scholarly journals Design of a SIW Variable Phase Shifter for Beam Steering Antenna Systems

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1013 ◽  
Author(s):  
Sara Salem Hesari ◽  
Jens Bornemann
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Phase Shifter ◽  
Beam Steering ◽  
Antenna System ◽  
Far Field ◽  
Cross Polarization ◽  
Varactor Diodes ◽  
Field Radiation ◽  
Better Than

This paper proposes a new beam steering antenna system consisting of two variable reflection-type phase shifters, a 3 dB coupler, and a 90° phase transition. The entire structure is designed and fabricated on a single layer of substrate integrated waveguide (SIW), which makes it a low loss and low-profile antenna system. Surface mount tuning varactor diodes are chosen as electrical phase control elements. By changing the biasing voltage of the varactor diodes in the phase shifter circuits, the far-field radiation pattern of the antenna steers from −25° to 25°. The system has a reflection coefficient better than −10 dB for a 2 GHz bandwidth centered at 17 GHz, a directive radiation pattern with a maximum of 10.7 dB gain at the mid-band frequency, and cross polarization better than 20 dB. A prototype is fabricated and measured for design verification. The measured far-field radiation patterns, co and cross polarization, and the reflection coefficient of the antenna system agree with simulated results.

scholarly journals Ultralow Profile, Low Passive Intermodulation, and Super-Wideband Ceiling Mount Antennas for Cellular and Public Safety Distributed Antenna Systems

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2456
Author(s):  
Kok Jiunn Ng ◽  
Mohammad Tariqul Islam ◽  
Adam M. Alevy ◽  
Mohd. Fais Mansor
Keyword(s):  
Radiation Pattern ◽  
Public Safety ◽  
Ground Plane ◽  
Antenna System ◽  
Band Ratio ◽  
Antenna Performance ◽  
Distributed Antenna ◽  
Small Disc ◽  
Passive Intermodulation ◽  
Better Than

This paper presents an ultralow profile, low passive intermodulation (PIM), and super-wideband in-building ceiling mount antenna that covers both the cellular and public safety ultra high frequency (UHF) band for distributed antenna system (DAS) applications. The proposed antenna design utilizes a modified 2-D planar discone design concept that is miniaturized to fit into a small disc-shaped radome. The 2-D planar discone has an elliptical-shaped disc monopole and a bell-shaped ground plane, a stub at the shorting path, with asymmetrical structure and an additional proximity coupling patch to maximize the available electrical path to support the 350 MHz band range. The proposed design maximizes the radome area with a reduction of about 62% compared to similar concept type antennas. Besides, the proposed design exhibits an improved radiation pattern with null reduction compared to a typical dipole/monopole when lies at the horizontal plane. A prototype was manufactured to demonstrate the antenna performance. The VSWR and radiation pattern results agreed with the simulated results. The proposed antenna achieves a band ratio of 28.57:1 while covering a frequency range of 350–10000 MHz. The measured passive intermodulation levels are better than −150 dBc (2 × 20 Watts) for 350, 700 and 1920 MHz bands.

Cross Polarized 2x2 LTE MIMO System for Automotive Shark Fin Application

2020 ◽  
Vol 35 (10) ◽  
pp. 1207-1216
Author(s):  
Djordje Preradov ◽  
Daniel Aloi
Keyword(s):  
Mimo System ◽  
Antenna System ◽  
Small Distance ◽  
Design Parameters ◽  
Cross Polarization ◽  
Physical Constraints ◽  
Mimo Antenna ◽  
Planar Monopole Antenna ◽  
Fin Design ◽  
Better Than

In this research we propose two orthogonally placed FR4 printed planar monopole antenna elements for use in the automobile roof top shark fin antenna for LTE MIMO applications. The discussed MIMO antenna system is designed to cover the worldwide LTE frequency band from 698MHz to 2700MHz. The goal of this research is to achieve satisfactory MIMO performance across the whole band while staying within physical constraints of the shark fin style antenna. The target reflection coefficient (S11) of each element is -6dB. Because of physical constraints of the automotive shark fin design antenna MIMO decorrelation is achieved by cross polarization and small distance separation. Correlation better than -12dB is targeted and achieved in higher bands, while in lower frequency bands antennas would not benefit from MIMO performance. Numerical simulation of the MIMO antenna system is performed using FEKO in order to verify the design parameters. Simulation findings are confirmed by manufacturing antennas and testing in the lab.

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