Abstract: An acoustic resonator includes a first electrode, a second electrode, and a barium strontium titanate (BST) dielectric layer disposed between the first electrode and the second electrode, where the acoustic resonator is switched on as a resonator with a resonant frequency if a DC (direct current) bias voltage is applied across the BST dielectric layer. The acoustic resonator is also switched off if no DC bias voltage is applied across the BST dielectric layer. Furthermore, the resonant frequency of the acoustic resonator can be tuned based on a level of the DC bias voltage, with the resonant frequency increasing as the level of the DC bias voltage applied to the BST acoustic resonator increases.

Abstract: Parallel plate tunable varactors having a bulk capacitance contribution to a total capacitance increased compared to a fringing capacitance contribution are disclosed. The contribution of the bulk capacitance to the total capacitance of an exemplary BST varactor is increased by increasing the area/perimeter ratio of the active region, thereby improving the tunability and other properties of the varactor. In an exemplary embodiment, an active region of the varactor has a lateral shape with a perimeter that is less than a perimeter of an equivalent area square. In various exemplary embodiments, the shape of the active region may be substantially circular or substantially octagonal. Methods for fabricating and designing such varactors are also disclosed.

Abstract: An acoustic resonator includes a first electrode, a second electrode, and a barium strontium titanate (BST) dielectric layer disposed between the first electrode and the second electrode, where the acoustic resonator is switched on as a resonator with a resonant frequency if a DC (direct current) bias voltage is applied across the BST dielectric layer. The acoustic resonator is also switched off if no DC bias voltage is applied across the BST dielectric layer. Furthermore, the resonant frequency of the acoustic resonator can be tuned based on a level of the DC bias voltage, with the resonant frequency increasing as the level of the DC bias voltage applied to the BST acoustic resonator increases.

Abstract: An acoustic resonator includes a first electrode, a second electrode, and a barium strontium titanate (BST) dielectric layer disposed between the first electrode and the second electrode, where the acoustic resonator is switched on as a resonator with a resonant frequency if a DC (direct current) bias voltage is applied across the BST dielectric layer. The acoustic resonator is also switched off in no DC bias voltage is applied across the BST dielectric layer. Furthermore, the resonant frequency of the acoustic resonator can be tuned based on a level of the DC bias voltage, with the resonant frequency increasing as the level of the DC bias voltage applied to the BST acoustic resonator increases.

Abstract: An Inverted-F antenna (IFA) includes a tunable parallel LC resonator physically inserted between two antenna bodies of the IFA structure. The LC resonator is comprised of a tunable capacitor C1 connected in parallel with a combination of a DC blocking capacitor C2 and an inductor L1 connected in series to each other. A DC bias voltage is applied to the tunable capacitor C1 through a DC bias resistor R1, in order to adjust the capacitance of the tunable capacitor C1. The IFA exhibits dual band characteristics, and its resonant frequencies and bandwidths may be turned by adjusting the capacitance of the tunable capacitor C1. The tunable capacitor C1 may be a BST capacitor.

Abstract: A log-periodic dipole array system employs a structure for the transmitter and the receiver designed in a way such that they compensate for the non-linear characteristics of each other to realize linear phase characteristics as a pair. Radiation elements on the receiver are positioned with respect to its corresponding transmission line in an order opposite to the positioning of the radiation elements on the transmitter. Although neither the transmitter dipole array nor the receiver dipole array itself has linear phase characteristics, the overall dipole array antenna system can realize linear phase characteristic. The log-periodic dipole array system has the advantages that linear phase characteristics can be obtained without sacrificing high radiation efficiency and gain.

Abstract: A wafer antenna comprises a wafer substrate, a plurality of antenna elements integrated on the wafer substrate for radiating and receiving a radio frequency signal, an electrical connection integrated on the wafer substrate; a feed network integrated on the wafer substrate for distributing the RF signal from the electrical connection to the antenna elements and from the antenna elements to the electrical connection, and a plurality of tunable dielectric phase shifters integrated on the wafer substrate with each of the tunable dielectric phase shifters coupled to a corresponding one of the antenna elements and controlling the phase of the RF signal coupled to the corresponding one of the antenna elements.

Abstract: An impedance matching circuit employs a variable capacitor, such as a BST capacitor. The bias voltage to the variable capacitor may be adjusted in order to match several different frequencies used with the antenna to the signal source.

Abstract: A capacitor for use with RF signals of an operating frequency has a parallel plate configuration including a bottom electrode, a top electrode, and a dielectric layer disposed between the bottom and top electrodes, and an additional mass layer disposed on top of the top electrode. The parallel plate configuration is capable of receiving a DC voltage bias that affects the capacitance value of the parallel plate configuration, and exhibits a standing wave resonance frequency at the operating frequency. The mass layer has a density and a thickness selected to dampen the magnitude of the resonance of the parallel plate configuration at the standing wave resonance frequency and shift the standing wave resonance frequency away from the operating frequency.

Abstract: A log-periodic dipole array system employs a structure for the transmitter and the receiver designed in a way such that they compensate for the non-linear characteristics of each other to realize linear phase characteristics as a pair. Radiation elements on the receiver are positioned with respect to its corresponding transmission line in an order opposite to the positioning of the radiation elements on the transmitter. Although neither the transmitter dipole array nor the receiver dipole array itself has linear phase characteristics, the overall dipole array antenna system can realize linear phase characteristic. The log-periodic dipole array system has the advantages that linear phase characteristics can be obtained without sacrificing high radiation efficiency and gain.

Abstract: A tunable component such as a tunable BST (Barium Strontium Titanate) capacitor is added inside the antenna structure, and the input impedance of the antenna is tuned by tuning this tunable component, rather than adding a multiple-component impedance matching network at the feed point of the antenna outside the antenna as in conventional solutions. With this structure, the input impedance of the antenna may be adjusted very precisely and efficiently.

Abstract: Ferroelectric thin film devices including a passivation structure to reduce or control a leakage path between two electrodes and along an interface between a ferroelectric thin film layer and a passivation layer are described. Methods for fabricating such devices are also disclosed. The passivation structure includes a first passivation layer that includes an opening exposing a portion of the ferroelectric thin film layer allowing a second passivation layer to contact the thin film layer through the opening. In an exemplary embodiment, the opening is a rectangular ring surrounding an active region of a capacitor. In another exemplary embodiment, the second passivation layer also contacts the second electrode, a portion of which is also exposed through the opening. In another exemplary embodiment, current flows along the interface between the thin film layer and the passivation layer in an integrated resistor.

Abstract: A circuit topology is configured to flatten out a phase- and amplitude-response over a specified range of frequencies. The circuit topology also provides a large cumulative phase-shift. In one embodiment, the circuit topology cascades a plurality of all-pass sections, with the center-frequencies of each all-pass section staggered to create a substantially flat phase-response over a frequency range. Further, in one embodiment the plurality of all-pass sections has at least one all-pass section that is different from another all-pass section. Each all-pass section includes a tunable capacitor and has a center-frequency that can be varied by electronically tuning the capacitor. Each center frequency is selected to obtain substantially constant amplitude and phase response over a desired frequency range and capacitance tuning range.