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Purpose: The purpose of this paper is to design a suitable guard trace to reduce the electromagentic interference between two closely spaced high frequency transmission lines. A novel cross-shaped resonator combined via fence is passed down to alleviate far-end and near-end crosstalk (NEXT) in tightly coupled high-speed transmission lines. The distance between the adjacent transmission lines is increased stepwise as a function of trace width. Design/methodology/approach: A rectangular-shaped resonator via fence is connected by a guard trace has been proposed to overcome the coupling between the traces that is separated by 2 W. Similarly, by creating a cross-shaped resonator via fence connected by guard trace that reduces the spacing further by 1.5 W. Findings: A tightly coupled transmission line structure that needs separation by a designed unit cell structure. Further research needs to be conducted to improve the NEXT, far-end crosstalk (FEXT) and spacing between the transmission lines. Originality/value: This study portrays a novel method that combines the resonators via fence with a minimum spacing between the tightly coupled transmission lines which reduce the NEXT and FEXT; thereby reducing the size of the routing area. The resultant test structures are characterized at high frequencies using time domain and frequency domain analysis. The following scattering parameters such as insertion loss, NEXT and FEXT of the proposed method are measured as 1.504 dB, >30 dB and >20 dB, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a reconfigurable loop-based filter performing compound reconfiguration. The designed filter is capable of functioning as a bandstop or bandpass filter by a simple approach of cascading the resonator to the transmission line connecting source and load. Shifting of operating frequencies is characterised by switching between a loop and a C-shaped resonator. To demonstrate the working of the proposed concept, a compound reconfigurable filter operating at 1.5 GHz and 1.6 GHz is developed. The filter is developed on a compact layout of size 0.27 × 0.12 λg2. The proposed prototype is fabricated and measured for real-time validation. [ABSTRACT FROM AUTHOR]

This article presents a compact reconfigurable filter performing bandwidth reconfiguration covering the entire L‐band frequency range. The reconfigurable filter is developed using a C‐shaped resonator coupled to the source and load through varactor diodes. To reverse bias the diodes symmetrically both the diodes are fed with a common bias voltage. Hence the DC bias voltage is administered evenly to the diodes resulting is equi‐proportional coupling between the resonator and the nodes. This results in reconfiguring the bandwidth of the operating frequency. The designed filter is capable of tuning 3‐dB bandwidth from 0.613 to 1.353 GHz with the center frequency as 1.5 GHz. The percentage bandwidth of the filter is varied from 44.5% to 91.76%. The insertion loss offered by the filter is very less with the minimum value of 0.42 dB. The proposed filter is simple, compact and finds it application in power agile systems operating with different transmission power levels at different time instances. [ABSTRACT FROM AUTHOR]

A microstrip bandwidth reconfigurable filtering antenna is implemented by simply tuning the transmission zeroes. The proposed filtering antenna is developed by integrating the filter characteristics into the 50 Ω microstrip feed line of the antenna through two independent coupled resonators. The energy coupling between the transmission line and the planar loop resonator and dual F shaped resonator generates the transmission zeroes. These transmission zeroes at specified lower frequencies are generated in order to provide better selectivity over the edges of the pass band to promote high suppression of interferences. The varactor diodes are explicitly loaded at distinct locations in the resonators to achieve bandwidth reconfiguration. The two transmission zeros are tuned between 1.6-1.9 GHz and 2.1-2.42 GHz respectively by varying the capacitance of the two varactor diodes with percentage bandwidth of 17.1% and 14.1% respectively to support mobile and wireless short range applications. The proposed filtenna provides insertion loss less than 3 dB with good impedance matching below 15 dB. [ABSTRACT FROM AUTHOR]

In this paper, a portable system for noninvasive detection of fractures in human bones is presented. A planar microwave ring resonator is used as the sensor. The proposed planar microwave sensor is designed using the finite integration-based CST Microwave Studio and tested on a human bone covered by porcine tissues. Fracture induced in the bone was detected by monitoring the transmission characteristics of the sensor as it scans the affected region. The resonant frequency of the ring resonator has been observed at every scan point, and the values are plotted using iterative curvature-based interpolation, improved new edge directed interpolation, and Lanczos imaging technique. The extent of fracture is then derived from the image. The average accuracy of the detected fracture for Lanczos method of resampling was 98.86%. The specific absorption rate was below the minimum level of 1.6 W/Kg at every point of scanning. Portable noninvasive monitoring of fractures in the tibial bone will help in immobilizing the affected part at an earlier stage, thereby reducing the recovery time for patients. [ABSTRACT FROM AUTHOR]

Abstract: This article presents the design and testing of a novel frequency reconfigurable microwave filter. The filter structure is composed of an all stop resonator coupled with C‐ and E‐shaped parasitic resonators. PIN diodes are located at suitable positions to achieve multi‐band reconfiguration from 1.2 to 3.2 GHz making the filter suitable for multiple wireless communication systems. The frequency and bandwidth of the filter are governed by the length of the resonators and coupling between the resonators and the transmission line, respectively. A sharp rejection of −30 dB is observed between the passbands. The proposed filter offers 56% size reduction with flat group delay performance. The prototype filter is fabricated and the simulation results are validated using experimental measurements. The measurement results show good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

In this paper, a novel planar microwave sensor for nondestructive measurement of strain during testing of printed circuit board (PCBs) is proposed. Planar microstrip patch bridged on both sides with squared split ring resonator is used to measure strain. Measurement of stress of isotropic dielectric materials in their linear elastic region that are uses as PCB substrates is also done using the proposed method. The designed microwave probe works at a frequency of 2.45 GHz. The feasibility of the use of time-domain reflectometry method to monitor strain in materials is presented here. The proposed sensor exhibits a sensitivity of about 333 ps for every 1% change in strain. Finite integration technique and real-time measurements have been done to corroborate the relation derived between the transmit time and the strain experienced by the material. The correlation between the simulated and measured strain is about 99.3%. The proposed sensor can be used for faster and accurate testing of PCB substrates without requiring complex calibrations. [ABSTRACT FROM PUBLISHER]

This letter presents the design and implementation of a compact microstrip filter with frequency and bandwidth (BW) reconfiguration. The proposed filter consists of a transmission line coupled with a U-shaped microstrip line resonator. Varactor diodes are deployed at specific locations and are tuned to achieve BW and frequency reconfiguration from 0.8 to 1.5 GHz. The transition from the bandpass mode to the bandstop mode is achieved by reconfiguring the transmission zeros simultaneously. The filter percentage lower passband edge tuning and 17.33% higher passband edge tuning. The proposed filter has simple geometry, low profile, and offers a higher level of operational flexibility in the designed frequency range. The filter is tuned with the help of simple actuators requiring simple bias circuitry. The prototype filter is fabricated, and the simulation results are validated using the experimental measurements. [ABSTRACT FROM AUTHOR]

This paper presents the design of a novel linear analog planar phase shifter deploying split-ring resonator (SRR) and complementary split-ring resonator (CSRR) structures. Based on the advantages of these structures, a triband phase shifter is designed for multiple target systems to operate at 0.85, 1.69, and 2.46 GHz bands finding applications for European RFIDs, Satellite Radio Broadcast System, Mobile Services, and ISM Band, respectively. The effect of SRR and CSRR coupling with host transmission line is also analyzed on the basis of Bloch mode theory and the modes are validated through Eigen mode analysis. The proposed phase shifter design shows a good agreement between simulated and measured results. A 90° ± 8°shift in phase is observed at lower and upper bands, and a 135° ± 8°shift is observed in center band with reasonable group delay components. [ABSTRACT FROM AUTHOR]