{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T11:19:30Z","timestamp":1780053570241,"version":"3.54.0"},"reference-count":45,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2017,10,24]],"date-time":"2017-10-24T00:00:00Z","timestamp":1508803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions.<\/jats:p>","DOI":"10.3390\/s17102422","type":"journal-article","created":{"date-parts":[[2017,10,24]],"date-time":"2017-10-24T10:39:18Z","timestamp":1508841558000},"page":"2422","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":76,"title":["Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Andreas","family":"Bogner","sequence":"first","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Carsten","family":"Steiner","sequence":"additional","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Stefanie","family":"Walter","sequence":"additional","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Jaroslaw","family":"Kita","sequence":"additional","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Gunter","family":"Hagen","sequence":"additional","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1410-6979","authenticated-orcid":false,"given":"Ralf","family":"Moos","sequence":"additional","affiliation":[{"name":"Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,10,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Comini, E., Faglia, G., and Sberveglieri, G. (2009). Solid State Gas Sensing, Springer International Publishing AG.","DOI":"10.1007\/978-0-387-09665-0"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"B\u0103nic\u0103, F.-G. (2012). Chemical Sensors and Biosensors: Fundamentals and Applications, John Wiley & Sons, Ltd.","DOI":"10.1002\/9781118354162"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Jaaniso, R., and Tan, O.K. (2013). Fundamentals of Semiconductor Gas Sensors. Semiconductor Gas Sensors, Woodhead Publishing Ltd.","DOI":"10.1533\/9780857098665"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.snb.2006.09.047","article-title":"Metal Oxide-Based Gas Sensor Research: How to?","volume":"121","author":"Barsan","year":"2007","journal-title":"Sens. Actuators B Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1240","DOI":"10.1016\/j.snb.2016.09.047","article-title":"A Non-Contact Microwave Sensor for Monitoring the Interaction of Zeolite 13X with CO2 and CH4 in Gaseous Streams","volume":"238","author":"Zarifi","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1109\/JSEN.2014.2345477","article-title":"Detection of Volatile Organic Compounds Using Microwave Sensors","volume":"15","author":"Zarifi","year":"2015","journal-title":"IEEE Sens. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.snb.2013.03.092","article-title":"Microwave-based gas sensor with phthalocyanine film at room temperature","volume":"189","author":"Rossignol","year":"2013","journal-title":"Sens. Actuators B Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1016\/j.snb.2016.06.048","article-title":"Microwave Gas Sensing with a Microstrip Interdigital Capacitor: Detection of NH3 with TiO2 nanoparticles","volume":"236","author":"Bailly","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1021\/acssensors.6b00297","article-title":"Microwave Gas Sensing with Hematite: Shape Effect on Ammonia Detection Using Pseudocubic, Rhombohedral, and Spindlelike Particles","volume":"1","author":"Bailly","year":"2016","journal-title":"ACS Sens."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Chen, L.F., Ong, C.K., Neo, C.P., Varadan, V.V., and Varadan, V.K. (2004). Microwave Electronics: Measurement and Materials Characterization, John Wiley & Sons, Ltd.","DOI":"10.1002\/0470020466"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"714","DOI":"10.2478\/v10048-010-0002-x","article-title":"Application of Microwave Moisture Sensor for Determination of Oil Palm Fruit Ripeness","volume":"10","author":"Yeow","year":"2010","journal-title":"Meas. Sci. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1558","DOI":"10.1088\/0957-0233\/13\/10\/308","article-title":"Microwave Microstrip Ring Resonator as a Paper Moisture Sensor: Study with Different Grammage","volume":"13","author":"Yogi","year":"2002","journal-title":"Meas. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1109\/36.628789","article-title":"Microstrip Ring Resonator for Soil Moisture Measurements","volume":"35","author":"Sarabandi","year":"1997","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1088\/0957-0233\/10\/3\/014","article-title":"A Microwave Microstrip Ring Resonator as a Moisture Sensor for Biomaterials: Application to Wheat Grains","volume":"10","author":"Abegaonkar","year":"1999","journal-title":"Meas. Sci. