A novel fast lock-in phase-locked loop frequency synthesizer with direct frequency presetting circuit

This paper proposes a novel, fast lock-in, phase-locked loop (PLL) frequency synthesizer. The synthesizer includes a novel mixed-signal voltage-controlled oscillator (VCO) with a direct frequency presetting circuit. The frequency presetting circuit can greatly speed up the lock-in process by accurately the presetting oscillation frequency of the VCO. We fully integrated the synthesizer in standard 0.35 mu m, 3.3 V complementary metal-oxide-semiconductors (CMOS) process. The entire chip area is only 0.4 mm(2). The measured results demonstrate that the synthesizer can speed up the lock-in process significantly and the lock-in time is less than 10 mu s over the entire oscillation frequency range. The measured phase noise of the synthesizer is -85 dBc/Hz at 10 kHz offset. The synthesizer avoids the tradeoff between the lock-in speed and the phase noise/spurs. The synthesizer monitors the chip temperature and automatically compensates for the variation in frequency with temperature.

A fast-settling frequency-presetting PLL frequency synthesizer with process variation compensation and spur reduction

This paper proposes a fast-settling frequency-presetting PLL frequency synthesizer. A mixed-signal VCO and a digital processor are developed to accurately preset the frequency of VCO and greatly reduce the settling time. An auxiliary tuning loop is introduced in order to reduce reference spur caused by leakage current. The digital processor can automatically compensate presetting frequency variation with process and temperature, and control the operation of the auxiliary tuning loop. A 1.2 GHz integer-N synthesizer with 1 MHz reference input Was implemented in a 0.18μm process. The measured results demonstrate that the typical settling time of the synthesizer is less than 3μs,and the phase noise is -108 dBc/Hz@1MHz.The reference spur is -52 dBc.

A 1.1GHz LC VCO with Automatic Amplitude Control for Tuner Applications

This paper presents an LC VCO with auto-amplitude control （AAC）, in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.

Monolithically Integrated Optoelectronic Receivers Implemented in 0. 25μm MS/RF CMOS

A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.

Psychosocial well-being of African migrant children in Ireland: a cultural orientation

This thesis explores the psychosocial wellbeing of sub-Saharan African migrant children in Ireland. A sociocultural ecological (Psychosocial Working Group, 2003) and resilience lens (Masten & Obradovic, 2008; Ungar, 2011) is used to analyse the experiences of African migrant children in Ireland. The research strategy employs a mixed-methods design, combining both an etic and emic perspective. Grounded theory inquiry (Strauss and Corbin, 1994) explores the experiences of African migrant children in Ireland by drawing on multi-sited observations over a period of six months in 2009, and on interviews and focus group discussions conducted with African children (aged 13-18), mothers and fathers. An emically derived ‘African Migrant Child Psychosocial Well-being’ scale was developed by drawing on data gathered through rapid ethnographic (RAE) free listing exercises carried out in Cork, Dublin and Dundalk with sixty-one participants (N=21 adults, N=28 15-18-year-olds, N=12 12-14-year-olds) and three African community key informants to elicit local understandings of psychosocial well-being. This newly developed scale was used alongside standardised measures of well-being to quantitatively measure the psychosocial adjustment of 233 African migrant children in Cork, Dublin and Dundalk aged 11-18. Findings indicate that the psychosocial wellbeing of the study population is satisfactory when benchmarked against the psychosocial health profile of Irish youth (Dooley & Fitzgerald, 2012). These findings are similar to trends reported in international literature in this field (Georgiades et al., 2006; Gonneke, Stevens, Vollebergh, 2008; Sampson et al., 2005). Study findings have implications for advancing psychosocial research methods with non-Western populations and on informing the practice of Irish professionals, mainly in the areas of teaching, psychology and community work.

