RF performance evaluation of ferroelectric varactor shunt switches

Abstract

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Challenges and opportunities for multi-functional oxide thin films for voltage tunable radio frequency/microwave components

“…BST films exhibit an excellent tunable behavior at room temperature (in the case of 40%-60% concentration of barium), which lays the foundation for the microwave tunable devices. 5,6 The range of capacitance tuning in BST varactors is quite large (>3:1 in the linear region) and varactor devices are relatively simple in nature. Also, BST thin film based varactors have exhibited high power handling capability which is also attractive for applications in microwave and millimeter-wave communications.…”

“…The dielectric tuning is relatively good, more than 3:1 tuning range on high resistivity Si compared to 4:1 obtained on sapphire substrates. 6,14,39 The dielectric loss-tangent is almost doubled for the high resistivity Si, meaning the quality factor will be degraded by a factor of 2. Also, the integration of BST thin film on low-resistivity Si (standard CMOS Si) degrades the dielectric properties some more, as the relative dielectric constant at zero-bias drops to below 500.…”

A Low Voltage Tunable Analog Phase Shifter Utilizing Ferroelectric Varactors

“…Our group has been investigating properties of the nano-structured BST thin-films for use in a number of microwave/millimetre wave applications [3]. Currently, a ferroelectric varactor shunt switch which is useful for low power, low voltage microwave/millimeterwave switching is under investigation [4][5][6]. The device operation is based on the nonlinear dielectric tunability of a ferroelectric thinfilm sandwiched between two metal layers in a parallel plate configuration.…”

Ferroelectric Varactor Shunt Switches for Broadband Phase Control Applications

“…Our group has been investigating properties of the ferroelectric Barium Strontium Titanate (BST) thin-films for use in a number of microwave/millimetre wave applications. Currently, a ferroelectric varactor shunt switch which can be useful for low power, low voltage microwave/millimeterwave switching is under investigation [3][4][5]. The device operation is based on the nonlinear dielectric tunability of a ferroelectric thin-film sandwiched between two metal layers in a parallel plate configuration.…”