{"id":"https://openalex.org/W2999205039","doi":"https://doi.org/10.1109/access.2020.2966125","title":"Compact Metamaterial Based $4\\times4$ Butler Matrix With Improved Bandwidth for 5G Applications","display_name":"Compact Metamaterial Based $4\\times4$ Butler Matrix With Improved Bandwidth for 5G Applications","publication_year":2020,"publication_date":"2020-01-01","ids":{"openalex":"https://openalex.org/W2999205039","doi":"https://doi.org/10.1109/access.2020.2966125","mag":"2999205039"},"language":"en","primary_location":{"id":"doi:10.1109/access.2020.2966125","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2020.2966125","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/8948470/08957034.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://ieeexplore.ieee.org/ielx7/6287639/8948470/08957034.pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5048765185","display_name":"Arshad Karimbu Vallappil","orcid":"https://orcid.org/0000-0002-4302-6150"},"institutions":[{"id":"https://openalex.org/I4576418","display_name":"University of Technology Malaysia","ror":"https://ror.org/026w31v75","country_code":"MY","type":"education","lineage":["https://openalex.org/I4576418"]}],"countries":["MY"],"is_corresponding":true,"raw_author_name":"Arshad Karimbu Vallappil","raw_affiliation_strings":["Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia"],"affiliations":[{"raw_affiliation_string":"Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia","institution_ids":["https://openalex.org/I4576418"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5024376824","display_name":"M. K. A. Rahim","orcid":"https://orcid.org/0000-0002-5488-9277"},"institutions":[{"id":"https://openalex.org/I4576418","display_name":"University of Technology Malaysia","ror":"https://ror.org/026w31v75","country_code":"MY","type":"education","lineage":["https://openalex.org/I4576418"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Mohamad Kamal A. Rahim","raw_affiliation_strings":["Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia"],"affiliations":[{"raw_affiliation_string":"Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia","institution_ids":["https://openalex.org/I4576418"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5034962640","display_name":"Bilal A. Khawaja","orcid":"https://orcid.org/0000-0003-1537-5502"},"institutions":[{"id":"https://openalex.org/I4210151290","display_name":"Islamic University of Madinah","ror":"https://ror.org/03rcp1y74","country_code":"SA","type":"education","lineage":["https://openalex.org/I4210151290"]},{"id":"https://openalex.org/I929597975","display_name":"National University of Sciences and Technology","ror":"https://ror.org/03w2j5y17","country_code":"PK","type":"education","lineage":["https://openalex.org/I929597975"]}],"countries":["PK","SA"],"is_corresponding":false,"raw_author_name":"Bilal A. Khawaja","raw_affiliation_strings":["Department of Electrical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah, Saudi Arabia","Department of Electronics and Power Engineering (EPE), PN-Engineering College (PNEC), National University of Sciences and Technology (NUST), Karachi, Pakistan"],"affiliations":[{"raw_affiliation_string":"Department of Electrical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah, Saudi Arabia","institution_ids":["https://openalex.org/I4210151290"]},{"raw_affiliation_string":"Department of Electronics and Power Engineering (EPE), PN-Engineering College (PNEC), National University of Sciences and Technology (NUST), Karachi, Pakistan","institution_ids":["https://openalex.org/I929597975"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5091164054","display_name":"Muhammad Naeem Iqbal","orcid":"https://orcid.org/0000-0003-2237-6810"},"institutions":[{"id":"https://openalex.org/I4576418","display_name":"University of Technology Malaysia","ror":"https://ror.org/026w31v75","country_code":"MY","type":"education","lineage":["https://openalex.org/I4576418"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Muhammad Naeem Iqbal","raw_affiliation_strings":["Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia"],"affiliations":[{"raw_affiliation_string":"Advance RF and Microwave Research Group (ARFMRG), Faculty of Engineering, School of