Microwave photonics(MWP)represents a significant optical signal processing system,standing at the confluence of microwave engineering and photonics.It presents a promising way for meeting the growing demands of contem...Microwave photonics(MWP)represents a significant optical signal processing system,standing at the confluence of microwave engineering and photonics.It presents a promising way for meeting the growing demands of contemporary communication systems,radar,sensing,and signal processing.Driving the rapid advancement of MWP are pivotal technologies such as optical frequency combs,photonic integrated circuits,and advanced modulation formats.The integration of photonic integrated circuit technology with hybrid integration techniques holds the promise of realizing MWP systems on a single chip,while comb shaping technology endows MWP systems with programmable and reconfigurable capabilities.In this paper,we present a review of our recent research,which focused on exploring the full spectrum of potential applications for quantum dash lasers in MWP systems.Leveraging principles of finite impulse response filters,our MWP system not only facilitates conventional filtering but also enables instantaneous frequency measurement and waveform generation.A distinguishing feature of MWP filters is their uniform delay.After converting it into a uniform phase difference,it underpins the development of MWP-based phase antenna array systems.Furthermore,this uniform delay finds application in time-interleaved photonic analog-to-digital conversion.展开更多
The stability criteria of any fin-stabilized flying object are a decisive metric in evaluating its overall performance and results in mission success.Flight stability depends on many parameters such as body configurat...The stability criteria of any fin-stabilized flying object are a decisive metric in evaluating its overall performance and results in mission success.Flight stability depends on many parameters such as body configuration,the center of gravity location,atmospheric conditions,and flight manoeuvres.These manoeuvres are needed for better target interception especially for moving targets located at short ranges,resulting in high frequencies either in pitch or yaw directions.This study examines the impact of body pitch frequency on the stability of a supersonic fin-stabilized object.Time-dependent numerical simulations are implemented to model the unsteady flow field induced by a simple harmonic motion in the case study missile.The missile’s tail section dominates the lift force generated compared to the forebody,resulting in a downstream shift of the missile’s center of pressure and,consequently,an increase in the static stability margin as the pitching frequency increases.However,pitch-damp aerodynamic derivatives remain unchanged at various pitching frequencies,indicating frequency independence.The validity of the results is confirmed compared with wind tunnel data.展开更多
基金supported by the National Research Council Canada(Grant Nos.HTSN-206 and HTSN-245)by the Natural Sciences and Engineering Research Council of Canada.
文摘Microwave photonics(MWP)represents a significant optical signal processing system,standing at the confluence of microwave engineering and photonics.It presents a promising way for meeting the growing demands of contemporary communication systems,radar,sensing,and signal processing.Driving the rapid advancement of MWP are pivotal technologies such as optical frequency combs,photonic integrated circuits,and advanced modulation formats.The integration of photonic integrated circuit technology with hybrid integration techniques holds the promise of realizing MWP systems on a single chip,while comb shaping technology endows MWP systems with programmable and reconfigurable capabilities.In this paper,we present a review of our recent research,which focused on exploring the full spectrum of potential applications for quantum dash lasers in MWP systems.Leveraging principles of finite impulse response filters,our MWP system not only facilitates conventional filtering but also enables instantaneous frequency measurement and waveform generation.A distinguishing feature of MWP filters is their uniform delay.After converting it into a uniform phase difference,it underpins the development of MWP-based phase antenna array systems.Furthermore,this uniform delay finds application in time-interleaved photonic analog-to-digital conversion.
文摘The stability criteria of any fin-stabilized flying object are a decisive metric in evaluating its overall performance and results in mission success.Flight stability depends on many parameters such as body configuration,the center of gravity location,atmospheric conditions,and flight manoeuvres.These manoeuvres are needed for better target interception especially for moving targets located at short ranges,resulting in high frequencies either in pitch or yaw directions.This study examines the impact of body pitch frequency on the stability of a supersonic fin-stabilized object.Time-dependent numerical simulations are implemented to model the unsteady flow field induced by a simple harmonic motion in the case study missile.The missile’s tail section dominates the lift force generated compared to the forebody,resulting in a downstream shift of the missile’s center of pressure and,consequently,an increase in the static stability margin as the pitching frequency increases.However,pitch-damp aerodynamic derivatives remain unchanged at various pitching frequencies,indicating frequency independence.The validity of the results is confirmed compared with wind tunnel data.
