most geologic changes have a seismic response but sometimes this is expressed only in certain spectral ranges hidden within the broadband data. spectral decomposition is one of the methods which can be utilized to help interpreting such cases. there are several time-frequency methods including: short-time fourier transform (stft), continuous wavelet transform (cwt), wigner-ville distribution (w...

The nonlinearity inherent in the Traveling Wave Tube (TWT) amplifier distorts amplified signals and results in reduced efficiency and bandwidth, limiting its use in communication and electronic countermeasure applications. Signal predistortion is an effective technique for suppressing nonlinear distortion in TWTs that provides high suppression and requires simple circuits for implementation. Wh...

As data communication rates climb toward ten Gbls, clock recovery and synchronization become more dificult, if not impossible, using conventional electronic circuits. We present in this article experimental results of a high speed clock and carrier recovery using a novel device called the photonic oscillator that we recently developed in our laboratory. T h i s device is capable of recovering c...

geophysical data are always affected by different sources of anomaly. these sources are classified in to three groups: first group is relatively deep sources commonly called as regional effects, second group is near surface sources or local effects and third group is high frequency noises. the only common way to separate the anomaly is separation with respect to the signal frequency. there are ...

Propagation of radio occultation (RO) signals through the lower troposphere results in high phase acceleration and low signal to noise ratio signal. The excess Doppler estimation accuracy in lower troposphere is very important in receiving RO signals which can be estimated by sliding window spectral analysis. To do this, various frequency estimation methods such as MUSIC and ESPRIT can be adopt...

The magnetic alloy loaded radio-frequency system has been installed in the KEK 12 GeV synchrotron. This system is a high field gradient radio-frequency system and is designed to operate not only as a fundamental harmonic system to increase the insufficient matching voltage, supplied by 4 conventional ferrite cavities but also as a second radiofrequency system to alleviate the space charge effec...