Electrical Characterisation of SOI Substrates Incorporating WSix Ground Planes

Silicon-on-insulator (SOI) substrates incorporating tungsten silicide ground planes (GPs) have been shown to offer the lowest reported crosstalk figure of merit for application in mixed signal integrated circuits. The inclusion of the silicide layer in the structure may lead to stress or defects in the overlying SOI layers and resultant degradation of device performance. It is therefore essential to establish the quality of the silicon on the GPSOI substrate. MOS capacitor structures have been employed in this paper to characterize these GPSOI substrates for the first time. High quality MOS capacitor characteristics have been achieved with minority carrier lifetime of similar to 0.8 ms. These results show that the substrate is suitable for device manufacture with no degradation in the silicon due to stress or metallic contamination resulting from the inclusion of the underlying silicide layer.

Ultralow Silicon Substrate Noise Crosstalk Using Metal Faraday Cages in an SOI Technology

In mixed signal integrated circuits noise from the digital circuitry can upset the sensitive analogue circuitry. The Faraday cage structure reported here is based on the unique ground plane SOI technology developed some of the authors. The suppression of crosstalk achieved is an order of magnitude greater than that previously published for frequencies up to 10 GHz. The significance of the technology will be even greater as the operating frequency is increased. This collaborative EPSRC project was judge as tending to outstanding.

Accurate substrate modelling of RF CMOS

The losses within the substrate of an RF IC can have significant effect on performance in a mixed signal application. in order to model substrate coupling accurately, it is represented by an RC network to account for both resistive and dielectric losses at high frequency (> 1 GHz). A small-signal equivalent circuit model of an RF IC inclusive of substrate parasitic effect is analysed in terms of its y-parameters and an extraction procedure for substrate parameters has been developed. By coupling the extracted substrate parameters along with extrinsic resistances associated with gate, source and drain, a standard BSIM3 model has been extended for RF applications. The new model exhibits a significant improvement in prediction of output reflection coefficient S-22 in the frequency range from 1 to 10 GHz in device mode of operation and for a low noise amplifier (LNA) at 2.4 GHz. Copyright (C) 2006 John Wiley & Sons, Ltd.

Convergence and tracking analysis of a variable normalised LMF (XE-NLMF) algorithm

The least-mean-fourth (LMF) algorithm is known for its fast convergence and lower steady state error, especially in sub-Gaussian noise environments. Recent work on normalised versions of the LMF algorithm has further enhanced its stability and performance in both Gaussian and sub-Gaussian noise environments. For example, the recently developed normalised LMF (XE-NLMF) algorithm is normalised by the mixed signal and error powers, and weighted by a fixed mixed-power parameter. Unfortunately, this algorithm depends on the selection of this mixing parameter. In this work, a time-varying mixed-power parameter technique is introduced to overcome this dependency. A convergence analysis, transient analysis, and steady-state behaviour of the proposed algorithm are derived and verified through simulations. An enhancement in performance is obtained through the use of this technique in two different scenarios. Moreover, the tracking analysis of the proposed algorithm is carried out in the presence of two sources of nonstationarities: (1) carrier frequency offset between transmitter and receiver and (2) random variations in the environment. Close agreement between analysis and simulation results is obtained. The results show that, unlike in the stationary case, the steady-state excess mean-square error is not a monotonically increasing function of the step size. (c) 2007 Elsevier B.V. All rights reserved.

Making Sense of Leaving Care: The contribution of Bridges Model of Transition to Understanding the Psycho-social process.

This paper is based on research into the transition of young people leaving public care in Romania. Using this specific country example, the paper aims to contribute to present understandings of the psycho-social transition of young people from care to independent living by introducing the use of Bridges (2002) to build on existing theories and literature. The research discussed involved mixed methods design and was implemented in three phases: semi-structured interviews with 34 care leavers, focus groups with 32 professionals, and a professional-service user working group. The overall findings confirmed that young people experience two different, but interconnected transitions - social and psychological - which take place at different paces. A number of theoretical perpectives are explored to make sense of this transition including attachment theory, focal theory and identity. In addition, a new model for understanding the complex process of transitions was adapted from Bridges’ (2002) to capture the clear complexity of transition which the findings demonstrated in terms of their psycho-social transition. The paper concludes with messages for leaving and after care services with an emphasis on managing the psycho-social transition from care to independent living.

