scholarly journals Accurate and Rigorous Calibration of Intradyne Coherent Receiver Using Polarization-Multiplexed Signal Generated within Intradyne Coherent Transmitter

2020 ◽  
Vol 10 (10) ◽  
pp. 3467
Author(s):  
Qiang Wang ◽  
Yang Yue
Keyword(s):  
Polarization Control ◽  
Calibration Signal ◽  
Innovative Technique ◽  
State Of Polarization ◽  
Active Stabilization ◽  
Constant State ◽  
Novel Method ◽  
Coherent Receivers ◽  
Coherent Receiver ◽  
Optical Transceivers

Coherent optical transceivers offer significant advantages over direct-detect optical transceivers. However, both intradyne coherent transmitters (ICT) and intradyne coherent receivers (ICR) are more complicated and require careful calibration. Traditionally, an ICR is calibrated through heterodyne beating using a single-polarized signal. Active stabilization to maintain a constant state of polarization for the calibration signal is necessary, leading to a relatively complicated setup. We demonstrate a novel method through heterodyne beating using a polarization-multiplexed signal. No polarization control is needed, resulting in a much simpler configuration. The calibration results obtained through the polarization-multiplexed signal match with the results using a single polarized signal. Moreover, this polarization-multiplexed signal can be generated within the intradyne coherent transmitter without using any external components. This innovative technique enables the calibration of a coherent receiver for deployment in the field throughout its lifetime.

Analysis of generalized principal state of polarization and the piezoelectric polarization control system

2007 ◽  
Author(s):  
Zhengyong Li ◽  
Chongqing Wu ◽  
S. S. Yang ◽  
C. Y. Tian ◽  
M. Cheng ◽  
...  
Keyword(s):  
Control System ◽  
Piezoelectric Polarization ◽  
Polarization Control ◽  
State Of Polarization

Stabilization of a cylindrical capillary bridge far beyond the Rayleigh–Plateau limit using acoustic radiation pressure and active feedback

1997 ◽  
Vol 351 ◽  
pp. 345-357 ◽  
Author(s):  
MARK J. MARR-LYON ◽  
DAVID B. THIESSEN ◽  
PHILIP L. MARSTON
Keyword(s):  
Radiation Pressure ◽  
Acoustic Radiation ◽  
Surrounding Water ◽  
Capillary Bridge ◽  
Axisymmetric Mode ◽  
Active Feedback ◽  
Active Stabilization ◽  
Novel Method ◽  
Acoustic Radiation Pressure ◽  
Plateau Limit

A novel method of suppressing the Rayleigh–Plateau capillary instability of a cylindrical liquid bridge is demonstrated which uses the radiation pressure of an ultrasonic wave to control the shape of the bridge. The shape of the bridge is optically sensed and the information used to control the spatial distribution of the radiation stress on the surface of the bridge. The feedback is phased so as to suppress the growth of the axisymmetric mode which normally becomes unstable when the slenderness, given by the length to diameter ratio, exceeds π. Stabilization is achieved out to a slenderness of 4.3 for a bridge density matched to the surrounding water bath in a Plateau tank. Breakup of such long bridges was found to produce a satellite drop from the receding thread of liquid. The active stabilization mechanism used may have application to other capillary systems.

Active Stabilization of a Two-Satellite Tether in Elliptic Orbits Using Coulomb Forces

2011 ◽  
Vol 110-116 ◽  
pp. 4537-4543
Author(s):  
Hao Zhang ◽  
Yu Shan Zhao ◽  
Peng Shi
Keyword(s):  
Feedback Control ◽  
Hybrid Control ◽  
Control Law ◽  
State Matrix ◽  
Periodic Control ◽  
Elliptic Orbits ◽  
Active Stabilization ◽  
Dynamics And Control ◽  
Constant State ◽  
And Control

This paper investigates the dynamics and control of a charged two-craft tether formation in elliptical orbit. Due to the fact that the inter-spacecraft Coulomb forces are not sufficient to stabilize the tether, a method of hybrid control is proposed which uses conventional thrusts and Coulomb forces. A feedback control law is developed which could asymptotically stabilize the tether size and attitude while mitigating plume impingement issues. The equations governing this system are periodic in time, thus a feedback control using constant gains can not work. A periodic control law is suggested basing on Floquet theory. The control law consists of two main parts. First Floquet transformation is utilized to transform the system into a new linear system with a constant state matrix but a periodic control matrix. Then a feedback control is used to stabilize the new system. Numerical examples are provided to demonstrate the performance of the control law.

