Ultrawide-band tunable true-time delay lines using ferroelectric varactors
Journal article, 2005

This paper reports on compact tunable true-time delay lines based on ferroelectric (Ba/sub 0.25/Sr/sub 0.75/TiO/sub 3/) varactors integrated on high-resistivity silicon. The delay lines are based on lumped elements, physically implemented as synthetic coplanar-strip lines. An approximate analytical design procedure, exactly valid for omega to 0, is proposed. The physical size of the fabricated delay lines is 2.0*0.33 mm/sup 2/, including bias pads. Measurements are performed from room temperature (RT) down to 80 K. The measurements reveal ultrawide-band characteristics for both group delay and insertion loss. At RT, the absolute group delay is tau /sub delta /(RT, 0 V) approximately=70 ps with tunability of 20% under 20-V dc bias, the insertion less than 3.5 dB, and the reflection loss better than 12 dB below 20 GHz. At 145 K, the absolute group delay is increased to tau /sub delta /(145 K, 0 V) approximately=100 ps with a tunability of 50% under 20-V applied bias. At 7 GHz, the insertion loss is 3 dB, resulting in figures-of-merit of 0.03 dB/ps and 50 ps/mm. The leakage current at RT is less than 0.1 mu A

coplanar waveguides

ferroelectric devices

barium compounds

delay lines

strip lines

varactors

strontium compounds

Author

Dan Kuylenstierna

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Andrei Vorobiev

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Peter Linner

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Spartak Gevorgian

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Transactions on Microwave Theory and Techniques

0018-9480 (ISSN)

Vol. 53 6, pt.2 2164-70

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/TMTT.2005.848805

More information

Created

10/6/2017