Ferroelectric MIM capacitors for compact high tunable filters

Rosa De Paolis (1) , Sandrine Payan (2) , Mario Maglione (2) , Guillaume Guegan (3) , Fabio Coccetti (1)

1 LAAS-MINC - Équipe MIcro et Nanosystèmes pour les Communications sans fil
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 STMicroelectronics

The voltage- and frequency-dependent material properties of (Ba,Sr)TiO3 (BST) thin film have been extracted up to 67 GHz by means of a lumped elements equivalent circuit validated by fitting on de-embedded experimental data. The tunability is 73% (0-10 V bias), and the loss tangent is better than 0.06 (value at 0 V at 1 GHz). This varactor has been exploited in the design of a compact tunable filter implemented by using coupled resonators in lumped element in silicon planar technology. This solution yields a very compact size, and experimental results show a filter center frequency tuning of 83% (997 MHz - 1830 MHz) while maintain almost constant the fractional bandwidth at 35% upon the application of a 0-10 V bias. The insertion loss is between 3.8 and 4.4 dB, and the return loss is better than 14 dB.

Domaines: Electromagnétisme; Micro et nanotechnologies/Microélectronique

Rosa De Paolis, Sandrine Payan, Mario Maglione, Guillaume Guegan, Fabio Coccetti. Ferroelectric MIM capacitors for compact high tunable filters. IEEE 15th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF 2015), Jan 2015, San Diego, United States. pp.70-72, ⟨10.1109/SIRF.2015.7119878⟩. ⟨hal-02082720⟩