Compact circular polarization filtenna for wireless power transfer applications

Nowadays, Internet of Things (IoT) electronic devices are needed to realize the fifth generation (5G) device-to-device communication. Obviously, current developments tend to focus more towards structure compactness for mobility purposes. However, the main weakness for mobile devices is its power supply. This can be improved by increasing the individual battery capacity or having external batteries. These proposed solutions will increase the weight of the devices, hence making them heavier to carry around. Most total IoT devices are also required to be multi-functional depending on different radio frequencies (RF). Commonly, the RF signal radiated is solely used for data communication. This useful RF signal can also be converted into small energy, instead of being left to disperse into the environment. This relates to wireless energy harvesting called as rectifying antenna (rectenna) which converts RF signal to direct current (DC). A generic rectenna consists of the combination of several components such as antenna, filter, diode and resistive load. The aim of this research is to develop a compact or miniaturized RF front-end component for the rectenna. Compactness can be achieved by embedding the filter into the antenna to form a filtenna. Non-contacted electromagnetic coupling technique with the circular patch antenna operated at 2.45 GHz is selected as the basic design and the simulation work was done using the Computer Simulation Technology (CST) software. To enhance the quality of propagation and the multi-functional properties, the proposed design optimized for circular polarization (CP) and wider bandwidth. Therefore, the modification of the basic design change to proximity coupled feeding technique with double layered configuration is presented. Analysis of the slot line resonator near to the transmission line on several locations is discussed to realize a filtenna. In this research, several different designs of antennas and filters are presented with different compactness, CP, and higher resonant rejection properties. All proposed designs are fabricated and validated through measurement studies. Good agreement is shown between simulation and measurement results. By having approximately 45-50 % of size reduction as compared to the conventional 2.45 GHz microstrip patch antenna, the developed antennas are compact in size with higher resonant rejection up to third harmonic and exhibit 5.2 dB gain

5G beam-steering 2×2 butler matrix with slotted waveguide antenna array

In this research paper, substrate integrated waveguide (SIW) was proposed as a technique by realizing bilateral edge walls to produce a compact 5G beam-steering antenna at 24 GHz. The beam forming network is produced using SIW directional coupler perform as 2×2 Butler Matrix (BM) fed with SIW slotted waveguide antenna array. The output signal is steered from -29 degrees and +29 degrees when the signal is fed to the respective input ports. If one of the input ports is fed, the signal is evenly distributed between the adjacent output ports with 90 degree constant phase shift. The compact size of directional coupler was designed by longitude slots on the surface of SIW substrate with bandwith of 16.85% at the operating frequency. The proposed antenna produce gain of 6.34 dB at operating frequency and the promising outcome of the beam steering make proposed design suitable for 5G communications especially with tracking capabilities

Dual band antenna for radio frequency identification applications

Radio Frequency Identification (RFID) has the highest growth of applications system and is the most interesting field of research in communication technology. RFID systems have been implemented in various applications such as Electronic Toll Collection (ETC) and monitoring systems for railway stations. One of the ETC applications is the Touch & GO system that uses the Short Range RFID (SRRFID) technology. This technology benefits users as they are able to pay their toll automatically by passing through the toll gate without queuing for a long time. On the other hand, the monitoring system for railway stations uses the Long Range RFID (LRRFID) technology. Railway employees use this technology to monitor locations and automatically control the speed of trains from the railway station. Applications of LRRFID technology are meant for high-end users thus this technology has a higher marketability value as compared to SRRFID. Generally, LRRFID uses: (i) Ultra High Frequency (UHF) band and (ii) Industrial, Scientific and Medical (ISM) band. Both these bands can be applied using a single RFID multipurpose application reader. For this application, a multiband antenna is needed to fulfill the dual application. The aim of this research project is to develop a dual band antenna design operating the UHF and ISM bands having linear and circular polarization capabilities. A square patch antenna is selected as the basic design and modifications on the radiating patch were conducted using Computer System Technology (CST). The simulation from the CST resulted in development of dual band diamond shaped linear polarized antenna. The newly developed antenna has good return loss for frequencies in both bands. To enhance the quality of propagation of this antenna, a pair of slots was introduced to the radiating patch which transformed the proposed antenna to become a circular polarization antenna. Both antennas had air gap introduced between dielectric substrate layer and ground plane to boost the gain and efficiency of the antennas. The developed antennas have good gains, approximately 7~9 dBi and antenna efficiency is about 85~95%

Aperture slot size effect to wide band open air gap radial-line slot array performance

A wideband open air gap radial line slot array (RLSA) antenna is presented for point-to-point application. This article investigates the optimum slot arrangement and the effect of slot width to the RLSA antenna. Eight models were developed and simulated with slot width taking range in values from 1 to 8 mm. Results from simulation shows optimum performance at 6-mm slot width. The 2-mm slot width gave similar performance to the 6-mm slot width in term of gain and directivity. Both antennas were fabricated and measured, from the measurement; a better return loss performance of about 28% was realized at 6-mm slot width when compared to 2-mm slot width RLSA. However, both antennas produced the same gain. A better sidelobe level of 2.9 dB was achieved with the 2-mm slot width antenn

