scholarly journals Tilted-Beam Switched Array Antenna for UAV Mounted Radar Applications with 360° Coverage

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1240 ◽  
Author(s):  
Cheol Ung Lee ◽  
Gunhark Noh ◽  
ByungKuon Ahn ◽  
Jong-Won Yu ◽  
Han Lim Lee
Keyword(s):  
Elevation Angle ◽  
Array Antenna ◽  
Antenna Element ◽  
Antenna Gain ◽  
Beam Characteristic ◽  
Aerial Vehicle ◽  
Radar Applications ◽  
Half Power ◽  
Peak Gain ◽  
Better Than

A highly efficient antenna array for unmanned aerial vehicle (UAV) mounted radar applications with a tilted-beam characteristic and a 360° beam coverage is proposed in this paper. The proposed array antenna is configured by four planar super J-pole antennas with 2-dimensional ground reflectors. Each super J-pole antenna element provides a high directivity where the peak gain is tilted about 45° facing toward the ground from the bottom of a UAV body. Thus, the air-to-ground communication difficulty due to the altitude difference between the UAV and ground targets can be effectively solved. Further, the four super J-pole elements with a switched operation can cover the whole 360° areas around the UAV while high antenna gain is maintained. To verify the performance, the proposed structure was implemented at 5.9 GHz with an overall volume of 0.88 × 0.88 × 0.83 λo3. The measured 10-dB impedance bandwidths for all four antenna elements were better than 27.2% and the isolation among the four antenna ports was also always better than 13 dB. The measured peak gain was better than 7.4 dBi and tilted at 45° in the elevation angle. Lastly, the measured half power beam widths in elevation and azimuth planes were more than 60° and 87°, respectively.

scholarly journals Compact Switched-Beam Array Antenna with a Butler Matrix and a Folded Ground Structure

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Young-Jun Kim ◽  
Ye-Bon Kim ◽  
Hyun-Jun Dong ◽  
Yong Soo Cho ◽  
Han Lim Lee
Keyword(s):  
Phase Shifters ◽  
Capacitive Coupling ◽  
Array Antenna ◽  
Impedance Bandwidth ◽  
Ground Structure ◽  
Butler Matrix ◽  
Beam Array ◽  
Aerial Vehicle ◽  
Microcontroller Unit ◽  
Better Than

A compact switched-beam array antenna, based on a switched Butler matrix with four folded ground antennas, is presented for unmanned aerial vehicle (UAV) applications. The folded ground structure, including a slotted patch radiator surrounded by multiple air-gapped ground layers, is adopted to maximize compactness. The extra ground layers provide extra capacitive coupling around the patch antenna, resulting in a down-shift of resonant frequency and a reduction in the antenna size. Also, to optimize aerial operation with a wider beam coverage, the 1 × 4 array is integrated with a switched Butler matrix controlled by a microcontroller unit (MCU). The choice of the Butler matrix reduces the complexity of beamforming circuitry and avoids the use of high-cost phase shifters requiring extra control-bit signals. Further, the array antenna is optimized for high isolation among the antenna ports and a minimal UAV body effect. Then, the proposed structure was verified at 1.96 GHz for test purposes only, and the array size, excluding the antenna case, was 2.16λo × 0.54λo × 0.07λo. The measured 10 dB impedance bandwidth for all antenna elements in the array was always better than 3.4%, and the isolation among the antenna ports was also better than 19 dB. The measured peak gain, excluding the loss of the switched Butler module, was about 9.98 dBi, on average. Lastly, the measured peak scan angles were observed at −39°, −17°, 9° and 31° according to switching modes.

scholarly journals Dual-Polarized Crossed Bowtie Dipole Array for Wireless Communication Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhi-Ya Zhang ◽  
Shuang Li ◽  
Shao-Li Zuo ◽  
Jia-Yue Zhao ◽  
Xiao-dong Yang ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Phase Distribution ◽  
Base Station ◽  
Array Antenna ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Antenna Gain ◽  
Base Station Antennas ◽  
Dual Polarized ◽  
Dual Polarized Antenna

A dual-polarized array with downtilted radiation patterns is proposed for wireless communication applications. The proposed dual-polarized antenna element achieves an enhanced impedance bandwidth and compact dimensions by introducing a parasitic circular patch and vertical metal cylinders, which is a good candidate for radiating elements in base station antennas. By optimizing the amplitude and phase distribution along the feed, a radiation pattern with a downtilted angle is obtained. The dual-polarized array antenna achieves an impedance bandwidth for VSWR≤1.5, covering the frequency bands for 3G/LTE systems. Moreover, the proposed array achieves high port isolation, the stable antenna gain over the entire operating band. Therefore, the proposed array antenna is very suitable for potential wireless communication applications. A prototype has been manufactured and measured. The measurements, that match the design objectives, are also presented.

