TY - CONF A1 - Prasetiadi, A. E. A1 - Jost, M. A1 - Schulz, Bärbel A1 - Quibeldey, M. A1 - Rabe, Torsten A1 - Follmann, R. A1 - Jakoby, R. T1 - Liquid-Crystal-Based Amplitude Tuner Fabricated N2 - A 30GHz liquid-crystal-based amplitude tuner is proposed for the first time. The amplitude of a signal can be controlled by using the interference principle. An input signal is divided into a tunable liquid crystal phase shifter and a fixed transmission line. Later, the divided signals are combined together at the output port. The output amplitude depends on the phase difference between the tunable and the fixed line. The low temperature co-fired ceramic technology is utilized to fabricate the device. The measurement shows an attenuation range of 11 dB to 30 dB with a maximum biasing voltage of 100V. T2 - 12th European Microwave Integrated Circuits Conference CY - Nürnberg, Germany DA - 09.10.2017 KW - LTCC technology KW - Liquid crystals KW - RF components PY - 2017 SN - 978-2-87487-048-4 SN - 2325-0305 SP - 345 EP - 348 PB - IEEE AN - OPUS4-44752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prasetiadi, A .E. A1 - Jost, M. A1 - Schulz, Bärbel A1 - Quibelday, M. A1 - Rabe, Torsten A1 - Follmann, R. A1 - Jakoby, R. T1 - Liquid-Crystal-Based Amplitude Tuner Fabricated N2 - 30GHz liquid-crystal-based amplitude tuner is proposed for the first time. The amplitude of a signal can be controlled by using the interference principle. An input Signal is divided into a tunable liquid crystal phase shifter and a fixed transmission line. Later, the divided signals are combined together at the output port. The output amplitude depends on the phase difference between the tunable and the fixed line. The low temperature co-fired ceramic technology is utilized to fabricate the device. The measurement shows an attenuation range of 11 dB to 30 dB with a maximum biasing voltage of 100V. T2 - 47th European Microwave Conference CY - Nürnberg, Germany DA - 10.10.2017 KW - LTCC technology KW - Liquid crystals KW - RF components PY - 2017 SN - 978-2-87487-047-7 SN - 2325-0305 SP - 1085 EP - 1088 PB - IEEE AN - OPUS4-44753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jost, M. A1 - Strunck, S. A1 - Heunisch, Andreas A1 - Wiens, A. A1 - Prasetiadi, A.E. A1 - Weickhmann, C. A1 - Schulz, Bärbel A1 - Quibeldey, M. A1 - Karabey, O.H. A1 - Rabe, Torsten A1 - Follmann, R. A1 - Koether, D. A1 - Jakoby, R. T1 - Continuously tuneable liquid crystal based stripline phase shifter realised in LTCC technology N2 - This work presents the design, fabrication and measurements of a low temperature cofired ceramic (LTCC) integrated liquid crystal (LC) phase shifter. The effective permittivity of the phase shifter and therefore its differential phase shift can be tuned continuously by orienting the LC directors with electric fields. The phase-shift demonstrator is designed for Ka-band frequencies around 30 GHz and represents a stripline filled with LC, embedded inside an LTCC multilayer structure, which provides a space-qualified and hermetically-sealed LC cavity within an RF-capable material system. The total length of the device is 37 mm while the phase shifting LC section has a length of 14.6 mm. At 30 GHz it exhibits a differential phase shift of 60° with an insertion loss around 6 dB, resulting in a figure of merit around 10°/dB. An advantage is that the insertion loss is nearly independent of the tuning state of the LC. The response time of the phase shifter, depending on the desired LC orientation, is between 62 ms and 37 s. T2 - EuMC 2015 - 45th European microwave conference CY - Paris, France DA - 07.09.2015 PY - 2015 SN - 978-2-87487-039-2 SP - 1260 EP - 1263 AN - OPUS4-35268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prasetiadi, A. E. A1 - Jost, M. A1 - Schulz, Baerbel A1 - Quibeldey, M. A1 - Rabe, Torsten A1 - Follmann, R. A1 - Jakoby, R. T1 - Liquid-crystal-based amplitude tuner and tunable SIW filter fabricated in LTCC technology N2 - Tunable microwave devices will play an important role in future wireless systems, in which high-frequency bands, e.g. millimeter waves, will become promising, due to its huge spectrum availability. At such frequency bands, liquid crystals (LCs) exhibit low microwave loss, which is excellent compared with the other tuning elements. In this paper, LC-based microwave components are fabricated by using low temperature co-fired ceramic technology, allowing the integration of the LC into microwave structures. The first component, the Amplitude tuner, controls the signal’s amplitude by using the interference concept, which exhibits a tunable attenuation range from 11 dB to 30 dB at 30 GHz. The second component is a 3-pole tunable bandpass filter, which is realized by using a substrate integrated waveguide topology, enabling a device with comparatively high-quality factors (Q-factors). The measurement results show Q-factors in the range of 68 to 100 for a frequency tuning of 29.4–30.1 GHz, i.e. a tuning range of 700 MHz, accompanied by an insertion loss 2 dB to 4 dB. KW - Passive components and circuits KW - Filters KW - Microwave technology PY - 2018 U6 - https://doi.org/10.1017/S1759078718000600 SN - 1759-0787 VL - 10 IS - 5-6 SP - 674 EP - 681 PB - Cambridge University Press AN - OPUS4-46985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bochnig, M. S. A1 - Oh, M.-J. A1 - Nagel, T. A1 - Jost-Brinkmann, P.-G. A1 - Ziegler, Fred T1 - Comparison of the shock absorption capacities of different mouthguards N2 - In this in vitro study, the protective qualities of different mouthguard types were examined during small hard object collisions. The aim was to investigate inconclusive aspects of hard inserts, nylon nets, and air spaces as reinforcements in the anterior region and the protection qualities of ethylene vinyl acetate (EVA). Five different mouthguards with a labial thickness between 2 mm and 11 mm made of materials of varying stiffness were investigated. As a negative control, the same experiments were performed without a mouthguard. Different combinations of EVA and labial inserts ((polyethylene terephthalate glycol-modified [PETG]), nylon mesh, air space) were tested. Using a stainless steel pendulum device, blows of different energy (0.07-2.85 joules) were applied to the center of the crown of a pivoted tooth in a custom-built jaw model. A laser Doppler vibrometer measured the tooth deflection, while an acceleration sensor attached to the pendulum measured the braking accelerations. Tooth deflection was reduced up to 99.7% compared to no mouthguard, and the braking acceleration was reduced up to 72.2% by increasing the mouthguards' labial thickness in combination with labial inserts of different stiffness and a built-in air space between the front teeth and the mouthguard. The mouthguards made of soft materials (EVA with nylon mesh) showed slightly better protection qualities than the more rigid mouthguards of similar thickness (PETG; P<.05). However, with increasing impact energy, their protective capacities decreased to a greater extent than the stiffer mouthguards. The combination of increased labial thickness and labial inserts of varying stiffness and eventually an air space offers the best protection capacities for hard, small object collisions. KW - Shock absorbtion KW - Hard object collisions KW - Mouthguard PY - 2017 U6 - https://doi.org/10.1111/edt.12324 SN - 1600-4469 VL - 33 IS - 3 SP - 205 EP - 213 PB - John Wiley & Sons, Ltd CY - Hoboken, NJ, USA AN - OPUS4-41098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -