a digital look-up table adaptive predistortion technique using a six-port receiver for power amplifier linearization is presented. the system is designed in ka-band for a dvb-s2 satellite link. we use a six-port receiver at the linearizationloop in place of classic heterodyne receivers. the six-port receiver is implemented by the use of passive microwavecircuits and detector diodes. this approa...

In 2005 IEEE (The Institute of Electrical and Electronic Engineers) introduced a new standard model for Power System Stabilizers, the PSS4B. This is an advanced multi-band stabilizer that may give a better performance than the regular PSSs often used today. The new stabilizer has three parallel control blocks, each aiming at damping different oscillatory modes or different frequency bands of th...

We recorded local field potentials (LFPs) and single-unit activity simultaneously in the macaque primary visual cortex (V1) and studied their responses to drifting sinusoidal gratings that were chosen to be "optimal" for the single units. Over all stimulus conditions, the LFP spectra have much greater power in the low-frequency band (< or = 10 Hz) than higher frequencies and can be described as...

The majority of medical accelerators for radiation therapy use frequencies in the S-band range. Having a compact accelerator allows for a wide range of treatments. The size and weight of the accelerator are substantially reduced if a higher frequency is used. X-band frequencies are suitable for such applications. X-band accelerator technology has been used in high-energy, as well as, industrial...

Gallium Nitride (GaN) amplifiers have demonstrated very high power density as well as wide band width in previous research. This paper examines their use in supplying flat gain, power, and linearity across a large band width. It demonstrates two types of power amplifiers: a Ft Doubler (FT2) amplifier and a Cascode amplifier, both of which require a simple PCB tune. Both amplifiers show 0.2 to 4...

This is Part II of the paper “Witt vectors and a question of Keating and Rudnick” [Ka-WVQKR]. Here we prove an independence result for tuples of character sums, formed with a variable character and its powers. In the Appendix, we prove an independence result for tuples of character sums formed with variable pairs of characters and products of the two.

BACKGROUND The EEG is considered as building block of functional signaling in the brain. The role of EEG oscillations in human information processing has been intensively investigated. PURPOSE To study the quantitative EEG correlates of short term memory load as assessed through Sternberg memory test. METHODS The study was conducted on 34 healthy male student volunteers. The intervention co...

In time-constraint activities, such as sports, it is advantageous to be prepared to act even before knowing precisely what action will be needed. Here, we studied the relation between neural oscillations during motor preparation and amount of uncertainty about the direction of the upcoming target. Ten right-handed volunteers participated in a cued center-out task. A brief visual cue identified ...