Search

Summary A new circular cavity‐backed slot antenna, which produces unidirectional radiation patterns, has been developed for wireless communication systems. The antenna utilizes substrate‐integrated waveguide (SIW) technology to create a low‐profile cavity. The metal cladding on top of the cavity has an engraved circular ring slot for radiation, and a microstrip transition feeding mechanism is used to excite the perturbed circular slot antenna element located away from the centre of the cavity. Two rectangular cuts, including slots and a shorted via probe, improve radiation performance and bandwidth matching by nearly −40 dB over the working frequency range. An optimized spacing of 0.6 mm is established between the patch centre and the input microstrip transition feed, which produces a circularly polarized (CP) wave. The antenna uses CP SIW technology to operate within a wide impedance bandwidth of 12.18% (10.02–11.31 GHz) below −10 dB and an ARBW of 320 MHz (10.40–10.72 GHz). Both experimental and simulated results agree on s‐parameters, and the antenna's gain, axial ratio, and radiation patterns are consistent. With 7.45 dB CP gain and planar integration, the antenna radiates unidirectional, making it suitable for lightweight wireless broadband applications. [ABSTRACT FROM AUTHOR]

We propose a method for increasing the bandwidth of a substrate‐integrated‐waveguide (SIW) cavity‐backed antenna with taper‐based microstrip SIW transition feeding. For radio transmission, a circular slot is etched on top of the SIW cavity. For optimal antenna design, the slot is etched slightly away from the cavity center to generate circularly polarized waves. Simulations show a wide axial ratio bandwidth of 7.860% between 11.02 GHz and 11.806 GHz. Experimental results confirm a similar wide axial ratio bandwidth of 4.9% between 10.8 GHz and 11.35 GHz. An SIW feed from an inductive window excites the radiating circular slot, resulting in a simulated wide impedance range of 1.548 GHz (10.338 GHz–11.886 GHz) and bandwidth of 13.93%. Experimental results show a wide impedance of 2.08 GHz (10.2 GHz–12.08 GHz) and bandwidth of 18.84%. The SIW cavity‐backed antenna creates a unidirectional pattern, leading to gains of 6.61 dBi and 7.594 dBi in simulations and experiments, respectively. The proposed antenna was fabricated on a Rogers RT/Duroid 5880 substrate, and the reflection coefficient, radiation patterns, and gains were tested and compared using a computer simulator. The developed broadband antenna seems suitable for X‐band applications. [ABSTRACT FROM AUTHOR]

A novel‐shaped dual‐polarized low‐profile multiple‐input multiple‐output (MIMO) antenna with high isolation is proposed for 5G/WLAN application. An 8‐element MIMO antenna design comprises two unique planar radiators (chamfer, circular). Each radiator has dual feed and dual polarization characteristics. The prototype is fabricated with an FR‐4 dielectric substrate. A decoupling structure maintains desirable isolation for self‐isolated elements (≤ $\le $−12 dB) using substrate integrated waveguide stubs between inter‐ports and high isolation among the adjacent radiating elements (≤ $\le $−15 dB). The simulation was performed by using CST microwave studio. The simulated results of the proposed MIMO antenna are compared with the measurement results. Furthermore, ECC and DG are investigated. [ABSTRACT FROM AUTHOR]

Summary: This article communicates a novel compact four‐element orthogonal cavity‐backed antenna for 5G applications with enhanced isolation. The proposed dumbbell‐shaped substrate integrated waveguide–multiple input/multiple output (SIW‐MIMO) antenna resonate at 5.25 GHz (sub‐6 GHz) based on vias and resonate at 27 GHz (mm‐wave) with copper filling vias using FR‐4 substrate. Both prototypes are separately designed, fabricated, and tested using same dimension (40 mm × 40 mm × 1.6 mm) as well as same radiating structure. Moreover, SIW MIMO antenna design performances are compared between FR‐4 and Rogers RT/Duroid substrate. Deployment of SIW technique in MIMO antenna minimizes the antenna footprint and mutual coupling without involving any decoupling structure. The antenna simulation characteristics of both operating bands are compared and validated with the measurement results. Furthermore, the MIMO diversity parameters are examined. [ABSTRACT FROM AUTHOR]