Uncertainty analysis of intermodulation-based antenna measurements

Intermodulation measurement principle has been proposed for characterizing transponder antennas. Although the method seems to offer certain advantages compared to traditional antenna characterization methods, the measurement uncertainty has not yet been well characterized. We aim at identifying the main sources of measurement uncertainty and estimating the achievable accuracy in a certain case at 1 GHz.Peer reviewe

Kompaktin antennimittauspaikan epäideaalisuudet

Tämän diplomityön kirjallisuuskatsauksessa tutkittiin kompakteihin antennimittauspaikkoihin kehitettyjä häiriöiden tunnistus- ja korjausmenetelmiä, sekä arvioitiin niiden sopivuutta millimetri- ja alimillimetriaaltoalueelle. Menetelmien avulla voidaan parantaa antennimittauspaikkaa ja mittaustarkkuutta. Tutkittujen menetelmien avulla analysoitiin ADMIRALS RTO-antennin mittauksia hologrammiin perustuvassa kompaktissa antennimittauspaikassa. Mittauspaikan hiljaisesta alueesta löydettiin vaakatasossa suunnasta 6°...8° tuleva häiriösignaali, joka näkyi myös antennin mitatussa suuntakuviossa. Työssä arvioitiin mitatun hiljaisen alueen laadun vaikutusta mitattuun suuntakuvioon. Simulointien perusteella mitattu epäideaalinen hiljainen alue laskee ADMIRALS RTO:n simuloidun pääkeilan olkapäitä enimmillään 3 dB atsimuuttitasossa. Elevaatiotasossa - 3 dB : n keilanleveys kasvaa 26% epäideaalisen hiljaisen alueen vaikutuksesta. Parhaiten hiljaisen alueen vaikutus näkyy kaksiulotteisissa suuntakuvioissa. Epäideaalisen hiljaisen alueen vaikutuksesta simuloidun pääkeilan muoto vääristyy mitatun elliptisen pääkeilan kaltaiseksi. Mitatulla hiljaisen alueen kentällä on huomattava vaikutus mitattavan antennin suuntakuvioon. Lisäksi tutkittiin tasoaallon erilaisten epäideaalisuuksien vaikutusta antennin mitattuun suuntakuvioon. Esimerkiksi hiljaisen alueen amplitudissa oleva kupu leventää mitattua pääkeilaa ja laskee sivukeilatasoa, amplitudissa oleva kuoppa puolestaan kaventaa mitattua pääkeilaa ja nostaa sivukeilatasoa. Hiljaisen alueen vaiheessa olevat häiriöt täyttävät suuntakuvion minimejä

Characterization of Transponder Antennas Using Intermodulation Response

The intermodulation measurement technique enables measuring transponder antennas without any cable connections. This contactless technique exploits the inherent nonlinearity of the transponder to generate intermodulation products that can be measured. In this paper, we relate the transponder antenna properties to the intermodulation response, and use this relation to calculate the gain andimpedance matching of the transponder antenna. Additionally, we consider the limitations of the measurement method and present three different measurement geometries for measuring the radiation pattern. The presented equations and methods are experimentally verified by measuring an example harmonic transponder.Peer reviewe

Implementation of Sensor RFID: Carrying Sensor Information in the Modulation Frequency

An approach that can be used for exploiting the sensing capabilities of radio-frequency identification (RFID) is presented and formulated. In this approach, sensor information is carried through the modulation frequency of RFID . The aim of this work is to investigate the sensor concept and to characterize the sensor performance both theoretically and experimentally. Furthermore, the operation of the sensor radio-frequency (RF) parts and oscillator are described analytically, and the equationsare verified by simulations and measurements. The concept is experimentally demonstrated at a single carrier frequency to test its suitability for ultra-high frequency (UHF) RFID applications, and shown to be feasible for implementing sensors that can be read across distances up to 14 meters.Peer reviewe

Tuotannon layoutin suunnittelu ja toteutus

Opinnäytetyö tehtiin Pamon Oy:lle. Työn tarkoituksena oli tutkia Hollolan tehtaan tuotannon kulkua erityisesti layoutin kannalta. Tavoitteena oli suunnitella layout uusiksi tai parantaa olemassa olevaa layoutia ja parantaa sitä kautta tuotannon toimivuutta, ohjattavuutta ja läpäisyaikoja. Työ toteutettiin selvittämällä nykyisen layoutin suunnittelun lähtökohdat ja ongelmakohdat. Edellisen layoutin suunnitteluperusteita sovellettiin uuteen layoutiin. Tietoja tuotannon toiminnasta kerättiin haastattelemalla tuotantopäällikköä ja henkilöstöä. Työssä hyödynnettiin kirjallista materiaalia layout- suunnittelusta. Suunnittelu- ja piirtotyö toteutettiin SolidWorks- ja AutoCAD-ohjelmistoilla. Työn tuloksena Pamonille saatiin kehitettyä toimiva layout-malli joka parantaa tuotannon toimivuutta ja antaa tilaa yhtiön kasvaville tuotantomäärille.This thesis was made for Pamon Oy. The purpose of the thesis was to study the flow of the production in their Hollola factory, especially from the layout perspective. The aim was to either design a new layout or to develop the old one to achieve greater functionality and controllability, as well as shorter lead-times for the production. The work was carried out by examining the design principles and existing problems in the current layout. These principles were then applied in making a new layout. Information regarding the functionality of the production chain was collected by interviewing the production manager and staff. Literature dealing with layout design was also utilized. The designing and drawing was done with SolidWorks and AutoCad software. The thesis resulted in obtaining a functioning layout for Pamon, which improves the operation and allows the company to raise its production amounts

