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The preferential placement of the platforms in a coherent RF network to suppress sidelobe energy close to the array mainbeam is analyzed in this work. A linear array consisting of nine platforms within a 9000λ array size is optimized with a genetic algorithm. A large set of platform layouts that achieve sidelobe suppression of nearly 3 dB exists. The layouts are tolerant to position error on the order...
Antennas formed by a single cylinder with a longitudinal slot are presented. It has been shown that the antennas allow flush installation and can be efficiently used either as a single radiating element or as an element in antenna arrays. Physical phenomena that were utilized to produce uniform field distribution along the slot and as the consequence, to create optimal directivity, have been studied.
This paper discusses bandwidth and polarization challenges in modern dual-polarized ultra-wideband (UWB) electronically scanned array (ESA) aperture design and two recent solution advances aiming to remedy such issues: a 6:1 Planar Ultrawideband Modular Antenna (PUMA) array and a 10:1 Sliced Notch Antenna (SNA) array. The proposed arrays enable wide bandwidth, low cross-polarization, and high efficiency...
A 2k factorial design with 3 factors was applied to perform analysis of skin, antenna type, and solution frequency. A homogeneous skin model was used to contrast the antenna's behavior in free-space and on-skin in order to determine if the antenna tested will withstand the effects of the human body when used as part of a body area network. It was determined that: the bandwidth was not affected in...
A compact ultra-wideband multi antenna system is presented in this paper. The concept is based on the simultaneous excitation of different Characteristic Modes on each antenna element by multiple decoupled ports. This enables a 484 port antenna with low port to port coupling having only 121 physical antenna elements.
Effects of cylindrical and rectangular finite sized ground planes on the isolation between flush mounted linearly-polarized wideband antennas in K/Ka-band is presented. The impact is analyzed by first presenting the isolation between the antennas in free space, with good correlation between measurement, Friis transmission and simulation. Measurement results show that the ground planes decrease isolation...
A compact printed monopole antenna array using neutralization line to reduce the mutual coupling is proposed. The antenna size is 40 × 80 mm2 with an impedance bandwidth of 3.1 to 12 GHz. Details of the antenna design and simulation results are presented and discussed. Both of the reflection coefficient and radiation characteristics achieve a good improvement.
In this paper, we investigate the feasibility of substantial bandwidth enhancement of a low-frequency miniaturized antenna on a robotic flyer through magnetic coupling with similar elements in a tight flight formation. The dimensions of a single radiating element are confined to within λ/10 × λ/10 × λ/10 for operation at around 300 MHz. Variations of end-loaded meandered line dipoles are studied and...
This paper emphasizes on improving the efficacy of patch antennas with meta-material lens embedding. Antenna performance is described in terms of various performance metrics viz. efficiency, gain, directivity, main lobe and power radiation level and bandwidth. For enhancing these parameters Metamaterials (MMs) are used as an uniform flat lens along with the antenna. For analysis purpose, a patch antenna...
We present one of the very first reconfigurable, ultra-wideband (UWB) tightly-coupled array (TCA) with tunable band-rejection capabilities. The array is dual-polarized, achieving a 4:1 bandwidth (1–4GHz) while scanning down to 60° in all planes with a VSWR<3. The dipoles are fed via a novel folded Marchand balun, customarily used for differential excitation, matching and impedance transformation...
Microfluidic focal plane arrays (MFPAs) can provide beam-scanning capability without active RF devices. However, recent work showed that passive resonant feed networks of these MFPAs limit the performance in terms of bandwidth and loss as the FPA size gets larger for high gain applications (e.g. <3% bandwidth for >8 elements). This paper alleviates this issue by introducing a novel microfluidically...
Wideband millimeter-wave arrays are of increasing importance for a growing number of communications or sensing applications. Existing arrays are either narrow-band, prohibitively expensive, or cannot be scaled. In this paper, we present a new class of low-cost ultra-wideband millimeter-wave array operating across the Ka-W bands (26–86 GHz). The proposed design concept and the optimized layout are...
A single-layer wideband reflectarray antenna employing sub-wavelength phase-shifting elements is presented. The element is composed of double concentric square meander line rings and its size is a fifth of a wavelength. By changing the length of the meander line, a phase variation range of about 360° is achieved with an almost constant slop across the 9 to 11 GHz. Using this element, a 48 × 48 — element...
This paper presents the numerical design of a metallic reflectarray antenna at millimeter waves and investigates the radiation discrepancy due to the manufacture distortion. The metallic elements are convex and exhibit linear phase variation with respect to its height and frequency, and may provide a broader bandwidth in the composition of reflectarray antenna. The antenna is investigated at mmW....
The partially parallel-feeding traveling-wave waveguide slot array has an advantage to reduce the frequency dependence of radiation pattern and obtains broadband characteristics. However, conventional post-loaded radiating slots limit the bandwidth of the array. Therefore, the waveguide narrow-wall cavity slot on iris is proposed to extend the bandwidth of the radiating elements. 24-element two-line...
A general design of a high-gain wideband single-layer radial line slot array antenna is discussed for V-band applications with a 6GHz gain bandwidth, to be compared with that of planar Fabry-Perot cavity antennas that is in general narrower. The antenna is based on a simple laminated single layer and a planar integrated feeding structure is proposed as a preliminary choice to excite such design.
In this paper, the design of aperture-couplet rectangular dielectric resonator antennas arrays is illustrated. The effect of slot feed on the dielectric resonator antenna (DRA) and the effect of the spacing between array elements is observed. This paperwork can be useful for WLAN applications with the operating frequency 5.8 GHz.
This paper presents a new method to calculate slot conductance which takes mutual coupling between the adjacent elements in an array into account. This method is explained for calculating slot conductances of inclined slots in the narrow wall of a rectangular waveguide. Then a slot array with this type of radiating elements is designed for −35 dB side lobe level. The results show that proposed method...
The antenna is usually the critical component in systems for sensing and communications. This is because the quality of the system, often expressed as some form of signal-to-interference-plus-noise ratio, is usually dominated by the antenna's gain to the desired signal and its suppression of unwanted signals. For increasing its gain (and suppression capability), an antenna requires an increasing electrical...
In this paper the development of a wearable 3D FMCW radar sensor system for firefighters to enhance eyesight in smoky surroundings during hazardous situations is described. In order to obtain a real-time capable, small and lightweight sensor, two orthogonal oriented frequency-scanning meander-line antennas are combined with small broadband 57 GHz to 63 GHz FMCW radar-modules. This arrangement is used...
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