In this paper, a digitally controlled boost DC-DC power converter featuring high-resolution Dyadic Digital Pulse Width Modulator (DDPWM) is proposed to achieve Limit-Cycle oscillations (LCOs)-free operation, high DC accuracy, low output voltage ripple at switching frequency. The effectiveness of the DDPWM in suppressing onset LCOs, increasing and reducing verified by both Simulink/Modelsim co-s...

A stable single-frequency pulsed laser is a critical element for lidar applications, such as high spectral resolution lidar, direct detection Doppler wind lidar and so on. We have designed a laser diode dual-end-pumped, single-frequency Qswitched Nd:YAG laser with 1064 nm wavelength output for the laser transmitter of lidar. Injection seeding is performed by utilizing an electro-optic phase mod...

A useful method for eliminating the detrimental effect of laser frequency instability on Brillouin signals by employing the self-heterodyne detection of Rayleigh and Brillouin scattering is presented. From the analysis of Brillouin scattering spectra from fibers with different lengths measured by heterodyne detection, the maximum usable pulse width immune to laser frequency instability is obtai...

We have used a commercially available liquid-crystal spatial light modulator within a reflective optics pulse-shaping apparatus to shape ultrashort pulses with temporal resolution approaching 10 fs. Using the spatial light modulator as a phase modulator, we produce a variety of complex ultrafast waveforms, including odd pulses, high repetition rate (.23 THz) pulse trains, and asymmetric pulse t...

An analysis is presented for the transfer functions of a particular pulse-width modulator and power switch subsystem that has been widely used in practical switching-mode d-c regulator systems. The switch and filter are in a "buck" configuration, and the switch is driven by a con­ stant-frequency variable duty-ratio push-pull magnetic modulator employing square-loop cores. The two transfer func...

The wireless smart sensors have been proposed not only for high-risk and chronically ill patients but also in the healthcare field. The radio frequency(RF) transmitter is necessary to fabricate wireless smart sensors. This paper presents a proposal of the complementary metal-oxide-semiconductor(CMOS) RF transmitter using pulse width modulation(PWM) method. The major advantage of the PWM is a pe...

This paper presents a new Pulse Width Modulation (PWM) controller for Unmanned Aerial Vehicle (UAV) precision sprayer for agriculture using a TL494 fixed-frequency pulse width modulator together with a data acquisition board and developed software. An UAV can be remotely controlled or flown autonomously by pre-programmed flight plans. The PWM controller was implemented through the guidance syst...

this paper presents a novel control approach used in shunt active power filter based on variable structure control combined with random pwm technique (rvsc) that provides robust, fast, and more favorable performance for active power filter. this control strategy is compared with two other strategies to show the effectiveness of the introduced methods; pulse width modulated proportional-integral...

In this paper, a new technique for fine tuning of spacecraft autopilots based on pulse-width pulse-frequency (PWPF) modulators is presented. PWPF is one of the most commonly used approaches to control signal modulation. Its main application is found in spacecraft controllers to produce discontinuous on-off control signals for two situational actuators. The main reasons for the popularity of thi...