Trade-off Between Optimal Efficiency and Envelope Correlation Coefficient for Antenna Clusters

This paper introduces a theory for assessing and optimizing the multiple-input-multiple-output performance of multi-port cluster antennas in terms of efficiency, channel correlation, and power distribution. A method based on a convex optimization of feeding coefficients is extended with additional constraints allowing the user to control a ratio between the power radiated by the clusters. The formulation of the problem makes it possible to simultaneously optimize total efficiency and channel correlation with a fixed ratio between power radiated by the clusters, thus examining a trade-off between these parameters. It is shown that channel correlation, total efficiency, and allocation of radiated power are mutually conflicting parameters. The trade-offs are shown and discussed. The theory is demonstrated on a four-element antenna array and on a mobile terminal antenna.Comment: 10 pages, 12 figure

Design and Measurement-Based Evaluation of Multi-Antenna Mobile Terminals for LTE 3500 MHz Band

Design of multi-element antennas for small mobile terminals operating at higher frequencies remains challenging despite smaller antenna dimension and possibility of achieving electrically large separation between them. In this paper, the importance of the type of radiating elements operating at 3400-3600 MHz and their locations on the terminal chassis are highlighted. An isotropic radiation pattern that receives incoming signals from arbitrary directions is obtained by combining the radiation patterns of multiple antennas with localized chassis current distribution. Four multiport antennas configurations with two- and eight-element antennas are designed and evaluated experimentally in indoor propagation environments. Our proposed designs of multi-element antennas provide the highest MIMO channel capacity compared to their counterparts using antennas with less localized chassis current distribution, even in the presence of user's hand

Change in body mass index during transition to statutory retirement : an occupational cohort study

Background: Retirement is a major life transition affecting health behaviors. The aim of this study was to examine within-individual changes in body mass index (BMI) during transition from full-time work to statutory retirement by sex and physical work characteristics. Methods: A multiwave cohort study repeated every 4 years and data linkage to records from retirement registers. Participants were 5426 Finnish public-sector employees who retired on a statutory basis in 2000-2011 and who reported their body weight one to three times prior to (w(-3), w(-2), w(-1)), and one to three times after (w(+1), w(+2), w(+3)) retirement. Results: During the 4-year retirement transition (w(+1), vs. w(-1)) men showed decline in BMI, which was most marked among men with sedentary work (-0.18 kg/m(2), 95% CI -.30 to -0.05). In contrast, BMI increased during retirement transition in women and was most marked among women with diverse (0.14 kg/m(2), 95% CI 0.08 to 0.20) or physically heavy work (0.31 kg/m(2), 95% CI 0.16 to 0.45). Physical activity during leisure time or commuting to work, alcohol consumption or smoking did not explain the observed changes during retirement transition. Conclusions: In this study statutory retirement was associated with small changes in BMI. Weight loss was most visible in men retiring from sedentary jobs and weight gain in women retiring from diverse and physically heavy jobs.Peer reviewe

Childhood risk factors and carotid atherosclerotic plaque in adulthood : The Cardiovascular Risk in Young Finns Study

Background and aims: Carotid plaque is a specific sign of atherosclerosis and adults with carotid plaque are at increased risk for cardiovascular outcomes. Atherosclerosis has roots in childhood and pediatric guidelines provide cut-off values for cardiovascular risk factors. However, it is unknown whether these cut-offs predict adulthood advanced atherosclerosis. Methods: The Cardiovascular Risk in Young Finns Study is a follow-up of children that begun in 1980 when 2653 participants with data for the present analyses were aged 3-18 years. In 2001 and 2007 follow-ups, in addition to adulthood cardiovascular risk factors, carotid ultrasound data was collected. Long-term burden, as the area under the curve, was evaluated for childhood (6-18 years) risk factors. To study the associations of guideline-based cut-offs with carotid plaque, both childhood and adult risk factors were classified according to clinical practice guidelines. Results: Carotid plaque, defined as a focal structure of the arterial wall protruding into lumen > 50% compared to adjacent intima-media thickness, was present in 88 (3.3%) participants. Relative risk for carotid plaque, when adjusted for age and sex, was 3.03 (95% CI, 1.76-5.21) for childhood dyslipidemia, 1.51 (95% CI, 0.99-2.32) for childhood elevated systolic blood pressure, and 1.93 (95% CI, 1.26-2.94) for childhood smoking. Childhood dyslipidemia and smoking remained independent predictors of carotid plaque in models additionally adjusted for adult risk factors and family history of coronary heart disease. Carotid plaque was present in less than 1% of adults with no childhood risk factors. Conclusions: Findings reinforce childhood prevention efforts and demonstrate the utility of guideline-based cutoffs in identifying children at increased risk for adulthood atherosclerosis.Peer reviewe