scholarly journals Triangular Slot-Loaded Wideband Planar Rectangular Antenna Array for Millimeter-Wave 5G Applications

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 778
Author(s):  
Iftikhar Ahmad ◽  
Houjun Sun ◽  
Umair Rafique ◽  
Zhang Yi
Keyword(s):  
Antenna Array ◽  
Millimeter Wave ◽  
Communication Systems ◽  
Ground Plane ◽  
Simulated Data ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Single Antenna ◽  
Rectangular Patch ◽  
Half Power

This paper presents a design of a triangular slot-loaded planar rectangular antenna array for wideband millimeter-wave (mm-wave) 5G communication systems. The proposed array realizes an overall size of 35.5 × 14.85 mm2. To excite the array elements, a four-way broadband corporate feeding network was designed and analyzed. The proposed array offered a measured impedance bandwidth in two different frequency ranges, i.e., from 23 to 24.6 GHz and from 26 to 45 GHz. The single-antenna element of the array consists of a rectangular patch radiator with a triangular slot. The partial ground plane was used at the bottom side of the substrate to obtain a wide impedance bandwidth. The peak gain in the proposed array is ≈12 dBi with a radiation efficiency of >90%. Furthermore, the array gives a half-power beamwidth (HPBW) of as low as 12.5°. The proposed array has been fabricated and measured, and it has been observed that the measured results are in agreement with the simulated data.

scholarly journals Machine Learning for the Dynamic Positioning of UAVs for Extended Connectivity

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4618
Author(s):  
Francisco Oliveira ◽  
Miguel Luís ◽  
Susana Sargento
Keyword(s):  
Machine Learning ◽  
Cellular Networks ◽  
Real Data ◽  
Emerging Technology ◽  
Machine Learning Algorithms ◽  
Base Stations ◽  
Aerial Vehicle ◽  
Positioning Algorithm ◽  
The Military ◽  
Better Than

Unmanned Aerial Vehicle (UAV) networks are an emerging technology, useful not only for the military, but also for public and civil purposes. Their versatility provides advantages in situations where an existing network cannot support all requirements of its users, either because of an exceptionally big number of users, or because of the failure of one or more ground base stations. Networks of UAVs can reinforce these cellular networks where needed, redirecting the traffic to available ground stations. Using machine learning algorithms to predict overloaded traffic areas, we propose a UAV positioning algorithm responsible for determining suitable positions for the UAVs, with the objective of a more balanced redistribution of traffic, to avoid saturated base stations and decrease the number of users without a connection. The tests performed with real data of user connections through base stations show that, in less restrictive network conditions, the algorithm to dynamically place the UAVs performs significantly better than in more restrictive conditions, reducing significantly the number of users without a connection. We also conclude that the accuracy of the prediction is a very important factor, not only in the reduction of users without a connection, but also on the number of UAVs deployed.

Simultaneous beam steering of multiple signals based on optical wavelength-selective switch

2015 ◽  
Vol 7 (3-4) ◽  
pp. 391-398
Author(s):  
Giovanni Serafino ◽  
Antonio Malacarne ◽  
Claudio Porzi ◽  
Paolo Ghelfi ◽  
Marco Presi ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Phase Shifter ◽  
Phased Array ◽  
Beam Steering ◽  
Array Antenna ◽  
Ring Resonators ◽  
Antenna Element ◽  
Phased Array Antenna ◽  
Wavelength Selective Switch

A novel, photonics-based scheme for the independent and simultaneous beam steering of multiple radio frequency signals at a wideband phased-array antenna is presented. As a proof of concept, a wavelength-selective switch (WSS) is employed both as a wavelength router to feed multiple antenna elements and as a tunable phase shifter to independently control the phase of each signal at any antenna element. In the experiment, two signals at 12.5 and 37.5 GHz are simultaneously fed to the four output ports of the WSS with independent and tunable phase shifts, emulating the independent steering of two signals in a four-element phased-array antenna. The results confirm the precision and flexibility of the proposed scheme, which can be realized both with bulk components or resorting to photonic integrated circuits, especially for wide-band applications. The architecture for a possible integrated implementation of the proposed solution is presented, employing a structure based on micro-ring resonator. Starting from these results, the feasibility of an integrated version of the presented architecture is also considered. The proposed photonic integrated circuit realizing the beam-forming network might be based on tunable true-time delay, as well as on phase shift through micro-ring resonators, and could be conveniently implemented with CMOS-compatible silicon technology.

