A Ka-Band Electronically Tunable Ferroelectric Filter

• Published in: IEEE microwave and wireless components letters Vol. 19; no. 6; pp. 356 - 358
• Main Authors: Courreges, S., Yuan Li, Zhiyong Zhao, Kwang Choi, Hunt, A., Horst, S., Cressler, J.D., Papapolymerou, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2009; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Band pass filters; Bandwidth; Barium strontium titanate (BST); Barium strontium titanates; Bias; Binary search trees; Capacitors; Circuit properties; Dielectric, amorphous and glass solid devices; Electric potential; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Engineering Sciences; Exact sciences and technology; Ferroelectric materials; Ferroelectricity; Filter bank; Frequency; Frequency filters; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave filters; Microwaves; Noise levels; Resonator filters; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Tunable circuits and devices; Voltage; Low voltage; Tunable circuit; High Q factor; Ferroelectric materials; Ka band; Bias voltage; Tunable filter; Insertion loss; Microwave; Ferroelectric capacitors; Microwave filter; Barium strontium titanate (BST)
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2009.2020012

This letter presents a three-pole tunable Ka-band coplanar filter that includes six high-Q BST ferroelectric capacitors. It tunes from 29 GHz up to 34 GHz (17%) with low bias voltages ranging from 0 V to 30 V. The filter has fractional bandwidths of 9.5-12.2%. It has a good insertion loss for this category of Ka-band ferroelectric filters, which is between 6.9 dB (0 V) and 2.5 dB (30 V). Two tone measurements showed that the filter has a minimum OIP3 of 15 dBm between 0 V and 30 V. The highest OIP3 value is 26 dBm achieved at a dc bias of 30 V.