| 2. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
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Ferroelectrically tuneable delay lines
- 2004
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Ingår i: Conference Proceedings. 34th European Microwave Conference, 12-14 Oct. 2004. ; vol.1, s. 157-60
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Konferensbidrag (refereegranskat)abstract
- Ferroelectric (Ba/sub 0.25/Sr/sub 0.75/TiO/sub 3/) varactors are integrated on a Si substrate to form compact wideband true-time tuneable delay lines. The delay-line design is of the lumped element approach, implemented as a synthetic coplanar strip (CPS) line. The physical size of the delay lines is 2.0*0.33 mm/sup 2/. Up to 20 GHz, the measured delay time per unit length is approximately constant equal to 40 ps/mm (corresponding to a slow wave factor of 12) and the losses are about 0.049 dB/ps. The tuneability under 30 V DC-bias is 10%
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| 3. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
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Ultrawide-band tunable true-time delay lines using ferroelectric varactors
- 2005
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 53:6, pt.2, s. 2164-70
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Tidskriftsartikel (refereegranskat)abstract
- 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
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