- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[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) - Design of an Asymmetrical Quadruple-ridge Flared Horn Feed: a Solution to Eliminate Polarization Discrepancy in the Offset Reflecting Systems
摘要： Quadruple-ridge Flared Horns (QRFHs) have been showing qualified performance as the feed antennas for the reflecting systems in the Square Kilometre Array (SKA). However, due to the offset optics of the SKA reflecting system, identical illuminations from dual polarizations of the feed would result in different system performance. This difference would become more severe towards high frequencies and may cause the worse polarization unqualified for the desired specification. In this paper, an asymmetrical QRFH feed working over SKA Band B (covering frequencies 4.6–24 GHz) is proposed and optimized to tackle this problem. The asymmetrical Band-B feed is composed of two different and orthogonal pairs of both ridges and sidewall quad-pieces, so as to provide orthogonal polarizations but different illuminations. Simulated results show that, by this asymmetrical design different illuminations can be provided for two polarizations, and the polarization discrepancy has been eliminated over most of the bandwidth. Benefitting from the elimination, both polarizations of the Band-B feed have now achieved the SKA specification in terms of aperture efficiency.
关键词： polarization discrepancy,offset reflector antenna,quadruple-ridge flared horn
更新于2025-09-23 15:23:52
-
12- and 21-GHz Dual-band Dual-circularly Polarized Offset Parabolic Reflector Antenna Fed by Microstrip Antenna Arrays for Satellite Broadcasting Reception
摘要： In December 2018, satellite broadcasting for 4K/8K ultra-high-definition television (UHDTV) will begin in Japan. It will be provided in the 12-GHz (11.7 to 12.75 GHz) band with right- and left-hand circular polarizations. BSAT-4a, a satellite used for broadcasting UHDTV, was successfully launched in September 2017. This satellite has not only 12-GHz-band right- and left-hand circular polarization transponders but also a 21-GHz-band experimental transponder. The 21-GHz (21.4 to 22.0 GHz) band has been allocated as the downlink for broadcasting satellite service in ITU-R Regions 1 (Europe, Africa) and 3 (Asia Pacific). To receive services provided over these two frequency bands and with dual-polarization, we implement and evaluated a dual-band and dual-circularly polarized parabolic reflector antenna fed by 12- and 21-GHz-band microstrip antenna arrays with a multilayer structure. The antenna is used to receive 12- and 21-GHz-band signals from in-orbit satellites. The measured and experimental results prove that the proposed antenna performs as a dual-polarized antenna in those two frequency bands and has sufficient performance to receive satellite broadcasts.
关键词： microstrip antenna,dual band antenna,circular polarization,reflector antenna,dual polarized antenna
更新于2025-09-23 15:22:29
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Biomass SAR Instrument: Development Status and Performance Overview
摘要： Biomass, ESA’s 7th Earth Explorer mission, will provide the first global scale, systematic measurements of the global distribution of biomass. This paper describes the Biomass instrument, an imaging synthetic aperture radar (SAR) at P-band. It provides an overview of the mission application and architecture, the instrument requirements and technical concept, and the predicted instrument performance.
关键词： SAR,Instrument,Biomass,P-band,Reflector Antenna
更新于2025-09-09 09:28:46
-
[IEEE 2018 Iranian Conference on Electrical Engineering (ICEE) - Mashhad (2018.5.8-2018.5.10)] Electrical Engineering (ICEE), Iranian Conference on - An Efficient Method for Calculation of Physical Optics Integral for Large Reflector Antennas
摘要： In this paper, an efficient and very fast method for analyzing electromagnetic wave scattering from a smooth shaped PEC has been presented. The idea of this paper is based on using a powerful Gauss-Legendre quadrature technique and simultaneously mapping the 3D Physical Optics integral to 2D integral. This idea leads to a more accurate and less time-consuming algorithm due to avoiding surface meshing and 3D numerical integration.
关键词： physical optics,large reflector antenna,Gauss-Legendre quadrature
更新于2025-09-04 15:30:14