Metamaterial Essay

3. Metal width; increasing the width of the metal will reduce the inductance; somehow it will resonate at early frequency.

Here we cut a cylindrical slot in the patch with outer radius R1 and inner radius R2 (R1>R2) as shown in Fig.5. By using cylindrical slot in the above rectangular slot antenna we get all three bands as with improved return loss and bandwidth as shown in Figure 6. The three bands which we are getting are better as compared to previous result of microstrip patch antenna with four rectangular slots.

Among numerous choices, it is the most simple and result oriented approach. After selecting the resonant mode, it is the resonator’s dielectric constant value and its aspect ratio (a/h) that define the obtainable bandwidth. In simple geometric shapes such as cylindrical DRAs the smallest possible εr value makes Q-factor low which as a consequence results in wider bandwidth [34].

By using a twister pair of wires the electromagnetic signals generated by the wires cancel each other out due to their opposite polarity.

and a compressive force on the other one. These axial forces will cause an opposite change in the stiffness of the resonators and this opposite change separates their resonance frequencies[5]. These double-ended resonators also provide a differential output which has so many advantages like cancelling the output’s offset and effect of temperature variations on frequency.

Electromagnetic waves are continually used to upgrade and advance our technology, being implicated for its use in microwave ovens, radio waves for telecommunications and x-rays in medicine.

The amplitude affects the strength of the force, that is the length of the force vectors in the electromagnetic wave. The wavelength of the wave depends only on the frequency with which the electron in the transmitting antenna is oscillating up and down; and the speed of light.

According to Cez Verosa at Tech Times.com college students from the University of Leicester found it is possible. It uses heated plasma with high amounts of electromagnetism. You can not see through it though.

A later development of radar technology was the use of Microwave radio transmissions to identify enemy aircraft. A cavity magnetron produced the microwaves, and the British reduced these in size so that they could be carried in aircraft (Sheehan 42).

Shortly after arriving in Karlsruhe, Hertz found some large induction coils that could produce a pulsed high voltage and a pair of spark micrometers with brass knobs forming an adjustable spark gap, which he hoped could be used to transmit electromagnetic waves as predicted by Maxwell. With a battery and an interrupter attached to the primary coil, he could obtain a pulsed high voltage across a secondary coil. He then invented a high-frequency oscillating antenna by forming a dipole with two metal

Window embedded wire antennas have been introduced at FM frequencies for low-power or receive-only applications. The power transmitted by the army radios at VHF and UHF frequencies can exceed tens of watts. At these power levels, it is of crucial importance to isolate the interior of the vehicle from the antenna radiation. In addition, this isolation eliminates the affects of the cabin interior and passengers on the antenna input impedance and radiation pattern. Hence a transparent ground plane will be needed behind the radiating element to reduce the radiation inside the vehicle and at the same time increase the directivity of the antenna. A wire-mesh or a more sophisticated band-selective ground plane can be used as the reflecting element. A meshed patch antenna on a mesh ground plane can provide the required isolation with the cabin interior. However because of the sub-wavelength dimensions of the armored windows at VHF and UHF frequencies a patch antenna, if feasible, cannot provide the one octave bandwidth required by the army radios. In this paper a monopole bow-tie antenna backed by a cavity (armored window) is proposed. Because of the limited thickness of the window glass, the radiation element and the transparent ground plane need to be placed very close to each other. Therefore the gain and/or the

Wavelength: Microwave is a short wavelength wave. The wavelength of the microwave transmitted by Bluetooth is about 12.5cm. (Miller, A.B. 2001)

On old radios the antenna was detrimental to the radio’s operation. Today, the antenna is not necessary. AM radio does not have as good of quality as FM but it can travel farther distances. FM signals can be interfered by things such as mountains or other barrier

operation but also needs to have an appropriate proposed design. It employs two techniques to improve the radiation pattern. These techniques are the use of an angled dipole and vertical copper plates arranged on the ground plane for improvement in the radiation pattern of lower and upper bands, respectively radiation profile in both bands, namely similar gain, wide beamwidth. One of the popular techniques for broadening the patch antenna bandwidth is to incorporate a U-slot on its surface. They have the ability to confine the power in certain directions instead of scattering the power everywhere.

YIG(Yttrium Iron Garnet) is a -------------- material that has some very useful properties at microwave frequencies. A