Wireless charging is a technology of transmitting power through an air gap to electrical devices for the purpose of energy replenishment. The recent progress in wireless charging techniques and development of commercial products have provided a promising alternative way to address the energy bottleneck of conventionally portable battery-powered devices. However, the incorporation of wireless charging into the existing wireless communication systems also brings along a series of challenging issues with regard to implementation, scheduling, and power management. In this paper, we present a comprehensive overview of wireless charging techniques, the developments in technical standards, and their recent advances in network applications. In particular, with regard to network applications, we review the static charger scheduling strategies, mobile charger dispatch strategies and wireless charger deployment strategies. Additionally, we discuss open issues and challenges in implementing wireless charging technologies. Finally, we envision some practical future network applications of wireless charging.

Wireless Charging Technologies: Fundamentals, Standards, and Network Applications

We propose a compact planar ultrawideband (UWB) antenna with 3.4/5.5 GHz dual band-notched characteristics. The antenna consists of a beveled rectangular metal patch and a 50 Omega coplanar waveguide (CPW) transmission line. By etching two nested C-shaped slots in the patch, band-rejected filtering properties in the WiMAX/WLAN bands are achieved. The proposed antenna is successfully simulated, designed, and measured showing broadband matched impedance, stable radiation patterns and constant gain. An equivalent circuit model of the proposed antenna is presented to discuss the mechanism of the dual band-notched UWB antenna. A UWB antenna and a single band-notched one are also provided for references.

A Compact Ultrawideband Antenna With 3.4/5.5 GHz Dual Band-Notched Characteristics

This paper presents a novel broadband rectenna for ambient wireless energy harvesting over the frequency band from 1.8 to 2.5 GHz. First of all, the characteristics of the ambient radio-frequency energy are studied. The results are then used to aid the design of a new rectenna. A novel two-branch impedance matching circuit is introduced to enhance the performance and efficiency of the rectenna at a relatively low ambient input power level. A novel broadband dual-polarized cross-dipole antenna is proposed which has embedded harmonic rejection property and can reject the second and third harmonics to further improve the rectenna efficiency. The measured power sensitivity of this design is down to $- {\bf 35}\;{\bf dBm}$ and the conversion efficiency reaches 55% when the input power to the rectifier is $- {\bf 10}\;{\bf dBm}$ . It is demonstrated that the output power from the proposed rectenna is higher than the other published designs with a similar antenna size under the same ambient condition. The proposed broadband rectenna could be used to power many low-power electronic devices and sensors and found a range of potential applications.

A High-Efficiency Broadband Rectenna for Ambient Wireless Energy Harvesting

Reactive matching is extended to wide bandwidths using the impedance property of LC-ladder filters. In this paper, we present a systematic method to design wideband low-noise amplifiers. An SiGe amplifier with on-chip matching network spanning 3-10 GHz delivers 21-dB peak gain, 2.5-dB noise figure, and -1-dBm input IP3 at 5 GHz, with a 10-mA bias current.

A 3-10-Ghz low-noise amplifier with wideband LC-ladder matching network

With the development of wireless communication technology, the need for bandwidth is increasing continuously, and the growing need makes wireless spectrum resources more and more scarce. Cognitive radio (CR) has been identified as a promising solution for the spectrum scarcity, and its core idea is the dynamic spectrum access. It can dynamically utilize the idle spectrum without affecting the rights of primary users, so that multiple services or users can share a part of the spectrum, thus achieving the goal of avoiding the high cost of spectrum resetting and improving the utilization of spectrum resources. In order to meet the critical requirements of the fifth generation (5G) mobile network, especially the Wider-Coverage , Massive-Capacity , Massive-Connectivity , and Low-Latency four application scenarios, the spectrum range used in 5G will be further expanded into the full spectrum era, possibly from 1 GHz to 100 GHz. In this paper, we conduct a comprehensive survey of CR technology and focus on the current significant research progress in the full spectrum sharing towards the four scenarios. In addition, the key enabling technologies that may be closely related to the study of 5G in the near future are presented in terms of full-duplex spectrum sensing, spectrum-database based spectrum sensing, auction based spectrum allocation, carrier aggregation based spectrum access. Subsequently, other issues that play a positive role for the development research and practical application of CR, such as common control channel, energy harvesting, non-orthogonal multiple access, and CR based aeronautical communication are discussed. The comprehensive overview provided by this survey is expected to help researchers develop CR technology in the field of 5G further.

