scholarly journals ULTRA-WIDEBAND SCANNING ANTENNA ARRAY WIRE EMITTERS

Doklady BGUIR ◽  
2019 ◽  
pp. 5-12
Author(s):  
O. A. Yurtsev ◽  
A. A. Popov
Keyword(s):  
Antenna Array ◽  
Frequency Band ◽  
Antenna Arrays ◽  
Ultra Wideband ◽  
Linear Lattice ◽  
Matching Criterion ◽  
Single Emitter ◽  
Phase Scan ◽  
Overlap Coefficient ◽  
Scanning Antenna

The aim of the work is to determine the properties of the ultra-wideband scanning antenna array of wire emitters. A single element of the grid is a three-dimensional antenna Vivaldi. Numerical simulation of antenna arrays and single Vivaldi emitters was carried out by the method of integral equations in the thin-wire approximation using the original program and the MMANA program. The dimensions of all elements of a single emitter are determined by the criterion of matching and the shape of the radiation pattern for operation in the frequency range 2–18 GHz. The described variant of the antenna according to the matching criterion (SWR < 2) has a frequency overlap coefficient of 12. The narrowing of the frequency band of a single emitter in the composition of non-scanning and scanning gratings within the angle of 30 degrees is determined. The article deals with the range properties of antenna arrays depending on the parameters of the emitters and the possibility of phase scanning. It is shown that the greatest frequency band in agreement has a lattice with a minimum step of placement of emitters. In a flat antenna array, when scanning in the H-plane, the frequency band according to the matching criterion decreases by 2–3 times. It is shown that the linear lattice without scanning has a frequency overlap coefficient equal to 6 according to the criterion of matching emitters. This ratio decreases as the phase scan sector increases. In a flat lattice, the frequency overlap coefficient and the phase scan sector are smaller than in a linear lattice and decrease with the number of rows. The reduced antenna array has a number of design advantages and can be used in systems with ultra-wideband signals.

MATHEMATICAL MODEL OF A MODIFIED ROTMAN LENS BASED ON AN ASYMMETRIC STRIPE LINE

2021 ◽  
pp. 102-107
Author(s):  
Ю.Г. Пастернак ◽  
В.А. Пендюрин ◽  
Ф.С. Сафонов
Keyword(s):  
Mathematical Model ◽  
Wave Propagation ◽  
Antenna Array ◽  
Experimental Model ◽  
Frequency Band ◽  
Antenna Arrays ◽  
Main Type ◽  
Wide Band ◽  
Antenna System ◽  
Overlap Coefficient

Печатные линзы Ротмана из-за своей достаточной простоты построения и за свои широкополосные свойства, а именно за счет коэффициента частотного перекрытия (может достигать 2-3 и даже более), являются одним из основных перспективных направлений для формирования лучей в многолучевых антенных решетках (МАР). Принцип работы таких линз основан на различных путях распространения волны внутри ее структуры, благодаря которому линза может работать в сверхширокой полосе частот. Но из-за этого возникает новая проблема, а именно: увеличение габаритных размеров антенной системы. Вследствие чего такую конструкцию очень сложно интегрировать в компактную систему приемопередатчика. Эту проблему предлагается решить путем разработки более компактной линзы Ротмана, сложенной пополам. Такой кардинальный метод изменения (уменьшения) габаритных размеров линзы Ротмана мы объясняем тем, что основным типом волны, переносящим подавляющую долю энергии, является волна ТЕМ, для которой практически отсутствует дисперсия в СВЧ-ламинатах с малыми потерями. А для радиолокации, радиопеленгации и связи нужны именно такие способы решения технических трудностей. Но перед тем как создать опытную модель или макет антенной решетки, необходимо провести ряд экспериментов, расчетов и подтвердить заданные технические характеристики ФАР. В данной работе была создана и посчитана математическая модель линзы Ротмана, основанная на том, что ее свернули пополам Rotman printed lenses are one of the main promising directions for ray formation in multipath antenna arrays (MAA) due to their sufficient simplicity of construction and their wide-band properties, namely, due to the frequency overlap coefficient (it can reach 2-3 or even more). The principle of operation of such lenses is based on different paths of wave propagation within its structure, thanks to which the lens can work with an extremely wide frequency band. However, because of this, a new problem arises - an increase in the overall dimensions of the antenna system. As a result, this design is very difficult to integrate into a compact transceiver system. This problem is proposed to be solved by developing a more compact Rotman lens folded in half. We explain this cardinal method of changing (reducing) the overall dimensions of the Rotman lens by the fact that the main type of wave that transfers the overwhelming share of energy is the TEM wave, for which there is practically no dispersion in microwave laminates with small losses. And for radar, radio direction finding and communication, these are the ways to solve technical difficulties. Before creating an experimental model or layout of the antenna array, it is necessary to conduct a number of experiments, calculations and confirm the specified technical characteristics of the PAA. In this paper, a mathematical model of the Rotman lens was created and calculated based on the fact that it was folded in half

scholarly journals Experimental study on improving the accuracy of marine gravimetry by combining moving-base gravimeters with GNSS antenna array

