Abstract-In this paper, the design and analysis of a compact coplanar waveguide-fed ultra wideband pentagon antenna are presented. To achieve ultra wideband performance, two modifications are introduced. The first one is to remove a small fan angle on each side of the ground plan, and the second one is to modify the sharp of the patch in the width. The optimal dimensions can be achieved by a parametric analysis. The antenna design exhibits a very wide operating bandwidth of 16.7 GHz with a return loss better than 10 dB in the frequency range from 4.46 GHz to 21.14 GHz. The gain of the proposed antenna is 6.3 dBi. This antenna configuration will be useful for UWB indoor application as it is easy to fabricate and integrate with RF circuitry. All simulations in this work were carried out by using the electromagnetic software CST.

Rail inspections are required and used to ensure safety and preserve the availability of railway infrastructure. According to the statistics published by railroad administrations worldwide, the transverse fissure appearing in railhead is the principal cause of rail accidents. These particular defects are initiated inside the railhead. Detection of these cracks has always been challenging because a defect signature remains mostly small until the defect size reaches a significant value. The present work deals with the theoretical analysis of an integrated contact-less system for rail diagnosis, which is based on ultrasounds. The generation of these waves was performed through non-ablative laser sources. Rotational laser vibrometry was used to achieve the reception of the echoes. Detection of flaws in the rail was monitored by considering special ultrasound wave signal based indicators. Finite element modeling of the rail system was performed, and transverse defect detection of the rail was analyzed.

In this paper, a high-performance microstrip diplexer is designed and manufactured. The design is based on two pairs rectangular open-loop resonators band-pass filters and a novel zigzag junction. It operates at 3.5 GHz for the fifth-generation (5G) sub-6-GHz and 5 GHz for Wi-Fi communications. The proposed diplexer is considerably miniaturized with a global compact size of 30×17 mm 2 . In addition, it presents low insertion losses less than 0.5 dB at both channels in comparison with the previous diplexers. Moreover, the isolation is higher than 20 dB, and the return loss is better than 14 dB at the bandwidths. To confirm the simulation results, the presented diplexer is manufactured and measured where a good agreement is observed.

No abstract

No abstract