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A Differentially-Fed Dual-Polarized Magnetic Dipole Antenna for Spaceborne Applications
摘要： This paper presents a novel differentially-fed dual-polarized magnetic dipole antenna with stable radiation pattern, platform independence, wide bandwidth and robust structure for spaceborne applications. The proposed antenna is formed by a dual-polarized magnetic dipole backed by a specially designed rectangular cavity. The magnetic dipole consists of two perpendicular parallel-plate waveguides with stepped edges to broaden the impedance bandwidth, providing good structural reliability which is critical to spaceborne antennas. A cross-shaped conductor fed by two pairs of capacity coupling feeding probes is utilized to drive the dual-polarized magnetic dipole antenna. The specially designed rectangular cavity has four metal plates in four corners to shape the radiation pattern at E and H planes. Furthermore, thanks to the cavity, the size of the conducting platform that the antenna mounted on has limited impact on antenna’s electrical performances, particularly the radiation pattern. A prototype is fabricated and tested. Measured results show that the antenna achieves a fractional bandwidth of 18.5% with -10 dB reflection coefficient. The realized gain is about 8.5 dBi. A stable radiation pattern with a 3 dB beamwidth of 70o±3o and -4 dBi maximum beamwidth of 152o is observed. The measured cross-polarization is lower than -20 dB within ±65o. Measured results are in good agreement with simulated ones.
关键词： magnetic dipole,stable radiation pattern,differentially-fed,Dual-polarization,platform independence
更新于2025-09-10 09:29:36
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Characterization of Acoustic Sources by Optical Feedback Interferometry
摘要： Sound can be described as the propagation of pressure variations in compressible media that involves compression and expansion and induces a change in the density of the medium. This change in acoustic pressure as it induces a change of the refractive index can be measured by optical methods, the most recent being the optical feedback interferometry. With this technique, a laser diode is beaming on a reflective surface thus creating a cavity where the acoustic wave propagates. This paper presents a novel experimental technique to measure radiation pattern of acoustic sources based on optical feedback interferometry in a laser diode.
关键词： acoustic,radiation pattern,optical feedback interferometry,ultrasound
更新于2025-09-09 09:28:46
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Study of Horizontally Polarized Omnidirectional Microstrip Antenna Arrays
摘要： This paper presents two microstrip antenna arrays for horizontally polarized (HP) omnidirectional application, namely rectangular patch antenna array and H-shaped patch antenna array. There are eight patch elements placed with back-to-back structure, four patch elements on each side. Antenna arrays are fed by a split eight power divider. The H-shaped patch antenna array has better omnidirectional performance than rectangular patch antenna array. The H-shaped antenna array is fabricated and measured. Both simulated and measured results show that the bandwidth of the designed H-shaped antenna array is 36 MHz with a center frequency 2.35 GHz. Horizontally polarized gains are greater than 7 dBi over the resonant band (S11 < ?10 dB), while the cross-polarization level is less than ?25 dB. The proposed H-shaped antenna array has high directivity (half-power beam-width is only 20 deg) and good omnidirectional performance (gain variation less than 1.5 dBi) at the center frequency.
关键词： horizontal polarization,omnidirectional radiation pattern,microstrip antenna,Antenna array
更新于2025-09-09 09:28:46
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid, Spain (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - A 2D Method for Acquiring the Radiation Pattern of Two-Identical Vivaldi Antennas by Using a Stepped-Frequency Continue Wave (SFCW) Radar and a Rotation Stage
摘要： A simple measuring method for acquiring the radiation pattern of an ultra-wide band Vivaldi antenna is presented. The measuring is performed by combining two identical Vivaldi antennas and some of the intrinsic properties of a stepped-frequency continue wave radar (SFCW radar) in the range from 1.0 GHz to 6.0 GHz. A stepper-motor provided the azimuthal rotation for one of the antennas from 0? to 360?. The tests have been performed within the conventional environment (laboratory / of?ce) without using an anechoic chamber or absorbing materials. Special measuring devices have not been used either. This method has been tested with different pairs of Vivaldi antennas and it can be also used for different ones (with little or no change in the system), as long as their operational bandwidth is within the frequency range of the SFCW radar.
关键词： Azimuthal Radiation Pattern,SFCW Radar,Antenna Gain Characterization
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - SIW Based Antenna Array with Power Equalization in Elevation Plane for 5G Base Stations
摘要： In this paper, we present a 5G base station phased array antenna concept based on the power flux equalization in the elevation plane. We designed an aperture- coupled microstrip patch sub-array fed by a substrate integrated waveguide to produce a cosecant radiation pattern in the elevation plane. The antenna is designed to be operational at frequencies around 28.5GHz, targeting a candidate 5G mm-wave frequency band. The dimensions of the cosecant antenna sub-array support wide-angle scanning of the final phased array antenna in the horizontal plane. The antenna exhibits good impedance and radiation properties in the scanning range +/- 45deg.