scholarly journals Sensing Unsteady Pressure on MAV Wings: A New Method for Turbulence Alleviation

2014 ◽  
Vol 629 ◽  
pp. 48-54 ◽  
Author(s):  
Matthew James Marino ◽  
Simon Watkins ◽  
Roberto Sabatini ◽  
Alessandro Gardi
Keyword(s):  
Pressure Coefficient ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Mean Flow ◽  
Low Reynolds Numbers ◽  
Air Vehicle ◽  
Active Stabilization ◽  
Novel Method ◽  
The Relationship ◽  
Terminal Area

Experiments at low Reynolds numbers were performed on a pressure tapped NACA 2313 wing in a 3 x 2 x 9 meter wind tunnel under nominally smooth (Ti = 1.2%) and turbulent (Ti = 7.2%) flows at a mean flow velocity of 8ms-1(Re ≈120,000). The NACA 2313 wing is a replica of Micro Air Vehicle (MAV) wing of the Flash 3D aircraft used at RMIT University for research purposes. Unsteady surface pressures were measured to understand if the information could be adopted for resolving turbulence-induced perturbations and to furthermore use it in a turbulence mitigation system. Two span-wise locations of chord-wise pressure were acquired when tested under the two different flow conditions. It was discovered that at both span-wise locations, a local Coefficient of Pressure (Cp) held high correlation to the chord-wise Cp integration and allowed for a linear relationship to be formed between the two variables. The defined relationship provided a 95% confidence for angles of attack below stall and was used to estimate the integrated chord-wise pressure coefficient at a particular span wise location. The relationship between a single pressure tap and the integrated Cp of that chord-wise section was valid for the two different span-wise locations with similar defining equations. As one pressure tap is sufficient to adequately estimate the integrated Cp on a chord-wise wing section, a limited amount of pressure taps across the wings span approximates the pressure distribution across the span and eventually approximates the flight perturbations. Being a novel method of sensing aircraft disturbance, applications are not restricted to MAV. The methodology presented could very well be applied to larger aircraft to reduce the effects of turbulence within the terminal area and can provide other means of active stabilization.

scholarly journals Novel Method for Processing the Dynamic Calibration Signal of Pressure Sensor

Sensors ◽  
2015 ◽  
Vol 15 (7) ◽  
pp. 17748-17766 ◽  
Author(s):  
Zhongyu Wang ◽  
Qiang Li ◽  
Zhuoran Wang ◽  
Hu Yan
Keyword(s):  
Pressure Sensor ◽  
Dynamic Calibration ◽  
Calibration Signal ◽  
Novel Method

The removal and morphology of intact biofilms from implanted venous access devices

1995 ◽  
Vol 53 ◽  
pp. 1020-1021
Author(s):  
M.A. Gregory ◽  
G.P. Hadley
Keyword(s):  
Patient Selection ◽  
Surgical Oncology ◽  
Venous Access ◽  
Common Procedure ◽  
Indwelling Catheters ◽  
Careful Patient ◽  
Novel Method ◽  
The Subject ◽  
Vascular Catheters ◽  
Venous Access Devices

The insertion of implanted venous access systems for children undergoing prolonged courses of chemotherapy has become a common procedure in pediatric surgical oncology. While not permanently implanted, the devices are expected to remain functional until cure of the primary disease is assured. Despite careful patient selection and standardised insertion and access techniques, some devices fail. The most commonly encountered problems are colonisation of the device with bacteria and catheter occlusion. Both of these difficulties relate to the development of a biofilm within the port and catheter. The morphology and evolution of biofilms in indwelling vascular catheters is the subject of ongoing investigation. To date, however, such investigations have been confined to the examination of fragments of biofilm scraped or sonicated from sections of catheter. This report describes a novel method for the extraction of intact biofilms from indwelling catheters.15 children with Wilm’s tumour and who had received venous implants were studied. Catheters were removed because of infection (n=6) or electively at the end of chemotherapy.

Sign in / Sign up

Export Citation Format

Share Document