Full Spectrum Sharing in Cognitive Radio Networks Toward 5G: A Survey

On-antenna power combining is an emerging topic of high interest, where high-power amplifiers (HPA) are directly connected to a multiport antenna. Compared to other on-circuit power combining technics, improved efficiency, higher radiated power, smaller associated monolithic microwave integrated circuits (MMIC) and enhanced heat dissipation are achieved. This technic can be used in addition to spatial power combination within an array, to further improve the radiated power. However, several of these multiport antennas result in a common-mode parasitic effect, only occurring when the beam is steered, which reduces the radiated power. This paper exposes this phenomenon through infinite array simulations and explains its origin. A solution to mitigate this problem is finally proposed.

Common-Mode Loss Mitigation of a Differentially Fed Eight-port On-antenna Power Combining Patch Implemented in a Scanning Phased Array

This microwave component (10) comprises a waveguide (12) comprising an upper layer, a lower layer, and a central layer (18) interposed between the upper layer and the lower layer, said layers defining a propagation zone (19) of an electromagnetic wave, the propagation zone (19) extending along a propagation axis, and comprising a cavity (32) delimited by the upper layer, the lower layer, and, laterally, by two opposite lateral edges (36) of the central layer (18). The waveguide (12) comprises at least one dielectric bar (28) disposed in the propagation zone (19), the dielectric bar (28) being delimited in one of the upper layer and the lower layer or being disposed in the cavity (32) away from the side edges (36) of the cavity (32).

Microwave component and method for manufacturing the same

Disclosed is an assembly for the propagation of waves of frequencies between 1 GHz and 10 THz, including: (a) a waveguide to guide the waves, the waveguide being produced from a plastic material, a part of the waves propagating inside this waveguide and another part of the waves propagating outside this waveguide; and (b) a protective covering which surrounds the waveguide delimiting one or more spaces between the waveguide and the covering, in which space or spaces the waves propagating outside the waveguide are contained, the protective covering thus forming a barrier to protect these waves from external disturbances.

Plastic waveguide for the propagation of waves in the frequency range comprised between 1 ghz and 10 thz

The modulation includes in amplifying the microwave signal phase shifted by a given angle into a first sinusoidal signal, in order to obtain a first amplified signal; and in amplifying the microwave signal phase shifted by the given angle increased by π into a second sinusoidal signal phase shifted by π with respect to the first signal, in order to obtain a second amplified signal phase shifted by π with respect to the first amplified signal; the modulated microwave signal being the sum of the first amplified signal and the second amplified signal.

Device for modulating a microwave signal, transponder including such a device, and responder beacon equipped with such a transponder

In this paper, the design and realization of an new antenna for localization with RFID is presented This antenna has a high directivity of about 8 dBi with a bandwidth of about 16 MHz A very good agreement is found between experimental results and simulation using the commercial software CST Microwave Studio Experiments and results of the localization system are presented

Anthony Ghiotto

Papers

Common-Mode Loss Mitigation of a Differentially Fed Eight-port On-antenna Power Combining Patch Implemented in a Scanning Phased Array

Microwave component and method for manufacturing the same

Plastic waveguide for the propagation of waves in the frequency range comprised between 1 ghz and 10 thz

Device for modulating a microwave signal, transponder including such a device, and responder beacon equipped with such a transponder

Design and realization of a new antenna for localization with RFID