ELEC3550 Wireless Communications

TASK

Different antennas are available: yagi and horn antennas, as well as celluar and celluar antennas.

You should research these technologies thoroughly and pay particular attention to how they are used, as well as their strengths and weaknesses.

Your opinion on which antenna types are going to be the best in the future medium- and long distance wireless links.

Compare and contrast multiplexing techniques CDMA & FDMA within the wireless networking area.

An engineering group in your area asks you to submit information about the most advanced wireless technologies.

You should thoroughly research these technologies and pay attention to how they are used, as well as their strengths and weaknesses.

Provide your opinion on which antenna types will be the dominant in the future.

Answer:

Yagi: The Yagi can be composed of two or three straight elements.

Each element has a half-inch electrical wavelength.

The Yagi antenna is constitutionally a balanced one. This means that the antennas can be either unbalanced or balanced.

Coaxial cable can also be used to feed this antenna. This is why the device connects at the feedline, known as the balun.

Here are the strengths and limitations of the Yagi antenna:

1. Strength

Weakness

Simple handling and maintenance

Do not listen to the noise

High directives can be achieved

Atmospheric effects can be a problem

Broader coverage

Bandwidth and frequency range are restricted

High gains are possible

Electrical characteristics are affected by degradation

You need less power

Horn Antennas also known by the name microwave horn antenna

These antennas are made up of flaring metals and waveguide that are designed to direct radio waves as a beam.

There are many types available, including pyramid horn antenna, conical and corrugated horn.

Its effect allows the transition within free spaces and the waveguide.

Here are the strengths and limitations of Horn antennas.

Strength

Weakness

Good idea to match the impedance.

Flare angle and flare length must not exceed a minimum of 3 inches

Avoid standing waves

The flare angle design and directivity are determined

Weak beam width

There are small, minor lobes.

Cellular Antennas also know as Cellular Antennas.

This is used to connect with cell phone adapters cables or with repeaters, inline amplifiers, or directly with an antenna.

Here are the strengths and limitations of the Cellular antenna.

Strength

Weakness

Can be used remotely

Some data and signals could be lost at times

Wireless service

Environmental effects

Helical Antenna: Helical antenna is a type of wire antenna that has the forms helix.

The operation frequency for the helical antenna ranges from 30 MHz to 3 GHz.

This simple antenna emits circular polarized waves.

These antennas are useful for extraterrestrial communication. They can also be used to relay satellite signals and other applications.

Strength

Weakness

Larger bandwidth

An antenna of large size will require more space because it takes up so much space

With increasing turns, efficiency decreases

It can also be used in the VHF and HF band

Future Prospective

Since it operates in a specific mode, Helical antenna will be the dominant antenna.

Normal radiation or perpendicular radiation: The radiation field from the helix in this radiation mode is normal.

Radiated waves have a circular polarization.

Comparing to the wavelength, the dimension of the Helix is smaller.

Axial and beam modes of operation: This radiation mode uses circularly polarized waves. The radiation field follows the helical path, with the radiation field pointing in the direction of end-fire.

Radiations that are directional are wider than those produced by the axis at oblique angles in the minor lobes.

Comparing and Contrasting CDMA & FDMA

* Every user can use the simultaneous occurrence of transmissions and similar frequencies

* Spreading wideband signals multiplies all narrowband signals

* Users who have their own pseudo-codes

* Only the receiver can detect the pseudo-code desired

* The receiver should know the codeword that the transmitter has sent.

* The channel remains idle when it’s not in use

* The narrowband system, which is the usual name for the bandwidth used by the channels, refers to the channel’s bandwidth.

* FDMA suits Analog links

* Very little equalizer is required to separate symbol time

* IS combined FDD to duplexing

* In order to minimize interference, tight filtering may be necessary

Advanced wireless technologies: Wireless Gigabit has been selected.

Wireless Gigabit alliance is also known as WiGig.

It can transfer video and audio files, as well as data at 7Gb per second.

It operates at 60 GHz frequency modes.

This technology overcomes signal decay and is known as adaptive beamforming.

Adjusting the antennas to adjust for the broadcasted wave amplitudes and phaseshift is how it works.

Reciprocity of these signals is a great way to solve many problems.

WiGig is secure

The encryption strength of WEP 64bit or 128bit.

Simple encryption, which offers little security but are relatively easier to crack.

This key is used in WSP – PSK (WPA-pre shared key).

WIGIG uses WPA2_AES (“Advanced Encryption Standard”)

The technology is small and portable, uses low power and is cost-effective. It also transfers files faster.

However, there are some disadvantages. For example, wireless connections can create less protocol. This can lead to problems. Also, more equipment is required and may increase the cost of the technology.

These technologies are used in inter-vehicle communication system, wireless WLAN service, video transfer, and office appliances.

The future impact of this technology is likely to be significant, so it should be adopted as a requirement.