Star-Junction X-Band Coupled Resonator Multiplexer

A novel design of coupled resonator star-junction multiplexer is presented. The multiplexer has been designed at the X-band with four non-contiguous channels. The multiplexer topology is based on coupled resonator structure, and it consists of thirteen waveguide cavities, one of which serves as a resonating junction. The multiplexer is miniaturized in comparison to other conventional multiplexers, as it does not contain manifolds, circulators... etc. It also has reduced number of connections to the resonating junction

Novel multiplexer topologies based on coupled resonator structures

Novel multiplexer structures based on all-resonator topologies are presented here. The proposed multiplexers consist of only resonators without extra manifolds or circulators or power dividers. They can achieve various requirements of different filtering responses and arbitrary number of channels with miniaturized size. The proposed multiplexers are synthesized using optimization technique where coupling coefficients between coupled resonators are found. Different structures with various properties and responses are presented including symmetrical and asymmetrical channels. Reduction of the complexity of optimization processes is also presented

Coupled-resonator 3-dB power divider

This paper presents a technique to synthesise a coupled resonator power divider. . The design of the proposed power divider is based on coupling matrix optimization for multiple coupled resonators with multiple outputs. The synthesis employs coupling matrix optimisation techniques similar to those developed for coupled resonator filters. The realisation of such dividers is possible using microstrip resonators, waveguide cavities, or other types of resonators

Novel star-junction coupled-resonator multiplexer structures

Star-junction multiplexers are used when the number of channels is relatively small since the resonating junction has to be connected to many filters' outputs. In this paper, novel topologies of star-junction multiplexers with resonating junctions are proposed. The advantage of the proposed topologies is that the number of connections to the resonating junction is reduced and thus allowing multiplexers with more channels to be implemented. An optimization technique is used to synthesize the coupling matrix of the proposed multiplexers, and numerical examples are illustrated in this paper. Citation: T. Skaik," Novel star-junction coupled-resonator multiplexer structures," Progress In Electromagnetics Research Letters, Vol. 31, 113-120, 2012

A Quad-band Rectifier Design with Improved Matching Bandwidth for RF Energy Harvesting Applications

A quad-band energy harvester is proposed here. The harvester is formed of rectifiers and matching circuits at different frequency bands: GSM-900 (890-960 MHz), GSM-1800 (1800-1870 MHz), ISM 2.45 GHz (2.45-2.457 GHz) and LTE-band 7 (2.6-2.67 GHz). The harvester is formed of two dual-band matching circuits and two rectifiers instead of the conventional design with four single-band matching circuits and four rectifiers. The matching circuits are designed with improved matching bandwidth by employing several microstrip stubs to compensate for the limited matching bandwidth of the non-linear rectifier. Each rectifier is a four-stage voltage doubler with HSMS 285x Schottky diodes. The RF-DC conversion efficiency is simulated over frequency for various input power levels

A Broadband Star-Shaped Slotted Microstrip Antenna for RF Energy Harvesting Applications

This paper presents design of a broadband antenna for RF/microwave energy harvesting applications. The antenna operates within the frequency range 790 MHz to 3.4 GHz. The antenna is designed over wide frequency range to collect energy of signals of various communication systems such as: digital TV, GSM-900, GSM-1800, UMTS, LTE, WiFi, and WiMax. The antenna is designed using microstrip technology on an FR-4 substrate with dielectric constant of 4.3 and thickness of 1.6 mm. The conducting element is formed of a star-shaped microstrip patch. Moreover, crescent and rectangular slots are cut onto the patch element to broaden the bandwidth. The antenna is designed using CST simulation software and the maximum simulated inband gain reaches 3.93 dBi at 1.7 GHz

Coupled Resonator Diplexer for LTE-Advanced System

This paper presents the design of a microstrip hairpin diplexer. The design is based on coupledresonator structure using U-Shaped resonators. It is designed to meet The Long Term Evolution-Advanced (LTEA) system Band 7, operating at uplink (UL): 2.50–2.57 GHz and downlink (DL): 2.62–2.69 GHz for base transceiver station antenna. The structure has three ports with 10-coupled resonators with direct coupling to produce diplexer with chebyshev filtering response. The diplexer does not involve any external junctions for distribution of energy, so it can be miniaturized in comparison to conventional diplexers

Design of diplexers for E-band communication systems

E-Band diplexers have been designed to be used as front-end components in the transceivers of point-to-point wireless communication systems. They are specified to work at the frequency bands 71-76 GHz and 81-86 GHz. Three designs are presented here, two of which are the conventional T-junction and manifold diplexers, and the third is a novel compact structure based on coupled resonators

Synthesis of coupled resonator-based multiplexers with generalised structures using coupling matrix optimisation

Design techniques of coupled resonator circuits used in synthesising two port filters and three port diplexers are developed to synthesise N port multiplexers. Novel general structure is proposed and it can achieve an unlimited arbitrary number of channels, different responses and various properties and characteristics without extra resonators, external junctions or power distribution network in a compact size. The synthesis of the proposed multiplexers is based on optimisation approach where the coupling coefficients between resonators presented by coupling matrix are found from optimisation techniques by minimising a cost function

Design of a Tri-band Double Wire Square Loop Frequency Selective Surface for Mobile Signal Shielding

This paper presents the design of a novel frequency selective surface (FSS) structure. The proposed FSS structure here is constructed of square loops of copper wires interconnected together using iron wires and thus forming a wire net. It is designed to shield the mobile signals of different networks: GSM 900, GSM 1800 and 3G and hence operating as an electromagnetic bandstop filter. A single cell consists of double square copper loops with outer loop tuned at GSM 900 and the inner loop tuned at GSM 1800 and 3G frequency bands. The structure can be easily manufactured and installed in outdoor areas. The simulation results of transmission coefficients show stable frequency response for both the TE and TM polarizations for angle of incidence from 00 to 300