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Schwerthoeffer, U., Weigel, R., and Kissinger, D. (2013, January 9\u201311). A Highly Sensitive Glucose Biosensor Based on a Microstrip Ring Resonator. Proceedings of the IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO), Singapore.","DOI":"10.1109\/IMWS-BIO.2013.6756148"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.sna.2015.06.031","article-title":"High resolution microwave microstrip resonator for sensing applications","volume":"233","author":"Zarifi","year":"2015","journal-title":"Sens. Actuators A Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"675","DOI":"10.1002\/cplu.201600137","article-title":"Chemical Sensors Based on Metal\u2013Organic Frameworks","volume":"81","author":"Yi","year":"2016","journal-title":"ChemPlusChem"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7736","DOI":"10.3390\/s110807736","article-title":"Planar Zeolite film-Based Potentiometric Gas Sensors Manufactured by a Combined Thick-film and Electroplating Technique","volume":"11","author":"Marr","year":"2011","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"28915","DOI":"10.3390\/s151128915","article-title":"Correlating the Integral Sensing Properties of Zeolites with Molecular Processes by Combining Broadband Impedance and DRIFT Spectroscopy\u2014A New Approach for Bridging the Scales","volume":"15","author":"Chen","year":"2015","journal-title":"Sensors"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1751","DOI":"10.3390\/s6121751","article-title":"Zeolite-based Materials for Gas Sensors","volume":"6","author":"Xu","year":"2006","journal-title":"Sensors"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Bahoumina, P., Hallil, H., Lachaud, J.L., Rebiere, D., Dejous, C., Abdelghani, A., Frigui, K., Bila, S., Baillargeat, D., and Zhang, Q. (2017, January 1\u20134). Chemical Gas Sensor Based on a Novel Capacitive Microwave Flexible Transducer and Composite Polymer Carbon Nanomaterials. Proceedings of the Symposium on Design, Test, Integration and Packaging of MEMS\/MOEMS (DTIP), Cannes, France.","DOI":"10.1109\/DTIP.2017.7984509"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Zarifi, M.H., Gholidoustb, A., Abdolrazzaghic, M., Shariatyb, P., Hashisho, Z., and Daneshmand, M. (2017). Sensitivity Enhancement in Planar Microwave Active-Resonator Using Metal Organic Framework for CO2 Detection. Sens. Actuators B Chem., in press.","DOI":"10.1016\/j.snb.2017.08.169"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Bailly, G., Harrabi, A., Rossignol, J., Michel, M., Stuerga, D., and Pribetich, P. (2017). Microstrip Spiral Resonator For Microwave-Based Gas Sensing. IEEE Sens. Lett., 1.","DOI":"10.1109\/LSENS.2017.2716413"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1615","DOI":"10.1109\/TMTT.2016.2641438","article-title":"Microwave Sensors for Dielectric Sample Measurement Based on Coupled-Line Section","volume":"65","author":"Piekarz","year":"2017","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Yakhlef, Y., Benhabiles, M.T., Benkhaoua, L., and Riabi, M.L. (2017, January 15\u201317). Compact Miniature Sensors Based on Tapered Lines Coupled Metamaterial Resonators. Proceedings of the First IEEE MTT-S International Microwave Bio Conference (IMBIOC), Gothenburg, Sweden.","DOI":"10.1109\/IMBIOC.2017.7965785"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Denoual, M., Pouliquen, M., Jorel, C., Radu, C., Robbes, D., Harnois, M., de Sagazan, O., Grand, J., Awala, H., and Mintova, S. (2017, January 19\u201321). Zeolite-Based Thermal Mass Gas Sensor with Self-Identification Algorithm. Proceedings of the Symposium on Design, Test, Integration and Packaging of MEMS\/MOEMS (DTIP), Gothenburg, Sweden.","DOI":"10.1109\/DTIP.2017.7984464"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Reinecke, T., Walter, J.-G., Kobelt, T., Ahrens, A., Scheper, T., and Zimmermann, S. (June, January 30). Biosensor Based on a Split-Ring Resonator. Proceedings of the SENSOR 2017, Nuremberg, Germany.","DOI":"10.5162\/sensor2017\/A3.4"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1016\/j.snb.2016.06.168","article-title":"Microwave-Based Sensors with Phthalocyanine Films for Acetone, Ethanol and Methanol Detection","volume":"237","author":"Rydosz","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.apcatb.2006.03.012","article-title":"Investigation of the Selective Catalytic Reduction of NO by NH3 on Fe-ZSM5 Monolith Catalysts","volume":"66","author":"Devadas","year":"2006","journal-title":"Appl. Catal. B Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"791","DOI":"10.1002\/ceat.201000546","article-title":"Monitoring the Ammonia Loading of Zeolite-Based Ammonia SCR Catalysts by a Microwave Method","volume":"34","author":"Hagen","year":"2011","journal-title":"Chem. Eng. Technol."