End-of-Life care and people with intellectual disabilities: A multi-media educational resource

Aim This study aimed to develop and evaluate a multi-media educational resource in palliative and end-of-life care for specialist palliative care and intellectual disability services which promoted collaborative working. Methods: A mixed methods design involving three phases was used. Qualitative data were obtained from semi-structured interviews with a purposive sample of professionals (n=30) and family carers (n=5) and from two focus groups with people with intellectual disabilities (n=17). Data were content analysed as outlined y Newell and Burnard (2006). This identified training needs and issues, in end-of-life care for this population which were confirmed through quantitative data from services in a regional scoping study analysed using descriptive statistics. A DVD and manual were developed and evaluated with twelve professionals. Data were collected using a solicited diary, the Readiness for Inter-professional Learning Scale, Likert Scales and an evaluation questionnaire. Thematic analysis and descriptive statistics appropriate to data were used.Results: Findings suggest that this resource demonstrates the need for and benefits of partnership working and transferability of this learning to practice could address issues at end-of-life for people with intellectual disabilities. Conclusions: Findings of this study have importance for partnership working and service provision in end-of-life care for this population.

Prevalence and Causes of Prescribing ErrorsL The PRescribing Outcomes for Trainee Doctors Engaged in Clinical Training (PROTECT) Study

Objectives: Study objectives were to investigate the prevalence and causes of prescribing errors amongst foundation doctors (i.e. junior doctors in their first (F1) or second (F2) year of post-graduate training), describe their knowledge and experience of prescribing errors, and explore their self-efficacy (i.e. confidence) in prescribing.

Method: A three-part mixed-methods design was used, comprising: prospective observational study; semi-structured interviews and cross-sectional survey. All doctors prescribing in eight purposively selected hospitals in Scotland participated. All foundation doctors throughout Scotland participated in the survey. The number of prescribing errors per patient, doctor, ward and hospital, perceived causes of errors and a measure of doctors’ self-efficacy were established.

Results: 4710 patient charts and 44,726 prescribed medicines were reviewed. There were 3364 errors, affecting 1700 (36.1%) charts (overall error rate: 7.5%; F1:7.4%; F2:8.6%; consultants:6.3%). Higher error rates were associated with : teaching hospitals (p,0.001), surgical (p = ,0.001) or mixed wards (0.008) rather thanmedical ward, higher patient turnover wards (p,0.001), a greater number of prescribed medicines (p,0.001) and the months December and June (p,0.001). One hundred errors were discussed in 40 interviews. Error causation was multi-factorial; work environment and team factors were particularly noted. Of 548 completed questionnaires (national response rate of 35.4%), 508 (92.7% of respondents) reported errors, most of which (328 (64.6%) did not reach the patient. Pressure from other staff, workload and interruptions were cited as the main causes of errors. Foundation year 2 doctors reported greater confidence than year 1 doctors in deciding the most appropriate medication regimen.

Conclusions: Prescribing errors are frequent and of complex causation. Foundation doctors made more errors than other doctors, but undertook the majority of prescribing, making them a key target for intervention. Contributing causes included work environment, team, task, individual and patient factors. Further work is needed to develop and assess interventions that address these.

Delivering Social Work Education on Case Reviews and Inquiry Reports: An Exploratory Study of Students' Perspectives in Northern Ireland

It is self-evident that we live in the age of inquiry where the negative impact of risk has been examined through numerous formal processes. In the wake of such scrutiny, there have been repeated recommendations for better training of the professionals charged with safeguarding the welfare of vulnerable individuals. Yet there has been very little examination of how student social workers, in particular, evaluate this training. This exploratory study responded to this gap through a mixed-methods design centring on the views of qualifying and post-qualifying social work students attending courses within two regional universities in Northern Ireland. The study found that, in the main, the cohorts responded favourably to certain aspects of the curriculum and how they were delivered. That said, the emotive nature of the case review and inquiry reports was inadequately addressed in the classroom and was not processed afterwards through a psycho-social framework. In effect, students were often left with residual anxieties that potentially hampered learning. On the basis of the findings, the study calls for further research into this highly significant area of professional competence.

