Antennas come in a variety of shapes and sizes; they vary from large arrays to a small wire. Much of this variance is based on the broad use of radio waves and practicality; for instance you wouldn't use an antenna from a small radio to send a signal to a satellite. Antennas work by creating a resonating flow of charge along its element. The resonance is caused by a magnetic field fluctuating through an inductor that is fixed to a capacitor. As a magnetic field fluctuates across a conductor it causes charges to move.
A superhetrodyne reciever is fitted to most modern radios in order to use the method of hetrodyning. Hetrodyning is used with AM and FM radio to ensure a more convenient and efficient experience. There are many differences between AM and FM radio such as AM has the capability to have a larger number of channels but has not got the best quality. FM does not have the same capability of the number of channels but the space between the channels is much wider which makes the quality much better. Although FM radio is limited to 100 radio channels this is made up for in the quality of the radio broadcasted and is therefore the better option.
PART 1 The Electromagnetic Spectrum is the range of frequencies of possible electromagnetic radiation. The Spectrum ranges from 0 Hertz up to 2.4x1023 Hertz. The exact wavelength limits of the Spectrum are unknown however it is widely believed that the short wavelength limit is equal to the Planck Length (1.616x10-35m) and the long wavelength limit is the length of the Universe. Electromagnetic radiation (EMR) is an occurrence that takes the form of self-propagating waves produced by the motion of electrically charged particles, which can move through matter or a vacuum. Physicists have observed that as well as acting like waves, EMR acts like a stream of massless particles (called ‘photons’).
Ground waves travel from the antenna along the surface of the earth. Ionospheric waves, otherwise known as sky waves, are made up of radio waves that come from a transmitting antenna and go into the sky. The ionosphere is the region of the rare field and ionized atmosphere around the earth, from 50 to 200 miles. Last but not least are the tropospheric waves. These waves are parts of the original wave which is reflected into the troposphere, an area of clouds and storms from 3 to 7 miles high.
They are also used in radios, televisions and wireless headphones. The antennae on your television set receive the signal, in the ... ... middle of paper ... ...nd are produced by the hottest regions of the universe. Things like supernova explosions (the way massive stars die), neutron stars and pulsars, and black holes are all sources of gamma rays. Unlike optical light and X-rays, gamma rays cannot be captured and reflected in mirrors. The high-energy photons would pass right through such a device.
The interaction makes vibrational, electronic or nuclear changes in energy levels. This difference between energy levels includes a range of electromagnetic spectrum. Types of electromagnetic radiation include gamma rays, x-rays, ultraviolet, visible, infrared, microwaves and radio wave. Energies, wavelengths, frequencies, or wave number can be used to describe the radiations. Infrared spectroscopy (IR spectroscopy) is a type of spectroscopy that involves the infrared region of the electromagnetic spectrum.
The data is modulated onto the carrier wave by changing the amplitude of this sine wave. The radio station uses and amplifier in order to amplify the signal. For large AM stations the signal is amplified to about 50,000 watts. After the signal has been amplified the radio station sends the radio waves out into space with the help of an antenna. This is essentially how data gets transmitted from an AM station onto a radio receiver.
The range and effects the radiation have on the magnetic and electrical fields. All the information within this report will then be summarised into a academic poster. Structure of an atom: The atom is a unit of matter, which are so small that the use of an electron microscope must be used in order to see images of an atom. The atom has a dense central nucleus which contains positively charged protons and also neutrons which have no charge. Orbiting the nucleus are electrons these are negatively charged.
It consists of a single driven element connected to the transmitter or receiver with a transmission line, and additional parasitic elements: a so-called reflector and one or more directors. The reflector element is slightly longer than the driven dipole, whereas the directors are a little shorter. This arrangement shows in figure 1.2.2. Fig 1.2.2 Yagi Uda Antenna 1.2.3 Reflector Antennas: An antenna reflector is a device that reflects electromagnetic waves. Antenna reflectors can exist as a standalone device for redirecting radio-frequency (RF) energy, or can be integrated as part of an antenna assembly .
Included in the electromagnetic spectrum are light waves, television waves, and microwaves. Visible light is also a smaller part of the electromagnetic spectrum, but it has its own visible-light spectrum. All the electromagnetic energy frequencies that humans can see are defined as visible light. It is created by electrons that have lost energy inside the atom. The energy given off by those electrons then becomes light photons (Congdon, Donald, 306;310).