This article presents a novel dual-fed triple-frequency bands antenna using quarter-mode (QM)/ Eight-mode (EM) substrate integrated waveguide (SIW) cavity resonators. A V-shaped slot is etched into the patch to divide the half-mode cavity into one QM and two EM cavities. One section of the EM cavity and QM cavity are excited with the help of individual micro-strip feedlines. This configuration yields two distinct frequency bands at 4.85 GHz due to TE110 mode of the EMSIW cavity and 5.87 GHz due to TE110 mode of the QMSIW cavity confirming the self-diplexing property. Later, when both the EM cavity sections are joined with the help of two metallic strips, an additional resonance appears at 7.34 GHz due to the excitation of TE120 mode. As compared to the conventional counterparts, the proposed structure is compact and simple. The footprint of the top patch is 0.6λ1 × 0.3λ1. To authenticate the proposed idea, the design is experimentally verified, and the measured results show a good covenant with the simulated results.

In this paper, a new printed triple-band planar antenna combing two different modified monopoles and an arc-shaped defected ground plane is proposed and studied. The used two simple monopoles consist of a rectangular ring and a rectangular patch attached a straight metal strip. And a compact arc-shaped defected ground structure is proposed and used to excite higher resonance frequency and improve the impedance matching of the antenna at lower and middle resonance frequencies. The main radiation element of the proposed antenna composed of only two simple monopoles can support three omnidirectional radiation modes at three desired bands. To indicate the working mechanism of the antenna, the design process is illustrated and the parametric studies are carried out. The experimental results of the fabricated prototype confirm that the triple-band antenna has better radiation efficiencies, appropriate gains, and stable omnidirectional radiation patterns. And the tested results also show that the antenna can provide enough bandwidths of 2.35–2.52, 3.2–4.16, and 5.13–5.87 GHz to cover all the desired 2.4/5.2/5.8 GHz WLAN and 3.5/5.5 GHz WiMAX operations. Moreover, the presented antenna has a very simple structure. Thus, the designed antenna has high practicality and broad prospects for WLAN and WiMAX applications.

A simple design for triple-band circularly polarized (CP) wide slot antennas is proposed and experimentally investigated. The proposed antenna having a microstrip-fed rectangular patch with T-shaped notch for triple-band operation and a modified wide square slot on ground plane for CP operation. The measured 10 dB reflection bandwidths are 1.24% (≈340 MHz from 2.56 to 2.9 GHz), 9.63% (≈430 MHz from 4.25 to 4.68 GHz), and 5.34% (≈490 MHz from 8.93 to 9.42 GHz). The generated 3 dB axial ratio bandwidths of the proposed antenna are 7.54, 8.98, and 1.65% at operating frequencies around 2.65, 4.45, and 9.09 GHz, respectively. The measured peak gains within the 3 dB axial ratio bands are 3.03, 3.5, and 5.64 dBi. The simulated and measured results for the return loss, axial ratio, and antenna gain show a good agreement, which validate the antenna design.

To incorporate two different communication standards in a single device, a compact triple-band antenna is proposed in this paper. The proposed antenna is formed by etching an inverted L-shaped slot on the patch with defected ground structure. The antenna is targeted to excite three separate bands first from 2.39–2.51, second from 3.15–3.91, and third from 4.91–6.08 GHz that covers entire Wireless Local Area Network (WLAN) (2.4/5.2/5.8 GHz) and Worldwide Interoperability for Microwave Access (WiMAX) (2.5/3.5/5.5) bands. Thus, the proposed antenna provides feasibility to integrate WLAN and WiMAX communication standards in a single device with good radiation pattern quality. Furthermore, a prototype of the proposed antenna fabricated and measured to validate the design, shows a good agreement between simulated and measured results. The simulation and measurement results show that the designed antenna is capable of operating over the 2.39–2.51 GHz, 3.15–3.91 GHz, and 4.91–6.08 GHz frequency bands while rejecting frequency ranges between these three bands. The proposed antenna offers a compact size of 20 × 30 mm2 as compared with earlier reported papers.