ABSTRACT
Explicit integral representations for the wave fields generated by air-coupled or underwater transducers in an acoustic medium with a submerged elastic (metallic or laminate composite) plate are obtained in the form of path Fourier integrals. Together with the far-field asymptotics for the incident, reflected, transmitted and guided waves that were derived from those integrals, they proved to be a convenient tool for the in-depth study of wave phenomena inherent in such acoustic-elastic structures. The present paper is focused on the non-conventional properties of backward leaky waves such as the increased wave energy transfer through the plate due to the increasing occurrence of energy vortices impeding lateral outflow of wave energy. The transformation of classical Lamb waves into leaky guided waves due to a fluid loading, especially in the backward wave range, the energy properties of those waves and the appearing traveling Scholter-Stoneley waves as well as source energy partition among the reflected, transmitted and guided waves are also numerically illustrated and discussed.
ABSTRACT
We present a practical design and implementation of a broadband sample holder suitable for microwave experiments with superconducting integrated circuits at millikelvin temperatures. Proposed design can be easily integrated in standard dilution cryostats, has flat pass band response in a frequency range from 0 to 32 GHz, allowing the RF testing of the samples with substrate size up to 4 × 4 mm(2). The parasitic higher modes interference in the holder structure is analyzed and prevented via design considerations. The developed setup can be used for characterization of superconducting parametric amplifiers, bolometers, and qubits. We tested the designed sample holder by characterizing of a superconducting flux qubit at 20 mK temperature.
