Abstract
We present comparative characteristics of microwave variable capacitors (varactors) fabricated on Na0.5K0.5NbO3 (NKN), AgTa0.5Nb0.5O3 (ATN) and Ba0.5Sr0.5TiO3 (BST) ferroelectric films sintered by pulsed laser deposition technique. Two port 2 μm finger gap coplanar waveguide interdigital capacitive (CPWIDC) structures were defined on ferroelectric films surface by a standard lift off technique. Results of the microwave on-wafer tests performed in frequency range 1 to 40 GHz have been examined with a de-embedding technique to extract device characteristics from the measured S-parameters. The frequency dispersion of capacitance was 37%, 4.3%, and 17%; the voltage tunability (200 kV/cm) 22%, 4.7%, and 22% at 20 GHz; loss tangent ∼0.23, 0.068, and 0.137 at 20 GHz for NKN/Nd:YAlO3, ATN/Al2O3, and BST/Al2O3 films capacitors.
| Original language | English |
|---|---|
| Pages (from-to) | 619-622 |
| Number of pages | 4 |
| Journal | Thin Solid Films |
| Volume | 515 |
| Issue number | 2 SPEC. ISS. |
| DOIs | |
| Publication status | Published - 25 Oct 2006 |
| Externally published | Yes |
Keywords
- Barium strontium titanate
- Coplanar waveguides
- Epitaxial films
- Ferroelectric ceramics
- Pottasium sodium niobate
- Pulsed laser deposition
- Scattering parameters measurement
- Silver tantalate niobate
- Voltage tunable microwave devices