Evolution Process of a Broadband Coplanar- Waveguide-fed Monopole Antenna for Wireless Customer Premises Equipment

In this paper a design process of a broadband printed monopole antenna using stepped cut at four corners (CSFC) technique is proposed. The CSFC is a technique that four corners a patch (rectangular/square) of planar monopole antennas are cut in order to enhance the impedance bandwidth. The technique can be used to design any different types of planar monopole antenna in specific frequency ranges. Therefore, to become more acquaintance with the CSFC technique an evolution process of single band to broadband antenna is represented. However, the proposed antenna is designed for wireless indoor customer premises equipment (CPE) using the coplanar waveguide (CPW) feeding technique. Moreover, the antenna is simulated using CST software and also fabricated and tested so as to validate the results. The simulated and measured -10 dB reflection bandwidth is 104% (850MHz to 2.7 GHz) to cover GSM (900 and 1800 MHz), WiFi (2.4 GHz) and LTE (2.6 GHz) applications. High efficiency and gain as well as omnidirectional and quasi-omnidirectional of radiation pattern at lower and upper frequencies have been achieved

DYNAMIC BIFURCATIONS IN SYSTEMS WITH NOISE

The aim is to study the properties of the dynamic bifurcations including to analyse the breachs of the probabilistic symmetry, hysteresis phenomenum at dinamic bifurcations in presence of the noises; to investigate the correlating connections between noise and prognosis error in the non-linear chaotic systems. The boundary between stochastic and dynamic scenarios of the bifurcation transfer has been specified; the method for measurement in the internal noise in the bifurcation systems has been proposed. The adhesion zones of the finite states on the surface "rate of changing controlling parameters-initial conditions" have been discovered. The results have been approved on the international conferences, at the Institute of Cosmic Investigations (Russian Academy of Sciences), Institute of Radio Engineering and Electronics (Russian Academy of Sciences). Application field: radio physics, biology, medicine, economicsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Comparison of Polypropylene and FR4 Dielectric Cavity for RLSA Antenna Design at 5.8GHz

The Radial Line Slot Array (RLSA) Antenna is very pleasing due to low profile appearance and high gain characteristic. Recent research on RLSA is to produce a light weight, durable and easy fabrication process. Thus, FR4 is an alternative substrate to replace the polypropylene. This paper presents a comparison of polypropylene and FR4 dielectric substrate for linear polarized Radial Line Slot Array (RLSA) antenna at 5.8 GHz frequency. Both antennas implemented the same radiating slot design in an antenna with diameter of 200mm. The results show an improvement of radiation pattern using FR4 dielectric substrate as compare to polypropylene dielectric base. However, the reflection coefficient for polypropylene substrate show specific resonant at 5.8GHz frequency while FR4 substrate introduce multiple resonant. This paper also suggested FR4 board can be a potential substrate and major component for RLSA antenna development in future

Wide band open ended air gap RLSA antenna at 26ghz frequency band

RLSA antenna is a popular candidate for many applications such as Direct Broad- cast Satellite Reception, Point to Point Microwave Link, RFID and Wimax Application. This is due to its capability of carrying high speed signal with high directivity characteristic and capabil- ity of beam steering and beam shaping. This paper will introduce the RLSA antenna designed at the frequency of 26 GHz for wireless backbone application. The antenna design was utilize open ended air gap as a separator between radiation surface and ground plane. The open air gap cavity structure normally implemented in broadband planar antennas. This structure normally provide a wide bandwidth and good return loss on the desired frequency. Therefore, an investigation of this technique and hybrid with FR4 board as a cavity material will be very interesting due to condition of easy to manufacture, lighter the antenna weight and durable. The model of RLSA antenna at 26 GHz has been simulated. The results obtained a -25 dB of reflection coefficient, 23.68 dBi of directivity gain with wide antenna bandwidth capability. This research found an opportunity of utilizing RLSA antenna concept for extreme high frequency band application. Copyright © 2013 The Electromagnetics Academy

A low cost thin film flexible plastic graphene-conductive polymer composite antenna

In this project, a flexible thin film and environment friendly graphene-conductive polymer composite antenna was developed on a low cost plastic film for wearable application at 2.4 GHz. Nowadays, extreme research growths on graphene conductive polymer materials has been explored due to mechanical flexibility, high efficiency, low cost and electric field-controllable properties. These special properties made this material as a promising conductor for biomedical application and RF wireless application. Within this context, exploitation of ink-jet printing graphene together with conductive polymer, poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) were developed in this project and printed on plastic film substrate with dielectric permittivity, εr of 2.3. In addition, parametric studies of the number of printing layer towards antenna resistivity performance are also performed. The final antenna printing produces conformability to the surfaces, ability of design versatility, and low manufacturing costs with compact size of 0.16λ0 × 0.42λ0 or 9.88cm2 and wide bandwidth of 84.17% which serve the requirements of wearable antenna application at 2.4GHz