Invention Grant
- Patent Title: Ferroelectric varactors suitable for capacitive shunt switching
- Patent Title (中): 铁电变容二极管适用于电容分流开关
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Application No.: US10575754Application Date: 2004-10-15
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Publication No.: US07692270B2Publication Date: 2010-04-06
- Inventor: Guru Subramanyam , Andre Vorobiev , Spartak Gevorgian
- Applicant: Guru Subramanyam , Andre Vorobiev , Spartak Gevorgian
- Applicant Address: US OH Dayton
- Assignee: University of Dayton
- Current Assignee: University of Dayton
- Current Assignee Address: US OH Dayton
- Agency: Dinsmore & Shohl LLP
- International Application: PCT/US2004/034266 WO 20041015
- International Announcement: WO2005/043669 WO 20050512
- Main IPC: H01P7/10
- IPC: H01P7/10

Abstract:
A ferroelectric varactor suitable for capacitive shunt switching is disclosed. High resistivity silicon with a SiO2 layer and a patterned metallic layer deposited on top is used as the substrate. A ferroelectric thin-film layer deposited on the substrate is used for the implementation of the varactor. A top metal electrode is deposited on the ferroelectric thin-film layer forming a CPW transmission line. By using the capacitance formed by the large area ground conductors in the top metal electrode and bottom metallic layer, a series connection of the ferroelectric varactor with the large capacitor defined by the ground conductors is created. The large capacitor acts as a short to ground, eliminating the need for vias. The concept of switching ON and OFF state is based on the dielectric tunability of the ferroelectric thin-films. At 0 V, the varactor has the highest capacitance value, resulting in the signal to be shunted to ground, thus isolating the output from the input. This results in the OFF state of the switch. By applying a small voltage to the center conductor of the CPW, the varactor's capacitance can be reduced allowing the signal to be transmitted through resulting in the ON state of the device. Such a varactor shunt switch eliminates majority of problems plaguing the RF MEMS shunt switches.
Public/Granted literature
- US20070176217A1 Ferroelectric varactors suitable for capacitive shunt switching Public/Granted day:2007-08-02
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