves with polymers and deals only exceptionally writh particle radiation. Electromagnetic waves comprise a very broad range of frequencies that extends over more than 20 orders of magnitude from the radiofrequency region up to the region of hard y-rays emitted from radionuclides or being part of the cosmic rays (see Table I.l). 

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