关键词： cosecant radiation pattern,microstrip patch antenna,substrate integrated waveguide,phased array antenna,5G base station
更新于2025-09-04 15:30:14
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Metamaterial inspired featherlight artificial plasma horn antenna for astronomical and communication applications
摘要： In this article, we introduce a novel type of horn antenna constructed using artificial plasma sheets. This metamaterial inspired negative permittivity antenna fabricated using thin metallic wires in a specialized manner is observed to have same radiation performance of an equivalent conventional metallic horn structure. This novel plasma antenna can replace the conventional one in all microwave applications. The featherlight weight and the ability to remove the problems related with wind resistance and rain accumulation of this new structure may result in a rethinking of the use of horn antennas in astronomical data collection.
关键词： horn antenna,metamaterials,artificial plasma medium,radiation pattern,satellite application
更新于2025-09-04 15:30:14
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - A 2D Method For Acquiring The Radiation Pattern Of Two-Identical Vivaldi Antennas By Using A Stepped-Frequency Continue Wave (SFCW) Radar And A Rotation Stage
摘要： A simple measuring method for acquiring the radiation pattern of an ultra-wide band Vivaldi antenna is presented. The measuring is performed by combining two identical Vivaldi antennas and some of the intrinsic properties of a stepped-frequency continue wave radar (SFCW radar) in the range from 1.0 GHz to 6.0 GHz. A stepper-motor provided the azimuthal rotation for one of the antennas from 0? to 360?. The tests have been performed within the conventional environment (laboratory / of?ce) without using an anechoic chamber or absorbing materials. Special measuring devices have not been used either. This method has been tested with different pairs of Vivaldi antennas and it can be also used for different ones (with little or no change in the system), as long as their operational bandwidth is within the frequency range of the SFCW radar.
关键词： Azimuthal Radiation Pattern,SFCW Radar,Antenna Gain Characterization
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Multiband Pattern-Reconfigurable PIFA for 5G MIMO Mobile Terminals
摘要： In this paper, a multiband pattern-reconfigurable Planar Inverted-F Antenna (PIFA) for Fifth Generation (5G) Multiple Input Multiple Output (MIMO) mobile terminal is presented. A driven cross patch antenna surrounded by four PIFA elements are combined to form a Cross Patch Quadruple PIFA (CPQPIFA) to produce pattern reconfiguration. The direction of the radiation beam changes when the four metal shorting PIN diodes placed in between the driven cross patch antenna and the PIFA element are initiated separately. Activation of these four PIN diodes produces eight different beam directions at port 1 and port 2. The proposed CPQPIFA design is very versatile as it resonates at three frequency bands ranging from 22 GHz to 30 GHz while achieving reflection coefficient of less than -15dB. Besides that, a high isolation between two CPQPIFAs reduces the mutual coupling to result in an Envelope Correlation Coefficient (ECC) of less than 0.03. Along with its advantage in achieving stable pattern reconfiguration and low ECC, the proposed MIMO antenna is deemed suitable for future 5G mobile terminal application.
关键词： mobile terminal,PIFA,reconfigurable MIMO,5G,millimeter wave,radiation pattern
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Radiation Pattern Reconfigurable Antenna Design Using Characteristic Modes
摘要： In this paper, a radiation pattern reconfigurable antenna is presented, which is able to switch between a bidirectional and a unidirectional radiation pattern. The proposed antenna is conceived from the characteristic mode analysis of two parallel metallic plates, with the same and different sizes. By means of two PIN diodes, the size of the lower plate of the two parallel metallic plates can be modified, changing the behavior of the radiation pattern. During the ON/OFF switching, the operating frequency is shifted, what is solved by introducing a varactor diode in the antenna. Thus, the operating frequency is adjusted for the switching state.
关键词： Radiation pattern,Varactor diode,Characteristic Modes,PIN diode,Reconfigurable antenna
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Hybrid simulations with measurements as improved technique to obtain the complex antenna responses on structures
摘要： With the growth of multiple antenna systems (SIMO, MIMO), the knowledge of the complex antenna responses have to be obtained with a good accuracy to be used in the vector signal processing step. However these responses may depend on the structure where antennas are integrated. Furthermore, these structures completely change between terrestrial, naval or aerial applications. Actual techniques to obtain antenna responses are mainly based on measurements and are often limited or complex in the case of integration over a non-trivial structure (building, vehicle, plane, boat …). An emergent technique is to hybridized measurements and simulations to obtain the desired accurate data.
关键词： measurement,simulation,antenna complex responses,refit,radiation pattern,hybridization
更新于2025-09-04 15:30:14