Tunable microstrip resonators with ferroelectric capacitors





tunable microstrip resonator, ferroelectric capacitor, frequency rangе


The question of increasing the tuning band of microstrip resonators that use ferroelectric capacitors for tuning in the region of increased electric lengths is considered which allows using them in the upper part of the centimeter band (Ku-band, K-band). Band properties of regular and step-irregular resonators operating at the lowest resonant frequency are analyzed.

It is determined that step-irregular resonators possess a wider tuning band than regular ones. Their use allows widening the tuning band by 1.5 or more times. If the ferroelectric capacitor overlapping in capacity Cmax/Cmin = 2.2 then at frequencies 10 GHz and 20 GHz step resonators can provide 28% and 22% tuning band, respectively.


J. Sigman, C. D. Nordquist, P. G. Clem, et al., “Voltage–controlled Ku–band and X–band tunable combline filters using barium–strontium–titanate,” IEEE Microwave Wireless Compon. Lett. 18, No. 9, 593 (2008).

J. Nath, D. Ghosh, J. P. Maria, et al., “An electronically tunable microstrip bandpass filter using thin–film Barium–Strontium–Titanate (BST) varactors,” IEEE Trans. Microwave Theory Tech. 53, No. 9, 2707 (2005).

V. V. Pleskachev and I. B. Vendik, “Figure of merit of tunable ferroelectric planar filters,” in Proc. of Int. Symp. Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves, June 2004 (2004), pp. 697–699.

X.–P. Liang and Y. Zhu, US Patent No. 6717491 B2 (6 April 2004).





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