Design of an interlocked four-port MIMO antenna for UWB automotive communications

2021 ◽  
pp. 1-8
Author(s):  
M. Saravanan ◽  
R. Kalidoss ◽  
B. Partibane ◽  
K. S. Vishvaksenan
Keyword(s):  
Multiple Input Multiple Output ◽  
Performance Estimation ◽  
Ultra Wideband ◽  
Antenna Element ◽  
Frequency Range ◽  
Mimo Antenna ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Operating Bandwidth ◽  
Peak Gain

Abstract The design, analysis, fabrication, and testing of a four-port multiple-input multiple-output (MIMO) antenna is reported in this paper for automotive communications. The MIMO antenna is constructed using the basic antenna element exploiting a slot geometry. Two such antennas are developed on the same microwave laminate to develop a two-port MIMO antenna. Two such microwave laminates are interlocked to create the four-port MIMO scheme. The most distinct feature of the proposed architecture is that the inter-port isolation is well-taken care without the need for an external decoupling unit. The four-port MIMO antenna has an overall volume of 32 × 15 × 32 mm3. The prototype MIMO antenna is fabricated and the measurements are carried out to validate the simulation results. The antenna offers ultra-wideband (UWB) characteristics covering the frequency range of 2.8–9.5 GHz. The average boresight gain of the antenna ranges from 3.2 to 5.41 dBi with the peak gain at 8 GHz. The simulated efficiency of the antenna is greater than 73% within the operating bandwidth. The MIMO parameters such as envelope correlation coefficient, diversity gain, and mean effective gain are evaluated and presented. The appropriateness of the proposed antenna for deployment in the shark fin housing of the present-day automobiles is verified using on-car performance estimation.

scholarly journals Multifunctional Partially Reflective Surface for Smart Blocks

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6508
Author(s):  
Jae Hee Kim ◽  
Dong-Jin Lee ◽  
Tae-Ki An ◽  
Jong-Gyu Hwang ◽  
Chi-Hyung Ahn
Keyword(s):  
High Gain ◽  
Antenna Gain ◽  
High Gain Antenna ◽  
Reflective Surface ◽  
Antenna Performance ◽  
Directional Radiation ◽  
Performance Deterioration ◽  
Polarization Characteristics ◽  
Half Power ◽  
Gain Characteristic

In general, a partially reflective surface (PRS) is mainly used to increase the gain of an antenna; some metallic objects placed on the PRS degrades the antenna performance because the objects change the periodic structure of the PRS. Herein, we propose a multifunctional PRS for smart block application. When a passenger passes over a smart block, the fare can be simultaneously collected and presented through the LED display. This requires high gain antenna with LED structure. The high gain characteristic helps the antenna identify passengers only when they pass over the block. The multifunctional PRS has a structure in which an LED can be placed in the horizontal direction while increasing the antenna gain. We used the antenna’s polarization characteristics to prevent performance deterioration when LED lines are placed in the PRS. We built the proposed antenna and measured its performance: At 2.41 GHz, the efficiency was 81.4%, and the antenna gain was 18.3 dBi. Furthermore, the half-power beamwidth was 18°, confirming a directional radiation pattern.

scholarly journals Radiation Pattern Reconfigurable Waveguide Slot Array Antenna Using Liquid Crystal

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongyu Shi ◽  
Jianxing Li ◽  
Shitao Zhu ◽  
Anxue Zhang ◽  
Zhuo Xu
Keyword(s):  
Dielectric Constant ◽  
Liquid Crystal ◽  
Electric Field ◽  
Radiation Pattern ◽  
Array Antenna ◽  
Antenna Element ◽  
Waveguide Slot ◽  
Radiation Direction ◽  
Coupled Resonator

In this paper, we proposed a radiation pattern reconfigurable waveguide slot array antenna using liquid crystal (LC). Together with the waveguide slot, the designed complementary electric-field-coupled resonator functions like a switch controlled by the dielectric constant of the LC, which can control the antenna element to radiate or not. Thus, the array factor and radiation pattern can be manipulated. The proposed antenna was simulated, fabricated, and measured. Its radiation direction can be reconfigured to 46° or 0° at about 15 GHz.

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