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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 2.Compare and Contrast the multiplexing techniques CDMA and FDMA in the area of wireless networking? Answers: 1.An antenna is the component of the microwave link that interrelates with open space. It is the structure that conveys the electromagnetic energy from open space into transmission lines and vise-versa (Mishra, 2007). Antennas are made and designed in different shapes and sizes according to frequency requirements. Horn Antenna This microwave antenna is also called open waveguide. It operates as a feed component for huge radio astronomy, communication dishes and satellite tracking. A horn antenna is a hollow antenna which is used to properly match the waveguide to a large radiating aperture by shaping the movement little by little. The horn antenna is mainly used for broadband signals. Advantages of horn antenna include broadband application, high gains (10-25db), simple to design and excite and it is also easy to construct (Kumar Shukla, 2015). Disadvantages of horn antenna include diffraction at the edges and low cross polarization level. Yagi antenna Yagi-Uda antenna is a high directive antenna. It consists of an array of parasitic components which are kept in parallel to the driven components. The driven component is half wave dipole antenna and the parasitic components are metallic rods of longer and shorter length relative to resonant length. The parasitic elements of longer lengths are inductive and are used as reflectors while the parasitic elements of shorter lengths are capacitive and are used as directors. Some of the advantages of Yagi-Uda antenna include high gain capability, low cost and ease of construction, and the radiation pattern of a Yagi-Uda antenna is unidirectional. Among the disadvantages is that to acquire high gains, the antenna can become very long. In addition, the gain is limited to around 20dB for a single antenna (Poole). Cellular antennas Cellular networks mainly use smart-antenna technology. The smart antenna array consists of an array of antenna elements. Some advantages of smart antenna include; wide radio coverage through range extension, increased capacity, and mitigates fading in multipath environments. In addition, it is possible to achieve maximum data rates while using smart antennas. In the future, the dominant player for medium and long distance wireless links is likely to be the smart antennas. This can be supported by the fact that Their radiation patterns help adaptively to maximize communication quality. Along with Space Division Multiple Access (SDMA) technique, they enhance beam tracking in mobile communication They ensure greater efficiency and increase frequency reuse in cellular environment The system capacity can be increased using interference reduction on the downlink and interference rejection on the uplink. Hence, for better coverage, reduced interference, reduced fading under multipath effects, smart antennas are highly appropriate and likely to be the prevailing player in the future of medium- and long-distance wireless links 2.Comparison and contrast on multiplexing techniques CDMA and FDMA in the area of wireless networking. Multiplexing is the method through which numerous signals are pooled into a single signal domain (Haas, 2014). The signal is then taken apart into the original signals on the receiving end. Multiple Access applies multiplexing techniques to separate the information of individual entities in one common signal domain. Among the multiplexing techniques are CDMA and FDMA. Code Division Multiple Access (CDMA) depends on the spread spectrum where all users can broadcast in the same frequency band at the same time (Dorf, 2015). However, each transmitter-receiver pair employs a particular spreading waveform for demodulating the information. The spreading waveforms of different users have very low cross correlation which is why CDMA is inherently interference limited. Frequency Division Multiple Access (FDMA) is the frequently used multiplexing technique. Channel bandwidth is subdivided into non-overlapping sub-channels. Each channel is then assigned the frequency slot or band permanently. All users can transmit their information simultaneously over the band allocated to them. The bands are separated from each other by guard bands which are essential to steer clear of inter-channel interference. Comparison between CDMA and FDMA multiplexing techniques Parameter FDMA CDMA Technique Overall bandwidth of a channel is shared by multiple users The time as well as the bandwidth is shared by multiple users Interference effects neighboring frequency bands interference is produced because of non-linearity of satellite transponder amplifier Performance is affected because of neighboring time and frequency slots. However, due to frequency hoping the effect is less. Code word No code word is required Code words or signature waveforms are required to demodulate the information. Power efficiency Power efficiency is reduced Full power efficiency is possible Guard times and band Guard bands are required Guard times and bands are both required References Dorf R. C. (2015). The Engineering Handbook, Second Edition. London : CRC Press Haas E. (2014). Design, Evaluation and Implementation of a Multi-carrier Transmission System for Aeronautical Communications 5th Edition. Germany: Herbert Utz Verlag Kumar S. Shukla S.(2015).WAVE PROPAGATION AND ANTENNA ENGINEERING 2nd Edition. London: PHI Learning Pvt. Ltd Mishra A. R. (2007).Advanced Cellular Network Planning and Optimisation: 2G/2.5G/3G...Evolution to 4G. England: John Wiley Sons LTD Poole . Radio-Electronic.com. Antennas and Propagation: Yagi Antenna / Yagi-Uda Antenna. Retrieved August 18, 2017 from https://www.radio-electronics.com/info/antennas/yagi/yagi.php