| 1. |
- Sjöblom, Peter, et al.
(författare)
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An adaptive impedance tuning CMOS circuit for ISM 2.4-GHz band
- 2005
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Ingår i: IEEE Transactions on Circuits and Systems Part 1: Fundamental Theory and Applications. - 1057-7122. ; 52:6, s. 1115-1124
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Tidskriftsartikel (refereegranskat)abstract
- The difficulties encountered in matching an antenna to its optimal impedance are reduced with an adaptive 0.35-mu m CMOS circuit based on several switched shunt capacitors arranged in capacitor banks and on a few external series inductors. As high-quality inductors are difficult to obtain in CMOS, the inductors are placed either in an low-temperature cofired ceramic (LTCC) substrate or is a lumped component outside the core circuit. The circuits, presented here through a range of simulations, are optimized to function within the ISM 2.4-GHz band, but the general approach employed to improve matching can be used for other frequency bands as well. The circuits discussed provide a VSWR <= 2 match for every impedance with VSWR <= 5. There is a 1-dB power loss for a perfect 50 Omega -> 50 Omega transformation, a break-even point at VSWR = 1.5, and a 3-dB increase in delivered power for VSWR = 4.3.
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| 2. |
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| 3. |
- Sjöblom, Peter, et al.
(författare)
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Can diabetes medication be reduced in elderly patients? : An observational study of diabetes drug withdrawal in nursing home patients with tight glycaemic control
- 2008
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Ingår i: Diabetes Research and Clinical Practice. - : Elsevier BV. - 0168-8227 .- 1872-8227. ; 82:2, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To explore the feasibility of withdrawal of diabetes medication in elderly patients with HbA1c £ 6.0%.Methods: HbA1c was measured in 98 patients with known diabetes in 17 nursing homes in Sweden. 32 subjects with HbA1c £ 6.0% participated in the drug withdrawal study. After measuring plasma glucose on three consecutive days, diabetes drugs were reduced, i.e. complete withdrawal of oral anti-diabetic drugs (OADs), complete insulin withdrawal when doses were £ 20 units/day and reduced by half in patients on more than 20 units/day.Results: We identified 31 episodes of plasma glucose £ 4.4 mmol/l, most of them nocturnal (n=17). Mean HbA1c was 5.2 % ± 0.4 compared to 7.1 % ± 1.6 in the non-intervention group. Three months after the diabetes drug discontinuation, 24 patients (75%) remained in the intervention group and mean HbA1c was then 5.8 %. ± 0.9. Six months after baseline investigation mean HbA1c in the intervention group was 5.8 % ± 1.1 compared with 6.6 % ± 1.4 in the non-intervention group.Conclusions: Hypoglycaemic events are common among elderly patients with type 2 diabetes. The withdrawal of diabetes medication in elderly with tight glycaemic control is safe and may decrease the risk for hypoglycaemia.
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| 4. |
- Sjöblom, Peter, et al.
(författare)
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Characterization of CMOS Impedance Tuning Unit
- 2007
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Ingår i: Analog Integrated Circuits and Signal Processing. - : Springer Science and Business Media LLC. - 0925-1030 .- 1573-1979. ; 52:3, s. 79-87
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Tidskriftsartikel (refereegranskat)abstract
- The use of reconfigurable matching has become more and more desirable as mismatches between such interfaces as antenna and receiver increase. The present paper investigates reconfigurable matching by measurements of a CMOS Impedance Tuning Unit (ITU) designed for Digital Video Broadcasting for Handheld devices (DVB-H). The ITU consists of switched capacitors arranged in three capacitor banks, with inductors between them, thus creating a reconfigurable ladder matching network. It is demonstrated that any mismatch up to VSWR = 8 can be transformed to a mismatch better than VSWR = 2, that IIP2 = 7 dBm and IIP3 = 0.5 dBm, and that loss is 2.1 dB.
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| 5. |
- Sjöblom, Peter, et al.
(författare)
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CMOS antenna tuning unit for 2.4 GHz ISM band
- 2005
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Ingår i: 2005 IEEE MTT-S International Microwave Symposium. - 0780388453 ; , s. 279-282
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Konferensbidrag (refereegranskat)abstract
- Antenna matching is improved with adaptive 0.35 μm CMOS circuits based on switched shunt capacitors arranged in capacitor banks and external series inductors. The simulated circuits are optimized for the ISM 2.4 GHz band. The circuits provide a VSWR ⩽ 2 match for every impedance with VSWR ⩽ 5. There is a 1 dB power loss for a perfect 50 Ω → 50 Ω transformation, a break-even point at VSWR = 1.5, and a 3dB increase in delivered power for VSWR = 4.3
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| 6. |
- Sjöblom, Peter, et al.
