Surface Micromachined Dielectrophoretic Gates for the Front-End Device of a Biodetection System

2005 ◽  
Vol 128 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Conrad D. James ◽  
Murat Okandan ◽  
Paul Galambos ◽  
Seethambal S. Mani ◽  
Dawn Bennett ◽  
...  
Keyword(s):  
Phase Separation ◽  
Radio Frequency ◽  
Fluorescent Labeling ◽  
Frequency Range ◽  
Flowing Fluid ◽  
Separation Device ◽  
Air Samples ◽  
Biological Particles ◽  
Front End ◽  
Biological Analytes

We present a novel separation device for the front-end of a biodetection system to discriminate between biological and non-biological analytes captured in air samples. By combining AC dielectrophoresis along the flow streamlines and a field-induced phase-separation, the device utilizes “dielectrophoretic gating”to separate analytes suspended in a flowing fluid based on their intrinsic polarizability properties. The gates are integrated into batch fabricated self-sealed surface-micromachined fluid channels. We demonstrate that setting the gate to a moderate voltage in the radio frequency range removed bacteria cells from a mixture containing non-biological particles without the need for fluorescent labeling or antibody-antigen hybridization, and also validate experimentally basic relations for estimating the gate performance.

Design of Control System for Hydraulically Vibrated Processing Tomato Fruit Seedling Separation Device

2014 ◽  
Vol 651-653 ◽  
pp. 693-696
Author(s):  
Li Hong Wang ◽  
Rong Qing Liang ◽  
Cheng Song Li ◽  
Za Kan ◽  
Jin Wei Qin
Keyword(s):  
Tomato Fruit ◽  
Simulation Software ◽  
Signal Frequency ◽  
System Control ◽  
Frequency Range ◽  
Hydraulic Simulation ◽  
Separation Device ◽  
Processing Tomato ◽  
Input Signal Frequency ◽  
Set Up

Eccentric style processing tomato fruit seeding separation device exist high machining and assembly precision or other issues. In order to solve this problem, the mode of vibration of hydraulic replaced the eccentric style to drive the fruit seedling separation roller to separate processing tomato effectively. To facilitate adjustment of the hydraulic system, a kind of control circuit PLC as the core was designed according to the actual production requirements. PLC and other elements were selected. The system control signal frequency was initially set up as 1~5 HZ, within the frequency range hydraulic simulation software was used to simulate and analyze the hydraulic vibration system. The result shows that the system rams steady when the input signal frequency range was 1~5HZ.

scholarly journals Design of a Multiband Global Navigation Satellite System Radio Frequency Interference Monitoring Front-End with Synchronized Secondary Sensors

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2594
Author(s):  
Aiden Morrison ◽  
Nadezda Sokolova ◽  
James Curran
Keyword(s):  
Radio Frequency ◽  
Global Navigation Satellite System ◽  
Low Cost ◽  
Satellite System ◽  
Radio Frequency Interference ◽  
Navigation Satellite ◽  
Inertial Measurement ◽  
Front End ◽  
Global Navigation ◽  
Global Navigation Satellite

This paper investigates the challenges of developing a multi-frequency radio frequency interference (RFI) monitoring and characterization system that is optimized for ease of deployment and operation as well as low per unit cost. To achieve this, we explore the design and development of a multiband global navigation satellite system (GNSS) front-end which is intrinsically capable of synchronizing side channel information from non-RF sensors, such as inertial measurement units and integrated power meters, to allow the simultaneous production of substantial amounts of sampled spectrum while also allowing low-cost, real-time monitoring and logging of detected RFI events. While the inertial measurement unit and barometer are not used in the RFI investigation discussed, the design features that provide for their precise synchronization with the RF sample stream are presented as design elements worth consideration. The designed system, referred to as Four Independent Tuners with Data-packing (FITWD), was utilized in a data collection campaign over multiple European and Scandinavian countries in support of the determination of the relative occurrence rates of L1/E1 and L5/E5a interference events and intensities where it proved itself a successful alternative to larger and more expensive commercial solutions. The dual conclusions reached were that it was possible to develop a compact low-cost, multi-channel radio frequency (RF) front-end that implicitly supported external data source synchronization, and that such monitoring systems or similar capabilities integrated within receivers are likely to be needed in the future due to the increasing occurrence rates of GNSS RFI events.

Radio Observations of Two Large Solar Disturbances

1951 ◽  
Vol 4 (1) ◽  
pp. 51
Author(s):  
JV Hindman ◽  
AG Little ◽  
R Payne-Scott ◽  
DE Yabsley ◽  
CW Allen
Keyword(s):  
Radio Frequency ◽  
Solar Flares ◽  
Radio Frequency Power ◽  
Frequency Range ◽  
Power Flux ◽  
Apparent Position ◽  
Radio Receivers ◽  
Solar Origin ◽  
Solar Disturbances ◽  
Frequency Power

On February 17 and 21-22, 1950, two exceptionally large radio-frequency disturbances of solar origin were observed on seven radio receivers working in the frequency range from 62 to 9400 Mc/s. At each of the frequencies the radio-frequency power flux was recorded continuously during the disturbance and at several frequencies the polarization of the radiation was examined. The apparent position of the origin of the radiation was determined at one frequency. The time of commencement and the duration of the disturbances at the different frequencies were compared with each other and with those of associated phenomena, solar flares, radio fade-outs, and geomagnetic effects. The two disturbances show marked similarities and marked differences ; these are summarized.

scholarly journals Radio-frequency interference mitigating hyperspectral L-band radiometer

2017 ◽  
Vol 6 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Peter Toose ◽  
Alexandre Roy ◽  
Frederick Solheim ◽  
Chris Derksen ◽  
Tom Watts ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Thermal Emission ◽  
Absolute Error ◽  
Radio Frequency Interference ◽  
Frequency Range ◽  
Passive Remote Sensing ◽  
Extended Frequency ◽  
L Band ◽  
Radiometric Signal ◽  
Microwave Radiometers

Abstract. Radio-frequency interference (RFI) can significantly contaminate the measured radiometric signal of current spaceborne L-band passive microwave radiometers. These spaceborne radiometers operate within the protected passive remote sensing and radio-astronomy frequency allocation of 1400–1427 MHz but nonetheless are still subjected to frequent RFI intrusions. We present a unique surface-based and airborne hyperspectral 385 channel, dual polarization, L-band Fourier transform, RFI-detecting radiometer designed with a frequency range from 1400 through  ≈  1550 MHz. The extended frequency range was intended to increase the likelihood of detecting adjacent RFI-free channels to increase the signal, and therefore the thermal resolution, of the radiometer instrument. The external instrument calibration uses three targets (sky, ambient, and warm), and validation from independent stability measurements shows a mean absolute error (MAE) of 1.0 K for ambient and warm targets and 1.5 K for sky. A simple but effective RFI removal method which exploits the large number of frequency channels is also described. This method separates the desired thermal emission from RFI intrusions and was evaluated with synthetic microwave spectra generated using a Monte Carlo approach and validated with surface-based and airborne experimental measurements.

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