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Zhimin Shi ◽  
Junjian Lang ◽  
Xinghui Liang ◽  
Zhibo Zhou ◽  
Aizhi Guo ◽  
...  
Keyword(s):  
Antenna Array ◽  
Real Time ◽  
Frequency Band ◽  
Antenna Arrays ◽  
Measurement Errors ◽  
Measurement Accuracy ◽  
Tectonic Activity ◽  
Gravity Measurement ◽  
Vertical Position ◽  
Point Positioning

AbstractThe gravity field is one of the Earth’s basic physical fields. The geoid can be calculated and the tectonic activity underground can be inversed by gravity anomaly. With the development of various ship-borne gravimeters and navigation technology, including the Global Navigation Satellite System (GNSS) and Strapdown Inertial Navigation System (SINS), the precision of marine gravimetry has been significantly improved (achieve or better than 1mGal). Errors arising from calculations of the correction term have become the main source of gravity measurement errors. At present, the traditional approach is to deploy a GNSS antenna, connect the GNSS antenna to the gravimeter, record the real-time position through data acquisition software, and then use this position to calculate the gravity correction item afterward. Two errors are inevitable. (1) The GNSS antenna position error is large. The pseudorange point positioning method is generally used to obtain real-time GNSS antenna positions, and the positioning accuracy is poor compared with that of precise point positioning. (2) The position coordinates of the gravimeter contain systematic errors related to the ship’s attitude. In this paper, a joint experiment including GNSS antenna arrays and ship-borne gravimeters was designed to evaluate the measurement accuracy via repeat lines on the same ship. The experimental results show the following: (1) attitude accuracies of 0.0299° for the yaw angle, 0.0361° for the pitch angle, and 0.1671° for the roll angle can be obtained at baseline lengths of 25 and 4 m. (2) The GNSS antenna array has an obvious role in determining the point acceleration in the low-frequency band (0–0.01 Hz) and the point position and velocity in the high-frequency band (0.01–1 Hz). (3) The vertical position eccentricity causes an absolute error of 1 mGal and a relative error of $${10}^{-1}$$ 10 - 1 mGal in gravity measurements and can be corrected by the GNSS antenna array method. (4) Using a GNSS antenna array can obviously improve the measurement accuracy of an instrument with a precision equaling or exceeding 1 mGal, but cannot obviously improve that to an instrument with poor precision (2 mGal or below).

scholarly journals Single-element based ultra-wideband antenna array concepts for wireless high-precision 2-D local positioning

2013 ◽  
Vol 11 ◽  
pp. 297-305 ◽  
Author(s):  
M. Gardill ◽  
G. Fischer ◽  
R. Weigel ◽  
A. Koelpin
Keyword(s):  
Antenna Array ◽  
High Precision ◽  
Antenna Arrays ◽  
Ultra Wideband ◽  
Antenna Element ◽  
Single Element ◽  
Angle Of Arrival ◽  
Wideband Antenna ◽  
Local Positioning System ◽  
5 Ghz

Abstract. We generally categorize the approaches for ultra-wideband antenna array design, and consequently propose simplified concepts for antenna arrays for a high-precision, ultra-wideband FMCW radar 2-D local positioning system to obtain robustness against multi path interference, perform angle of arrival analysis, as well as instantaneous heading estimation. We focus on low-cost and mechanical robust, industrial-application ready antennas. The antenna arrays are optimized for operation in the 5 GHz to 8 GHz frequency range and are designed towards supporting full omnidirectional 360° as well as partial half-plane direction of arrival estimation. Two different concepts for vehicle- as well as wall-mounted antenna array systems are proposed and discussed. We propose a wideband unidirectional bow-tie antenna array element having 97% impedance and 37% pattern bandwidth and a robust vehicle mounted omnidirectional antenna element having more than 85% impedance and pattern bandwidth.

scholarly journals A Transient UWB Antenna Array Used with Complex Impedance Surfaces

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
A. Godard ◽  
L. Desrumaux ◽  
V. Bertrand ◽  
J. Andrieu ◽  
M. Lalande ◽  
...  
Keyword(s):  
Antenna Array ◽  
Frequency Band ◽  
Beam Steering ◽  
Complex Impedance ◽  
Two Dimensions ◽  
Ultra Wideband ◽  
Uwb Antenna ◽  
Radiation Characteristics ◽  
Radar Applications

The conception of a novel Ultra-Wideband (UWB) antenna array, designed especially for transient radar applications through the frequency band (300 MHz–3 GHz), is proposed in this paper. For these applications, the elementary antenna must be compact and nondispersive, and the array must be able to steer in two dimensions. The geometry of the elementary antenna and its radiation characteristics are presented. The array beam steering is analyzed and a technique making the increase of the transient front-to-back ratio possible is described.

