Channel emulator RF module test hardware development

Abstract. The constant evolution of wireless communication systems set more and more stringent demands for the equipment used to test these systems. The hardware and software solutions used in the measurement equipment are extremely complex. Because of this complexity, the production process of these equipment needs to include strict testing. In this thesis, a radio frequency (RF) tester module for production testing of channel emulator RF module is designed. The thesis begins with an introduction to the device that needs to be tested, the channel emulator RF module. This RF module is part of the Keysight Technologies’ latest channel emulator model, PROPSIM FS16. The design of this thesis needs to enable the testing of the RF performance of the RF module transceiver. Benefits of modular production principle are introduced on a general level, and the justification for the production testing is given. It is concluded that testing hardware in a modular testing system is necessary for ensuring the production flow and for ensuring that the final product fulfills the specifications promised to the customer. Principles of RF testing are considered on a general level and the requirements regarding the designed RF tester module are presented. It is concluded that the RF tester module needs to route instrumentation signalling to the RF module. In addition, RF tester module needs to provide local oscillator signalling as well as DC power to the RF module. In the design part, the hardware design of the RF tester module printed circuit assembly (PCA) is presented. General RF design principles are discussed and aspects regarding the RF tester module PCA are considered with details. These include isolation, crosstalk and noise. Chosen components and the designed switching networks are elaborated and justified against the given requirements. It is found out that the instrumentation can be routed via a passive network, but the local oscillator networks need amplification to ensure correct power level. Active network power levels are verified with simulations and found out to be adequate. PCA layout design principles are reviewed on the extent that they play a prominent role in the RF PCA schematic design with the emphasis on the signal grounding issues. Lastly, the verification and calibration of the designed PCA is described, and the validation of the RF tester module in the complete RF test system is presented. It was found out that some local oscillator signal levels are lower in the final design, than was expected based on the simulations. This caused some delay in the validation phase, by producing false negative test results. After test parameter adjustments, it was found out that the required tests can be executed successfully with the designed RF tester module.Radiokanavaemulaattorin RF-moduulin testauslaitteiston kehitys. Tiivistelmä. Langattomien tietoliikennejärjestelmien jatkuva kehitys asettaa aina vain tiukempia vaatimuksia niiden testaamiseen tarkoitetuille laitteille. Näissä mittalaitteissa käytetyt laitteisto- ja ohjelmistoratkaisut ovat äärimmäisen monimutkaisia. Tästä johtuen, nämä laitteet täytyy tuotantovaiheessa testata erittäin tarkasti. Tässä opinnäytetyössä suunnitellaan RF-testimoduuli kanavaemulaattorin RF-moduulin tuotantotestaukseen. Aluksi esitellään testattava laite, eli kanavaemulaattorin RF-moduuli. Esiteltävä RF-moduuli on Keysight Technologiesin viimeisimmän kanavaemulaattorin PROPSIM FS16 osa. Tässä työssä esiteltävän laitteen tarkoituksena on mahdollistaa RF-moduulin lähetin-vastaanottimen suorituskyvyn testaaminen. Modulaarisen tuotannon edut esitellään yleisellä tasolla, jonka jälkeen perustelut tuotantotestaukselle esitellään. Päädytään johtopäätökseen, että moduulien testaus tuotannossa on välttämätöntä, jotta tuotannon kulku ja asiakkaalle luvatut spesifikaatiot voidaan varmistaa. RF-testauksen periaatteet käsitellään yleisellä tasolla, minkä jälkeen esitellään tämän työn RF-testimoduulin vaatimukset. Testimoduulin tulee reitittää testauksessa tarvittava instrumentaatio RF-moduulille. Tämän lisäksi RF-moduuli tarvitsee paikallisoskillaattorisignaalit ja DC tehonsyötön toimiakseen. Suunnitteluosiossa käydään läpi RF-testimoduulin piirilevysuunnittelu. RF- suunnittelussa huomioon otettavat seikat käsitellään niiltä osin kuin ne ovat relevantteja tässä työssä. Näitä ovat isolaatio, ylikuuluminen ja kohina. Valitut komponentit ja suunnitellut kytkinverkot esitellään ja perustellaan aiemmin esiteltyihin vaatimuksiin pohjaten. Havaitaan että instrumentaatiolle riittää pasiivinen kykentäverkko, mutta paikallisoskillaattorien verkkoihin tarvitaan vahvistusta. Aktiivisten verkkojen tehotasot testataan simuloinneilla ja havaitaan riittäviksi. Suunnittelun lopuksi käsitellään piirilevyn layout-suunnittelun RF-teknisesti tärkeimmät seikat, merkittävimpänä maadoitus. Lopuksi työssä suunniteltu RF-testimoduuli verifioidaan ensin piirilevytasolla, kalibroidaan ja validoidaan lopullisessa testijärjestelmässä. Havaitaan että välitaajuusoskillaattoreiden signaali on alhaisempi kuin on arvioitu. Tämä aiheuttaa virheellisiä testituloksia ja viivettä testirajojen asettelussa. Testiparametrien säädön jälkeen voidaan todeta, että työssä suunniteltua RF-testimoduulia voidaan käyttää RF- moduulin testausjärjestelmässä