(författare)
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Dual band ISM 2.4 GHz and 5 GHz finger antenna
- 2005
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Ingår i: [Host publication title missing]. ; 2, s. 1284-1288
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Konferensbidrag (refereegranskat)abstract
- A dual band antenna for two ISM bands at 2.4 GHz and 5 GHz has been evaluated. The antenna structure derives its advantage by deploying several radiators as fingers spreading from a single feeding point. Each radiator functions as both a half-wave and a quarter-wave radiator. Arranging them in parallel matches the half-wave resonance to 50 W. By carefully selecting the angle to ground plane and using mutual coupling, the quarter-wave resonance is also matched to 50 W. On average, the efficiency on the 2.4 GHz band is 71%, while on the 5 GHz band the efficiency is 75%. When placed close to a large shielding plane, performance is somewhat lowered, but still continues at a high level.
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| 7. |
- Sjöblom, Peter, et al.
(författare)
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Impedance Tuning Unit for DVB-H Front-End
- 2006
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Ingår i: [Host publication title missing].
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- When implementing low frequency antennas in small devices, e.g., mobile phones using DVB-H, a large mismatch is inevitable. If a impedance tuning unit is introduced reflection losses and noise are reduced while gain is improved. A ITU consisting of 6 switched capacitances and 2 fixed LTCC inductors is studied. Simulations show that since a VSWR = 10 mismatch is reduced to better than VSWR = 2, the ITU increases the power delivered by 2.9 dB to 4.2 dB for an antenna mismatch between VSWR = 4 and VSWR = 8. In the same time, the average noise figure for VSWR = 4 is reduced by 1.4 dB from 4.6 dB to 3.2 dB; and for VSWR = 8 it is reduced by 2.8 dB from 6.4 dB to 3.7 dB. The highest noise figure for VSWR = 8 is reduced by 4.2 dB from 9.1 dB to 4.9 dB.
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| 8. |
- Sjöblom, Peter
(författare)
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Köln E52 – Radioraritet med rörande varmt mottagande
- 2007
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Ingår i: Elektronik i Norden. - 1103-2944. ; , s. 48-50
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Den kanske allra bästa radiomottagaren under andra världskriget heter Köln E52, figur 1, och konstruerades och byggdes av Telefunken. Den har med åren blivit en raritet eftersom kriget, tillsammans med tidens tand, reducerat antalet mottagare betydlig. Det var därför med stor glädje och förvåning som en sådan apparat nyligen återupptäcktes på Lunds Tekniska Högskola (LTH).
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| 9. |
- Sjöblom, Peter, et al.
(författare)
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Measured CMOS Reconfigurable Matching Network and its Switched High Quality Capacitor Building Blocks
- 2007
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Ingår i: [Host publication title missing].
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Switched capacitors are here investigated for use in reconfigurable matching networks, particularly for DVB-H frequencies. A $0.13$ $mu$m CMOS circuit is evaluated through both simulations and measurements. Source grounded NMOS transistors are used to switch high quality metal capacitors located above metal layer 8. The quality factor and tuning range depend on frequency, switch voltage, capacitor size, and transistor width. There is a clear trade-off between quality factor and tuning range, and measurements show quality factors above 50, 100, and 150 at tuning ranges of 3.9, 2.4, and 1.6, respectively. A reconfigurable matching network with the switched capacitors has been realized using external inductors and the measured matching domain for the DVB-H frequency band is shown. The total loss of the network is 1.0 dB, a result of the high quality switched capacitors.
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| 10. |
- Sjöblom, Peter, et al.
(författare)
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Measured CMOS Switched High-Quality Capacitors in a Reconfigurable Matching Network
- 2007
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Ingår i: IEEE Transactions on Circuits and Systems II: Express Briefs. - 1549-7747. ; 54:10, s. 858-862
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Tidskriftsartikel (refereegranskat)abstract
- Switched capacitors are here investigated for use in reconfigurable matching networks, particularly for DVB-H frequencies. A 0.13 um CMOS circuit is evaluated through both simulations and measurements. Source grounded NMOS transistors are used to switch high quality metal capacitors located above metal layer 8. The quality factor and tuning range depend on frequency, switch voltage, capacitor size, and transistor width. There is a clear trade-off between quality factor and tuning range, and measurements show quality factors above 50, 100, and 150 at tuning ranges of 3.9, 2.4, and 1.6, respectively. A reconfigurable matching network with the switched capacitors has been realized using external inductors and the measured matching domain for the DVB-H frequency band is shown. The total loss of the network is 1.0 dB, a result of the high quality switched capacitors.
