Wireless Propagation and Communication-Free-Samples for Students

Questions: 1.Different antenna, such as yagi, horn, and celluar antennas, etc. has different merits. Research these technologies in details and pay specific attention to how they are used as well their strengths and weakness. Provide an opinion regarding which antenna types will become the dominant players in the future of medium- and long-distance wireless links. 2.Compare and contrast the multiplexing techniques CDMA and FDMA in the area of wireless networking? 3.A local engineering group ask you to present your finding of the most recent advanced wireless technologies. Research these technologies in details and pay specific attention to how they are used as well their strengths and weakness. Provide an opinion regarding which antenna types will become the dominant players in the future. Answers: 1.Different types of antennas In case of television and broadcasting Yagi-uda antenna is used most commonly. The performance index of this type of antenna is better (Aouani et al., 2014). This type of antenna is mostly used for the better directivity and high gain and the frequency range of the antenna is between 30MHz to 3GHZ and relies in between the UHF and the VHF frequency bands. Strengths The directivity is high. Power consumption is low. The maintenance and handling cost is low and also easy. The frequency range is large that can be covered by the Antenna The bandwidth is of lower value and the gain is high. Weakness Atmospheric changes can affect this kind of antenna This kind of antenna is also affected by the noise. Applications The Yagi antenna is particularly useful in case of the applications where an RF antenna design is required to create required gain and directivity (Han et al., 2015). It is also useful in case of optimum transmission and reception conditions can be obtained. Horn Antennas A horn antenna functions on the basis of microwave frequencies and for this reason it is called Microwave antenna also (Inui et al., 2015). There are many kinds of antennas which are available in the market and those are conical horn, pyramid horn antenna and the corrugated horn antenna. Strengths It has a narrow range of beam width. Many small minor lobes are created. It has a good impedance matching Directivity is an important factor and it has a greater value Weakness The value of the flare angle and the length of the flare should be good enough The directivity should be high but the design of the flare angle is not advantageous for the antenna Applications Horn antennas are used as short distance radars. It is also used in various cameras which are used in speed enforcement. Cellular antenna Those antennas which are used in the mobile phones or cell phones are called cellular antenna (Yin et al., 2013). The main thing about the cellular antenna is that it can be used as the conjunction between the data signal and the mobile phone. Strengths The cellular antennas are used for the communication along very long distances like 45 miles and more. It has a huge capacity to transfer a lot of data per second. It is very suitable for the transfer of data in long distances. Weakness There is always a connection problem in case of using the cellular antennas. The damage of this kind of antennas can damage the whole communication system. Increased number of the antennas in each base station. Applications Cellular antennas are used in mobile phones. It is also used for long distance communication. These antennas are used in the cellular base stations. Selection of antenna type for medium and long distance Cellular antennas are most suitable for long distance communication. This type of antenna is used in case communication in more than 65 miles distance. 2.Comparison and contrast of FDMA and CDMA CDMA refers to code division multiple accesses and it is a method that has the access of different channels and it is a blend of several radio communications (Sarkar, Srivastava Saurav, 2014). It is created by spreading the codes using orthogonal codes. It is a suitable example of multiple accesses. FDMA refers to Frequency Division Multiple Access and it is a method that utilises the channel for accessing and it also acts as a channelization protocol (Yang Marzetta, 2013). It provides the users several bands of frequency and is mainly used in satellite communication. CDMA FDMA Every user uses the same frequency band and the transmission is simultaneous in nature. It is inactive in case when the channel is not active. It uses the spectrum by distributing various orthogonal codes. In FDMA the frequency band is distributed in several disjoint subbands. All terminals can act simultaneously. Every terminal has individual frequency levels. It uses continuous transmission scheme. It also uses continuous transmission scheme. It has no absolute limits of cell capacity. It has limited cell capacity 3.Most recent advanced wireless technologies RFID is one of the latest wireless technologies which is used to identify the position of several objects and to keep record of those objects. RFID stands for Radio Frequency Identification Detector. RFID functions on the basis of Radio frequency signals. It consists of different parts like tags and receiver (Lo Lee, 2013). RFID tags are attached to several objects and it connects with the receiver to transfer several signals regarding the position and information about the object. The receiver receives the signal and helps to keep track of those objects. Strength RFID tags can be used to keep track of objects as well as pet animals. RFID system is more efficient in case of retailing business and stores to keep track of the objects very easily and it is better than the barcode scanner. RFID can be used in electronic identification of vehicles and automatic toll collection system. Weakness RFID is used in small range like 100 meters only. In case of long range RFID the cost is very high. Best type of antenna for use in future In future the long range communication will be the main factor to determine the best option among the antennas (Ding et al., 2015). From that point of view the Cellular antennas can be the most useful antennas in future. References Aouani, H., Rahmani, M., Navarro-Ca, M., Maier, S. A. (2014). Third-harmonic-upconversion enhancement from a single semiconductor nanoparticle coupled to a plasmonic antenna. Nature nanotechnology, 9(4), 290-294. Ding, Z., Zhong, C., Ng, D. W. K., Peng, M., Suraweera, H. A., Schober, R., Poor, H. V. (2015). Application of smart antenna technologies in simultaneous wireless information and power transfer. IEEE Communications Magazine, 53(4), 86-93. Han, S., Chih-Lin, I., Xu, Z., Rowell, C. (2015). Large-scale antenna systems with hybrid analog and digital beamforming for millimeter wave 5G. IEEE Communications Magazine, 53(1), 186-194. Inui, T., Koga, H., Nogi, M., Komoda, N., Suganuma, K. (2015). A miniaturized flexible antenna printed on a high dielectric constant nanopaper composite. Advanced Materials, 27(6), 1112-1116. Lo, Y. T., Lee, S. W. (2013). Antenna Handbook: theory, applications, and design. Springer Science Business Media. Sarkar, D., Srivastava, K. V., Saurav, K. (2014). A compact microstrip-fed triple band-notched UWB monopole antenna. IEEE Antennas and Wireless Propagation Letters, 13, 396-399. Yang, H., Marzetta, T. L. (2013). Performance of conjugate and zero-forcing beamforming in large-scale antenna systems. IEEE Journal on Selected Areas in Communications, 31(2), 172-179. Yin, H., Gesbert, D., Filippou, M., Liu, Y. (2013). A coordinated approach to channel estimation in large-scale multiple-antenna systems. IEEE Journal on Selected Areas in Communications, 31(2), 264-273.