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In today's modern society, people are getting more conscious of the built environment's energy efficiency and sustainability. Sustainable architectural design reduces negative environmental effect by improving energy efficiency, health, comfort, safety, livability for inhabitants, and the ecosystem at large. Other considerations include effective maintenance and optimization of the resources. All of this is achieved by incorporating appropriate technology within the building. Recent developments in the field of IoT, cloud computing, machine learning, artificial intelligence, and other smart wireless technologies could support solutions for building automation systems. Therefore, it is utmost important to determine the potential of these cutting-edge and smart wireless technologies for building automation and management. In this research work, the role of building technologies in creating a smart and sustainable built environment is identified and discussed. To emphasize the importance, a survey is being conducted to identify the current demand for building management systems, as well as their awareness and present scenario.

With the goals of a better power factor and reduction in energy use, variable frequency drives (VFDs) have been standardized in various industrial applications including Heating, Ventilation, and Air-conditioning (HVAC) systems. However, key issues related to the deterioration in the power quality associated parameters (voltage harmonic distortion and current harmonic distortion) due to the growing number of VFDs demand a wholesome analysis of the problems faced by the users. In this present work, an analysis has been performed to investigate the potential impact of using alternating current (AC) line reactor and direct current (DC) link choke combination on harmonic mitigation in a VFD driven water-cooled centrifugal chiller compressor. Using a combination of AC line reactor and DC link choke as one of the low cost solutions in harmonic mitigation of a VFD driven load in HVAC systems can be decided based on the investigation done in this research work.

For modern wireless communication systems, miniaturized multiband antennas with enhanced bandwidth and gain are desired to achieve optimum system performance. A planar microstrip patch antenna is preferred because of its small size, low cost, and ease of fabrication. For impedance matching, a conductive metallic patch can be fed by different techniques to deliver the maximum power to the microstrip antenna. The various configurations of inset feed, co-axial feed, aperture feed, and proximity feed, and CPW feed, which are used to excite micro-strip patch antennas, are reviewed in this research paper. Different feeding mechanisms are discussed to improve antenna performance in terms of S11 parameter, bandwidth, gain, and radiation pattern suitable for different wireless communication applications.

In this paper a compact wideband Filtenna structure with stopband characteristics has been presented. The proposed filtenna is a planar elliptical patch with a CSRR structure embedded in the partial ground. The elliptical shape is utilized to attain the wideband characteristics whereas the CSRR is etched out to filter out the undesired bands. This filtenna design exhibits an impedance bandwidth of 3.3 GHz ranging from 2.47 GHz to 5.77 GHz covering the WLAN (2.4/5.2 GHz) and WiMAX (2.5/ 3.5/ 5.5 GHz) bands and effectively rejects the higher bands beyond 5.77 GHz. The designed filtenna achieves a maximum gain of 4.11 dBi and a bidirectional radiation pattern over the desired bandwidth. The overall dimensions of the proposed filtenna is 40 mm x 50 mm x 1.6 mm with the patch area 14 mm x 10 mm. The proposed filtenna is designed, simulated and optimized using CST Microwave Studio and has been fabricated and tested to validate the proposed design.

A dual-band slotted patch antenna with thin dielectric has been proposed for Ku–band applications. A rectangular patch with pair of bent slots at each side of center has been designed and resonant at 11.95 GHz and 14.25 GHz with respect to ITU standard. A dual resonance ultrathin metamaterial absorber (MMA) based on circular rings and shorted stubs operating at same frequency bands have been designed. Its behavior at an oblique angle of incidence and polarization sensitivity has been also observed. In this research work, it has been obtained that when dual–band slotted patch antenna is surrounded by proposed MMA structure, it significantly enhances in-band stealth capability of the antenna. The monostatic and bistatic RCS of the proposed design has been reduced significantly whilst maintaining and preserving the antenna radiation performance. This design finds its application in satellite and wireless communication.

