Antenna Transmitter Research Paper

In electronics, an antenna is an electrical apparatus that will modify electric power to radio waves or vice versa. It is often being use as a transmitter and receiver. Antenna transmitter will send an alternating current that is in radio frequency to radiate the electromagnetic energy to electromagnetic waves. Antenna receiver will receive the power of an electromagnetic wave to produce a tiny voltage at the terminal to be amplified. The shape and size of the antenna’s structure will decide how much the antenna transmitter can radiate, how well the antenna receiver can receive and the direction of radiation that being radiate or receive.

Antenna is the main segment of the equipment that uses radio, example like radio broadcasting, cell phone,

Waveguides are hollow metal tubes and often are in rectangular shape or circular in cross section. Waveguides have wideband range and power or communication signals can be transfer. Waveguides usually operate at microwave frequencies which is 300MHz and above. It will perform as a high pass filter at the cutoff frequency and will pass over the waveguide. If the frequency from an energy turnout to be too small or below the cutoff frequency, the frequency will be debilitate.

The cutoff frequency will describe the high-pass filter distinctive of the waveguide where the frequency that is higher than the cutoff frequency, the waveguide will sends power, however, the frequ ency that is lower than the cutoff frequency, the waveguide will be constrict. The equation to find the cutoff frequency of a rectangular cross sectioned waveguide: f_c=1/(2a√με)= c/2a where c = the speed of light withi the waveguide µ = the permeability of the material that fills the waveguide Ɛ = is the permittivity of the material that fills the waveguide a = length of the waveguide

The equation of cutoff frequency of a circular cross sectioned

Transverse Magnetic (TM) – determine that the H-field is at right angle to the axis of the waveguide, which have zero magnetic field in the path of propagation. Transverse Electric and Magnetic (TEM) – have zero electric and magnetic field in the path of propagation.

Hybric Mode – have both electric and magnetic field in the path of propagation.

There are different types of waveguide and one of it is dielectric waveguide. It is used to send radio wave. Dielectric waveguide can restrict the radio waves with total internal reflection from the step in refractive index because of the change in dielectric constant at the surface of the waveguide. Metal is not a good conductor for millimeter wave frequencies and above as it will increase the noises, hence, dielectric wave guide is being used. Dielectric waveguide can decrease the loss of the wave frequency and give an accurate information.

For example like optic fiber that used at optical wavelengths. Optic fiver is transparent fiber that made from silica or plastic with a diameter that is slightly thicker than human