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A unique coplanar-waveguide (CPW)-fed circularly polarised square slot antenna with enhanced impedance bandwidth (IBW) is presented. The antenna structure includes a pair of rectangular-shaped notches located at two opposite corners of the slot for achieving a significantly enhanced IBW of 12.06 GHz (2.76–14.82 GHz), and a pair of reverse L-shaped ground arms in the slot for realising circularly polarised radiation with 1.86 GHz (4.27–6.13 GHz) bandwidth. This proposed technique has the advantages of covering the whole of the ultra-wideband spectrum (3.1–10.6 GHz), an average gain of 3 dBi and a reduced antenna size of 25 × 25 × 0.8 mm3.

A novel design of circular microstrip antenna by employing rectangular slots cut modified ground plane profile is proposed, on thinner FR4 substrate. With the modifications in the resonant mode current paths and the fringing fields in the antenna cavity, as compared with a conventional ground plane design, proposed configuration yields 5.6% reduction in the resonance frequency, three times increase in the bandwidth, gain improvement by 0.5 dBi, and more than 40 dB reduction in the cross-polar level. As against the reported configurations in the literature, results obtained in the proposed design are better considering a single patch design, while employing a thinner and lossy substrate. The equivalent configurations of the proposed design can find applications in GSM 900 or Bluetooth and WLAN applications.

Proposed is a simple technique to enhance the bandwidth of a planar monopole antenna with overall dimensions of 30 × 10 mm2. With the proposed method, based on a modified ground plane and a loop feeding structure, the −6 dB bandwidth can be enhanced by ∼50% compared to the basic structure. Based on the simulation results, the antenna achieved a total efficiency higher than 70% on the entire band and the maximum realised gain varied between 2 and 4.8 dB. A prototype has been realised, and good agreement has been obtained between the measured and simulated results.

Artificial neural networks (ANNs) have acquired enormous importance in computing of the performance parameters of microstrip antennas due to their generalized and adaptive features. However, recently the concept of support vector machines (SVMs) has become very much popular in performance parameters computation due to several attractive features over ANNs. Specifically, SVMs outreach ANNs noticeably in terms of execution time. Likewise, ANNs are having multiple local minima problem, whereas a global and unique solution is provided by SVMs. In this paper, several performance parameters like: resonant frequency, gain, directivity, and radiation efficiency of slotted microstrip antennas with modified ground plane are computed with the help of SVM formulation. Comparisons of different parameters of simulated and computed values are illustrated. The achieved radiation patterns at particular resonant frequency in different planes are included as well. A prototype of the optimized antenna is also fabricated and characterized. A good agreement is attained among the computed, simulated, and measured results.

A novel multi-resonance small square monopole antenna with frequency band-notched function is presented. By cutting two modified Cshaped slots in the ground plane bandwidth is increased that provides a wide usable fractional bandwidth of more than 145% (2.85- 17.83). In order to achieve band-rejected function a pair of C-shaped parasitic structures were inserted in the ground plane and a frequency notched band of 5.08–5.93 GHz has been received. The measured results reveal that the bandwidth of the proposed antenna is from 2.85 GHz to 17.83 GHz for VSWR<2. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. The designed antenna has a small size of 12x18 mm2.

In this paper, a compact modified ground slot antenna is proposed. This antenna is designed for super ultra-wideband (UWB) applications. To reduce the interference effect on the WLAN and WiMAX systems, it comes up with dual band notched characteristics. In the antenna geometry, a pair of L-shaped stubs connected to the fork-shaped patch is employed to introduce single band-notched characteristics in 5.15-5.825 GHz for WLAN system. This feature also causes that the middle frequency of the band is highly improved. Moreover, a T-shaped stub is added to the center of the fork-shaped patch to generate the frequency band stop performance in 3.3-3.8 GHz for WiMAX system. Furthermore, we propose a modified ground plane including a pair of inverted T-shaped slits, cut from the ground plane, to improve the bandwidth to 164%. The simulation and measurement results indicate a very wide impedance bandwidth from 2.5 up to 23 GHz, with pre-designed dual band notched properties, for the proposed antenna. This slot antenna with abovementioned frequency bandwidth has a compact size of 24?25 mm2 , and therefore is suitable for many UWB applications.

A compact ultra-wideband (UWB) square and circular slot ground plane planar antenna with a modified circular patch for UWB communication is presented. This antenna has a low reflection coefficient and high gain in the range of 8.94 GHz, starting from 2.85 to 11.79 GHz. The proposed antenna demonstrates UWB behavior with electrically small dimensions of 0.18 λ0×0.14 λ0×0.015 λ0 (λ0 is the free-space wavelength at 2.85 GHz). The fractional bandwidth of the antenna is 122.1%, with stable radiations. The antenna's maximum gain stands at 2.79 dBi, and the antenna's peak efficiency stands at 72%, respectively. It is lightweight, compact, and easy to manufacture. Hence, it can be used for the complete range of UWB applications and covers Wi-Max/WLAN/ X-Band and Ku-Band.

A novel compact super-wideband (SWB) antenna with an optimised feed is presented. The antenna is composed of an asymmetric trapezoid ground plane and a modified rectangular monopole patch. It is demonstrated that the bandwidth of the antenna is significantly enhanced by introducing an asymmetric dual-branch feed with an L-shaped feed branch. The measurements indicate that the 2:1 VSWR bandwidth is from 1.05 to 32.7 GHz with a ratio bandwidth of 31:1. Since the antenna features an extremely wide bandwidth and the entire size is only 74 × 80 mm, it is useful for modern wireless communication applications.

Low-enthalpy geothermal systems are a promising source for renewable and clean energy for heating, cooling, and air conditioning residential buildings, contributing to the reduction in greenhouse gas emissions in line with the United Nations’ Sustainable Development Goals. Previous research emerged around the geothermal utilization of Sustainable Drainage Systems (SuDS) as multifunctional surfaces for stormwater control and energy saving, developing the water–energy nexus. However, these studies did not comprehensively considered the energy aspects for SuDS design, using non-standardized tests to measure the main thermal parameters. This research aims to address this gap by proposing a novel hybrid engineering procedure to study the thermal properties of SuDS layers and materials through experimental tests combined with steady-state and transient numerical simulations, using green swales operating under dry and wet conditions as a first case study for SuDS techniques. Novel materials incorporated into dry swales (expanded clay and construction and demolition waste) were tested. The results validated this new methodology, reporting an increase of 87% under dry conditions, and 51% under wet scenarios in the thermal insulation performance in comparison to standard materials. A better thermal performance of the systems can be achieved by approaching SuDS design from a holistic viewpoint that integrates energy aspects.

A dual-band coplanar waveguide (CPW)-fed bow-tie slot antenna is proposed, which consists of a bow-tie slot, a pair of sector parasitic patches and a modified grounded plane with a band-notch property. The impedance matching, the resonant mode, the radiation patterns and the current distributions are studied. To generate dual-band characteristics, a V-shaped slot is etched on the radiating ground. Experimental and simulated results demonstrate that the antenna exhibits two separate impedance bandwidths of 1450 MHz (about 32.8% centred at 4.43 GHz) and 3500 MHz (about 37.8% centred at 9.25 GHz), which satisfy aircraft radar and X-band applications.