An ultrafast 1 x M all-optical WDM packet-switched router based on the PPM header address

This paper presents an all-optical 1 x M WDM router architecture for packet routing at multiple wavelengths simultaneously, with no wavelength conversion modules. The packet header address adopted is based on the pulse position modulation (PPM) format, thus enabling the use of only a singlebitwise optical AND gate for fast header address correlation. It offers multicast as well as broadcast capabilities. It is shown that a high speed packet routing at 160 Gb/s can be achieved with a low channel crosstalk (CXT) of ~ -27 dB at a channel spacing of greater than 0.4 THz and a demultiplexer bandwidth of 500 GHz

The Integration Of Rectangular SIW Filter and Microstrip Patch Antenna Based On Cascaded Approach

This paper presents the technique for integrating the rectangular Substrate Integrated Waveguide (SIW) filter with the rectangular microstrip patch antenna to produce filtering and radiating element in a single device. To proof the concept, the integrated microwave filter and antenna at center frequency of 2 GHz was demonstrated and validated through simulation and measurement. It demonstrated promising measured results, which were ingood agreement with the simulated results. The integrated microwave filter and antenna would be beneficial in microwave systems where the reduction of overall volume and weight as well as cost is very important such as in base stations and multiplexer in any communication systems

Microstrip-Fed Circular Disc Monopole Antenna with Defected Waveguide Structure

This paper presented the microstrip-fed circular disc monopole antenna with defected waveguide structure. First, the microstrip-fed circular disc monopole antenna was designed. Next, the monopole antenna was designed with waveguide and lastly followed by the defected waveguide structure where the uniplanar compact (UC) structure was used. CST Microwave studio software was used for simulation and parametric studies process. Initially, the microstrip-fed circular disc monopole antenna was designed to achieve return loss less than -10dB for wideband frequencies. Then, the gain and directivity was improved with the integration of waveguide. The highest directivity of 11.38dBi found at 13.5GHz. However, low efficiency and narrower bandwidth were obtained. Next, uniplanar compact defected waveguide structure (UC DWS) was designed at inner surface of waveguide. The bandwidth achieved 3.09GHz where it covered from 10.91GHz to 14GHz. Meanwhile, the directivity maintained higher than the monopole antenna with highest directivity of 8.84dBi at 10GHz. The gain was also improved from 11GHz to 14GHz with highest gain of 6.38dB occurred at 13.5GHz

CPW-Fed Circular Disc Monopole Antenna with Defected Waveguide Structures

This paper presented a parametric study on coplanar waveguide-fed (CPW-fed) circular disc monopole antenna with defected waveguide structure (DWS). The CPWfed circular disc monopole antenna was designed to cover wideband frequencies. Afterward, the monopole antenna was attached to a waveguide with a uniplanar compact defected waveguide structure (UC DWS). The simulation design and parametric studies were done by using the CST Microwave studio software. Initially, the CPW-fed circular disc monopole antenna was designed to achieve return loss of -10dB from 2.36GHz to 10GHz. The directivity has improved significantly when the monopole antenna was attached to a waveguide where the highest directivity was 9.83dBi at 8.5GHz. However, narrower bandwidth and lower efficiency were achieved. It achieved a bandwidth of 0.49GHz and highest efficiency of -1.76dB at 8.5GHz. The UC DWS was then designed on the inner surface of the waveguide with smaller dimension with 6.25 x 6.25mm 2 and a small gap of 0.3mm. The directivity and gain have been improved. The highest directivity and gain were 7.10dBi at 8.5GHz and 5.42dB at 6.5GHz respectively. The bandwidth was 3.66GHz where it covered from 6.34GHz to 10GHz

A Parametric Study on Dual-Band Meander Line Monopole Antenna For RF Energy Harvesting

This paper studies the dual-band monopole antenna based on meander line structure for Global System for Mobile Communications (GSM) band applications, which is also has the potential to be used for RF energy harvesting. A meander line antenna with a conductor line is investigated during the design using the Computer Simulation Tool (CST) software. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. The comparison between simulation and measurement results for the return loss and radiation patterns are observed and are in good agreement. A bandwidth of 97 MHz and return loss of -19.29 dB is obtained at the first frequency band, i,e. 915 MHz, while a bandwidth of 46.2 MHz with a return loss of -16.27 dB are obtained at the second frequency band, i.e. 1800 MHz. This study is an early investigation in designing the RF energy harvesting to support green technology and sustainable development particularly for Wireless Sensor Network (WSN) as well as Radio Frequency Identification (RFID) applications

