kashif paracha

This paper aims to review some of the available tunable devices with emphasis on the techniques employed, fabrications, merits, and demerits of each technique. In the era of fluidic microstrip communication devices, versatility and stability have become key features of microfluidic devices. These fluidic devices allow advanced fabrication techniques such as 3D printing, spraying, or injecting the conductive fluid on the flexible/rigid substrate. Fluidic techniques are used either in the form of loading components, switching, or as the radiating/conducting path of a microwave component such as liquid metals. The major benefits and drawbacks of each technology are also emphasized. In this review, there is a brief discussion of the most widely used microfluidic materials, their novel fabrication/patterning methods.

Single section branch line coupler is popular because of its simplicity in design and fabrication. But it suffered from narrow bandwidth and poor out of band rejection characteristics. This paper overcomes these limitations by designing and simulating a Broadband 900 hybrid coupler implementable in planar microstrip circuit. Polydimethylsiloxane (PDMS) and a modified Zoflex Conductor (ZC) were used as the substrate and the conductor respectively. Copper particles obtained using Engraving machine was used to improve the conductivity of the ZC. The coupler is meant to operate at 6 GHz. It shows a return loss and isolation better than 18 dB within the frequency range of 3.64 GHZ to 7.64 GHz. The results exhibited a very low insertion loss better than 4 dB, from 3.64 GHZ to 7.64 GHz and a small phase variation better than 900±50 within the passband of 3.86 GHz to 7.34 GHz. A fractional bandwidth of 52.33% was achieved which is more than five times wider than that of conventional single ...

Currently, uninterrupted charging of Electric Vehicle (EV) is not possible due to grid overloading during day-time. The interruptions during charging causes uncertainty for users. This work proposes a solution to this vehicle charging problem by introducing a combination of Energy Storage Unit (ESU) and Photovoltaic (PV) panel charging along with the grid. The proposed solution is efficient in providing charging for EVs without any interruption in an office parking scenario. The important benefit of the proposed system is the rapid fulfillment of the charging demand of all EVs in parallel to lessening the added grid burden. The control algorithm is designed according to deterministic rule-based schemes. The proposed work is valid for the areas where parity level has already been reached. The efficacy of the proposed technique is evaluated under different charging situations using Matlab simulations. The results show that all connected EVs are charged fully without interruption. More...

Smart watch antenna design is challenging due to the limited available area and the contact with the human body. The strap of smart watch can be utilized effectively for integration of the antenna. In this study, an antenna integrated on a smart watch strap model using computer simulation technology (CST) was designed. The antenna was designed for industrial, scientific, and medical (ISM) frequency bands at 2.45 and 5.8 GHz. Roger 3003C was used as substrate due to its semi-flexible nature. The antenna size is 28.81 × 19.22 × 1.58 mm3 and it has a gain of 1.03 and 5.97 dB, and efficiency of 80% and 95%, at 2.45 and 5.8 GHz, on the smart watch strap, respectively. A unit cell was designed having a dimension of 19.19 × 19.19 × 1.58 mm3 to mitigate the effect of back radiation and to enhance the gain. The antenna backed by the unit cell exhibited a gain of 2.44 and 6.17 dB with efficiency of 50% and 72% at 2.45 and 5.8 GHz, respectively. The AMC-backed antenna was integrated into a sma...

Wearable antennas have gained much attention in recent years due to their attractive features and possibilities in enabling lightweight, flexible, low cost, and portable wireless communication and sensing. Such antennas need to be conformal when used on different parts of the human body, thus need to be implemented using flexible materials and designed in a low profile structure. Ultimately, these antennas need to be capable of operating with minimum degradation in proximity to the human body. Such requirements render the design of wearable antennas challenging, especially when considering aspects such as their size compactness, effects of structural deformation and coupling to the body, and fabrication complexity and accuracy. Despite slight variations in severity according to applications, most of these issues exist in the context of body-worn implementation. This review aims to present different challenges and issues in designing wearable antennas, their material selection, and f...

A planar, low-profile, dual-band and dual-polarized antenna on a semi-flex substrate is proposed in this paper. The antenna is fabricated on Rogers substrate with a thickness of 3.04 mm and sized at $70.4 \times 76.14 \times 3.11$ mm3 ( $0.37\lambda _{0} \times 0.40\lambda _{0}\times 0.016 \lambda _{0}$ ) only. The circular polarization property is enabled in the global navigation satellite system (GNSS) L1/E1 (lower) band by introducing a complementary split ring resonator on the antenna patch. Meanwhile, the antenna operates in the second (upper) 2.45 GHz WLAN band is enabled by etching a U-shaped slot on its ground plane. This simultaneous, dual-band and dual-polarized operation enables the proposed antenna to be applied in the indoor/outdoor wearable application. To isolate the antenna against the influence of the human body, a multiband artificial magnetic conductor (AMC) plane is added on the reverse side of the dual-band radiator. Comparison of the antenna without AMC in free...

This work reviews design aspects of liquid metal antennas and their corresponding applications. In the age of modern wireless communication technologies, adaptability and versatility have become highly attractive features of any communication device. Compared to traditional conductors like copper, the flow property and lack of elasticity limit of conductive fluids, makes them an ideal alternative for applications demanding mechanically flexible antennas. These fluidic properties also allow innovative antenna fabrication techniques like 3D printing, injecting, or spraying the conductive fluid on rigid/flexible substrates. Such fluids can also be easily manipulated to implement reconfigurability in liquid antennas using methods like micro pumping or electrochemically controlled capillary action as compared to traditional approaches like high-frequency switching. In this work, we discuss attributes of widely used conductive fluids, their novel patterning/fabrication techniques, and the...

This work reviews design aspects of liquid metal antennas and their corresponding applications. In the age of modern wireless communication technologies, adaptability and versatility have become highly attractive features of any communication device. Compared to traditional conductors like copper, the flow property and lack of elasticity limit of conductive fluids, makes them an ideal alternative for applications demanding mechanically flexible antennas. These fluidic properties also allow innovative antenna fabrication techniques like 3D printing, injecting, or spraying the conductive fluid on rigid/flexible substrates. Such fluids can also be easily manipulated to implement reconfigurability in liquid antennas using methods like micro pumping or electrochemically controlled capillary action as compared to traditional approaches like high-frequency switching. In this work, we discuss attributes of widely used conductive fluids, their novel patterning/fabrication techniques, and their corresponding state-of-the-art applications.

Around the world, countries are integrating photovoltaic generating systems to the grid to support climate change initiatives. However, solar power generation is highly uncertain due to variations in solar irradiance level during different hours of the day. Inaccurate modelling of this variability can lead to non-optimal dispatch of system resources. Therefore, accurate characterization of solar irradiance patterns is essential for effective management of renewable energy resources in an electrical power grid. In this paper, the Weibull distribution based probabilistic model is presented for characterization of solar irradiance patterns. Firstly, Weibull distribution is utilized to model inter-temporal variations associated with reference solar irradiance data through moving window averaging technique, and then the proposed model is used for irradiance pattern generation. To achieve continuity of discrete Weibull distribution parameters calculated at different steps of moving window...

A low-cost inkjet printing method for antenna fabrication on a polyethylene terephthalate (PET) substrate is presented in this paper. An office inkjet printer is used to have desired patterns of silver nanoparticle ink on the PET substrate without any postprocessing. Silver nanoparticle ink cures instantly as soon as it is ejected from the printer on a chemically treated PET substrate. The thickness of the silver nanoparticle layer was measured to be 300 nm with a sheet resistance of as low as 0.3 Ω/sq and a conductivity around 1.11 × 107 S/m with single layer deposition. A coplanar waveguide- (CPW-) fed Z-shape planar antenna on the PET substrate achieved the measured radiation efficiency of 62% and the IEEE gain of 1.44 dBi at 2.45 GHz. The printed antenna is also tested in bending conditions to ascertain its performance for the Internet of things (IoT) conformal applications for the future 5G network.

In this work, a new lattice based algorithm for blind equalization is developed. The proposed algorithm is a generalized version of an existing lattice-based soft constraint satisfaction multi-modulus algorithm (L-SCS-MMA) and is named as lattice-based soft constraint satisfaction multi-modulus algorithm of order p (L-SCS-MMA-p). Moreover, a slicer output has been incorparated in the blind estimate of the SCS-MMA algorithm to

Around the world, countries are integrating photovoltaic generating systems to the grid to support climate change initiatives. However, solar power generation is highly uncertain due to variations in solar irradiance level during different hours of the day. Inaccurate modelling of this variability can lead to non-optimal dispatch of system resources. Therefore, accurate characterization of solar irradiance patterns is essential for effective management of renewable energy resources in an electrical power grid. In this paper, the Weibull distribution based probabilistic model is presented for characterization of solar irradiance patterns. Firstly, Weibull distribution is utilized to model inter-temporal variations associated with reference solar irradiance data through moving window averaging technique, and then the proposed model is used for irradiance pattern generation. To achieve continuity of discrete Weibull distribution parameters calculated at different steps of moving window...

... Azzedine Zerguine Electrical Engineering Department King Fahd University of Petroleum & Minerals Dhahran,3126I, Saudi Arabia E-mail: azzedine@kfupm.edu.sa ... Comm., vol. 149, pp. 45-50, February 2002. [6] S. Abrar, A. Zerguine, and M. Deriche, "Soft constraint satisfaction ...

In this work, a new lattice based algorithm for blind equalization is developed. The proposed algorithm is a generalized version of an existing lattice-based soft constraint satisfaction multi-modulus algorithm (L-SCS-MMA) and is named as lattice-based soft constraint satisfaction multi-modulus algorithm of order p (L-SCS-MMA-p). Moreover, a slicer output has been incorparated in the blind estimate of the SCS-MMA algorithm to

ABSTRACT This work concentrates on the development of a Newton-like algorithm for blind equalization. This algorithm is obtained by applying a complex Taylor series on a recently proposed soft constraint satisfaction multi-modulus blind equalization algorithm of order p (SCS-MMA-p). The proposed algorithm is a generalized version of the SCS-MMA-p. This algorithm is called stochastic Newton-like soft constraint satisfaction multi-modulus algorithm of order p (SNL-SCS-MMA-p). Simulation results carried out, on both baud spaced and fractionally-spaced equalizers, to assess the performance of the prosed algorithm reveal great improvement in performance of the proposed algorithm against that of the SCS-MMA for different values of the parameter p.