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In this report, we demonstrate a new principle to improve the resolution of the acoustic microscopy, which is based on the sub-wavelength focusing of acoustic wave passing through an acoustically transparent mesoscale particle. In the…

General Physics · Physics 2017-12-06 I. V. Minin , Q. Tang , S. Bhuyan , J. Hu , O. V. Minin

Classifier-free guidance (CFG) succeeds in condition diffusion models that use a guidance scale to balance the influence of conditional and unconditional terms. A high guidance scale is used to enhance the performance of the conditional…

Computer Vision and Pattern Recognition · Computer Science 2025-06-27 Kaiyu Song , Hanjiang Lai

This paper is concerned with the problem of inverse scattering of time-harmonic acoustic plane waves by a two-layered medium with a locally rough interface in 2D. A direct imaging method is proposed to reconstruct the locally rough…

Numerical Analysis · Mathematics 2023-05-11 Long Li , Jiansheng Yang , Bo Zhang , Haiwen Zhang

Phononic integrated circuits, which manipulate GHz-frequency acoustic fields in {\mu}m-scale waveguides, provide new degrees of freedom for routing and manipulation of microwaves in deeply sub-wavelength geometries with associated…

Applied Physics · Physics 2025-08-14 A. Fahad Malik , Mahmut Bicer , Krishna C. Balram

The design and experimental implementation of a waveform for high-accuracy inter-node ranging in a coherent distributed antenna array is presented. Based on a spectrally-sparse high-accuracy ranging waveform, the presented multi-frequency…

Signal Processing · Electrical Eng. & Systems 2020-02-10 Sean Ellison , Jeffrey Nanzer

We present parameterized broadband spectral models valid at frequencies between 30-300 MHz for six bright radio sources selected from the 3C survey, spread in Right Ascension from 0-24 hours. For each source, data from the literature are…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Anna M. M. Scaife , George H. Heald

Multiple scattering of wave in strong heterogeneity can cause resonance-like wave anomaly where the signal exhibits low-frequency, high intensity, and slowly propagating wave packet velocity. For example, long period event in volcanic…

Classical Physics · Physics 2019-12-19 Yinbin Liu

This paper proposes a new sparse array source enumeration algorithm for underdetermined scenarios with more sources than sensors. The proposed algorithm decomposes the wideband signals into multiple uncorrelated frequency bands, computes…

Signal Processing · Electrical Eng. & Systems 2019-12-30 Yang Liu , John R. Buck

While functional materials with both light transmitting and electromagnetic shielding are highly desirable, only very few of them meet the stringent electromagnetic interference (EMI) shielding criteria for optoelectronic systems. Here, a…

The propagation of waves in highly inhomogeneous media is a problem of interest in multiple fields including seismology, acoustics and electromagnetism. It is also relevant for technological applications such as the design of sound…

Disordered Systems and Neural Networks · Physics 2013-05-29 Antonio M. Garcia-Garcia , Emilio Cuevas

Filtering modules are essential devices of modern microwave systems given their capability to improve the signal-to-noise ratio of the received signal or to eliminate the unwanted interferences. For discriminating between different…

This paper presents key performance metrics for near-field communication and sensing systems and their scaling behavior as a function of the antenna array aperture. Analytical expressions are derived for several standard array geometries to…

Signal Processing · Electrical Eng. & Systems 2026-01-09 Marcin Wachowiak , André Bourdoux , Sofie Pollin

Small-size acoustic arrays exploit spatial diversity to achieve capabilities beyond those of single-element devices, with applications ranging from teleconferencing to immersive multimedia. A key requirement for broadband array processing…

Signal Processing · Electrical Eng. & Systems 2025-08-19 Federico Miotello , Davide Albertini , Alberto Bernardini

Phased arrays, commonly used in IEEE 802.11ad and 5G radios, are capable of focusing radio frequency signals in a specific direction or a spatial region. Beamforming achieves such directional or spatial concentration of signals and enables…

Signal Processing · Electrical Eng. & Systems 2024-10-30 Nitin Jonathan Myers , Robert W. Heath

In this paper, a general methodology to study rigorously discontinuities in open waveguides is presented. It relies on a full vector description given by Maxwell's equations in the framework of the finite element method. The discontinuities…

Computational Physics · Physics 2020-06-24 Guillaume Demésy , Gilles Renversez

Slow waves and tunneling waves can meet at the cutoff wavelengths and/or transmission band edges of optical and quantum mechanical waveguides. The experimental investigation of this phenomenon, previously performed using various optical…

Optics · Physics 2020-02-19 Yong Yang , M. Sumetsky

We show that two-dimensional arrays of thin metallic wires can guide transverse electromagnetic (TEM) waves and focus them to the spatial dimensions much smaller that the vacuum wavelength. This guiding property is retained for the tapered…

Optics · Physics 2009-11-13 G. Shvets , S. Trendafilov , J. B. Pendry , A. Sarychev

We present a novel algorithm for high resolution coherent imaging of sound sources in random scattering media using time resolved measurements of the acoustic pressure at an array of receivers. The sound waves travel a long distance between…

Numerical Analysis · Mathematics 2017-12-15 Liliana Borcea , Ilker Kocyigit

Numerous types of antennas have been employed for microwave imaging of stratified media for ground penetrating radar (GPR), through-the-wall-radar imaging (TWRI), etc. This letter aims to investigate the impact of the different antennas…

Systems and Control · Electrical Eng. & Systems 2025-10-13 Adel Omrani , Sajjad Sadeghi

We briefly consider some design aspects of aperture arrays for use in radio astronomy, particularly contrasting the performance of dense and sparse aperture arrays. Recent insights have emerged in the final design phase of LOFAR which…

Astrophysics · Physics 2007-05-23 Robert Braun , Wim van Cappellen