Wednesday, May 6, 2020

Antennas for Wireless Sensor Networks- Free-Samples for Students

Questions: 1.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? Answers: 1.Differences Yagi, horn, cellular antenna Yagi antenna is also known as the Yagi-Uda array is the directional antenna which is often used for the communication whenever the frequency is above 10 MHz. This kind of antenna continues to be popular among the Amateur radio and the Citizen Band radio providers (Ammann John, 2005). It will be utilized at a number of the surface in the installation of the satellite communications techniques (Ammann John, 2005). The antenna offers unidirectional radiation in addition to the response pattern, however it concentrates the radiations and the response. Strengths It has a gain which allow a lower strength of the signal to be received. It has a directivity which enables the interference levels to be minimized. It design of the antenna is able to filter on the signal noise which is coming from the opposite direction (Chieh, Dick, Loui Rockway, 2014). This consequently tends to make Yagis the right choice when you have a high demand application for example the telecommunications. It is significantly simpler to aim the Yagi antenna than a few of the other arrays. There construction causes them to be much simpler to mount on the vertical towers. Weaknesses There is limitation of the bandwidth or the frequency. In case an individuals wants to have a high gain level, the antenna need to be very long. This kind of antenna experiences a degradation for the electrical characteristics as one moves away from the frequency range (Chieh, Dick, Loui Rockway, 2014). Horn antenna This really is an antenna which consist of the flaring metal waveguide which is shaped similar to the horn to direct the radio waves in the beam (Pelletier, Olvera-Hernandez, Watfa Ahmad, 2017). The horn has been utilized extensively especially to the UHF and the microwave frequencies, which is above the 300 MHz. Strengths Impedance matching is very good It has a greater directivity There is narrower beam width There is standing waves which are avoided. Weaknesses The designing of the flare perspective determines on the directivity The flare angle in addition to the length of the flare really should not be very small. Cellular antenna This antenna is utilized in the alignment with the powered signal booster for example the inline amplifier, repeater or even the connected directly to cell phone or maybe other devices which are with the cell adapter cable or even the coax adapter (Chieh, Dick, Loui Rockway, 2014). Strengths There is increased number of the users, due to the targeted nature of the frequencies of the antenna could be reused allowing on the increased on the user number. There is increased bandwidth: the bandwidth which is available increase from the reuse of the frequencies and adaptive arrays (Chiu, Liu, Gao Ying, 2013). Weaknesses It is more expensive, the cellular antenna are very complex, which uses the latest processing technology. There is the issue of location. The location needs to be considered that is optimal operation for the antenna. The antenna which would become dominant in these three would be cellular antenna. The reason for the choice is that there is increased number of users, as a result of the target frequencies and there is increased bandwidth (Chiu, Liu, Gao Ying, 2013). 2. Compare and contrast CDMA and FDMA. Similarities In both of these two techniques of wireless networking they uses the access technology. This is where the users is allowed to access on the single channels via the use of the resource allocation system. The users are able to establish on the communication within the network (Nilsson, 2009). In both there is the sending and receiving of the data which allows the flexible allocation of the resources. Additionally, both of these technologies have been used in the mobile devices application where the FDMA has been the analog version and the CDMA has been the latest technology through use of the 3G technology (Nilsson, 2009). Contrast CDMA is the telecommunication technique that is used in most radio communicating organization in order to access the communicating channels within minimum time whereas in FDMA is the technique which is used in the advanced Mobile Phone (Pelletier, Olvera-Hernandez, Watfa Ahmad, 2017). Additionally, when it comes to the FDMA the technique is used for the analogue mode of transmission, the technique is not effective in the transmission of the digital signal whereas when it comes to CDMA it is digital mode of the transmission which is 3G technology (Waldschmidt, Fugen Wiesbeck, 2002). In the FDMA technique it allows the total available bandwidth to be divided into the various frequencies whereas when it comes to CDMA the users are provided with the communication platform in which each is given the equal bandwidth level that has a similar speed of transmission as well as the same frequency. In the CDMA there is no fixed number of the users as comparison to the FDMA techniques (Pelletie r, Olvera-Hernandez, Watfa Ahmad, 2017). Moreover, the FDMA coordinates the access of the frequencies through the multiple users whereas when it comes to CDMA the access of the frequencies is through single users. The FDMA technology is used in the analog mobile phones whereas the CDMA uses the 3G technology which is used in most of the mobile devices References Ammann, M., John, M. (2005). Optimum design of the printed strip monopole. Chieh, J. C. S., Dick, B., Loui, S., Rockway, J. D. (2014). Development of a Ku-band corrugated conical horn using 3-D print technology. IEEE Antennas and Wireless Propagation Letters, 13, 201-204. Chiu, C. Y., Liu, X., Gao, F., Ying, Z. (2013, April). Constraints and performances of various antenna types in commercial mobile terminals. In Antennas and Propagation (EuCAP), 2013 7th European Conference on (pp. 894-897). IEEE. Pelletier, G., Olvera-Hernandez, U., Watfa, M., Ahmad, S. (2017). U.S. Patent No. 9,648,657. Washington, DC: U.S. Patent and Trademark Office. Nilsson, M. (2009, May). Directional antennas for wireless sensor networks. In Proc. 9th Scandinavian Workshop on Wireless Adhoc Networks (Adhoc'09). Waldschmidt, C., Fugen, T., Wiesbeck, W. (2002). Spiral and dipole antennas for indoor MIMO-systems. IEEE Antennas and Wireless Propagation Letters, 1(1), 176-178.

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