Second source power amplifier evaluation for Propsim channel emulator

Abstract. In this thesis, a Power Amplifier (PA) for Keysight Technologies’ PROPSIM F64 channel emulator transceiver is presented. The main characteristics and performance of a PA are examined and optional models for existing PA are evaluated. The main reason for an optional model is the cost and complexity of current PA with its two-sided bias voltage. In this work, the most important characteristic of a PA is the gain flatness on the operating band. Since the printed circuit board space (PCB) is very limited, the whole frequency band must be taken care of with single PA. The relevance of linearity, gain and current consumption in channel emulator transceiver are also elaborated. In the beginning of the evaluation, there were three suitable candidates for the PA. The S-parameters of first candidate were measured in laboratory on an evaluation board with a network analyzer. The measurements indicate that the upper frequency response is out of specifications. For the second option, the effect of bias inductor on the frequency response is analyzed. Since the biasing has an effect on the upper and lower ends of the response, a new measurement with a broadband inductor is carried out. Even with better biasing, the first PA variant cannot reach the specification, at least without further component tuning. During the evaluation process, the hardware team received a preproduction model of a PA from a known semiconductor supplier to be tested as a new candidate. The S-parameters of this new variant are also measured and it is observed that this variant has such good frequency response, matching, current consumption biasing and physical size that there is no need for further evaluation at this point.Vaihtoehtoisen tehovahvistimen evaluaatio Propsim kanavaemulaattoriin. Tiivistelmä. Tässä kandidaatintyössä esitellään tehovahvistin Keysight Technologies PROPSIM F64 kanavaemulaattorin lähetinvastaanottimeen. Tehovahvistimen tärkeimmät ominaisuudet sekä suorituskyky, kuten taajuuskaistan tasaisuus, lineaarisuus ja virrankulutus, käydään läpi ja olemassaolevalle tehovahvistimelle evaluoidaan vaihtoehtoisia malleja. Pääsyy vaihtoehtoisen tehovahvistimen etsimiselle on nykyisen tehovahvistimen kalleus ja sen käyttämä kaksipuoleinen käyttöjännite, jonka toteutus nostaa osaltaan laitteen valmistuskustannuksia. Tässä työssä tehovahvistimen tärkeimmäksi ominaisuudeksi määräytyy vasteen tasaisuus koko käytettävissä olevalla taajuusalueella. Johtuen piirilevytilan puutteesta, koko taajuusalue on katettava samalla vahvistimella. Myös vahvistimen lineaarisuuden, vahvistuksen ja virrankulutuksen vaikutusta kanavaemulaattorin suorituskykyyn analysoidaan työssä. Evaluaation alussa tehovahvistinvaihtoehtoina on kolme erilaista vaihtoehtoa. Näistä ensimmäisen S-parametrit mitataan laboratoriossa evaluaatiolevyllä piirianalysaattorin avulla. Mittaustuloksista voidaan todeta, ettei ensimmäinen testattu vahvistinvaihtoehto yllä annettuihin spesifikaatioihin, varsinkaan taajuusvasteen yläpään osalta. Tästä johtuen tehovahvistimen biasoinnin vaikutusta taajuusvasteeseen analysoidaan toisena vaihtoehtona ja todetaan, että biasoinnilla on vaikutus sekä taajuuskaistan ala- että yläpäähän. Ensimmäisen vahvistimen taajuusvaste mitataan laajakaistaisella biaskelalla. Mittaustuloksista voidaan todeta, että vastetta ei saada riittävän hyväksi ainakaan yksinkertaisilla komponenttimuutoksilla. Mittausten aikana testattavaksi saadaan uudeksi vaihtoehdoksi esituotantomalli tunnetun piirivalmistajan tehovahvistimesta. Tämän vahvistimen S-parametrit mitataan laboratoriossa ja sen todetaan olevan taajuusvasteeltaan, sovitukseltaan, virrankulutukseltaan, biasoinniltaan ja fyysiseltä kooltaan niin hyvä kompromissi, ettei jatkotutkimuksiin ole tarvetta käyttää enempää aikaa tässä vaiheessa

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

Joint Nordic prospective study on human herpesvirus 8 and multiple myeloma risk

An association between human herpesvirus 8 (HHV8) and multiple myeloma (MM) has been reported, though most studies have not confirmed such association. To follow-up on a previous prospective seroepidemiological study, where HHV8 tended to associate with MM risk, we linked five large serum banks in the Nordic countries with the Nordic cancer registries and 329 prospectively occurring cases of MM were identified, together with 1631 control subjects matched by age and gender. The HHV8 seroprevalences among cases and controls were similar (12 and 15%, respectively) and HHV8 seropositivity did not associate with the risk of MM, neither when considering positivity for lytic antibodies (relative risk (RR)=0.8, 95% confidence interval (CI)=0.5–1.1) nor for latent antibodies (RR=0.6, 95% CI=0.1–2.7). Similar risks were seen when analysis was restricted to case–control sets with at least 2 years lag before diagnosis (RR=0.8, 95% CI=0.5–1.2 and RR=0.9, 95% CI=0.1–4.2). In conclusion, the data indicate that HHV8 infection is not associated with MM

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

A prospective study of the relationship between prediagnostic Human Papillomavirus seropositivity and HPV DNA in subsequent cervical carcinomas

Several prospective studies with invasive carcinoma as endpoint have supported Human Papillomavirus as a cause of cervical carcinoma. However, the largest study used seroepidemiology and did not analyse presence of Human Papillomavirus DNA in the subsequent tumour. Linkage of serum bank registries and cancer registries had identified 196 women with a registered cervical carcinoma after donation of a serum sample. For the present study, biopsies for 127 cases could be located, verified to contain invasive carcinoma and be amplified by PCR. Three control women who had remained alive and without cervical carcinoma during an equal length of follow-up had been matched to each of the case women and tested for HPV antibodies. Presence of Human Papillomavirus DNA in the tumours was analysed by general primer and type specific PCR. HPV16-seropositive women had a relative risk of 4.4 (95% CI: 2.2–8.8) to develop cervical carcinoma carrying HPV16 DNA. By contrast, there was no excess risk for Human Papillomavirus 16-seropositive women to develop cervical carcinoma devoid of HPV16 DNA. Prediagnostic HPV16 seropositivity was strongly correlated with later HPV16 DNA positivity of the tumour (P<0.001) and prediagnostic HPV18 seropositivity correlated with HPV18 DNA in the tumour (P<0.03). The link between prediagnostic seropositivity and type of viral DNA in the cancer implies that the carcinogenic effect of infection with these viruses is dependent on persistent presence of type-specific viral DNA