Prospective Study of Human Papillomavirus Seropositivity and Risk of Nonmelanoma Skin Cancer

Cutaneous human papillomaviruses (HPVs) have been associated with squamous cell carcinoma (SCC) in case-control studies, but there are limited data from prospective studies assessing whether virus exposure predicts risk of future cancer development. Two major biobanks, the Southern Sweden Microbiology Biobank (1971-2003) and the Janus Biobank (1973-2003) in Norway, containing samples from 850,000 donors, were searched for incident skin cancer for up to 30 years using registry linkages. Altogether, 2,623 donors with samples taken before diagnosis of SCC or basal cell carcinoma (BCC) of the skin were identified. Prediagnostic samples and samples from 2,623 matched controls were tested for antibodies against 33 types of HPV. Baseline seropositivity to HPV types in genus beta species 2 was associated with SCC risk (odds ratio = 1.3, 95% confidence interval: 1.1, 1.7); this was also the case for samples taken more than 18 years before diagnosis (odds ratio = 1.8, 95% confidence interval: 1.1, 2.8). Type-specific persistent seropositivity entailed elevated point estimates for SCC risk for 29 HPV types and decreased point estimates for only 3 types. After multiple hypothesis adjustment, HPV 76 was significantly associated with SCC risk and HPV 9 with BCC risk. In summary, seropositivity for certain HPV types was associated with an increased risk for future development of SCC and BCC

Dynamic prediction of mortality after traumatic brain injury using a machine learning algorithm

Intensive care for patients with traumatic brain injury (TBI) aims to optimize intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The transformation of ICP and CPP time-series data into a dynamic prediction model could aid clinicians to make more data-driven treatment decisions. We retrained and externally validated a machine learning model to dynamically predict the risk of mortality in patients with TBI. Retraining was done in 686 patients with 62,000 h of data and validation was done in two international cohorts including 638 patients with 60,000 h of data. The area under the receiver operating characteristic curve increased with time to 0.79 and 0.73 and the precision recall curve increased with time to 0.57 and 0.64 in the Swedish and American validation cohorts, respectively. The rate of false positives decreased toPeer reviewe

Finnish study of intraoperative irrigation versus drain alone after evacuation of chronic subdural haematoma (FINISH) : a study protocol for a multicentre randomised controlled trial

Introduction Chronic subdural haematomas (CSDHs) are one of the most common neurosurgical conditions. The goal of surgery is to alleviate symptoms and minimise the risk of symptomatic recurrences. In the past, reoperation rates as high as 20%-30% were described for CSDH recurrences. However, following the introduction of subdural drainage, reoperation rates dropped to approximately 10%. The standard surgical technique includes burr-hole craniostomy, followed by intraoperative irrigation and placement of subdural drainage. Yet, the role of intraoperative irrigation has not been established. If there is no difference in recurrence rates between intraoperative irrigation and no irrigation, CSDH surgery could be carried out faster and more safely by omitting the step of irrigation. The aim of this multicentre randomised controlled trial is to study whether no intraoperative irrigation and subdural drainage results in non-inferior outcome compared with intraoperative irrigation and subdural drainage following burr-hole craniostomy of CSDH. Methods and analysis This is a prospective, randomised, controlled, parallel group, non-inferiority multicentre trial comparing single burr-hole evacuation of CSDH with intraoperative irrigation and evacuation of CSDH without irrigation. In both groups, a passive subdural drain is used for 48hours as a standard of treatment. The primary outcome is symptomatic CSDH recurrence requiring reoperation within 6months. The predefined non-inferiority margin for the primary outcome is 7.5%. To achieve a 2.5% level of significance and 80% power, we will randomise 270 patients per group. Secondary outcomes include modified Rankin Scale, rate of mortality, duration of operation, length of hospital stay, adverse events and change in volume of CSDH. Ethics and dissemination The study was approved by the institutional review board of the Helsinki and Uusimaa Hospital District (HUS/3035/2019 238) and duly registered at ClinicalTrials.gov. We will disseminate the findings of this study through peer-reviewed publications and conference presentations. Trial registration number NCT04203550Peer reviewe

The Effect of Various Restorative Materials on the Microhardness of Reparative Dentin

This study showed a statistically significant difference between the microhardness of reparative and primary dentin at both five- and eight-week intervals. Reparative dentin from occlusal trauma is harder than reparative dentin underlying a cavity preparation at the 99% level. No statistical difference was noted in the hardness of reparative dentin underlying different materials, but trends were observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66484/2/10.1177_00220345800590020101.pd