Electrical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia","institution_ids":["https://openalex.org/I4576418"]}]}],"institutions":[],"countries_distinct_count":3,"institutions_distinct_count":4,"corresponding_author_ids":["https://openalex.org/A5048765185"],"corresponding_institution_ids":["https://openalex.org/I4576418"],"apc_list":{"value":1850,"currency":"USD","value_usd":1850},"apc_paid":{"value":1850,"currency":"USD","value_usd":1850},"fwci":36.1701,"has_fulltext":true,"cited_by_count":38,"citation_normalized_percentile":{"value":0.9939171,"is_in_top_1_percent":true,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":95,"max":99},"biblio":{"volume":"8","issue":null,"first_page":"13573","last_page":"13583"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10069","display_name":"Antenna Design and Analysis","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10069","display_name":"Antenna Design and Analysis","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10936","display_name":"Millimeter-Wave Propagation and Modeling","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11383","display_name":"Advanced Antenna and Metasurface Technologies","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/metamaterial","display_name":"Metamaterial","score":0.7433743476867676},{"id":"https://openalex.org/keywords/bandwidth","display_name":"Bandwidth (computing)","score":0.6794992685317993},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5350561738014221},{"id":"https://openalex.org/keywords/optoelectronics","display_name":"Optoelectronics","score":0.34760674834251404},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.3387567400932312},{"id":"https://openalex.org/keywords/electronic-engineering","display_name":"Electronic engineering","score":0.32751959562301636},{"id":"https://openalex.org/keywords/physics","display_name":"Physics","score":0.2642582654953003},{"id":"https://openalex.org/keywords/engineering","display_name":"Engineering","score":0.14322632551193237}],"concepts":[{"id":"https://openalex.org/C110367647","wikidata":"https://www.wikidata.org/wiki/Q497166","display_name":"Metamaterial","level":2,"score":0.7433743476867676},{"id":"https://openalex.org/C2776257435","wikidata":"https://www.wikidata.org/wiki/Q1576430","display_name":"Bandwidth (computing)","level":2,"score":0.6794992685317993},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5350561738014221},{"id":"https://openalex.org/C49040817","wikidata":"https://www.wikidata.org/wiki/Q193091","display_name":"Optoelectronics","level":1,"score":0.34760674834251404},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.3387567400932312},{"id":"https://openalex.org/C24326235","wikidata":"https://www.wikidata.org/wiki/Q126095","display_name":"Electronic engineering","level":1,"score":0.32751959562301636},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.2642582654953003},{"id":"https://openalex.org/C127413603","wikidata":"https://www.wikidata.org/wiki/Q11023","display_name":"Engineering","level":0,"score":0.14322632551193237}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1109/access.2020.2966125","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2020.2966125","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/8948470/08957034.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:65096983e74044c4ab95e3c23a409821","is_oa":true,"landing_page_url":"https://doaj.org/article/65096983e74044c4ab95e3c23a409821","pdf_url":null,"source":{"id":"https://openalex.org/S112646816","display_name":"SHILAP Revista de lepidopterolog\u00eda","issn_l":"0300-5267","issn":["0300-5267","2340-4078"],"is_oa":true,"is_in_doaj":true,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"IEEE Access, Vol 8, Pp 13573-13583 (2020)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.1109/access.2020.2966125","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2020.2966125","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/8948470/08957034.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/7","score":0.6200000047683716,"display_name":"Affordable and clean energy"}],"awards":[{"id":"https://openalex.org/G2559205718","display_name":null,"funder_award_id":"04G65","funder_id":"https://openalex.org/F4320323300","funder_display_name":"Universiti Teknologi Malaysia"},{"id":"https://openalex.org/G3563567361","display_name":null,"funder_award_id":"06G20","funder_id":"https://openalex.org/F4320323300","funder_display_name":"Universiti Teknologi Malaysia"}],"funders":[{"id":"https://openalex.org/F4320321408","display_name":"Ministry of Education","ror":"https://ror.org/01p262204"},{"id":"https://openalex.org/F4320322724","display_name":"Ministry of Education, India","ror":"https://ror.org/048xjjh50"},{"id":"https://openalex.org/F4320323300","display_name":"Universiti Teknologi Malaysia","ror":"https://ror.org/026w31v75"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2999205039.pdf","grobid_xml":"https://content.openalex.org/works/W2999205039.grobid-xml"},"referenced_works_count":27,"referenced_works":["https://openalex.org/W606472541","https://openalex.org/W1520631570","https://openalex.org/W2028777965","https://openalex.org/W2054692642","https://openalex.org/W2056982161","https://openalex.org/W2080570649","https://openalex.org/W2086368569","https://openalex.org/W2116334496","https://openalex.org/W2133539128","https://openalex.org/W2144994826","https://openalex.org/W2264869098","https://openalex.org/W2343448572","https://openalex.org/W2402118217","https://openalex.org/W2584074851","https://openalex.org/W2591053396","https://openalex.org/W2604370370","https://openalex.org/W2605706051","https://openalex.org/W2608541944","https://openalex.org/W2620575208","https://openalex.org/W2624086964","https://openalex.org/W2790857535","https://openalex.org/W2909792452","https://openalex.org/W2930156537","https://openalex.org/W2955897898","https://openalex.org/W3037959685","https://openalex.org/W4240756890","https://openalex.org/W6681388595"],"related_works":["https://openalex.org/W1570806970","https://openalex.org/W2174268617","https://openalex.org/W4390331329","https://openalex.org/W2951552468","https://openalex.org/W2045305845","https://openalex.org/W2545051477","https://openalex.org/W2166662560","https://openalex.org/W3021878631","https://openalex.org/W4386932413","https://openalex.org/W1479671069"],"abstract_inverted_index":{"This":[0,189],"paper":[1],"proposes":[2],"a":[3,53,117],"novel":[4],"compact":[5,41,190],"4":[6,8],"\u00d7":[7,132],"butler":[9],"matrix":[10],"(BM)":[11],"with":[12,116],"improved":[13,192],"bandwidth":[14,153,193],"based":[15],"on":[16,52],"open-circuit":[17],"coupled-lines":[18],"and":[19,48,60,67,75,112,147,168,175,179,191],"interdigital":[20],"capacitor":[21],"unit-cell":[22],"to":[23,102,157,166],"develop":[24],"composite":[25],"right/left":[26],"handed":[27],"(CRLH)":[28],"transmission-line":[29],"(TL)":[30],"metamaterial":[31],"structure.":[32],"The":[33,65,105,124,160],"BM":[34,129,197],"is":[35,130,143,164,198],"implemented":[36],"by":[37],"the":[38,72,85,96,128,136,139,152,170,173,195],"combination":[39],"of":[40,90,99,108,122,127,138,194],"3dB":[42],"quadrature":[43],"hybrid":[44],"couplers,":[45],"0dB":[46],"crossover":[47],"45\u00b0":[49],"phase":[50,106,120,180],"shifter":[51],"single":[54],"FR4":[55],"substrate":[56],"(\u03b5r":[57],"=":[58,62],"4.3":[59],"h":[61],"1.66":[63],"mm).":[64],"simulated":[66,174],"measured":[68,176],"result":[69],"shows":[70,135],"that":[71,142,183],"return":[73],"loss":[74,77,89],"isolation":[76],"are":[78,114,185],"better":[79],"than":[80],"14":[81],"dB":[82],"at":[83],"all":[84],"ports,":[86],"good":[87,187],"insertion":[88],"-7":[91],"\u00b1":[92],"2dB,":[93],"which":[94,134],"cover":[95],"frequency":[97],"range":[98],"3.2":[100],"GHz":[101],"3.75":[103],"GHz.":[104],"difference":[107],"-45\u00b0,":[109],"135\u00b0,":[110],"-135\u00b0":[111],"+45\u00b0":[113],"achieved":[115],"maximum":[118],"average":[119],"tolerance":[121],"5\u00b0.":[123],"overall":[125],"dimension":[126],"70mm":[131],"73.7mm,":[133],"compactness":[137],"proposed":[140,196],"design":[141,167],"75%":[144],"size":[145],"reduction":[146],"8.2":[148],"times":[149],"improvement":[150],"in":[151,186],"(550MHz)":[154],"as":[155],"compared":[156],"conventional":[158],"BM.":[159],"CST":[161],"microwave":[162],"studio":[163],"used":[165],"perform":[169],"simulations.":[171],"Additionally,":[172],"scattering":[177],"parameters":[178],"differences":[181],"show":[182],"they":[184],"agreement.":[188],"suitable":[199],"for":[200],"5G":[201],"antenna":[202],"array":[203],"beamforming":[204],"network.":[205]},"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":12},{"year":2023,"cited_by_count":7},{"year":2022,"cited_by_count":9},{"year":2021,"cited_by_count":3},{"year":2020,"cited_by_count":4}],"updated_date":"2026-03-27T14:29:43.386196","created_date":"2020-01-23T00:00:00"}