Abstract: Systems, methods, and media for wireless power transfer are provided.

Abstract: Systems, methods, and media for wireless power transfer are provided.

Abstract: The subject method for delivering power to a moving target wirelessly via electromagnetic time reversal can find applications in wireless electrical transmission to portable devices, wireless heating of portable devices, novel wirelessly powered accelerometers, hyperthermic treatment of cancers, and many other applications. The subject non-linear time reversed electromagnetic waves based wireless power transmission (WPT) system targets either a single linear or non-linear object where a selective targeting between two diodes has been demonstrated simultaneously with different degrees of non-linearity in a three-dimensional ray-chaotic billiard model. A dual-purpose rectenna with harmonic generation for wireless power transfer by non-linear time-reversal has been designed for the subject system using the Schottky diode.

Abstract: The subject method for delivering power to a moving target wirelessly via electromagnetic time reversal can find applications in wireless electrical transmission to portable devices, wireless heating of portable devices, novel wirelessly powered accelerometers, hyperthermic treatment of cancers, and many other applications. The subject non-linear time reversed electromagnetic waves based wireless power transmission (WPT) system targets either a single linear or non-linear object where a selective targeting between two diodes has been demonstrated simultaneously with different degrees of non-linearity in a three-dimensional ray-chaotic billiard model. A dual-purpose rectenna with harmonic generation for wireless power transfer by non-linear time-reversal has been designed for the subject system using the Schottky diode.

Abstract: A system and method for safe communication in a complex scattering environment is achieved by means of providing a passive nonlinear object in the wave propagation environment which nonlinearly interacts with the waves to create an exclusive communication channel between the nonlinear object and any point where the waves can be collected. Excitations generated by the nonlinearity in the time-reversal mirror are gathered, time-reversed, and retransmitted into the environment. The retransmitted signals arrive and are reconstructed exclusively at the location of the nonlinear object or linear object depending on the linearity or nonlinearity of the retransmitted sonas. The principles of the system and method are useful in numerous applications where signal communication or power delivery is desired to an object whose location is not known or dynamically changed in an exclusive, highly localized, precise, and secure fashion.

Abstract: A near-field scanning microwave microscope images the permittivity and dielectric tunability of bulk and thin film dielectric samples on a length scale of about 1 micron or less. The microscope is sensitive to the linear permittivity, as well as to non-linear dielectric terms, which can be measured as a function of an applied electric field. A versatile finite element model is used for the system, which allows quantitive results to e obtained. The technique is non-destructive and has broadband (0.1-50 GHz) capability.

Abstract: A method of disentangling sample properties in a scanned sample requires a calibration sample in which two sample properties are variable. The calibration sample is scanned, and two measured variables are recorded during the scan. The two sample properties are measured quantitatively by an independent means. Using the data from the calibration sample, conversion functions are mathematically determined, in order to convert the two measured variables into the two sample properties. A sample, for which the two properties are unknown, is scanned, and the two measured variables are recorded. Using the conversion functions, the data from the scan is converted into the two sample properties of interest for the unknown sample. This method can be used with the first sample property being topography, so that effects due to the topography of the sample are eliminated from the computation of the second property of the unknown sample.

Abstract: An apparatus and method for accurately estimating the absolute value of surface resistances and penetration depths of metallic films and bulk samples. The apparatus carries out measurements using two nominally identical samples with flat sample surfaces which are brought together with a thin dielectric separation of variable thickness sandwiched between the samples in order to form a two-conductor parallel plate transmission line resonator which carries an electromagnetic wave. A liquid or gas of unknown dielectric properties fills the dielectric spacer. A resonant condition of the microwave signal is established and the resonant frequency and the quality factor Q are measured while the spacing between the sample plates is varied. The variation of the resonant frequency and Q with spacer thickness is then analyzed to yield absolute values of the sample surface resistance and penetration depth which are then further used for determination of absolute complex conductivity and surface impedance of the samples.

Abstract: The microscope includes a microwave generator connected to a mismatched transmission line which terminates in a probe with an exposed end. When a sample is brought into close proximity with the exposed end of the probe, the frequencies and quality factors of the standing wave resonances on the transmission line between the source and the probe are modified. The microwave signal reflected from the end of the probe varies as the capacitance between the probe and the sample changes and as the conductivity of the sample changes. Scanning the sample relative to the probe allows generation of an image from the variation of the reflected signal. Alternatively, to image a device with the microscope, a microwave signal is applied to the device, the probe is scanned over the device, and the signal that is picked up is recorded. In a second embodiment, a first lock-in amplifier is used to lock in the microscope at the resonant frequency, and a second lock-in amplifier is used to detect a curvature of the resonance.