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- 2017 (4) (entfernen)
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- Englisch (4)
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- LTCC technology (2)
- Liquid crystals (2)
- RF components (2)
- Ceramic spring (1)
- Dielectric materials (1)
- Electroceramics (1)
- Harsh environments (1)
- High-temperature stability (1)
- Spring constant (1)
- Thick films (1)
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.
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.
Metallic springs undergo oxidation and creep at elevated temperatures and their use is limited to temperature of about 650°C. Therefore, there is a need for stable materials which can easily withstand temperatures up to 1000°C for long periods in different atmospheres. Ceramic materials have been drawing attention due to their excellent properties. This work aimed at investigating the high-temperature stability of zirconia and alumina ceramic springs at elevated temperatures under different atmospheres (air, N2 and H2) in order to determine the limitation of use of these ceramic springs.
Implementation of Ba0.6Sr0.4TiO3-ZnO-B2O3 based tunable microwave phase shifters in LTCC technology
(2017)
Tunable dielectric Ba0.6Sr0.4TiO3-ZnO-B2O3 thick-films were analyzed regarding their integration potential into the LTCC technology. Therefore, tunable loaded line phase shifters based on metal-insulator-metal varactors with single- and double- printed BST thick-films were fabricated and co-sintered inside a four layer LTCC module. Microstructural and chemical investigations showed a sufficient compatibility and adhesion between the silver, BST composite and LTCC layers and a resulting morphology depending on the processing route. The microwave characterization of the LTCC-embedded phase shifters revealed comparable results to phase shifters with the same design on alumina substrates.