},{"key":"ref_31","unstructured":"Pozar, D.M. (2012). Microwave Engineering, John Wiley & Sons, Ltd.. [4th ed.]."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"16856","DOI":"10.3390\/s140916856","article-title":"A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests","volume":"14","author":"Dietrich","year":"2014","journal-title":"Sensors"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s00339-013-7800-6","article-title":"The Model Oxidation Catalyst \u03b1-V2O5: Insights from Contactless in Situ Microwave Permittivity and Conductivity Measurements","volume":"112","author":"Heine","year":"2013","journal-title":"Appl. Phys. A"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1016\/j.apcatb.2014.09.068","article-title":"Effect of Propene, Propane, and Methane on Conversion and Oxidation State of Three-Way Catalysts: A Microwave Cavity Perturbation Study","volume":"165","author":"Beulertz","year":"2015","journal-title":"Appl. Catal. B"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"263","DOI":"10.5194\/jsss-4-263-2015","article-title":"Ammonia Storage Studies on H-ZSM-5 Zeolites by Microwave Cavity Perturbation: Correlation of Dielectric Properties with Ammonia Storage","volume":"4","author":"Dietrich","year":"2015","journal-title":"J. Sens. Sens. Syst."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1007\/s11244-016-0626-7","article-title":"Influencing Parameters on the Microwave-Based Soot Load Determination of Diesel Particulate Filters","volume":"60","author":"Feulner","year":"2017","journal-title":"Top. Catal."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1240","DOI":"10.4271\/2015-01-1042","article-title":"Microwave-Based Catalyst State Diagnosis\u2014State of the Art and Future Perspectives","volume":"8","author":"Moos","year":"2015","journal-title":"SAE Int. J. Engines"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Hoffmann, R.K. (1983). Integrierte Mikrowellenschaltungen, Springer.","DOI":"10.1007\/978-3-662-12097-2"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1638","DOI":"10.4271\/2017-01-0945","article-title":"Radio-Frequency-Based Urea Dosing Control for Diesel Engines with Ammonia SCR Catalysts","volume":"10","author":"Dietrich","year":"2017","journal-title":"SAE Int. J. Engines"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1007\/s11244-016-0605-z","article-title":"Microwave Cavity Perturbation Studies on H-form and Cu Ion-Exchanged SCR Catalyst Materials: Correlation of Ammonia Storage and Dielectric Properties","volume":"60","author":"Rauch","year":"2017","journal-title":"Top. Catal."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/S1387-1811(97)00056-5","article-title":"The Effect of NH3 on the Ionic Conductivity of Dehydrated Zeolites Na Beta and H Beta","volume":"21","author":"Simon","year":"1998","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"9892","DOI":"10.1021\/jp971737m","article-title":"Structure and Electronic Properties of Potassium-Loaded Zeolite L","volume":"101","author":"Anderson","year":"1997","journal-title":"J. Phys. Chem. B"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"4119","DOI":"10.1039\/c0cp02264k","article-title":"Influence of Moisture Content and Temperature on the Dielectric Permittivity of Zeolite NaY","volume":"13","author":"Kraus","year":"2011","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3735","DOI":"10.1246\/bcsj.59.3735","article-title":"Temperature-Programmed Desorption of Ammonia on Zeolites. Influence of the Experimental Conditions on the Acidity Measurement","volume":"59","author":"Niwa","year":"1986","journal-title":"BCSJ"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"29","DOI":"10.5194\/jsss-3-29-2014","article-title":"Overview on Conductometric Solid-State Gas Dosimeters","volume":"3","author":"Marr","year":"2014","journal-title":"J. Sens. Sens. Syst."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/10\/2422\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:48:20Z","timestamp":1760208500000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/10\/2422"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,10,24]]},"references-count":45,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2017,10]]}},"alternative-id":["s17102422"],"URL":"https:\/\/doi.org\/10.3390\/s17102422","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,10,24]]}}}