Recently, harmonic imaging has been shown to increase image quality in medical imaging. This is believed to be caused by decreased sidelobes. It is also due to a decreased sensitivity to near-field aberrations owing to the lower transmission frequency, and the lower relative amplitude of the second harmonic in the near-field. One of the problems of limited diffraction beams has been the sidelob...

Isoliquiritigenin (ISL), a natural antioxidant, has antitumor activity in different types of cancer cells. However the antitumor effect of ISL on human tongue squamous carcinoma cells (TSCC) is not clear. Here we aimed to investigate the effects of synthetic isoliquiritigenin (S-ISL) on TSCC and elucidate the underlying mechanisms. S-ISL was synthesized and elucidated from its nuclear magnetic ...

Linear and planar antenna arrays are synthesized to have maximum directivity for a specified sidelobe level. The directivity is maximized subject to a given SLL. The beamwidth and the zeros of array factor are studied as well as the directivity. Maximum directivity-arrays are compared through some examples with super-directive, uniform, Dolph-Chebyshev and Riblet-Chebychev arrays to find a comp...

Target masking is a pervasive problem in radar signal processing: the range sidelobes of waveform’s matched filter response may cause strong target to prevent detection nearby weaker targets. Common solutions sidelobe level reduction for frequency-modulated waveforms result signal-to-noise ratio (SNR) loss. In this correspondence, we propose novel method using pulse diversity reduce while avoid...

Target masking due to high sidelobes in the range-Doppler domain is a common problem radar signal processing. Masking occurs when there large variation targets' signal-to-noise-ratio levels, caused by differences either range or cross section. In this letter, we consider design of waveform reduce far targets near targets. Our method based on time-frequency concatenation Costas sequence with shi...

N-continuous orthogonal frequency division multiplexing (NC-OFDM) was demonstrated to provide significant sidelobe suppression for baseband OFDM signals. However, it will introduce severe interference to the transmit signals. Hence in this letter, we specifically design a class of low-interference NC-OFDM schemes for alleviating the introduced interference. Meanwhile, we also obtain an asymptot...

Sequences with low aperiodic autocorrelation and crosscorrelation are used in communications remote sensing. Golay Shapiro independently devised a recursive construction that produces families of complementary pairs binary sequences. In the simplest case, Rudin–Shapiro sequences, general it what we call Golay–Rudin–Shapiro Calculations by Littlewood show sequences have mean square autocorrelati...

Schmidt proved in 2014 that if ε > 0, almost all binary sequences of length n have peak sidelobe level between ( √ 2 − ε)√n log n and ( √ 2 + ε) √ n log n. Because of the small gap between his upper and lower bounds, it is difficult to find improved upper bounds that hold for almost all binary sequences. In this note, we prove that if ε > 0, then almost all binary sequences of length n have pea...

Radio astronomical measurements of extended emission require knowledge of the beam shape and response because the measurements need correction for quantities such as beam efficiency and beamwidth. We describe a scheme that characterizes the main beam and sidelobe in all Stokes parameters employing parameters that allow reconstruction of the complete beam patterns and, also, afford an easy way t...