Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306281
A. Muhuri, A. Bhattacharya, R. Natsuaki, A. Hirose
Cryosphere plays a crucial role in regulating local and global climate. Glaciers form an important component of this frozen part of the Earth's system. They exist over a prolonged period and are largest reservoir of freshwater on Earth. The meltwater from the glaciers during warmer seasons contribute to the river systems in absence of other sources. The run-off is also useful for agriculture, power generation, and is rich in alluvium. Retreating glaciers gives rise to pro-glacial lakes formed by damming action of moraine or ice. Rupturing of ice dams have caused serious damage to infrastructure and human lives in the past. Such useful and dynamic characteristics of a glacier motivate us to study its movement. Monitoring glaciers through in-situ field measurements is a cumbersome process. Over the past decade, glaciers have been repeatedly observed through microwave sensors on-board various satellites. Various techniques have been proposed in the literature to estimate glacier velocity using microwave observations. Over the recent past, the trend in glacier velocity monitoring has shifted from interferometric tracking to intensity tracking. In this paper, we propose a method based on Stokes vector correlation of time lapse microwave observations. This method is proposed as an improvement over the conventional intensity correlation technique.
{"title":"Glacier surface velocity estimation using stokes vector correlation","authors":"A. Muhuri, A. Bhattacharya, R. Natsuaki, A. Hirose","doi":"10.1109/APSAR.2015.7306281","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306281","url":null,"abstract":"Cryosphere plays a crucial role in regulating local and global climate. Glaciers form an important component of this frozen part of the Earth's system. They exist over a prolonged period and are largest reservoir of freshwater on Earth. The meltwater from the glaciers during warmer seasons contribute to the river systems in absence of other sources. The run-off is also useful for agriculture, power generation, and is rich in alluvium. Retreating glaciers gives rise to pro-glacial lakes formed by damming action of moraine or ice. Rupturing of ice dams have caused serious damage to infrastructure and human lives in the past. Such useful and dynamic characteristics of a glacier motivate us to study its movement. Monitoring glaciers through in-situ field measurements is a cumbersome process. Over the past decade, glaciers have been repeatedly observed through microwave sensors on-board various satellites. Various techniques have been proposed in the literature to estimate glacier velocity using microwave observations. Over the recent past, the trend in glacier velocity monitoring has shifted from interferometric tracking to intensity tracking. In this paper, we propose a method based on Stokes vector correlation of time lapse microwave observations. This method is proposed as an improvement over the conventional intensity correlation technique.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122139013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306213
T. Zeng, Tian Zhang, Weiming Tian, Cheng Hu, Xiaopeng Yang
Global Navigation Satellite System (GNSS) provides opportunities for passive radar applications. This paper reports progress in space-surface bistatic synthetic aperture radar (SS-BiSAR) using Beidou-2 as transmitters of opportunity and a fixed ground-based receiver. Experiment is described and the obtained SAR image is presented and interpreted in detail. Results show that BiSAR using beidou-2 as illuminator is able to reflect different types of targets and SS-BiSAR using GNSS as illuminator of opportunity is potential to realize local area monitoring.
{"title":"Bistatic SAR imaging processing and experiment results using BeiDou-2/Compass-2 as illuminator of opportunity and a fixed receiver","authors":"T. Zeng, Tian Zhang, Weiming Tian, Cheng Hu, Xiaopeng Yang","doi":"10.1109/APSAR.2015.7306213","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306213","url":null,"abstract":"Global Navigation Satellite System (GNSS) provides opportunities for passive radar applications. This paper reports progress in space-surface bistatic synthetic aperture radar (SS-BiSAR) using Beidou-2 as transmitters of opportunity and a fixed ground-based receiver. Experiment is described and the obtained SAR image is presented and interpreted in detail. Results show that BiSAR using beidou-2 as illuminator is able to reflect different types of targets and SS-BiSAR using GNSS as illuminator of opportunity is potential to realize local area monitoring.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128005389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306242
U. Wegmuller, C. Werner, T. Strozzi, A. Wiesmann, O. Frey, M. Santoro
First results using the new Sentinel-1 SAR look very promising, but the special interferometrie wide-swath (IWS) data acquired in the TOPS mode makes InSAR processing challenging. Fhe steep azimuth spectra ramp in each burst results in very stringent co-registration requirements. Combining the data of the individual bursts and sub-swaths into consistent mosaics requires careful "bookkeeping" in the handling of the data and meta data and the large file sizes and high data throughputs require also a good performance. Considering these challenges good support from software is getting increasingly important. In this contribution we describe the Sentinel-1 support in the GAMMA Software, a high-level software package used by researchers, service providers and operational users in their SAR, InSAR and PSI work.
