Sökning: "impedance matching"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden impedance matching.

1. 1. Reconfigurable Impedance Matching Networks for Radio Receivers

   Författare :Peter Sjöblom; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Telekommunikationsteknik; Telecommunication engineering; Elektronik; Electronics; reconfigurable matching; switched capacitor; antenna tuning unit; impedance tuning unit; High frequency technology; Elektroteknik; microwaves; Högfrekvensteknik; mikrovågor;

   Sammanfattning : 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. LÄS MER

3. 2. An impedance approach to passive-active vibration control

   Författare :Jonas Svensson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hybrid passive-active vibration control; Active control; Euler- Bernoulli theory.; Impedance matching;

   Sammanfattning : The complementary advantages of active and passive vibration control have motivated research concerning hybrid configurations. Previous studies have mainly focused on active constrained layers (ACL). However, investigations pointing towards suboptimal performance of ACL have made it interesting to investigate other solutions. LÄS MER

4. 3. Pulmonary ventilation and perfusion assessed by electrical impedance tomography - Experimental studies in pigs

   Författare :Anneli Fagerberg; Göteborgs universitet; []
   Nyckelord :electrical impedance tomography; V Q matching; pig; endotoxinaemic ALI; ACE inhibitor;

   Sammanfattning : Pulmonary ventilation and perfusion and ventilation/perfusion (V/Q) matching determine gas exchange in every lung unit in the healthy state and in the pathologically altered lung. Mismatch of V and Q lead to hypoxaemia and hypercapnia and monitoring of V/Q relations are thus important in critical illness. LÄS MER

5. 4. Wideband Active and Passive Antenna Solutions for Handheld Terminals

   Författare :Peter Lindberg; Anders Rydberg; Anders Pers; Nicholas Buris; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; active antennas; impedance matching; dipole antennas; baluns; slot antennas; microstrip antennas; mobile antennas; multifrequency antennas; antenna proximity factors; receiving antennas; ferrite devices; Teknisk fysik;

   Sammanfattning : This thesis presents solutions and studies related to the design of wideband antennas for wireless handheld terminal applications. A method of electrically shortening the terminal chassis length to obtain resonance at high frequencies has been proposed and evaluated, thereby increasing the antennas impedance bandwidth. LÄS MER

7. 5. Embedded Element Patterns in Combination with Circuit Simulations for Multi-Port Antenna Analysis

   Författare :Kristian Karlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna efficiency; Greens function; multi-port antenna; impedance matching; reverberation chamber; correlation; antenna arrays; Embedded element pattern; optimization; antenna diversity;

   Sammanfattning : This thesis is a result from work on two different subjects, electromagnetic simulations of reverberation chambers and a methodology for the analysis of multi-port antennas. The subjects can be linked together by their contribution to knowledge in electromagnetic simulations and characterization of antennas. LÄS MER