In this research work, the design characterization of metamaterial absorber (MMA) has been analysed for a unit cell structure of shorted stubs circular rings metamaterial absorber. The simulated results show that dual resonance peaks occur at 17 GHz and 18 GHz with absorbance peak response of 99.99% and 99.83%, almost unity absorbance. The corresponding full width at half maximum (FWHM) bandwidth at these resonant frequencies are 4.90% and 5.07% respectively. A parametric study has been done to analysed the effect of variation of circular ring radius, shorted stubs length and rectangular bar length upon the resonance frequency. The analysis shows that we can achieve a lower resonant frequency with almost unity absorbance. Moreover, the resonant frequency drifts to lower value without affecting absorbance. The effect at oblique angle of incidence and polarization sensitivity is also considered for both TE and TM modes. So, this unit cell structure acts as a controllable and tunable MMA structure. The dual resonances MMA structure are becoming a prime technology for many present and future wireless communication systems such as radar cross section (RCS) reduction for stealth technology, satellite navigation systems, radar frequency identification and wireless handheld devices.

Agriculture has been the backbone of our country's economy and it will remain to continue for a long time. Over 70 percent of the rural population depends on agriculture. The contribution of agriculture to the gross domestic product (GDP) is about to 18% and have contributed up to 50% of the country's employment. The prognosis indicates that requirement to feed a world population of 9.1 billion people in 2050 necessitates the raise of total meal production nearby 70% between 2005 and 2050. Consequently, production would need to be almost doubled in the developing countries. In this context, we have proposed a new design concept of smart drip irrigation system for remote hilly areas where electricity and water connectivity are poor. The proposed system is powered through solar energy and provide a better alternative to conventional automatic irrigation systems. Thus, conserve electricity and water by reducing their usage.

A novel structure of three dimensional Cylindrical Shaped Frequency Selective Surface (CSFSS) has been structured and its polarization sensitivity has been analyzed. The effect of oblique angle of incident electromagnetic wave on the CSFSS by varying the circumference of the outer ring has been observed. The analysis has been made for oblique incident angles from 0° to 60°. The resultant frequency response reveals that the CSFSS structure has been found highly polarization insensitive and obtained a stable transmission response with respect to incident EM wave. Moreover, an analysis has been made to find out the effect of variation of the circumference on the resonant frequency and result shows a highly sensitive and interesting relation between them.

The three dimension cylindrical structure is interesting, challenging and offers excellent space utilization. With utilization of three-dimensional space, the unit cell size of the FSS can be further reduced. A novel design of three dimensional Cylindrical Shaped Frequency Selective Surface (CSFSS) based on a single circular ring structure has been proposed. Firstly, a circular ring has been chosen and its frequency response has been studied. Then by keeping all the parameter same a CSFSS structure has been drawn with varying height. A significant influence on the frequency response characteristics of the CSFSS viz a viz a stop-band and pass-band frequency response behavior has been observed. A polarization sensitivity analysis has been done for the TE and TM modes for oblique angle of incidence. A full width half maximum (FWHM) bandwidth analysis of CSFSS is also observed. By varying the parameters of the CSFSS, the resonant frequency could be tuned. A parametric analysis of the CSFSS is done. The widespread potential applications of the proposed CSFSS are found in area of communication, microwave and radar systems.

In this research work, the design characterization of metamaterial absorber has been investigated for X-band applications. For this purpose, a primary regular decagon shaped loop structure has chosen and its multi band response has been studied and analyzed. The simulated results show that absorption peaks occur at 8 GHz, 10 GHz and 12 GHz with absorbance peak response of 96 %, 93.36 % and 91.88 % with full width at half maximum (FWHM) bandwidth of 5.72 %, 4.00 % and 3.80 % respectively. By proper arrangement, we have achieved the absorption peaks for triple frequency band at incident electromagnetic wave. The scalability property of metamaterials was utilized. Field analysis reveals that the frequency selective surface (FSS) unit cell absorbers resonance peaks occur, when the intrinsic impedance of the regular decagon shaped structure matches with the free space impedance. The proposed absorber is predicted to be useful in various potential applications like stealth technology for aircraft, ships, military vehicles, ballistic missiles. Moreover, the design idea has the ability to be extended further to microwave, optical and terahertz regime.