{"title":"Sentinel-1 IWS mode support in the GAMMA software","authors":"U. Wegmuller, C. Werner, T. Strozzi, A. Wiesmann, O. Frey, M. Santoro","doi":"10.1109/APSAR.2015.7306242","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306242","url":null,"abstract":"First results using the new Sentinel-1 SAR look very promising, but the special interferometrie wide-swath (IWS) data acquired in the TOPS mode makes InSAR processing challenging. Fhe steep azimuth spectra ramp in each burst results in very stringent co-registration requirements. Combining the data of the individual bursts and sub-swaths into consistent mosaics requires careful \"bookkeeping\" in the handling of the data and meta data and the large file sizes and high data throughputs require also a good performance. Considering these challenges good support from software is getting increasingly important. In this contribution we describe the Sentinel-1 support in the GAMMA Software, a high-level software package used by researchers, service providers and operational users in their SAR, InSAR and PSI work.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133031950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306243
Xiaomin Ye, Ding Jing, Yongjun Jia, Xinzhe Yuan, Yi Zhang, Liming Cui, Ying Xu, Xuetong Xie
Rain cells or convective rain, the dominant form of rain in the tropics and subtropics, can be easy detected by Synthetic Aperture Radar (SAR) images with high horizontal resolution. The footprints of rain cells on SAR images are caused by the scattering and attenuation of the rain drops, as well as the downward airflow. In this study, we extracted sea surface wind structure caused by rain cells by using a RADARSAT-2 SAR image with a spatial resolution of 100 m for case study. We extracted the sea surface wind speed from SAR image by using CMOD4 geophysical model function with outside wind directions of NCEP final operational global analysis data and microwave scattermeter onboard Chinese HY-2 satellite, respectively. The root-mean-square errors (RMSE) of these SAR wind speeds, validated against NCEP and HY-2, are 1.48 m/s and 2.14 m/s, respectively. Circular signature patterns with brighter on one side and darker on the opposite side on SAR image were interpreted as the sea surface wind speed (or sea surface roughness) variety caused by downdarft associated with rain cell. The wind speed taken from the transect profile which superposes to the wind ambient vectors and go through the center of the circular footprint of rain cell can be fitted as a cosine or sine curve in high linear correlation with the values of no less than 0.80. The background wind speed, the wind speed cause by rain cell and the diameter of footprint of the rain cell with kilometers or tens of kilometers can be acquired by fitting curve. Eight cases interpreted and analysed in this study all showed the same conclusion.
{"title":"SAR observation on sea surface wind caused by rain cell","authors":"Xiaomin Ye, Ding Jing, Yongjun Jia, Xinzhe Yuan, Yi Zhang, Liming Cui, Ying Xu, Xuetong Xie","doi":"10.1109/APSAR.2015.7306243","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306243","url":null,"abstract":"Rain cells or convective rain, the dominant form of rain in the tropics and subtropics, can be easy detected by Synthetic Aperture Radar (SAR) images with high horizontal resolution. The footprints of rain cells on SAR images are caused by the scattering and attenuation of the rain drops, as well as the downward airflow. In this study, we extracted sea surface wind structure caused by rain cells by using a RADARSAT-2 SAR image with a spatial resolution of 100 m for case study. We extracted the sea surface wind speed from SAR image by using CMOD4 geophysical model function with outside wind directions of NCEP final operational global analysis data and microwave scattermeter onboard Chinese HY-2 satellite, respectively. The root-mean-square errors (RMSE) of these SAR wind speeds, validated against NCEP and HY-2, are 1.48 m/s and 2.14 m/s, respectively. Circular signature patterns with brighter on one side and darker on the opposite side on SAR image were interpreted as the sea surface wind speed (or sea surface roughness) variety caused by downdarft associated with rain cell. The wind speed taken from the transect profile which superposes to the wind ambient vectors and go through the center of the circular footprint of rain cell can be fitted as a cosine or sine curve in high linear correlation with the values of no less than 0.80. The background wind speed, the wind speed cause by rain cell and the diameter of footprint of the rain cell with kilometers or tens of kilometers can be acquired by fitting curve. Eight cases interpreted and analysed in this study all showed the same conclusion.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133205676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306297
Wang Wenguang, Wang Jun, Zhao Hui, Yuan Yun-neng, Sun Jinping
River detection from SAR images plays an important role in civilian applications. A new method for river detection is proposed in this paper, which includes fuzzy clustering, wavelet transform and using snake model. River area can be extracted by clustering and morphological processing. Then the edge of river is extracted with the wavelet modulus maximum method (WTMM), and is smoothed by the snake model. A Radarsat-1 image is used for the experiment. The experimental result shows that the method proposed in this paper is efficient for river detection and edge location.
