This paper presents a miniaturized, tunable, high-power, eight-port hybrid coupler, based on a lumped element hybrid coupler topology. The 90° hybrid couplers are ubiquitous elements used for feeding RF coils in quadrature in magnetic resonance imaging (MRI) systems. Due to the low Larmor frequency (64 MHz) of 1.5 T MRI, distributed elements are too large for practical circuits to drive multi-port

In this paper, a ring patch antenna with 1 GHz of bandwidth and three resonances is designed for the RF energy harvesting application. Two complementary split-ring resonators (CSRR) is etched out from the patch, designed at 6.8 GHz, near feed to enhance the bandwidth from 267 MHz to 1 GHz. Due to the introduction of CSRR, two additional resonances at 6.4 and 7.4 GHz are obtained with gain 5.5 and

The meta-surface is introduced into the design of band-notched monopole antennas with single/dual/triple notched bands around 3.6/5.5/7.2 GHz for ultra-wideband (UWB) communication. We show that strong coupling effects between the meta-surface and the antenna would be created through tuning the orientations of the meta-cells according to the field distributions on the antenna surface, and eventual

An 8 × 8 butler Vivaldi beam-steering antenna array is introduced for X-band application. Circularly polarized array is made of eight Vivaldi elements with 1×8 platform and an 8×8 beam feeding network. Vivaldi radiating element is used in array form to enhance impedance bandwidth and overall efficiency such as gain. Using microwave passive components, for instance, 3 dB branch line couplers and cr

A flexible and high gain saw-tooth-shaped boundary fractal wearable antenna is anticipated for WBAN applications. A square shape is converted to the saw-tooth-shaped boundary by sequentially rotating the square at an angle of 45° and overlaid on one another and repeated the same for three iterations. The geometry is built on a flexible jeans substrate, and the total size of the anticipated antenna

Multiple input multiple output (MIMO) systems, which use multiple antennas to deliver faster data rates, are one of the promising methods in 5G services. 5G is a popular issue among the world's main telecom firms currently. The sub-6 GHz band for 5G applications in various countries lies between 3 and 5 GHz. The sub-6 GHz 5G bands are 3.4?3.8 GHz in Europe, 3.1?3.55 GHz in the USA, and 3.3?3.6 GHz

A printed ultra-wideband (UWB) multiple input multiple output antenna with isolation enhancement and pattern diversity is presented, which is based on characteristic modes (CM) for upcoming wireless mobile platforms. The presented antenna is composed of dual UWB antenna elements (AEs) ? an antipodal Vivaldi and a circular-shaped monopole positioned on the two opposite edges of the antenna's rectan

The design of a low-cost, flexible, miniaturized, and a high code density chipless radio-frequency identification (RFID) tag is presented as a solution for tracking the transportation of biomass fuel pellets. The performance of the tag is presented and demonstrates the applicability of the design for different material systems, while maintaining a compact size of 5.06 cm. The tag consists of neste