A Planar Dual Notched Band Vivaldi Antenna for Wireless Communication Applications

With the aim of realizing a Vivaldi Antenna (VA) with stop bands for wireless communication applications, this paper introduces a novel, uncomplicated, easily fabricated, and compact planar VA featuring two distinctive rejected frequency bands. The designed VA is engraved onto an FR4-epoxy substrate, measuring 0.4243λ0×0.4296λ0 ×0.01315λ0 at 2.63 GHz. The integration of dual notched band functionality is ingeniously achieved through the implementation of a simple additional strip and a U-formed slit. A physical prototype of the VA was successfully constructed and meticulously measured with the R&S®ZNB Vector Network Analyser. The measured impedance bandwidth demonstrates that the realised VA operates from 2.63 GHz to beyond 12 GHz while effectively excluding two bands: 3.46-4.16 GHz (18.37 %) and 5.32-6.5 GHz (19.97 %). Simulated results indicate that the designed VA can provide stable unidirectional radiation patterns, reasonable realized gain, and acceptable radiation efficiency across its operating ranges, with notable drops observed at the two notched bands. As a result, these findings highlight the practical value of the designed VA for wireless communication applications, particularly in scenarios where the integration of filtering structures in antennas becomes essential to prevent interference with co-existing systems. The presented VA opens new avenues for enhancing wireless communication performance, catering to the increasing demand for reliable and interference-resistant solutions

Нова широкосмугова частково відбиваюча поверхня для покращення коефіцієнта посилення антени

У роботі запропонована нова широкосмугова частково відбиваюча поверхня (PRS) для покращення коефіцієнта підсилення друкованих антен. Запропонована PRS побудована з двох шарів, розділених повітряним зазором. Вона складається з індуктивного патчу з отвором у формі зірки або квітки, протравленого на нижніх гранях його двох шарів, та ємнісного патчу у формі зірки або квітки, розміщеного на верхній грані верхнього шару. Представлена PRS з функціонуванням у широкосмуговому діапазоні від 7,76 до 11,16 ГГц запропонована для покращення коефіцієнта підсилення друкованих антен, що працюють навколо цієї смуги. Корисність запропонованої PRS досліджується шляхом розміщення масиву 8×9 над одношаровою друкованою антеною. Коефіцієнт підсилення розглянутої антени значно покращується після впровадження PRS. Отже, корисність розробленої PRS демонструється для покращення коефіцієнта підсилення друкованих антен, що працюють в діапазоні частот X-зони.A novel wideband partially reflective surface (PRS) for printed antennas gain enhancement is proposed in this paper. The proposed PRS is constructed by two layers separated by an air-gap. It is composed by an inductive patch with a star flower-shaped aperture etched on the bottom faces of its two layers and a capacitive star flower-shaped patch that is placed on the top face of its upper layer. The presented PRS with a broadband operation extending from 7.76 GHz to 11.16 GHz is proposed to improve the gain of printed antennas operating around this band. The usefulness of the proposed PRS is examined by placing an array of 8 × 9 over a single-layer printed feeding antenna (FA). The gain of the considered FA is considerably enhanced after the implementation of the PRS. Hence, the usefulness of the designed PRS is demonstrated for enhancing the gain of printed antennas operating in X-band

A Compact Planar UWB Antenna with Triple Controllable Band-Notched Characteristics

A modified compact planar ultrawideband (UWB) monopole antenna with triple controllable band-notched characteristics is presented in this paper. The proposed antenna consists of a modified stair cased V-shaped radiating element and partial ground plane. The triple band-notched characteristics are achieved by embedding two different vertical up C-shaped slots with a vertical down C-shaped slot in the radiating patch and in the ground plane, respectively. Besides, the bandwidth of each rejected band can be independently controlled by adjusting the dimensions of the corresponding band notched structure. The proposed antenna with rejected bands characteristics is successfully simulated, prototyped, and measured. The measured results show that the antenna operates until upper 11 GHz for voltage standing wave ratio (VSWR) is less than 2, and exhibits bands rejection of 1.6–2.66 GHz (49.76%), 3-4 GHz (28.57%), and 5.13–6.03 GHz (16.12%). Moreover, the proposed antenna shows a near omnidirectional radiation patterns, stable peak gain, and with small group delay and transfer function variation on the whole UWB frequency range except in the notched frequency bands, which makes it suitable for being used in the future UWB applications