{"title":"River detection from SAR images","authors":"Wang Wenguang, Wang Jun, Zhao Hui, Yuan Yun-neng, Sun Jinping","doi":"10.1109/APSAR.2015.7306297","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306297","url":null,"abstract":"River detection from SAR images plays an important role in civilian applications. A new method for river detection is proposed in this paper, which includes fuzzy clustering, wavelet transform and using snake model. River area can be extracted by clustering and morphological processing. Then the edge of river is extracted with the wavelet modulus maximum method (WTMM), and is smoothed by the snake model. A Radarsat-1 image is used for the experiment. The experimental result shows that the method proposed in this paper is efficient for river detection and edge location.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114067435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306140
Jiaguo Lu
Space-borne digital array SAR with the character of flexible digital beam forming, high precision phase and amplitude control, and flexible sub-antenna construction is the most attractive device in the modern dynamic earth environment remote sense project. The digital array SAR can easily reach the multi-mission multi-mode, both high resolution and wide swath (HRWS), and adaptive-anti-interferer requirements. In this paper, we summarize the evolution of the digital array SAR systems, and introduce the advantages of the digital array technique in the space-borne SAR system. In our work, we explored architectures and RF modular; design a digital array module (DAM). By using these digital array SAR instruments, we get the high quality images and GMTI results through the airborne fly test. These works can improve the performance of the space-borne SAR on the modern global remote sensing.
{"title":"The technique challenges and realization of space-borne digital array SAR","authors":"Jiaguo Lu","doi":"10.1109/APSAR.2015.7306140","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306140","url":null,"abstract":"Space-borne digital array SAR with the character of flexible digital beam forming, high precision phase and amplitude control, and flexible sub-antenna construction is the most attractive device in the modern dynamic earth environment remote sense project. The digital array SAR can easily reach the multi-mission multi-mode, both high resolution and wide swath (HRWS), and adaptive-anti-interferer requirements. In this paper, we summarize the evolution of the digital array SAR systems, and introduce the advantages of the digital array technique in the space-borne SAR system. In our work, we explored architectures and RF modular; design a digital array module (DAM). By using these digital array SAR instruments, we get the high quality images and GMTI results through the airborne fly test. These works can improve the performance of the space-borne SAR on the modern global remote sensing.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125189650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306237
Lei Yang, Song Zhou, G. Bi
In this paper, we investigate the mechanism of Fast Factorized Back-projection (FFBP) algorithm by revealing the relationship between the echoed signal and the spectrum of synthetic aperture radar (SAR) image projected on different coordinate systems. Based on the spectral analysis, a modified FFBP algorithm for squint ultra-wide bandwidth (UWB) SAR imaging is presented. Comparing with the conventional FFBP algorithm, the sub-aperture images are recursively mapped on pseudo polar coordinate rather than original polar coordinate. With the pseudo polar coordinate, the spectrum of sub-aperture SAR image is compacted in a narrower range. Thus only a low Nyquist sample rate is applied to the BP maps which dramatically reduces the redundant back-projections in operation. Simulation results are presented to validate the effectiveness of the proposed method in squint UWB-SAR case.
{"title":"A modified fast factorized back-projection algorithm for squint UWB-SAR imaging","authors":"Lei Yang, Song Zhou, G. Bi","doi":"10.1109/APSAR.2015.7306237","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306237","url":null,"abstract":"In this paper, we investigate the mechanism of Fast Factorized Back-projection (FFBP) algorithm by revealing the relationship between the echoed signal and the spectrum of synthetic aperture radar (SAR) image projected on different coordinate systems. Based on the spectral analysis, a modified FFBP algorithm for squint ultra-wide bandwidth (UWB) SAR imaging is presented. Comparing with the conventional FFBP algorithm, the sub-aperture images are recursively mapped on pseudo polar coordinate rather than original polar coordinate. With the pseudo polar coordinate, the spectrum of sub-aperture SAR image is compacted in a narrower range. Thus only a low Nyquist sample rate is applied to the BP maps which dramatically reduces the redundant back-projections in operation. Simulation results are presented to validate the effectiveness of the proposed method in squint UWB-SAR case.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128279804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306185
D. Calabrese, V. Grimani, Pasquale Salemme
One of the major constraints of the SAR system is the relation between the antenna dimension and the azimuth resolution. The minimum Stripmap resolution is traditionally fixed at half of the antenna physical or equivalent dimension. By using a SAR in time sharing, the Discrete Stepped Strip (DI2S) technique, patent pending, allows the acquisition of different strip images either to increase azimuth resolution or to have a multi-image system, without increasing the number of receivers or partitioning the antenna. The beam spoiling technique can also be used to improve the azimuth resolution. In this paper the DI2S technique for the improved resolution will be illustrated comparing the achievable performance of the two techniques by using the same X band SAR system.
