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Your search keyword '"Pursula, Pekka"' showing total 31 results
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31 results on '"Pursula, Pekka"'

1. Toward the optical control of cryogenic quantum technologies

Author

Kemppinen, Antti, primary, Bera, Arijit, additional, Delrosso, Giovanni, additional, Nissilä, Jaani, additional, Senior, Jorden, additional, Mykkänen, Emma, additional, Tappura, Kirsi, additional, Vesterinen, Visa, additional, Selvasundaram, Pranauv, additional, Kohopää, Katja, additional, Ronzani, Alberto, additional, Wälchli, Ben, additional, Hunnakko, Joel, additional, Jabdaraghi, Robab Najafi, additional, Fordell, Thomas, additional, Ribeiro, Mario, additional, Hazra, Dibyendu, additional, Haatainen, Tomi, additional, Loreto, Renan Pires, additional, Hätinen, Joel, additional, Prunnila, Mika, additional, Aalto, Timo, additional, Lehtinen, Janne, additional, Manninen, Antti, additional, Govenius, Joonas, additional, Cherchi, Matteo, additional, and Pursula, Pekka, additional

Published
2023
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2. Integrated Radiometer at 240 GHz With SiGe MMIC Detector and GRIN Silicon Lens

Author

Pursula, Pekka, Lamminen, Antti, Forsten, Henrik, Sipola, Hannu, Tappura, Kirsi, Saarilahti, Jaakko, Varonen, Mikko, Ermolov, Vladimir, and Kantanen, Mikko

Abstract

We describe an integrated radiometer at 240 GHz consisting of a direct detection MMIC fabricated in BiCMOS SiGe and a silicon gradient refractive index (GRIN) lens. The planar GRIN lens enables placing the MMIC with an on-chip dipole antenna directly on the GRIN lens in the focal point of the lens. We describe, how this method of integration can be extended to larger detector arrays while presenting results of a single pixel in this article. The direct detection MMIC includes an on-chip dipole antenna, a low-noise amplifier (LNA), and a diode detector. The radiometer bandwidth (BW) is 38 GHz, defined by the monolithic microwave integrated circuit (MMIC). The GRIN lens is fabricated in high-resistivity silicon and has a gain of 12.2 dBi at 240 GHz with an on-chip feed antenna. The integrated radiometer achieves noise-equivalent temperature difference (NETD) of 0.5 K/Hz1/2. The radiometer with external chopping is stable up to an integration time of 100 s, as demonstrated by the Allan variance measurement, where an NETD of 0.03 K with 100-s integration time is measured.

Published
2024
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7. The Effect of Surface Passivation for Sub-THz Silicon Gradient Refractive Index Lens

Author

Lamminen, Antti, Tamminen, Aleksi, Saarilahti, Jaakko, Ermolov, Vladimir, Pursula, Pekka, VTT Technical Research Centre of Finland, Zachary Taylor Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University

Subjects
lens, silicon, THz, passivation, gradient index, antenna
Abstract

Funding Information: ACKNOWLEDGMENT This work was financially supported by the Academy of Finland under grant MilliRAD, number 314541. The authors would like to thank I. Huhtinen for the RF measurements. Publisher Copyright: © 2022 European Microwave Association. This paper describes a study of impact of different passivation methods on performance of gradient refractive index (GRIN) lenses. Three different passivation layers on top of lenses are studied: PolySi, PolySi and PECVD silicon oxide (PolySi+SiO2), and PECVD silicon oxide (SiO2). Antenna gains and radiation patterns of fabricated lenses are measured. The study shows that passivation methods have strong impact on silicon GRIN lenses performance. A model with a low-resistivity layer on top of high-resistivity Si can explain observed effects.

Published
2021

12. Readout Range and Sensing Resolution Optimization of a Reader for Fully Passive Wireless Sensors.

Author

Mc Caffrey, Colm, Flak, Jacek, and Pursula, Pekka

Subjects
SENSOR networks, DETECTORS, SIGNAL-to-noise ratio, WIRELESS sensor networks
Abstract

The zero-power sensor network is a platform that facilitates fully passive wireless sensing based on third-order intermodulation. This article describes the development, optimization, and evaluation of the reader for the interrogation of zero-power sensor devices. Detailed hardware architecture of the reader is included, along with the introduction of two different signal synthesis techniques for applications that require long readout range with lower resolution, or high resolution with shorter range. The reader is characterized with respect to the two critical limitations: 1) maximal readout distance due to the readers’ own self-intermodulation and 2) sensor readout resolution based on the minimal synchronized intermediate frequency step. The readout range is extended by applying signal isolation strategies, and the system is evaluated with respect to the signal-to-noise ratio demonstrating an extension of the readout range to a maximum of 15 m. A new approach to signal synthesis is implemented, which enhances the readout resolution of a sensor capacitance from 2.2% to 0.3% resolution. The enhancement is demonstrated at a readout distance of 5 m. [ABSTRACT FROM AUTHOR]

Published
2020
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13. Navigational aid with adaptive radar

Author

Hirvonen, Mervi, Kiuru, Tero, Häkli, Janne, and Pursula, Pekka

Abstract

A portable electronic navigational aid (104) e.g. for the blind (102), comprising a radio frequency, preferably millimeter wave, radar (218) with at least one transmitting (TX) channel and a plurality of receiving (RX) channels, at least one orientation sensor (220) configured to obtain data indicative of the orientation of the radar, and a processing element (210) configured to adaptively control (500, 602) the beamforming of the radar based on the data provided by the orientation sensor. A corresponding method is presented. An accessory, such as a replaceable cover, containing a radio frequency radar for attaching to an electronic host device is presented.Patent family as of 18.11.2021AU2015316666 AA 20170427 AU20150316666 20150914 AU2015316666 BB 20200305 AU20150316666 20150914 CA2961290 AA 20170314 CA20152961290 20150914 CN107106400 A 20170829 CN201580061986 20150914 CN107106400 B 20210507 CN201580061986 20150914 DE602015061555 D1 20201119 DE201560061555T 20150914 EP3193810 A2 20170726 EP20150784967 20150914 EP3193810 B1 20201104 EP20150784967 20150914 JP2017533443 T2 20171109 JP20170534006T 20150914 JP2021113822 A2 20210805 JP20210071196 20150914 KR20170057340 A 20170524 KR20177010042 20150914 US11137490 BB 20211005 US20140487190 20140916 US2016077202 AA 20160317 US20140487190 20140916 WO16042203 A2 20160324 WO2015FI50602 20150914 WO16042203 A3 20160519 WO2015FI50602 20150914Link to current patent family on right

Published
2017

21. 3D-Printable Bioactivated Nanocellulose–Alginate Hydrogels

Author

Leppiniemi, Jenni, primary, Lahtinen, Panu, additional, Paajanen, Antti, additional, Mahlberg, Riitta, additional, Metsä-Kortelainen, Sini, additional, Pinomaa, Tatu, additional, Pajari, Heikki, additional, Vikholm-Lundin, Inger, additional, Pursula, Pekka, additional, and Hytönen, Vesa P., additional

Published
2017
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