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| 11. |
- Sjöblom, Peter, et al.
(författare)
-
Measurement Setup for Impedance Tuning Unit Characterization
- 2007
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An Impedance Tuning Unit (ITU) has the ability to tune the impedance of for instance the antenna to better match another impedance. To effectively characterize a circuit containing an ITU, several functions in a measurement system need to be remotely controlled. In this paper such a measurement system is described. A line tune screw creates impedances for the ITU to match and a digital acquisition hardware (DAQ) controls the ITU. A LabVIEW interface is used to controll the DAQ and a network analyzer for measurements, as well as to collect, calculate and store data.
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| 12. |
- Sjöblom, Peter
(författare)
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Reconfigurable Impedance Matching Networks for Radio Receivers
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mobile phones become smaller but include more advanced functions for every new generation. This paradox is possible since reduced transistor size and increased integration of digital building blocks free space for new functions. Unfortunately, not all components are easily integrated or scaled, such as the antenna, since its performance is dependent on the size. Shrinking mobile phone size results in increased impedance mismatch, as the available antenna volume and the length of the ground plane are reduced. As a consequence, the performance of the whole mobile phone transceiver is degraded, since the noise increases and the output power decreases with increased mismatch. In this work, study of reconfigurable matching networks, and their improvement of receiver and transmitter performance with mismatched antennas, has been performed. In the general introduction, the matching network is introduced as an Impedance Tuning Unit (ITU) and the behaviour from the fundamental building blocks to system aspects are studied. Also, interaction with other building blocks in the receiver chain, such as low noise amplifier, mixer, and filter, is investigated. It is shown that noise performance and power transfer are improved by introducing an ITU, which has the ability to change its matching configuration. It is also shown that it is possible to realize an ITU for receivers in CMOS. Paper I and II examine antenna design and aspects such as shielding and coupling. Paper III is a parameter study of a switched capacitor. In paper IV, V, and VI ITU topologies are simulated and measured for 0.35 um and 0.13 um and for 2.4 to 2.5 GHz and 470 to 702 MHz. The results are presented together with system aspects relevant for receivers.
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| 13. |
- Sundin, Peter, et al.
(författare)
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International Science Programme : Annual Report for 2008
- 2009
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Rapport (populärvet., debatt m.m.)abstract
- ISP provides long-term support for the development of active and sustainable research environments within these basic sciences in developing countries. The support is directed to research groups and regional networks. The work is carried out in close cooperation with research groups at more advanced host institutions. Although Uppsala Univ. is the base of the operation, ISP functions as a national programme and host laboratories may be located at other Swedish universities, in other Nordic and European countries, and in the regions. This is to meet the requests from developing countries on their own terms.ISP support includes equipment, spare parts consumables, technical services, literature, computer hard- and software, and all costs associated with participating in meetings, exchange visits, training, etc. Besides what has been achieved in terms of development and maintenance of resources, contacts, etc., the outcome of ISP support in 2008 can be summarized by the following figures (assuming that one € equals 10 SEK):19 PhD graduations per M€ invested.54 MSc/MPhil graduations per M€ invested.80 international publications per M€ invested.27 regional or national publications per M€ invested.129 conference contributions (> 40% of which international) per M€ invested.
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| 14. |
- Östgren, Carl Johan, et al.
(författare)
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Fördel minska diabetesbehandling hos svårt multisjuka med lågt HbA1c : Positiva resultat från utsättningsstudie bland äldre i särskilt boende
- 2009
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 106:24-25, s. 1649-1651
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hypoglykemier kan orsaka försämring av intellektuella funktioner och ge symtom som oro och agitation. Äldre multisjuka patienter torde vara särskilt känsliga för sådana bieffekter. Vi har på patienter med typ 2-diabetes i särskilt boende genomfört en öppen strukturerad utsättningsstudie av insulin och perorala diabetesläkemedel hos patienter med HbA1c ≤6,0 procent. Av de 32 patienter som fick sina diabetesläkemedel minskade eller utsatta kunde 24 fullfölja studien. I denna grupp steg HbA1c under studien från 5,2 procent till måttliga 5,8 procent efter såväl 3 som 6 månader. Resultaten bör kunna tjäna som stöd för att under kontrollerade former minska eller avveckla diabetesbehandlingen i livets slutskede hos svårt multisjuka patienter med låga HbA1c-nivåer.
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