Characterization, modeling, and design for applications of waveguide impedance tuners and Schottky diodes at millimeter wavelengths

This work contributes to two fields of research at millimeter wavelengths: waveguide impedance tuners and Schottky diodes. Three novel impedance tuning devices for frequencies between 75-220 GHz are presented and new modeling and characterization methods applicable to millimeter-wave and THz Schottky diodes are introduced. In addition, the use of waveguide impedance tuners and Schottky diodes is demonstrated in three different applications. Waveguide tuners are used for dielectric material characterization at 75-110 GHz and in a fundamental frequency mixer diode test platform at 183 GHz. Schottky diodes characterized in this work are used in a novel MMIC frequency tripler for 75-140 GHz and in the aforementioned 183 GHz mixer diode test platform. Waveguide impedance tuners are widely used in a variety of applications at millimeter wavelengths, ranging from device matching to load-pull and noise parameter measurements. The three impedance tuners presented in this work are a multiwaveguide-band backshort, waveguide EH-tuner for 140-220 GHz, and a double-stub E-plane tuner for 75-110 GHz. All impedance tuners are based on the dielectric backshort concept, which offers resonance-free operation, low losses, and tuning with higher resolution than is possible with traditional backshorts. For example, at the center frequency of the W-band, 92 GHz, the VSWR of the multiwaveguide-band backshort is larger than 165 for all positions of the backshort and the phase resolution as a function of the backshort movement is 0.0825 (deg)/10 micrometers, which is 10 times more accurate than with a traditional backshort. The Schottky diode is the workhorse in almost all room temperature mixer and frequency multiplier applications at 100-3000 GHz. Design of Schottky-based circuits at these frequencies relies on accurate models for the Schottky diode. In this work, a novel method is presented for simultaneous extraction of Schottky diode series resistance and thermal resistance. The method avoids the inaccuracies inherent in the traditional I-V extraction methods caused by the self-heating of the diode, which can result in too small a value for the extracted series resistance. In addition, a quantitative comparison of low-frequency (1 MHz) and microwave frequency (3-10 GHz) capacitance determination techniques is performed for millimeter-wave and THz Schottky diodes

Vital Sign Monitoring Using FMCW Radar in Various Sleeping Scenarios

Remote monitoring of vital signs for studying sleep is a user-friendly alternative to monitoring with sensors attached to the skin. For instance, remote monitoring can allow unconstrained movement during sleep, whereas detectors requiring a physical contact may detach and interrupt the measurement and affect sleep itself. This study evaluates the performance of a cost-effective frequency modulated continuous wave (FMCW) radar in remote monitoring of heart rate and respiration in scenarios resembling a set of normal and abnormal physiological conditions during sleep. We evaluate the vital signs of ten subjects in different lying positions during various tasks. Specifically, we aim for a broad range of both heart and respiration rates to replicate various real-life scenarios and to test the robustness of the selected vital sign extraction methods consisting of fast Fourier transform based cepstral and autocorrelation analyses. As compared to the reference signals obtained using Embla titanium, a certified medical device, we achieved an overall relative mean absolute error of 3.6% (86% correlation) and 9.1% (91% correlation) for the heart rate and respiration rate, respectively. Our results promote radar-based clinical monitoring by showing that the proposed radar technology and signal processing methods accurately capture even such alarming vital signs as minimal respiration. Furthermore, we show that common parameters for heart rate variability can also be accurately extracted from the radar signal, enabling further sleep analyses.publishedVersionPeer reviewe

Finnish gelsolin amyloidosis causes significant disease burden but does not affect survival: FIN-GAR phase II study

Abstract Background Hereditary gelsolin (AGel) amyloidosis is an autosomal dominantly inherited systemic amyloidosis that manifests with the characteristic triad of progressive ophthalmological, neurological and dermatological signs and symptoms. The National Finnish Gelsolin Amyloidosis Registry (FIN-GAR) was founded in 2013 to collect clinical data on patients with AGel amyloidosis, including altogether approximately one third of the Finnish patients. We aim to deepen knowledge on the disease burden and life span of the patients using data from the updated FIN-GAR registry. We sent an updated questionnaire concerning the symptoms and signs, symptomatic treatments and subjective perception on disease progression to 240 members of the Finnish Amyloidosis Association (SAMY). We analyzed the lifespan of 478 patients using the relative survival (RS) framework. Results The updated FIN-GAR registry includes 261 patients. Symptoms and signs corresponding to the classical triad of ophthalmological (dry eyes in 93%; corneal lattice amyloidosis in 89%), neurological (numbness, tingling and other paresthesias in 75%; facial paresis in 67%), and dermatological (drooping eyelids in 86%; cutis laxa in 84%) manifestations were highly prevalent. Cardiac arrhythmias were reported by 15% of the patients and 5% had a cardiac pacemaker installed. Proteinuria was reported by 13% and renal failure by 5% of the patients. A total of 65% of the patients had undergone a skin or soft tissue surgery, 26% carpal tunnel surgery and 24% at least unilateral cataract surgery. As regards life span, relative survival estimates exceeded 1 for males and females until the age group of 70–74 years, for which it was 0.96. Conclusions AGel amyloidosis causes a wide variety of ophthalmological, neurological, cutaneous, and oral symptoms that together with repeated surgeries cause a clinically significant disease burden. Severe renal and cardiac manifestations are rare as compared to other systemic amyloidoses, explaining in part the finding that AGel amyloidosis does not shorten the life span of the patients at least for the first 75 years

Schottky- ja Gunn-diodien karakterisointi ja mallinnus millimetriaaltosovelluksia varten

Tässä diplomityössä on kehitetty sijaiskytkentä kolmelle erilaiselle Schottkysekoitindiodille ja ruuvipakkaukseen integroidulle Gunn-diodille. Sijaiskytkennät on suunniteltu toimimaan kaupallisissa piirisimulaattoreissa. Schottky- ja Gunndiodit on suunniteltu toimimaan millimetriaaltoalueella. Työn ensimmäisessä osassa Schottky-diodin toimintaa ja ominaisuuksia on tutkittu kattavin mittauksin. Sijaiskytkennän komponenttien arvot on saatu teoreettisten laskelmien ja piirisimulaattorin optimointimenetelmien avulla. Sijaiskytkennän toiminta sekoitinpiirissä on osoitettu. Fysikaalinen perusta Schottky-diodin toiminnalle ja kirjallisuuskatsaus Schottky-diodeista on esitetty. Työn jälkimmäisessä osassa on tutkittu pakatun Gunn-diodin taajuusvastetta sähkömagneettisen 3D-simulaattorin avulla. Gunn-diodin pakkauksen reaktiiviset elementit on selvitetty piirisimulaattorin optimointimenetelmien avulla ja sijaiskytkentä pakatulle Gunn-diodille on kehitetty. Gunn-diodien ja Gunnoskillaattoreiden teoreettinen perusta on esitetty