Health and Social Care Workers Perceptions of Novel Psychoactive substances in Northern Ireland

Background: The EU Early Warning System currently monitors more than 450 new psychoactive substances (EMCDDA, 2015), far outweighing the total number of illicit drugs under international control (UNODC, 2013). Due to the recent emergence of NPS and rapidly changing nature of the market, evidence about the way in which the emerging drugs are managed in health and social care settings is limited. Methods: The study adopted a mixed methods design, utilising a cross sectional survey and follow up telephone interviews to capture data from staff working in drug and alcohol related services in statutory and voluntary sectors, across the five Health and Social Care (HSC) Trust areas in Northern Ireland. 196 staff participated in the survey and 13 took part in follow up telephone interviews. Results: Study respondents reported that addressing NPS related issues with service users was a key aspect of their daily role and function. Levels of injecting behaviours were also viewed as relatively high by the study participants. Almost all workers used harm reduction as their primary approach when working with service users and the majority of respondents called for additional practical training in relation to addressing drug interactions and intervening with NPS related issues.

A Psychological Exploration of Long-Term LSD Users

All research involving the psychoactive compound lysergic acid diethylamide (LSD) was terminated globally following its prohibition more than 50 years ago, though illicit use remained fairly stable. A considerable resurgence of research interest in LSD has received considerable attention in various publications and professional fora. One of the main applications considered is LSD-assisted psychotherapy to address a number of difficulties like end-of-life anxiety, addiction/alcoholism, post-traumatic stress, and depression. However, due to the highly contradictory nature of early research findings and division in the literature, one is left uncertain as to whether psychology as a profession is currently equipped to critically evaluate these advances, let alone embrace them. The purpose of the present study was to contribute to current psychological knowledge on long-term LSD use. A group of long-term LSD users who claimed beneficial use were the focus here. A mixed methods design was employed. 110 users completed an online survey assessing for demographics, patterns of use, and specific personality traits through three psychometric measures, Big Five Inventory (BFI), General Self Efficacy scale (GSE) and Satisfaction With Life Scale (SWLS). Eight individual interviews were also conducted and analysed by Thematic Analysis (TA). Gaining different perspectives on reality and increasing self- awareness appeared to be essential elements of the belief system that these non-problematic long-term LSD users adopted in order to make sense of their LSD use. Qualitative findings also suggested the existence of a common set of life values, rules and the adoption of a hierarchical system between LSD users. Novices appeared to be tutored and guided by elders whose presence and input was valued and who were listened to and respected. A role for ‘wiser/elder’ users as those imparting valuable knowledge to novices was therefore also suggested. The underlying aim may possibly be an attempt to minimise risks and maximise potential benefits of LSD use. A prospective role for LSD as a deterrent of substance misuse, a ‘gateway drug to no drugs’ was also hinted and remains in need of iv further investigation. Claims regarding beneficial LSD use and ‘change’ through LSD use were confirmed by the participant sample. No noteworthy differences between psychometric scores of the LSD-using group and those of the general population (as suggested by normative data comparisons) were found, possibly due to methodological limitations, especially considering the highly subjective nature of the LSD experience and its effects. The determining role of extra-pharmacological variables or ‘set and setting’ in the outcome of LSD use suggested in earlier literature was re-validated. Knowledge on their specific components was enriched, and a potentially significant value for adopting a flexible, adaptable and solution-focused mind-set in order to better manage the effects of LSD was highlighted. Due to the highly selected nature of the participant sample, present findings should serve as suggestions for further research in order to clarify the aforementioned issues and to make explicit the mechanisms by which they operate. The complex nature of LSD, its use and its effects have been re-confirmed here. It is imperative that the current knowledge base on the substance is enriched before LSD is introduced in a clinical psychology professional context.