The quality of the current waveform generated by a current controlled, voltage source shunt active power filter depends basically on three factors: (i) The reference signal being generated; (ii) the modulation method used and (iii) the switching frequency of the PWM modulator. A new adaptive hysteresis band modulation method is proposed. In this paper, the periodical sampling constant hysteresi...

Department of Electrical Power and Machines Faculty of Engineering Cairo University Giza, Egypt Abstract The quality of the current waveform generated by a current controlled, voltage source shunt active power filter depends basically on three factors: (i) The reference signal being generated; (ii) the modulation method used and (iii) the switching frequency of the PWM modulator. A new adaptiv...

The combination of non-linear control and linear control proposed in [1] provides very fast transient response (voltage step from 1 V to 1.5 V in 2 μs). This non-linear control is based on hysteretic control of the Cout current. This system is very sensitive to effects like aging, temperature, input and output voltage variation, etc., that modify the switching frequency. This paper proposes a f...

A low power 22-mW 900MHz Frequency Synthesizer (FS), with an on-chip LC-tuned voltage controlled oscillator (VCO) for GSM applications is presented. The synthesizer possesses several novel features that include a completely integrated structure, a low phase noise on-chip LC VCO, a low-power Dual-Modulus Divider (DMD) in CML topology, a compensated charge pump with balanced switching, an on-chip...

Brain regions that are structurally connected might become functionally connected by synchronization in the gamma-frequency band. In a recent issue of Nature, Colgin et al. show spatially and temporally fine-grained gamma-band synchronization between different parts of the rat hippocampal formation, suggesting a theta-modulated switching of gamma-mediated communication.

The design and simulation of a 1.35 GHz fully integrated CMOS frequency synthesizer for a double band receiver is presented. The proposed synthesizer is based in a wide-band PLL topology with a high reference frequency. This approach allows obtaining low phase noise, fast switching time, a low divider ratio and a reduction in the total chip area. Besides, the use of a novel charge-pump circuit ...

this paper investigates the multi-band ofdm (mb-ofdm) based physical (phy) layer proposal for ieee 802.15.3a working group on short-range high data-rate ultra-wide-band (uwb) communications. an overview of the mb-ofdm phy layer architecture with its various parameters is presented and the optimal choice of critical parameters is discussed. next, we derive the theoretical un-coded bit error rate...

A scheme of frequency hopping spread spectrum (FHSS) frequency synthesizer suitable for synthesis of radio-frequency (RF) carrier signal in very high frequency (VHF) band is proposed, implemented and tested. The synthesizer is based on the direct digital frequency synthesis (DDFS or DDS) and phase locked loop (PLL) with dynamic monitoring of varicap’s voltage to reduce switching time. The resul...

The single phase inverter performance through the unipolar and bipolar strategies has been previously analyzed based on constant switching frequency pulse width modulation (CSFPWM). However, confined band variable PWM (CB-VSFPWM) is currently proposed as a new technique strategy to facilitate design of high order filter, reduce losses, current total harmonics distortion (THD) well. To evaluate ...

Working memory is responsible for the temporary manipulation and storage of information to support reasoning, learning and comprehension in the human brain. Background oscillations from subcortical structures may drive a gating or switching mechanism during working memory computations, and different frequency bands may be associated with different processes while working memory tasks are perfor...