First Investigations on Electrically Tunable Dual-Mode Liquid Crystal-based Substrate Integrated Waveguide Bandpass Filters for W-Band Applications

• Applicant: Professor Dr.-Ing. Rolf Jakoby
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 414102181

While modern communication comes with growing bandwidth demands, the radio frequency spectrum is limited. There are only few possibilities to increase the data throughput with limited resources. One possible solution for high data rate applications is to use higher carrier frequencies in the V- or W-band. Also, applications in the mm-wave bands above 110 GHz are discussed. With the increase in frequency many new, in lower frequencies well know devices, have to be scaled, adapted, or reinvented. Beside the active amplifier and mixing circuits, there is a large demand for passive components such as filters or antennas. While in the lower frequency range these components are usually realized as static components, tunable or reconfigurable components are of major importance for high frequency mobile communication applications. Possible components are definitely tunable high gain antennas, which are able to optimize the beam shape and direction on the fly to guarantee an almost ubiquitous link with constant quality of service. Also, tunable filters are key components as they allow the reconfiguration of the whole network. This research project focuses on the realization of tunable filter especially suited for operation at high frequencies. Former research results show the limitation of standard processing technologies for mm-wave circuits. Therefore, the major objective of this research project is to conduct basic investigations on tunable dual-mode LC-based filters, using substrate integrated waveguide technology. The advantage of using dual-mode filters is its reduced size, while making the passband-stopband transition sharper at the same time, to achieve better rejection. Beside the investigations on the feasibility of these new electronically tunable, dual-mode SIW bandpass filters at W-band, additional fundamental analysis will be performed by means of material characterization, EM simulations, and filter optimization. The concept will be demonstrated with a tunable dual-mode SIW filter in W-band.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr.-Ing. Holger Maune