Mohamed Aboualalaa

In this letter, a dual-band circular patch antenna is introduced. The antenna consists of a circular patch with a direct feed through microstrip feedline designed to radiate at 2.45 GHz with fractional bandwidth of 4.5%. A circular slot is inserted into the ground plane that radiates by capacitive coupling between the patch and the ground plane. This slot radiates at 1.95 GHz with fractional impedance bandwidth of 5%. The antenna achieves good radiation characteristics by inserting a reflecting

A new rectenna that can be utilized for sending/receiving data and scavenging radio frequency (RF) waves for linking and powering the Internet-of-Things (IoT) devices is proposed. The rectenna has three operating frequency bands; the lower frequency band is used for energy harvesting, and the other two frequency bands are assigned for data communication. It comprises a stacked four-layer antenna integrated with a voltage doubler rectifier. The antenna consists of a driven element, a planar refle

A dual-band mm-wave compact antenna is proposed in this paper. A quarter-wave half-slot resonator is used instead of a half-wave slot to achieve miniaturization of the antenna size. The antenna consists of two stacked half-slot resonators to radiate at two frequencies, f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> = 24 GHz and f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> = 28.5

A dual-frequency rectenna is introduced in this paper. An enhanced-gain antenna is integrated with the rectifying circuit for increasing the rectenna capability for scavenging. A voltage doubler circuit is used for the rectification. Moreover, a four-section matching network is employed for the matching between the antenna and the rectifier. The measured results reveal that the RF-to-DC conversion efficiency is more than 50% over wide range of the input power, from-3.5dBm to 10. 5dBm at f <sub x

This paper presents a dual-band split-ring structure that provides end-fire radiation characteristics for multi-input multi-output (MIMO) mm-wave 5G applications. The proposed single antenna element consists of a main split-ring resonator (SRR) directly fed using a high impedance microstrip transmission line. A lamda/4 transformer is employed to match the high impedance transmission line with a 50-ohm line. Two symmetric parasitic SRRs are used as directing elements to give end-fire radiation pr

Unlikely for a far-field wireless power transfer (WPT) system, designing a metasurface is critical for a near-field WPT system. First, a robust near-field WPT system using open-loop spiral resonators and a metasurface are designed, and then, the effectiveness of the metasurface is investigated in improving the power transfer efficiency (PTE) and misalignment effects. Furthermore, a study of planar and angular misalignments is also executed experimentally to prove the WPT system immunity. The pro

This letter introduces two concentric open-loop spiral resonators (OLSRs) that are used to improve magnetic field for nonradiative wireless power transfer (WPT) systems. OLSRs are fed through metal-insulator-metal (MIM) capacitive coupling using a 50-Ω microstrip transmission line. First, a single OLSR is designed and implemented for WPT, then two OLSRs are used instead of a single OLSR to emphasize the surface current on the spiral resonators. Therefore, it helps to intensify the electromagneti

Wireless power transfer (WPT) technologies have received much more attention during the last decade due to their effectiveness in wireless charging for a wide range of electronic devices. To transmit power between two points without a physical link, conventional WPT systems use two coils, one coil is a transmitter (Tx) and the other is a receiver (Rx) which generates an induced current from the received power. Two main factors control the performance of the WPT schemes, power transfer efficiency

A dual‐frequency band low input power rectenna is proposed in this study. The rectenna is comprised of a co‐planar waveguide (CPW) rectifier integrated with a rectangular split ring antenna loaded by a spiral strip line. A single diode series connection topology is used to miniaturise the losses at low input power. A spiral coil in addition to two short circuit stubs are used as a matching network for maximum power transfer between the antenna and the rectifying circuit. The proposed rectenna op

With the rapid development of the wireless systems and demands of low-power integrated electronic circuits, various research trends have tended to study the feasibility of powering these circuits by harvesting free energy from ambient electromagnetic space or by using dedicated RF source. Wireless power transmission (WPT) technology was first pursued by Tesla over a century ago. However, it faced several challenges for deployment in real applications. Recently, energy harvesting and WPT technolo

A dual-band slot antenna for 5G sub-6 GHz band is introduced in this paper. The square slot antenna with coplanar waveguide (CPW) feed is excited at two different positions using two feed lines to achieve a dual-band frequency operation. Two-way microstrip power divider is integrated with the two feed lines to feed the CPW slot. Then, a microstrip line to CPW transformer is implemented to convert from microstrip feed line into CPW feed to feed the radiating square slot. The obtained measured res

A novel multiple cascaded resonators wireless power transfer (WPT) design is proposed to provide an extended implanted depth for biomedical implants. Symmetrical four cascaded resonators are utilized in Tx/Rx to obtain high power transfer efficiency (PTE); each resonator consists of two concentric rectangular loops. KQ-product is calculated for a single resonator and compared with the four resonators WPT; four cascaded resonators achieve higher KQ-product value and produce a maximum measured PTE

A pattern reconfigurable antenna, composed of eight elements, is proposed for energy harvesting applications. Pattern reconfigurable antennas are a promising technique for harvesting from different wireless sources. The radiation pattern of the proposed antenna can be steered electronically using an RF switch matrix, covering an angle range from 0 to 360 degrees with a step size of 45 degrees. The proposed antenna primarily consists of an eight-dipole configuration that shares the same excitatio

A compact folded dipole antenna for millimeter-wave (MMW) energy harvesting is proposed in this paper. The antenna consists of two folded arms excited by a coplanar stripline (CPS). A coplanar waveguide (CPW) to coplanar stripline (CPS) transformer is introduced for wide band operation. The antenna radiates from 33 GHz to 41 GHz with fractional bandwidth about 21.6%. The proposed antenna shows good radiation characteristics and low VSWR, lower than 2, as well as average antenna gain is around 5