Sökning: "tunable devices"

Visar resultat 1 - 5 av 98 avhandlingar innehållade orden tunable devices.

1. 1. Tunable surfaces : using polyoxoniobates and -tantalates as molecular building blocks

   Författare :Mark Rambaran; C. André Ohlin; Jean-Francois Boily; Mari-Ann Einarsrud; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis describes and explains the use of aqueous polyoxometalates (POMs), as molecular building blocks in the fabrication of tunable solid-state materials, such as thin films.  Microwave irradiation in the synthesis of Nb10, Nb6 and Ta6 is a rapid and efficient alternative to conventional hydrothermal methods, while offering equal – if not greater yields – of product. LÄS MER

3. 2. Surface-Micromachined Vertical-Cavity Micro-Opto-Electro-Mechanical Devices on InP

   Författare :Nicolae Chitica; KTH; []
   Nyckelord :MOEMS; Optical MEMS; InP; GaInAsP; VCSEL; MOVPE; surface micromachining; tunable devices; vertical cavity devices; air-gap reflectors; III-V micromechanics;

   Sammanfattning : .... LÄS MER

4. 3. Tunable Bulk Acoustic Wave Resonators Based on BaxSr1-xTiO3 Thin Films

   Författare :John Berge; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; piezoelectric resonators; bulk acoustic wave devices; field induced piezoelectric effect; tunable devices; ferroelectric films;

   Sammanfattning : The main focus of this thesis is the study of a novel component based on ferroelectric BaxSr1−xTiO3 thin films – the tunable thin film bulk acoustic resonator (TFBAR). The tunable TFBAR utilizes a dc field induced piezoelectric effect in the ferroelectric film, in contrast to conventional fixed frequency TFBARs, widely used for filtering applications in wireless communication systems,which are based on ordinary piezoelectric materials. LÄS MER

5. 4. High Temperature Superconducting and Tunable Ferroelectric Microwave Devices

   Författare :Erik F. Carlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; varactors; tunable microwave circuits; conformal mapping; cryogenic probe station; ferroelectrics; high temperature superconductors; microwave circuits; narrow-band filters; phase-shifter;

   Sammanfattning : This thesis addresses some applications of High Temperature Superconductors (HTS) and ferroelectric materials in tunable microwave devices and circuits. The work is divided into three main areas: i) modeling of multilayered structures including ferroelectric layers, ii) realization and characterization of tunable coplanar waveguides (CPW), capacitors and resonators based on ferroelectrics, and iii) an investigation of microstrip HTS K-band filters. LÄS MER

7. 5. Ferroelectric niobate films for electrically tunable devices

   Författare :Jung-Hyuk Koh; KTH; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER