Types of Antennas and Communication Technologies

This assignment delves into various antenna types, including log periodic, wire, traveling wave, microwave, and reflector antennas. It also explores communication technologies such as Code Division Multiple Access (CDMA) and Frequency Division Multiple Access (FDMA), comparing their characteristics, advantages, and disadvantages.

Running head: NETWORKING AND COMMUNICATION
Networking and communication
Name of the student
Name of the University
Author Note

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Answer to question 1:
Antennas are termed as the basic requirements in an electric circuit as it helps to connect
the free space with transmitter equipment or the receiver equipment to the free space (Stutzman,
& Thiele, 2012). There are different types of antennas that will be discussed in this section. They
are:
 Log Periodic antennas (Bow Tie Antenna, Log-Periodic Dipole Array)
 Wire antennas (Short Dipole Antenna, Dipole Antenna, Monopole Antenna and Loop
Antenna)
 Travelling wave antennas (Helical Antenna, Yagi-Uda Antenna)
 Microwave Antennas (Rectangular Micro strip Antenna, Planar Inverted-F Antenna)
 Reflector Antennas (Corner Reflector, Parabolic Reflector)
A log-periodic antenna is a directional and multi-element antenna with a narrow beam. The
working of this type of antenna is based on its special characteristics where the active region of
the antenna shifts with a change in the frequency of operation (Hamidi et al., 2012). The main
advantages of this antenna are the wide bandwidth and the presence of same radiation resistance
over a range of frequencies. However, these antennas have a very low gain. Wire antennas are
also termed as a curved or linear antenna, are very simple and used in various applications. The
dipole antenna as the name suggests, has two metallic rods, which acts as the radiating element.
The major advantages of the wire antennas are the undistorted output and simple design.
However, the disadvantages include the big size of the antenna.
Travelling wave antennas are those types of antennas that use a guided mechanism for its
radiation properties. The working of this type of antenna includes the propagation of the waves

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along its axis. The main advantages of are the high gain, high directivity and less waste of power.
However, the disadvantage includes less noise resistance and less resistance to the atmosphere.
Microwave antennas are those types of antennas, which operates at the range of microwave
frequencies (Hancock et al., 2013). The working of this type of antenna involves the
transmission of energy by the use of microwave radiations. The main advantages of these
antennas are the presence of larger bandwidth and lack of interference in coherent signals. The
main disadvantages are the high transit time and the limitation to line of sight communication.
Reflector antennas are those antennas where the presence of a curved surface is a necessity for
the transmission and reception of the signals. The working of the antenna is achieved by
implementing the property of reflection of the signals and a feed to collect those signals. The
advantage of this antenna is wide bandwidth and high gain while the disadvantages are the
requirement of reflectors and drive element. The increased size and cost is also a hindrance to the
structure.
The main antenna types used for long distance as well as medium range communications
are the directional antennas. The directional antennas have a wide range of operation.
Answer to question 2:
Code Division Multiple Access (CDMA) involves the process of multiplexing that helps
the various signals to utilize a single transmission channel. The technology is basically used in
UHF bands. This basic use of the bandwidth is achieved by assigning specific codes for
transmission to a specific user (Ghafouri-Shiraz & Karbassian, 2012). The various techniques
that are used in this process are the direct sequence CDMA (DS-CDMA) or frequency hopping
techniques. The codes are orthogonal to each other. This helps in facilitating the selection of

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specific codes for transmission and reception. There is a presence of soft capacity in CDMA. The
users have the same bandwidth, which are divided by codes. Thus, the operation of the CDMA
process is done in the presence of interference and much noise.
Frequency division multiple access (FDMA) involves a process where the bandwidth
which is available is divided into channels with equal frequencies. These channels helps are then
used for transmission or reception (Ochiai, 2012). These processes include guard bands in
between the channels to minimize the presence of interference. The specific channels, which are
given to user, are transmitted and at the same time, the same channel is taken for reception. The
first generation of analog phones used this technique.
 Comparison between CDMA process and FDMA process (Patil, Karhe & Aher, 2012)
CDMA
Simultaneous transmission of signals and same frequency is used.
The narrowband signals are accompanied by wideband spreading.
The codeword are unique and orthogonal to each other.
The detected codes are analyzed in the receiver and others are detected as interference or
noise.
The receiver needs to know the transmitter code.
FDMA
Channel is idle, when not used.
The narrow bandwidth is a disadvantage of FDMA.
Less equalization is needed for symbol spreading.
FDMA is suitable for application in analog links.
Interference is minimized by the use of tight filtering.

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Duplexing is achieved when accompanied with frequency division duplex (FDD).
Answer to question 3:

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References:
Ghafouri-Shiraz, H., & Karbassian, M. M. (2012). Optical CDMA networks: principles, analysis
and applications (Vol. 38). John Wiley & Sons.
Hamidi, Z. S., Abidin, Z., Ibrahim, Z., Shariff, N., & Monstein, C. (2012). Modification and
Performance of Log Periodic Dipole Antenna. International Journal of Engineering Research
and Development, 3(3), 36-39.
Hancock, C. P., Dharmasiri, N., White, M., & Goodman, A. M. (2013). The design and
development of an integrated multi-functional microwave antenna structure for biological
applications. IEEE Transactions on Microwave theory and Techniques, 61(5), 2230-2241.
Ochiai, H. (2012). On instantaneous power distributions of single-carrier FDMA signals. IEEE
Wireless Communications Letters, 1(2), 73-76.
Patil, C. S., Karhe, R. R., & Aher, M. A. (2012). Review on Generations in Mobile Cellular
Technology. International Journal of Emerging Technology and Advanced Engineering, 2(10).
Stutzman, W. L., & Thiele, G. A. (2012). Antenna theory and design. John Wiley & Sons.