05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Integrated dispersive structures for bandwidth-enhancement of silicon grating couplers(2020) Klenk, Rouven H.; Schweikert, Christian; Hoppe, Niklas; Nagy, Lotte; Elster, Raik; Vogel, Wolfgang; Berroth, ManfredIn photonic integrated circuits grating couplers are commonly used to establish an efficient and stable fiber-to-chip link. However, the actual coupling efficiency of a fiber-to-chip interface depends strongly on the used wavelength and exhibits a maximum at a distinct target wavelength, determined by grating design parameters. In this paper, an enhancement of the optical bandwidth of silicon grating couplers by adding integrated dispersive structures is discussed. These are realized by single layers, prism-like geometries and additional silicon nitride gratings. Theoretical considerations for a bandwidth-enhancement by dispersive layers are performed and applied to an existing grating coupler design. A simulated 1dB-bandwidth of up to 90 nm at a maximum efficiency of - 0.65 dB in the C-band could be achieved, which is an enhancement to a factor of about 2 compared with the original coupler design.Item Open Access Fully integrated high quality factor GmC bandpass filter stage with highly linear operational transconductance amplifier(2017) Briem, Jochen; Mader, Marco; Reiter, Daniel; Amirpour, Raul; Grözing, Markus; Berroth, ManfredThis paper presents an electrical, fully integrated, high quality (Q) factor GmC bandpass filter (BPF) stage for a wireless 27 MHz direct conversion receiver for a bendable sensor system-in-foil (Briem, 2016). The core of 10 the BPF with a Q factor of more than 200 is an operational transconductance amplifier (OTA) with a high linearity at an input range of up to 300 mVpp,diff. The OTA’s signal-to-noise-and-distortion-ratio (SNDR) of more than 80 dB in the mentioned range is achieved by stabilizing its transconductance Gm with a respective feedback loop and a source degeneration resistance RDG. The filter stage can be tuned and is tolerant to global and local process variations due to offset and common-mode 15 feedback (CMFB) control circuits. The results are determined by periodic steady state (PSS) simulations at more than 200 global and local process variation parameter and temperature points and corner simulations. It is expected, that the parasitic elements of the layout have no significant influence on the filter behaviour. The current consumption of the whole filter stage is less than 600 μA.Item Open Access Adaptive triple-fed antenna and thinned RF-chip integration into ultra thin flexible polymer foil(2023) Fischer-Kennedy, Serafin B.; Özbek, Sefa; Wang, Shuo; Grözing, Markus; Hesselbarth, Jan; Berroth, Manfred; Burghartz, Joachim