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In this paper, the comparisons of four different Beidou B3 navigation antenna arrays with different radiation elements have been presented. For antenna elements, its size, bandwidth and gain properties have been observed. Then, four different four-element arrays constituted by different elements are presented. For these arrays, they have the same distance between elements and the same size ground...
In satellite-borne platforms where the reduction of size, weight and power are very critical design factors. To pursuing to this goal, we present a design for ultrawideband tightly coupled antenna array (TCDA) with wide angle scanning and low cross polarization. Although TCDAs possess the merit of wideband, wide-scanning performance, they need a balanced feeding structure which introduces several...
A time-modulated antenna array (TMAA) provides similar beamforming capability as a phased antenna array. The main difference is generation of sideband components. Such components limit allowable bandwidth of digitally modulated signals transmitted over the TMAA. Nevertheless, the time-modulation allows spatial filtration of mutually interfering signals. In this paper two experimental studies are presented...
Massive MIMO has been chosen as one of the candidate technologies of the fifth-generation mobile communication system (5G), and channel modeling of massive MIMO is of great importance. The most direct and effective approach to investigate the propagation characteristics of massive MIMO channels is channel measurements. However, there are only few measurements of massive MIMO channels, and there still...
An ultra-wideband (UWB) Tightly Coupled Dipole Array (TCDA) composed of a horizontal inter-digital electric dipole and two WAIM layers is designed. The antenna is excited by a pair of 50Ω coaxial lines feed. A prototype was simulated. Results show that a bandwidth more than 5.7:1, with VSWR ≤ 3 from 2.4GHz to 13.6GHz, was achieved. The angle of scanning ranges up to 55° in E-plane while 50° in H-plane.
a Microstrip Dual band patch antenna array with coaxial feed which resonates at 29–30 GHz (ka band) and 57–66 GHz (unlicensed V band) is presented in this paper. The unit cell is a star shaped patch antenna with thin low cost substrate (FR4 Epoxy substrate, with relative permittivity of 4.4 and a thickness of 1.6 mm) in which slots were created and it has a max gain of 4.2 dBi. The 1×2 and 1×4 linear...
A Fabry-Pérot cavity antenna with extended 3dB gain bandwidth is presented in this paper. The proposed structure consists of a rectangular-patch microstrip antenna, on top of which a planar partial reflective surface (PRS) is mounted. Two periodic planar structures, i.e. metasurfaces, with different unit cells are printed on both sides of a 1.5mm-thick Rogers 5880 substrate, forming a novel PRS. It...
Narrow bandwidth is a challenging problem for designing platform-mounted electrically small antennas in the high-frequency (HF) band. In this paper, we demonstrate a process that can be used to improve the bandwidth of a platform-mounted HF antenna or antennas by taking advantage of the presence of the platform. Specifically, we examine a simplified model for the Expeditionary Fighting Vehicle (EFV)...
Three dimensional (3D) antenna refers to an assembly of radiating element on one layer and feed line on another layer and was introduced to minimize the antenna design space. This configuration allows room to integrate more devices and thereby enhances the chip functionalities for an system on chip (SoC) radio frequency (RF) applications. The designed 3D antenna element is composed of vertical metal...
A superdirective array of electrically small dipole radiators can effectively be used as a compact and lightweight first-order probe (a directive antenna radiating predominantly spherical modes with the azimuthal index |μ| = 1) in spherical near-field antenna measurements at low frequencies. This contribution shows that a very narrow frequency bandwidth peculiar to superdirective antennas can be extended...
In this paper, we study performance of a simple electromagnetic band gap (EBG) resonator antenna (ERA) that has a composite all-dielectric superstructure and is excited by a small sparse array. The cavity of the antenna is excited by a 2×2 array of waveguide fed slots with an inter-element spacing of 1.8λo. The ERA exhibits high gain with an excellent directivity bandwidth of around 20%. The proposed...
We proposed silica-based post-wall waveguides (PWWs) with input and output (I/O) transitions from microstrip line for 71–76 GHz and 81–86 GHz, respectively. The PWWs were designed so that their reflection keeps lower than ™20 dB at the aimed frequencies. They were fabricated in silica substrates and the performance was measured. Realization of the bandwidth of 23.6% was confirmed at the lower band...
Improving antenna arrays characteristics such as power consumption, cost and complexity has gained wide attention in the context of cognitive radio networks. One antenna array configuration that offers great potential is the electronically-steerable parasitic array radiator (ESPAR) antenna. In this paper, we propose a transmitter patch ESPAR antenna system for underlay spectrum sharing in cognitive...
A conformal array antenna for omnidirectional coverage in the azimuth plane at Ku band is presented. An eight-faced prism structure has been used to obtain the omnidirectional radiation pattern following a maximum theoretical ripple criterion. The radiating element consists of a rectangular waveguide ended on a cavity-slot. An equal power eight-way radial-waveguide divider has been designed to feed...
A design of a dual linearly polarized superdirective array of electrically small self-resonant magnetic dipole elements is presented. The array exhibits the bandwidth of 12 MHz at 435 MHz central frequency with the directivity exceeding 9 dBi and the parasitic azimuthal modes suppressed below −45 dB. With these characteristics the array can effectively be used as a compact and light-weight first-order...
A polarization reconfigurable antenna using metasurface superstrate is proposed in this paper. The proposed antenna consists of a planar coupling slot with an array of metallic rectangular patches with PIN diodes which can be view as a reconfigurable metasurface superstrate, and a DC bias controlling circuit. When the PIN switches are OFF, the antenna can produce left-hand circular polarized (LHCP)...
The design of a millimeter-wave (mm-wave) dielectric resonator (DR) multiple-input-multiple-output (MIMO) antenna system is presented. The MIMO structure consists of four arrays each radiating in one of four opposite directions. Each array is composed of four cylindrical DR antenna elements (cDRAs) operating at 30 GHz with a fractional bandwidth of at least 6.7%. The elements are fed via slot coupling...
A simple pattern reconfigurable printed inverted-F antenna is presented for WLAN applications. The proposed low profile monopole antenna consists of one main radiator and one parasitic element. The antenna is capable of switching both the pattern and polarization across the full 205 MHz bandwidth, using only one PIN diode. The measured gain for the ON and OFF modes are 1.2 dBi and 4.2 dBi, respectively...
In this paper, a circularly polarized (CP) antenna with a broad axial ratio (AR) bandwidth for 60 GHz communication. The vertically polarized wave and the horizontally polarized wave are radiated by using a folded ground structure and a parasitic branch, respectively. The CP wave is completed by merging two orthogonally polarized waves. Conventional printed circuit board lamination is used to create...
5G, the new generation of mobile networks, attracts lots of interests and attentions in wireless communication with its aggressive performance goals. To be able to provide much higher data rate than today, 5G mobile networks will operate at frequencies higher than the crowded frequency bands used today, with broader bandwidth. Understanding the propagation characteristics of the wireless channel under...
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