Dual-Band monopole Antenna For Energy Harvesting System

A planar dual-band monopole antenna is presented for Global System for Mobile Communications (GSM) band applications, which also have the potential to be used for energy harvesting system. The proposed antenna comprises of a ground plane at the back of the FR4 substrate and three microstrip lines which are physically connected with each other at the top surface of the substrate. The monopole antenna achieves good return loss at resonance frequencies of 915 MHz and 1800 MHz with a bandwidth value of 124.2 MHz and 196.9 MHz respectively. The antenna gains of 1.97 dB and 3.05 dB are achieved at resonance frequencies of 900 MHz and 1800 MHz. Experimental results show good agreement with simulated performance. The output from the receiving antenna is also observed in order to analyze the relationship of the power level and the distance between transmitting and receiving antenna. This study is an early investigation in designing the RF energy harvesting system to support green technology and sustainable development particularly for Wireless Sensor Network (WSN) applications

Single Feed Square Aperture Circular Polarized Antenna

In recent years, circular polarized antennas become more important in wireless communication systems because of the ability of radiating circular polarized wave. In this paper, the design of single-feed square-aperture antenna with and without reflector towards the circular polarized antenna performance is presented. The antenna made of square ground plane, square-aperture and a probing strip feed by using microstrip transmission line. The design has achieved a target axial ratio, which is less than 3 dB at frequency range of 4 GHz to 6.5 GHz. When a square ground plane reflector is integrated on the CP antenna for the unidirectional pattern, the presented antenna enhanced gain about 8 dB

A New Class of Dual-mode Substrate Integrated Waveguide (SIW) Filter with Two Metalized Posts

This paper presents the investigation and characterization of dual-mode Substrate Integrated Waveguide (SIW) filter with two metalized posts on the cavity to reduce the overall volume of RF front-end subsystems. By introducing two vertical metalized posts and two diagonal metalized posts in dual-mode SIW filter, both SIW filters show different flow of Electromagnetics (EM) can be identify from the E-fields. In order to compare which dual-mode SIW filter gives the better performance, the designs are simulated at centre frequency 2 GHz using CST Studio Suite software and the results are validate through measurement. The measurement shows a good agreement with the simulated results. This design is suitable for any integration microwave system where the reduced complexity of the design and cost as well as weight is very important for the wireless communication systems

Current Developments of RF Energy Harvesting System for Wireless Sensor Networks

Energy harvesting or energy scavenging is basically a conversion process of the ambient energy into the electrical energy. The ambient energy exists around us in many different forms including thermal, chemical, electrical and radio frequency (RF). This technique significantly reduces the costs of replacing batteries periodically. Hence, energy harvesting offers various environmental friendly alternative energy sources, which include the vibration, electromagnetic wave, wind energy and solar power. This study will focus on RF energy harvesting that involves the generating of a small amount of the electrical power to drive circuits in wireless communication electronics devices. Recently, wireless sensor network (WSN) has been a crucial part of our daily life. The importance of WSN can be described by the use of sensors in many devices for home security including light sensors, room thermostat and alarm systems. This paper presents an overview and the progress achieved in RF energy harvesting, which involves the integration of antenna with rectifying circuit. Different combinations of antenna and rectifier topologies yield diverse results. Therefore, this study is expected to give an indication on the appropriate techniques to develop an efficient RF energy harvesting system

Rhombic Split Ring Resonator (R-SRR) Structure on Rectangular Patch Antenna Design

Abstract- This work focusing on the effect of the complementary rhombic split ring resonator (R-SRR) structure of gain, return loss and the radiation pattern the rectangular patch antenna design. The basic rectangular patch antenna design had been simulated in CST Microwave Studio simulation software. Then, the single unit of the R-SRR had been added into the patch antenna design. The targeting frequency of this antenna is 2.40 GHz for Wireless Local Area Network (WLAN) application. Compared with the conventional microstrip patch antenna with the same aperture size, the performance gain of the patch antennas is improved obviously and suitable for targeting frequency of 2.40 GHz. The parametric studies done this work work are the different variation pattern of R-SRR, different distance between two RSRR structure and different size of R-SRR