Topic
Pulse-frequency modulation
About: Pulse-frequency modulation is a research topic. Over the lifetime, 4151 publications have been published within this topic receiving 53039 citations. The topic is also known as: PFM.
Papers published on a yearly basis
Papers
More filters
04 Oct 2004
TL;DR: In this paper, the effects of modulating the master laser in injection-locked systems were explored, and an intrinsic conversion of master FM into slave AM was discovered, and the current theory was modified to model the frequency response for residual amplitude modulation suppression, FM efficiency, and FM-to-AM conversion.
Abstract: We explore the effects of modulating the master laser in injection-locked systems We experimentally and theoretically discovered an intrinsic conversion of master FM into slave AM We have modified the current theory to model the frequency response for residual amplitude modulation (RAM) suppression, FM efficiency, and FM-to-AM conversion
17 citations
TL;DR: In this article, a single-switched quasi-resonant flyback converter that features low switching loss and low switching noise at high switching frequency is investigated in order to realize near fully soft switching, a resonant inductor of primary side and an resonant capacitor of secondary side are utilized to recycle the transformer leakage energy and realize zero-current switching at turn off and valley switching (VS) at turn on of the primary switch.
Abstract: The demand of miniaturization of power systems has accelerated the research on high-switching-frequency power converters. A single-switched quasi-resonant flyback converter that features low switching loss and low switching noise at high switching frequency is investigated in this paper. In order to realize near fully soft switching, a resonant inductor of primary side and a resonant capacitor of secondary side are utilized to recycle the transformer leakage energy and realize zero-current switching (ZCS) at turn off and valley switching (VS) at turn on of the primary switch, and ZCS at turn off of diode. The VS is utilized based on the resonance between the resonant inductor and the equivalent switch drain capacitor. In the closed-loop control, a pulse frequency modulation mode with time fluctuation of switching period is implemented to realize VS at turn on of switch and an on – off control mode is utilized to improve the overall efficiency. Low cost, low losses, and low switching noise are all realized in the proposed prototype. The proposed concept has been validated on a 1 MHz 12 V/3 A prototype with 80 V dc input. The peak efficiency is 90.3% in the on – off mode by using GaN device without synchronous rectification.
17 citations
Patent•
22 Oct 1987TL;DR: In this paper, a tone synthesis modulation operation is performed, using this waveshape data as at least one of a signal to be modulated and a modulating signal is generated in a tone signal generated in response to the resampled signal.
Abstract: A tone generation system and method generates tone signals having complex harmonic components while reducing aliasing noise resulting from sampling of high frequency harmonics. In a first step, waveshape data which has been sampled with a second sampling frequency which is higher than a first sampling frequency is obtained. Then a predetermined tone synthesis modulation operation is performed, using this waveshape data as at least one of a signal to be modulated and a modulating signal. By performing this modulation operation in accordance with the higher second sampling frequency, occurrence of an aliasing component contained in a tone signal obtained as the output of the modulation operation in a frequency band below a frequency which is 1/2 of the first sampling frequency can be prevented. Then, the frequency band of the output signal of the modulation operation is limited to a frequency band below the frequency which is 1/2 of the first sampling frequency. By this arrangement, even if an aliasing noise component concerning the second sampling frequency occurs in a frequency region which is higher than the frequency which is 1/2 of the first sampling frequency, such aliasing noise component will be eliminated. Lastly the output signal of the third step is resampled with the first sampling frequency. In this manner, in a tone signal generated in response to the resampled signal, an aliasing component concerning the first sampling frequency becomes higher than 1/2 of the first sampling frequency so that it does not appear as the aliasing noise.
17 citations
Patent•
06 Mar 1989
TL;DR: In this paper, a continuous phase shift modulation (SPM) system is proposed, where, for each of the in-phase and quadrature components, adjacent half-cosine pulses of the same polarity are joined by a continuous transition modulation signal which maintains continuity of the waveform and at least its first derivative.
Abstract: A continuous phase shift modulation system wherein, for each of the in-phase and quadrature components, adjacent half-cosine pulses of the same polarity are joined by a continuous transition modulation signal which maintains continuity of the waveform and at least its first derivative When this occurs, the other component signal is adjusted to maintain constant the vector sum of the component signals
17 citations
TL;DR: In this article, an intra-ocular epi-retinal prosthesis device using a back-illuminated photosensor is proposed and demonstrated for the first time, based on a pulse frequency modulation, is fabricated on a transparent sapphire substrate.
Abstract: An intra-ocular epi-retinal prosthesis device using a back-illuminated photosensor is proposed and demonstrated for the first time. The photosensor, based on a pulse frequency modulation, is fabricated on a transparent sapphire substrate to detect the backside incident light. Experimental results show that the device is sensitive over a dynamic range of incident light of 30 dB.
17 citations