1.A Yagi antenna is a beam antenna that receives or radiates huge power in distinct directions. This type of antenna allows minimizing intrusion and expanding performance from undesired sources. Yagi antenna consists of several parallel components in a line. This antenna consists of a single driven component that is attached to the receiver or transmitter with a line of transmission (Sun et al., 2013). Yagi antenna is popularly used in High Frequency (HF) bands, Very High Frequency (VHF) bands and Ultra High Frequency (UHF) bands.
The advantages of Yagi antenna are as follows:
- The main advantage of Yagi antenna is that it is a directional antenna. This makes it one of the best antennas for receiving lower strength signals.
- The high gain of Yagi antenna provides it a relatively better range.
- This is cheaper and thus it makes this antenna cost effective (Cai et al., 2012).
The disadvantages of Yagi antenna are as follows:
- Bandwidth is less or limited.
- This type of antenna has a degradation in feed point impedance.
A Horn antenna is an antenna, which is composed of a blazing metal waveguide and is shaped like a horn (Mallahzadeh & Esfandiarpour, 2012). These are mainly used in Ultra High Frequency bands.
The advantages of Horn antenna are as follows:
- Extensible bandwidth
- Simple construction (Bilotti et al., 2012).
- Can operate in a broad range of frequencies.
The disadvantages of Horn Antenna are as follows:
- Low Standing Wave Ratio
- Average Gain
Cellular antenna is widely used in cellular networks. The advantages of cellular antenna are as follows:
- Can be easily used
- Simple construction
The disadvantages of Cellular antenna are as follows:
- Very expensive.
- Average gain.
The antenna that will be the dominant player in the future of medium and long distance wireless links is the New Digital Antenna (Sun et al., 2013). This particular antenna is cost effective, as well as the bandwidth of the antenna is extensible. This can be easily used by all individuals. This antenna will surpass all the existing antenna through its advantages.
2.Compare and contrast the multiplexing techniques CDMA and FDMA in the area of wireless networking.
Code Division Multiple Access
Frequency Division Multiple Access
To disperse the spectrum using angular codes
To divide the frequency bands into multiple smaller bands.
Separation of signal
Special receivers and coding.
Frequency domain is filtered
Every terminal can be active simultaneously at the same time and place without any kind of interruption (Glisic & Lepp?nen, 2013).
Every terminal has its own different frequency without any kind of interruption.
Capacity of cell
No specific limit on capacity of channel but CDMA is a system of limited interference.
Limited cell capacity
Flexible, scalable, soft handover, less panning of frequency needed.
Established, vigorous, strong, simple
Receivers complicated, more complicated power control is needed for senders.
Inflexible, frequencies are sparse resources
High complexity, faces some of the major problems, much less expectations, is further integrated with Frequency Division Multiple Access or Time Division Multiple Access.
Usually integrated with Time Division Multiple Access and Space Division Multiple Access.
The above table describes the comparison and contrast between Code Division Multiple Access and Frequency Division Multiple Access.
Code-division multiple access or CDMA is a method that is accessed by channel and is utilized by several communication technologies of radio (Glisic & Lepp?nen, 2013). This is an example of multiple accesses, from where information can be sent through various transmitters at a single time over a single channel of communication. This aspect enables various users to share a vast band of frequencies. CDMA allows a special coding scheme and spread spectrum technology to permit this feature. Each transmitter is assigned a single code in this special coding scheme. CDMA is utilized as the method of access in most of the mobile phone standards.
Frequency division multiple access or FDMA is a method that is accessed by channel and is utilized as a channelization protocol in multiple-access protocols. FDMA provides users an individual allotment of one or more frequency channels or bands. It is usually very common in communication of satellite. FDMA collaborates access between several users.
3.Most recent advanced wireless technologies are Bluetooth technology, RFID, NFC and Wi-Fi (Liang & Yu, 2015). The strengths and weaknesses of these technologies are as follows:
- It is cheaper
- Very convenient for attachment of various devices.
- Bluetooth technology can be installed very easily (Heydon, 2013).
- It can be utilized easily when the device has already installed the technology.
- Extremely virus prone when installed in mobile phones.
- It can be easily hacked.
- Connectivity is weak.
- The range in which Bluetooth can connect devices is less.
RFID: Radio Frequency Identification has certain merits and demerits.
- Security level is high
- RFID tags can store more data and information.
- RFID technology has a versatile nature.
- Tag has the write option along with read options.
- The programming part of RFID technology requires more time.
- RFID is extremely expensive.
NFC: Near Field Communication plays a major role in the mobile industry. It is another recent wireless technology.
- It has high security with password protection (Coskun, Ozdenizci & Ok, 2013).
- Convenience is the major benefit of this technology.
- It is extremely versatile and can be applied to various industries.
- It has high level of encryption that makes it suitable for academic areas.
- It is extremely expensive and thus it becomes tough to install it.
- It becomes very difficult for smaller organizations to install this system.
Wi-Fi: Wifi is another most recent advanced wireless technology (Bilotti et al., 2012). This technology helps to gain access to the internet.
- It provides high convenience for users to access the resources online.
- Users can access internet anywhere with the presence of public wifi.
- It can be developed with ease.
- It is cheaper and cost effective.
- Security is the major issue in wifi technology.
- It has a slower speed as compared to all other networks (Sun et al., 2013).
- Its coverage range is suitable for a home connection but not for a large area.
- It has huge interference leading to loss of connectivity.
Bilotti, F., Di Palma, L., Ramaccia, D., & Toscano, A. (2012). Self-filtering low-noise horn antenna for satellite applications. IEEE Antennas and Wireless Propagation Letters, 11, 354-357.
Cai, Y., Guo, Y. J., & Bird, T. S. (2012). A frequency reconfigurable printed Yagi-Uda dipole antenna for cognitive radio applications. IEEE Transactions on Antennas and Propagation, 60(6), 2905-2912.
Coskun, V., Ozdenizci, B., & Ok, K. (2013). A survey on near field communication (NFC) technology. Wireless personal communications, 71(3), 2259-2294.
Glisic, S. G., & Lepp?nen, P. A. (2013). Wireless communications: TDMA versus CDMA. Springer Science & Business Media.
Heydon, R. (2013). Bluetooth low energy: the developer's handbook. Prentice Hall.
Liang, C., & Yu, F. R. (2015). Wireless network virtualization: A survey, some research issues and challenges. IEEE Communications Surveys & Tutorials, 17(1), 358-380.
Mallahzadeh, A. R., & Esfandiarpour, S. (2012). Wideband H-plane horn antenna based on ridge substrate integrated waveguide (RSIW). IEEE antennas and wireless propagation letters, 11, 85-88.
Sun, H., Guo, Y. X., He, M., & Zhong, Z. (2013). A dual-band rectenna using broadband yagi antenna array for ambient RF power harvesting. IEEE Antennas and Wireless Propagation Letters, 12, 918-921.