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This paper presents a comprehensive numerical and experimental study of Planar Inverted-F Antennas (PIFA) involving all the parameters which may affect the characteristics of PIFA. It is found that PIFA characteristics are affected by a number of parameters including the dimensions of the ground plane, length, width, height and position of the top plate, positions and widths of shorting pin/plate and feed pin/plate. It is also found that the width of feed plate plays an important role in broadening the antenna bandwidth. It is shown that a fractional impedance bandwidth up to 65% can be obtained using an optimized design. Furthermore, a new empirical formula is introduced for the estimation of the central operational frequency of PIFA. These results are very useful for aiding PIFA design in practical applications.

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Nonfunctional requirements are ignored because functional requirements are considered to be more important than nonfunctional requirements, lack of knowledge and methodologies to accomplish nonfunctional requirement elicitation and the nature of agile software development process. This ignorance of nonfunctional requirements become the cause to failure of projects. Furthermore, cloud computing helps to practice twelve (12) agile principles including nonfunctional requirement elicitation. This study proposed a semi-automated methodology for eliciting nonfunctional requirement in agile development and cloud computing environment. The methodology used an NLP based automatic NFR extraction approach to fast the NFR elicitation process. The methodology is evaluated by applying on eProcurement dataset. The results are improved as compared to existing studies.

Radio frequency identification (RFID) is a key technology to realize IoT (Internet of Things) dreams. RFID technology has been emerging in sensing, identification, tracking, and localization of goods. In order to tag a huge number of things, it is cost-effective to use one RFID antenna for tagging different things. Therefore, in this paper a platform tolerant RFID tag antenna with tunable capability is proposed. The proposed tag antenna is designed and optimized using characteristic mode analysis (CMA). Moreover, this tag antenna consists of a folded patch wrapped around FR 4 substrate and a feeding loop element printed on a paper substrate. The inductive feeding loop is stacked over folded patch and it provides impedance match with RFID chip. Because of separate radiating and feeding element, this tag antenna has a versatility of impedance matching with any RFID chip. Furthermore, this tag is able to cover American RFID band (902–928 MHz) and can be tuned to European RFID band (865–868 MHz) by adding tunable strips. In order to demonstrate platform tolerant operation, the read range of RFID tag is measured by mounting it on different materials. The maximum read range of RFID tag is 4.5 m in free space or on dielectrics and 6.5 m above 200 × 200 mm2 metal plate, respectively.

This paper presents a four-element compact phased Planar Inverted-E Antenna (PIEA) array for 6 GHz beamforming applications. For compact phased arrays, the mutual coupling is a severe performance degrading factor. Therefore, three mutual coupling reduction techniques are employed, which include (i) PIEA as an array element which is a modified version of Planar Inverted-F Antenna (PIFA) by inserting another shorting plate, (ii) slots in the ground plane and (iii) two slits in each etched ground slot. With these techniques, the mutual coupling is reduced below −19 dB in the operational bandwidth from 5.7 to 6.4 GHz. The compact design with an inter-corner spacing of 0.013λ o and an inter-element spacing of 0.3λ o is achieved. The peak gain obtained by this compact phased array is 8.36 dBi. This array can scan up to a maximum scanning angle of ±70 o. A good general agreement is found between the measured and simulated results. INDEX TERMS Antennas, phased array, PIFA, beamforming, mutual coupling.

A novel ultrawide band planar inverted-F antenna with band-notched characteristics is presented in this paper. The planar inverted-F antenna uses two parasitic elements to enhance the bandwidth to cover the ultrawide band. The band-notched feature is added by inserting a W-shaped slot on the top radiating element of the antenna with a band rejection from 5.08 to 6 GHz (measured). Both the measured and simulated results are obtained to draw the conclusions.