scholarly journals Comparing simulated results of folded and unfolded log-periodic antenna used for observing the Sun

2019 ◽  
Vol 5 (2) ◽  
pp. 45-49
Author(s):  
Ли Ша ◽  
Li Sha ◽  
Йан Йихуа ◽  
Yan Yihua ◽  
Чень Чжицзюнь ◽  
...  
Keyword(s):  
Antenna Array ◽  
Frequency Band ◽  
Antenna Arrays ◽  
Return Loss ◽  
Low Frequency ◽  
High Gain ◽  
The Sun ◽  
Wide Bandwidth ◽  
Impedance Characteristics ◽  
Log Periodic Antenna

There are two antenna arrays located in Mingantu Spectral Radio Heliograph (MUSER). MUSER-I and MUSER-II cover the frequency band ranging from 0.4 to 2 GHz and from 2 to 15 GHz respectively. A third antenna array covering 30–240 MHz will be established in the coming years. A log-periodic antenna is one of the choices for MUSER low frequency band; it radiates structures capable of maintaining consistent impedance characteristics over a wide bandwidth. Due to the ability of achieving high gain, it is widely used in many broadband applications. In this program, folded and unfolded log-periodic antennas are simulated for the Meridian project. In order to improve its return loss, this antenna is optimized with the width of each pole and the height of the substrate. This optimized process has been implemented in the simulated software HFSS.

scholarly journals Frequency scanning antenna arrays with pentagonal dipoles of different impedances

2015 ◽  
Vol 12 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Nikola Boskovic ◽  
Branka Jokanovic ◽  
Aleksandar Nesic
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Scanning Angle ◽  
Frequency Scanning ◽  
Wide Range ◽  
Scanning Antenna ◽  
Antenna Characteristics

In this work we present the benefits of using pentagonal dipoles as radiating elements instead of classical printed dipoles in the design of frequency scanning antenna arrays. We investigate how impedance of pentagonal dipoles, which can be changed in a wide range, influences the overall characteristics of the uniform antenna array. Some very important antenna characteristics such as side lobe level, gain and scanning angle are compared for three different antenna arrays consisting of identical pentagonal dipoles with impedances of 500 ?, 1000 ? and 1500 ?.

scholarly journals Comparing simulated results of folded and unfolded log-periodic antenna used for observing the Sun

2019 ◽  
Vol 5 (2) ◽  
pp. 49-54
Author(s):  
Ли Ша ◽  
Li Sha ◽  
Йан Йихуа ◽  
Yan Yihua ◽  
Чень Чжицзюнь ◽  
...  
Keyword(s):  
Antenna Array ◽  
Frequency Band ◽  
Antenna Arrays ◽  
Return Loss ◽  
Low Frequency ◽  
High Gain ◽  
The Sun ◽  
Wide Bandwidth ◽  
Impedance Characteristics ◽  
Log Periodic Antenna

There are two antenna arrays located in Mingantu Spectral Radio Heliograph (MUSER). MUSER-I and MUSER-II cover the frequency band ranging from 0.4 to 2 GHz and from 2 to 15 GHz respectively. A third antenna array covering 30–240 MHz will be established in the coming years. A log-periodic antenna is one of the choices for MUSER low frequency band; it radiates structures capable of maintaining consistent impedance characteristics over a wide bandwidth. Due to the ability of achieving high gain, it is widely used in many broadband applications. In this program, folded and unfolded log-periodic antennas are simulated for the Meridian project. In order to improve its return loss, this antenna is optimized with the width of each pole and the height of the substrate. This optimized process has been implemented in the simulated software HFSS.

Ultra-Wideband Scanning Antenna Array With Rotman Lens

2017 ◽  
Vol 65 (9) ◽  
pp. 3435-3442 ◽  
Author(s):  
Amin Darvazehban ◽  
Omid Manoochehri ◽  
Mohammad Ali Salari ◽  
Parisa Dehkhoda ◽  
Ahad Tavakoli
Keyword(s):  
Antenna Array ◽  
Ultra Wideband ◽  
Scanning Antenna

scholarly journals Ultra-Wideband Dielectric Lens Antennas for Beamsteering Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Renan Alves dos Santos ◽  
Gabriel Lobão da Silva Fré ◽  
Luís Gustavo da Silva ◽  
Marcelo Carneiro de Paiva ◽  
Danilo Henrique Spadoti
Keyword(s):  
Antenna Array ◽  
Ultra Wideband ◽  
Printed Antennas ◽  
Lens Antennas ◽  
Dielectric Lens ◽  
Dielectric Lenses

This paper presents a high-directivity ultra-wideband beamsteering antenna array. An innovative beamsteering system based on hemispherical dielectric lenses fed by a set of different printed antennas is proposed. Diversity of signals in different spatial positions can be radiated at the same time. A prototype was manufactured and characterized, operating in a bandwidth varying from 8 GHz to 12 GHz with gain up to 13 dBi.

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