Presentation 2005-11-17
A 20GHz MOD-made BST Thin Film Tunable Phase Shifter for Phase Adjustment of Digital 360-degree PHEMT Phase Shifter
Minoru NODA, Yoshinobu SASAKI, Daniel POPOVICI, Masanori OKUYAMA, Makio KOMARU,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) We have newly designed and fabricated both Ba_xSr_<1-x>TiO_3(BST) ferroelectric thin film tunable phase shifter and pseudomorphic HEMT MMIC digital 360-degree phase shifter. A low loss BST thin film was obtained on MgO substrate by preparation of initial layer by Pulsed Laser Deposition (PLD) and following Metal-Organic-Decomposition(MOD) method. For the interdigital capacitors with finger spacing of 10μm, dielectric loss was found to be as low as 0.002 to 0.004 when applied surface electric field was from -/+40 to +/-40 kV/cm at measuring frequency of 1 MHz, where tunability was about 12%. Moreover, it increases up to about 40% in a Pt/BST/Pt stacked capacitor structure when the applied electric field was from -/+170 to +/-170 kV/cm at the same frequency. When applying dc bias voltage of 0 to 60V to the electrodes of the CPW pattern (width : 60μm, gap : 10μm, length : 2.5mm), a differential phase shift of 18 degree was obtained at 20GHz with insertion loss of about -2dB for Au/Cr interconnection. A 3-stage LC-ladder-type phase shifter with variable capacitors of BST film was designed to have a differential phase shift of about 40 degrees at 20GHz. A fabricated phase shifter shows successfully the shift of 40 degree at 20GHz with bias of 60V. The HEMT MMIC also shows a digital 360-degree phase shift with 11.25 degree interval, thus the BST phase shifter can be usable for phase adjustment of the MMIC. Finally it is found that the new BST film process is very promising for realizing a micro and millimeter-wave tunable device.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) Ferroelectric films / Phase shifters / MMIC phase shifters / Tunable circuits and devices
Paper # ED2005-164,MW2005-119
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Committee ED
Conference Date 2005/11/10(1days)
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Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) A 20GHz MOD-made BST Thin Film Tunable Phase Shifter for Phase Adjustment of Digital 360-degree PHEMT Phase Shifter
Sub Title (in English)
Keyword(1) Ferroelectric films
Keyword(2) Phase shifters
Keyword(3) MMIC phase shifters
Keyword(4) Tunable circuits and devices
1st Author's Name Minoru NODA
1st Author's Affiliation Graduate School of Engineering Science, Osaka Univ.()
2nd Author's Name Yoshinobu SASAKI
2nd Author's Affiliation Mitsubishi Electric Corporation, Semiconductor Group
3rd Author's Name Daniel POPOVICI
3rd Author's Affiliation Graduate School of Engineering Science, Osaka Univ.
4th Author's Name Masanori OKUYAMA
4th Author's Affiliation Graduate School of Engineering Science, Osaka Univ.
5th Author's Name Makio KOMARU
5th Author's Affiliation Mitsubishi Electric Corporation, Semiconductor Group
Date 2005-11-17
Paper # ED2005-164,MW2005-119
Volume (vol) vol.105
Number (no) 400
Page pp.pp.-
#Pages 5
Date of Issue