Beam steering using a single dipole antenna including a capacitive load

2002 ◽  
Author(s):  
H. Scott ◽  
V.F. Fusco
Keyword(s):  
Beam Steering ◽  
Dipole Antenna ◽  
Single Dipole ◽  
Capacitive Load

scholarly journals Design of a Novel Wideband Leaf-Shaped Printed Dipole Array Antenna Using a Parasitic Loop for High-Power Jamming Applications

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6882
Author(s):  
Eunjung Kang ◽  
Tae Heung Lim ◽  
Seulgi Park ◽  
Hosung Choo
Keyword(s):  
High Power ◽  
Beam Steering ◽  
Impedance Matching ◽  
Dipole Antenna ◽  
Array Antenna ◽  
Center Frequency ◽  
Steering Angle ◽  
Single Antenna ◽  
Loop Element ◽  
5 Ghz

This paper proposes a novel wideband leaf-shaped printed dipole antenna sensor that uses a parasitic element to improve the impedance matching bandwidth characteristics for high-power jamming applications. The proposed antenna sensor consists of leaf-shaped dipole radiators, matching posts, rectangular slots, and a parasitic loop element. The leaf-shaped dipole radiators are designed with exponential curves to obtain a high directive pattern and are printed on a TLY-5 substrate for high-power durability. The matching posts, rectangular slots, and a parasitic loop element are used to enhance the impedance matching characteristics. The proposed antenna sensor has a measured fractional bandwidth of 66.7% at a center frequency of 4.5 GHz. To confirm the array antenna sensor characteristics, such as its active reflection coefficients (ARCs) and beam steering gains, the proposed single antenna sensor is extended to an 11 × 1 uniform linear array. The average values of the simulated and measured ARCs from 4.5 to 6 GHz are −13.4 dB and −14.7 dB. In addition, the measured bore-sight array gains of the co-polarization are 13.4 dBi and 13.7 dBi at 4 GHz and 5 GHz, while those of the cross-polarizations are −4.9 dBi and −3.4 dBi, respectively. When the beam is steered at a steering angle, θ0, of 15°, the maximum measured array gains of the co-polarization are 12.2 dBi and 10.3 dBi at 4 GHz and 5 GHz, respectively.

scholarly journals Detection of Active Mobile Phone in Exam Hall

2019 ◽  
Vol 18 (3-2) ◽  
pp. 25-31
Author(s):  
Najla Aiman Nazari ◽  
Ili Najaa Aimi Mohd Nordin ◽  
Muhammad Rusydi Muhammad Razif ◽  
Noraishikin Zulkarnain ◽  
Nurulaqilla Khamis
Keyword(s):  
Mobile Phone ◽  
Detection System ◽  
Dipole Antenna ◽  
Total Efficiency ◽  
Diverse Range ◽  
Detection Range ◽  
Single Dipole ◽  
Detection Circuit ◽  
Radio Frequency Signals ◽  
Multi Band

The use of mobile phone as a cheating tool in the examination hall among students have considerably increased a burden to invigilators to ensure integrity in examination hall. Many active mobile phone detection schemes had been proposed as the solution to this problem. However, the detection system function in a small detection range of 1.5 to 2 meters from the detection circuit and does not distinguish various frequency bands of radio frequency signals. In order to have diverse range of RF mobile phone signals detection for alerting the invigilators of their specified monitoring region, antenna is proposed to be used. This is done by antenna design simulation using Computer Simulation Technology (CST) software. Two types of antenna; single-dipole antenna and multi-band dipole antenna are simulated to know the characteristics of VSWR, gain and total efficiency. From the simulation results, multi-band dipole antenna shows acceptable VSWR value which are approximate to 2 V, gain is equal to 2.85 dB and total efficiency is equal to 2.484 dB for 2.4 GHz signal. The results imply positive event that multi-band antenna can be a preferable tool in elaborating accurate RF signal detection of active mobile phone in examination hall.

scholarly journals A Time Modulated Printed Dipole Antenna Array for Beam Steering Application

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ruchi Gahley ◽  
Banani Basu
Keyword(s):  
Antenna Array ◽  
Beam Steering ◽  
Ground Plane ◽  
Differential Evolution Algorithm ◽  
Phase Variation ◽  
Time Instant ◽  
Dipole Antenna ◽  
Phase Shifters ◽  
Rf Switch ◽  
Rf Switches

This paper presents time modulated beam steered antenna array without phase shifters. The beam steering is analyzed considering a two-element time modulated antenna array (TMAA) of printed dipoles with microstrip via-hole balun. The proposed array resonates at the Industrial, Scientific, and Medical (ISM) radio bands, 2.45 GHz and 5.8 GHz, and offers wide bandwidth inherited due to modified structure of ground plane. Array elements are excited by complex exponential excitation signal through broadband power divider and radio frequency (RF) switches to achieve amplitude and phase variation without phase shifters. Differential Evolution algorithm is used to modify the time sequences of the RF switches connected to the antennas to generate radiation pattern with optimum dynamic efficiency by suppressing sideband radiations. Also switch-on time instant of RF switch connected to the subsequent element is modulated to steer the beam towards different directions. The proposed prototype is fabricated followed by parametric optimization. The fabrication results agree significantly well with simulated results.

scholarly journals Effect of Polarization on the Performance of Adaptive Antenna Arrays

2020 ◽  
pp. 661-668
Author(s):  
Amin H. Al Ka’bi ◽  
Keyword(s):  
Antenna Arrays ◽  
Electromagnetic Waves ◽  
Dipole Antenna ◽  
Adaptive Antenna ◽  
Dipole Antennas ◽  
Adaptive Antenna Arrays ◽  
Single Dipole ◽  
Simulation Results

The polarized electromagnetic waves impinging on adaptive antenna arrays have significant impact on their performance. In this paper we investigate the effect of polarized desired and undesired signals on the performance of electronically steered beam adaptive antenna arrays in terms of their output SINR’s (Signal to Interference plus Noise Ratios). To achieve this goal, we compare the performances of adaptive antenna arrays composed of single dipole antenna elements with those composed of cross-dipole antenna elements to illustrate the effect of polarized signals on their performance. Based on the experimental and simulation results, it will be shown that the adaptive antenna arrays using cross-dipole antennas provide better performance compared to those using single-dipoles, in presence of randomly polarized signals. However, if the desired signal polarization is well known, single-dipole antenna arrays exhibit better performance.

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