{"title":"DI2S improved resolution vs spoiling for X band comparison","authors":"D. Calabrese, V. Grimani, Pasquale Salemme","doi":"10.1109/APSAR.2015.7306185","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306185","url":null,"abstract":"One of the major constraints of the SAR system is the relation between the antenna dimension and the azimuth resolution. The minimum Stripmap resolution is traditionally fixed at half of the antenna physical or equivalent dimension. By using a SAR in time sharing, the Discrete Stepped Strip (DI2S) technique, patent pending, allows the acquisition of different strip images either to increase azimuth resolution or to have a multi-image system, without increasing the number of receivers or partitioning the antenna. The beam spoiling technique can also be used to improve the azimuth resolution. In this paper the DI2S technique for the improved resolution will be illustrated comparing the achievable performance of the two techniques by using the same X band SAR system.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116958850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306189
Michelangelo Villano, G. Krieger, A. Moreira
Staggered SAR is an innovative synthetic aperture radar (SAR) concept, where the pulse repetition interval (PRI) is continuously varied. This, together with digital beamforming (DBF) in elevation, allows high-resolution imaging of a wide continuous swath without the need for a long antenna with multiple azimuth apertures. As an additional benefit, the energy of range and azimuth ambiguities is spread over large areas: Ambiguities therefore appear in the image as a noise-like disturbance rather than localized artifacts. An analytical expression for the range-ambiguity-to-signal ratio (RASR) in staggered SAR is provided and a novel method for the estimation of the azimuth ambiguity-to-signal ratio (AASR) is proposed. A C-band design example based on a planar antenna is shown as well. The impact of staggered SAR operation on image quality is further assessed using highly oversampled F-SAR airborne data.
{"title":"Ambiguities and image quality in staggered SAR","authors":"Michelangelo Villano, G. Krieger, A. Moreira","doi":"10.1109/APSAR.2015.7306189","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306189","url":null,"abstract":"Staggered SAR is an innovative synthetic aperture radar (SAR) concept, where the pulse repetition interval (PRI) is continuously varied. This, together with digital beamforming (DBF) in elevation, allows high-resolution imaging of a wide continuous swath without the need for a long antenna with multiple azimuth apertures. As an additional benefit, the energy of range and azimuth ambiguities is spread over large areas: Ambiguities therefore appear in the image as a noise-like disturbance rather than localized artifacts. An analytical expression for the range-ambiguity-to-signal ratio (RASR) in staggered SAR is provided and a novel method for the estimation of the azimuth ambiguity-to-signal ratio (AASR) is proposed. A C-band design example based on a planar antenna is shown as well. The impact of staggered SAR operation on image quality is further assessed using highly oversampled F-SAR airborne data.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126821644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306150
Wen‐Hua Tu
A microstrip-parallel strip-fed circularly polarized spiral antenna is investigated. A wideband microstrip to parallel strip transition is designed in order to feed the spiral antenna. The transition shows a back-to-back return loss of better than 10 dB from 0.045 to 20 GHz except for a ripple at 2 GHz, while the back-to-back insertion loss is less than 2.4 dB. The final antenna shows a return loss of better than 10 dB from 2.5 to 13.5 GHz. The antenna axial ratio is better than 2.2 dB from 5 to 12 GHz.
{"title":"Wideband circularly polarized microstrip-parallel strip-fed spiral antenna","authors":"Wen‐Hua Tu","doi":"10.1109/APSAR.2015.7306150","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306150","url":null,"abstract":"A microstrip-parallel strip-fed circularly polarized spiral antenna is investigated. A wideband microstrip to parallel strip transition is designed in order to feed the spiral antenna. The transition shows a back-to-back return loss of better than 10 dB from 0.045 to 20 GHz except for a ripple at 2 GHz, while the back-to-back insertion loss is less than 2.4 dB. The final antenna shows a return loss of better than 10 dB from 2.5 to 13.5 GHz. The antenna axial ratio is better than 2.2 dB from 5 to 12 GHz.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127625597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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