Knowledge Centre
Find a document written by the best international scientists in our secure database.
24776 documents found.
High-gain and broadband SIW cavity-backed slots antenna for X-band applications
Substrate-integrated waveguide (SIW) technology has recently drawn attention to its benefits in the microwave field, such as integration in planar microwave circuits, low manufacturing cost, and high-quality factor compared to other technologies. In this paper, a broadband and high gain SIW cavity-backed L-shaped slot antenna structure has been designed and made for X-band applications. Three pair
Design and analysis of a planar UWB bandpass filter with stopband characteristics using MMR technique
In this paper, a ultra-wideband (UWB) bandpass filter with stopband characteristics is presented using a multi-mode resonator (MMR) technique. An MMR is formed by loading three dumbbell-shaped (Mickey and circular) shunt stubs placed in the center and two symmetrical locations from ports, respectively. Three circular and arrowhead defected ground structures on the ground plane are introduced to ac
A waveform design method for frequency diverse array systems based on diversity linear chirp waveforms
A frequency diverse array (FDA) radar has attracted wide attention, due to its capability to provide a range-angle dependent beampattern and to scan the spatial without phase shifters or rotating arrays. However, FDA systems will suffer from low echo signal energy or high sidelobe peaks when detecting targets by beamforming based on existing receivers. To reduce the sidelobe peak of detection resu
Toroidal dipole excitation in cylindrically arranged dogbone metallic inclusions
A significant excitation of toroidal moments in cylindrically arranged dogbone metallic inclusions is validated and presented in this paper. The antiparallel poloidal currents excited on the front and back faces of the proposed cylindrical dogbone inclusions create strong magnetic field confinement at the center generating intense toroidal moments on the structure. The significant excitation of to
Backfire suppressed low profile aperture coupled stacked patch antenna backed by a high impedance surface (HIS) reflector for UHF RFID reader applications
In this paper, a backfire suppressed aperture coupled circularly polarized (CP) stacked patch antenna for universal ultra-high frequency (UHF) radio frequency identification applications is presented. Cross-polarized backfire radiation patterns were successfully suppressed by a planar high impedance surface (HIS) reflector. The size of the fabricated antenna is 250 × 250 × 26.9 mm (0.71 × 0.71 × 0
Angle and polarization-independent miniaturized UWB FSS design
A single-layer ultra-wideband (UWB) stop-band frequency selective surface (FSS) has several advantages in wireless systems, including a simple design, low debugging complexity, and an appropriate thickness. This study proposes a miniaturized UWB stop-band FSS design. The proposed FSS structure consists of a square-loop and metalized vias that are arranged on a single layer substrate; it has an exc
Wide-band gain enhancement of a pyramidal horn antenna with a 3D-printed epsilon-positive and epsilon-near-zero metamaterial lens
In this article, we present a simple, low-cost solution for the gain enhancement of a conventional pyramidal horn antenna using additive manufacturing. A flat, metamaterial lens consisting of three-layer metallic grid wire is implemented at the aperture of the horn. The lens is separated into two regions; namely epsilon-positive and epsilon-near-zero (ENZ) regions. The structure of the ENZ region
5G beamforming techniques for the coverage of intended directions in modern wireless communication: in-depth review
The growing need of the compact and portable antennas with high speed and low latency wireless communication is the present and future demand of the voice over Internet protocol, on-demand bandwidth, and multimedia applications. Fifth-generation (5G) covers certain low-frequency bands under 6 GHz spectrum, and most of the high-frequency bands under 60 GHz. 5G is the part of the millimeter wave spe