TY - CONF A1 - Eberstein, Markus A1 - Glitzky, Carsten A1 - Gemeinert, Marion A1 - Rabe, Torsten A1 - Schiller, Wolfgang Arno A1 - Modes, C. T1 - Design of LTCC with high thermal expansion T2 - Proceedings and exhibitor presentations - 4th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies T2 - IMAPS/ACERS 4th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2008) CY - Munich, Germany DA - 2008-04-21 KW - LTCC KW - Glass ceramic composites KW - Coefficient of thermal expansion CTE KW - Design PY - 2008 SP - 000120 EP - 000126 PB - IMAPS, International Microelectronics and Packaging Society CY - Washington, DC AN - OPUS4-17436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eberstein, Markus A1 - Glitzky, Carsten A1 - Gemeinert, Marion A1 - Rabe, Torsten A1 - Schiller, Wolfgang Arno A1 - Modes, C. T1 - Design of LTCC with high thermal expansion JF - International Journal of Applied Ceramic Technology N2 - New applications of low-temperature co-fired ceramics (LTCC), such as pressure sensors or integrated functional layers, require materials that possess higher coefficients of thermal expansion (CTE). To fabricate LTCC with elevated CTE, two methods of material design are examined: firstly, glass ceramic composites (GCC), which consist of >50 vol% glass in the starting powder, and, secondly, glass-bonded ceramics (GBC), where glass is added as a sintering aid only. The CTE of GBC is mainly determined by the crystalline component. For GCC, the CTE can be well predicted, if CTE and elastic data of each phase in the microstructure are known. A nonlinear characteristic of the CTE versus phase composition was found with increasing Ecrystals/Eglass ratio and absolute CTE difference between the components. The glass composition and glass amount can be used to compensate the fixed properties of a crystalline material in a desired way. However, because the CTE and permittivity of a glass cannot be chosen independently, an optimum glass composition has to be found. For a given LTCC, it is possible to control the devitrification by shifting the glass composition. In this way, the resulting CTE values can be predicted more exactly and tailoring becomes possible. Different LTCC materials, based on the crystalline compounds Ba(La,Nd)2Ti4O12, ZrO2 (Y-TZP), SiO2 (quartz), and specially developed glasses, possessing an elevated CTE of around 10 × 10-6 K-1 while showing permittivity εr between 6 and 63, are introduced. KW - LTCC KW - Glass ceramic composites KW - Coefficient of thermal expansion CTE KW - Design PY - 2009 DO - https://doi.org/10.1111/j.1744-7402.2008.02316.x SN - 1546-542X SN - 1744-7402 VL - 6 IS - 1 SP - 1 EP - 8 PB - American Ceramic Soc. CY - Westerville, Ohio AN - OPUS4-18675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaebler, A. A1 - Moessinger, A. A1 - Goelden, F. A1 - Manabe, A. A1 - Goebel, M. A1 - Follmann, R. A1 - Koether, D. A1 - Modes, C. A1 - Kipka, A. A1 - Deckelmann, M. A1 - Rabe, Torsten A1 - Schulz, Bärbel A1 - Kuchenbecker, Petra A1 - Lapanik, A. A1 - Mueller, S. A1 - Haase, W. A1 - Jakoby, R. T1 - Liquid crystal-reconfigurable antenna concepts for space applications at microwave and millimeter waves JF - International journal of antennas and propagation N2 - Novel approaches of tunable devices for millimeter wave applications based on liquid crystal (LC) are presented. In the first part of the paper, a novel concept of a tunable LC phase shifter realized in Low Temperature Cofired Ceramics technology is shown while the second part of the paper deals with a tunable high-gain antenna based on an LC tunable reflectarray. The reflectarray features continuously beam scanning in between ±25°. Also first investigations on radiation hardness of LCs are carried out, indicating that LCs might be suitable for space applications. KW - Tunable antenna KW - Phase shifter KW - Liquid crystal KW - LTCC PY - 2009 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-194273 DO - https://doi.org/10.1155/2009/876989 SN - 1687-5877 VL - 2009 IS - Article ID 876989 SP - 1 EP - 7 PB - Hindawi Publishing Corporation CY - New York, NY, USA AN - OPUS4-19427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -