The Use of Injection Locked Magnetrons as a Source Microwave Processing Applications

MRS Proceedings ◽

10.1557/proc-347-119 ◽

1994 ◽

Vol 347 ◽

Cited By ~ 4

Author(s):

Chris M. Walker

Keyword(s):

Low Cost ◽

Cooling Water ◽

Low Frequency ◽

Cost Driver ◽

System A ◽

Order Of Magnitude ◽

Radar Applications ◽

L Band ◽

Tube Life ◽

Ku Band

ABSTRACTThe Injection Locked Magnetron (ILM) has been used as a source of coherent power in a number of radar systems. It has a number of characteristics that make it particularly suitable to heating applications, above competing tube types used in radar applications.Power available is dependent upon the frequency of operation, ranging from several hundred watts at Ku-band to tens of kilowatts at L-band. Operation could be either cw or pulsed, but at higher power levels pulsed operation would be required. Designs for tubes at 1 GHz and 15 GHz will be presented.ILMs could be made at any frequency from 800 MHz to 20 GHz, beyond which the magnetron becomes either too large to be practical or too small to fabricate. Locking bandwidths are typically 0.5%, sufficient to be able to guarantee the tube remains locked at the required operating frequency. A tuner would increase the tube life and compensate for frequency drift effects.The tube life is dependent on the desired frequency of operation, ranging from several hundred hours at high frequency to an order of magnitude higher at low frequency. Adding a tuner will increase this several fold. ILMs are inherently rugged and may be run in any orientation, having been developed for airborne radar applications. Tubes are operated directly into a circulator and consequently can operate into high VSWR.The magnetron is a low cost tube, hence its use in domestic microwave ovens. ELMs have a similar part count and complexity. Efficiency varies from approximately 45% in Ku-band to 80% at L-band. Operating voltages are lower for ILMs than other vacuum tubes, at 1 GHz a 100 kW system would require 20 kV and for a 15 GHz 200 watt system, a 2 kV power supply would be required. These would run in the region of 10% duty cycle, 1 kHz PRF. Tubes would have integral rare earth magnets and require cooling water. The required quantity of tubes would be the most significant cost driver.

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A 2×2 Antenna Array for L Band Phased Array RADAR Applications

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a1017.1291s52019 ◽

2019 ◽

Vol 9 (1S5) ◽

pp. 62-65

Keyword(s):

Antenna Array ◽

Input Signal ◽

Phased Array ◽

Dielectric Material ◽

Low Cost ◽

Operating Frequency ◽

Phase Array ◽

Phased Array Radar ◽

Radar Applications ◽

L Band

A Four element antenna array for the Phase array RADAR applications in the L Band with an operating frequency of 1.32GHz is presented. The four patches are been connected to four different transmitter circuit with which we can control the phase of the input signal. The antenna is having a size of 212mm×212mm×1.6mm with a gain of 8.78dB and directivity of 10.31dB at the operating frequency of 1.32GHz.. Low cost FR4 material is been used as the laminate base for the antenna which will act as the dielectric material.

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Studies of calcium-45 desaturation from kidney slices in flow-through chambers

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1978.234.1.r34 ◽

1978 ◽

Vol 234 (1) ◽

pp. R34-R38

Author(s):

T. Uchikawa ◽

A. B. Borle

Keyword(s):

Kinetic Parameters ◽

Rat Kidney ◽

Kidney Cells ◽

Tissue Slices ◽

Kidney Slices ◽

System A ◽

Order Of Magnitude ◽

Exponential Equations ◽

Flow Through ◽

Best Fit

This paper describes a method to measure calcium fluxes and calcium exchangeable pools in tissue slices by continuous perifusion in flow-through chambers. 45Ca desaturation from rat kidney slices can be analyzed as in an open three-compartment catenary system. A set of equations is given to calculate all the relevant kinetic parameters from the triple exponential equations which best fit the desaturation curves. The results show that the kinetic parameters obtained in kidney slices by this new method are in the same order of magnitude as those previously observed in cultured monkey kidney cells.

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A 40 Mb/s VLC System Reusing an Existing Large LED Panel in an Indoor Office Environment

Sensors ◽

10.3390/s21051697 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1697

Author(s):

Xicong Li ◽

Zabih Ghassemlooy ◽

Stanislav Zvánovec ◽

Paul Anthony Haigh

Keyword(s):

Modulation Depth ◽

Light Emitting Diode ◽

Low Cost ◽

Data Communication ◽

Experimental System ◽

Digital Signal ◽

Visible Light Communication ◽

Cost Driver ◽

Limiting Factors ◽

Light Sources

With advances in solid-state lighting, visible light communication (VLC) has emerged as a promising technology to enhance existing light-emitting diode (LED)-based lighting infrastructure by adding data communication capabilities to the illumination functionality. The last decade has witnessed the evolution of the VLC concept through global standardisation and product launches. Deploying VLC systems typically requires replacing existing light sources with new luminaires that are equipped with data communication functionality. To save the investment, it is clearly desirable to make the most of the existing illumination systems. This paper investigates the feasibility of adding data communication functionality to the existing lighting infrastructure. We do this by designing an experimental system in an indoor environment based on an off-the-shelf LED panel typically used in office environments, with the dimensions of 60 × 60 cm2. With minor modifications, the VLC function is implemented, and all of the modules of the LED panel are fully reused. A data rate of 40 Mb/s is supported at a distance of up to 2 m while using the multi-band carrierless amplitude and phase (CAP) modulation. Two main limiting factors for achieving higher data rates are observed. The first factor is the limited bandwidth of the LED string inside the panel. The second is the flicker due to the residual ripple of the bias current that is generated by the panel’s driver. Flicker is introduced by the low-cost driver, which provides bias currents that fluctuate in the low frequency range (less than several kilohertz). This significantly reduces the transmitter’s modulation depth. Concurrently, the driver can also introduce an effect that is similar to baseline wander at the receiver if the flicker is not completely filtered out. We also proposed a solution based on digital signal processing (DSP) to mitigate the flicker issue at the receiver side and its effectiveness has been confirmed.

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CrossGR

Proceedings of the ACM on Interactive Mobile Wearable and Ubiquitous Technologies ◽

10.1145/3448100 ◽

2021 ◽

Vol 5 (1) ◽

pp. 1-23

Author(s):

Xinyi Li ◽

Liqiong Chang ◽

Fangfang Song ◽

Ju Wang ◽

Xiaojiang Chen ◽

...

Keyword(s):

Gesture Recognition ◽

Low Cost ◽

User Involvement ◽

Recognition System ◽

Training Data ◽

Generative Adversarial Network ◽

Adversarial Network ◽

Target User ◽

Order Of Magnitude ◽

Training Examples

This paper focuses on a fundamental question in Wi-Fi-based gesture recognition: "Can we use the knowledge learned from some users to perform gesture recognition for others?". This problem is also known as cross-target recognition. It arises in many practical deployments of Wi-Fi-based gesture recognition where it is prohibitively expensive to collect training data from every single user. We present CrossGR, a low-cost cross-target gesture recognition system. As a departure from existing approaches, CrossGR does not require prior knowledge (such as who is currently performing a gesture) of the target user. Instead, CrossGR employs a deep neural network to extract user-agnostic but gesture-related Wi-Fi signal characteristics to perform gesture recognition. To provide sufficient training data to build an effective deep learning model, CrossGR employs a generative adversarial network to automatically generate many synthetic training data from a small set of real-world examples collected from a small number of users. Such a strategy allows CrossGR to minimize the user involvement and the associated cost in collecting training examples for building an accurate gesture recognition system. We evaluate CrossGR by applying it to perform gesture recognition across 10 users and 15 gestures. Experimental results show that CrossGR achieves an accuracy of over 82.6% (up to 99.75%). We demonstrate that CrossGR delivers comparable recognition accuracy, but uses an order of magnitude less training samples collected from the end-users when compared to state-of-the-art recognition systems.

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High-Gain Vivaldi Antenna with Wide Bandwidth Characteristics for 5G Mobile and Ku-Band Radar Applications

Electronics ◽

10.3390/electronics10060667 ◽

2021 ◽

Vol 10 (6) ◽

pp. 667

Author(s):

Raza Ullah ◽

Sadiq Ullah ◽

Farooq Faisal ◽

Rizwan Ullah ◽

Dong-you Choi ◽

...

Keyword(s):

Mobile Communication ◽

Middle Layer ◽

Bottom Layer ◽

High Gain ◽

Mirror Image ◽

Radar Applications ◽

Vivaldi Antenna ◽

5G Mobile Communication ◽

Element Array ◽

Ku Band

In this paper, antipodal Vivaldi antenna is designed for 5th generation (5G) mobile communication and Ku-band applications. The proposed designed has three layers. The upper layer consists of eight-element array of split-shaped leaf structures, which is fed by a 1-to-8 power divider network. Middle layer is a substrate made of Rogers 5880. The bottom layer consists of truncated ground and shorter mirror-image split leaf structures. The overall size of the designed antenna is confined significantly to 33.31 × 54.96 × 0.787 (volume in mm3), which is equivalent to 2λo× 3.3λo× 0.05λo (λo is free-space wavelength at 18 GHz). Proposed eight elements antenna is multi-band in nature covering Ku-bands (14.44–20.98 GHz), two millimeter wave (mmW) bands i.e., 24.34–29 GHz and 33–40 GHz, which are candidate frequency bands for 5G communications. The Ku-Band is suitable for radar applications. Proposed eight elements antenna is very efficient and has stable gain for 5G mobile communication and Ku-band applications. The simulation results are experimentally validated by testing the fabricated prototypes of the proposed design.

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Patients in intensive care unit for COVID-19 pneumonia: the lung ultrasound patterns at admission and discharge. An observational pilot study

The Ultrasound Journal ◽

10.1186/s13089-021-00213-x ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Persona Paolo ◽

Valeri Ilaria ◽

Zarantonello Francesco ◽

Forin Edoardo ◽

Sella Nicolò ◽

...

Keyword(s):

Intensive Care ◽

Lung Ultrasound ◽

Low Cost ◽

Low Frequency ◽

Specific Pattern ◽

University Hospital ◽

Left Hemithorax ◽

Significant Difference ◽

The Right ◽

B Lines

Abstract Background During COVID-19 pandemic, optimization of the diagnostic resources is essential. Lung Ultrasound (LUS) is a rapid, easy-to-perform, low cost tool which allows bedside investigation of patients with COVID-19 pneumonia. We aimed to investigate the typical ultrasound patterns of COVID-19 pneumonia and their evolution at different stages of the disease. Methods We performed LUS in twenty-eight consecutive COVID-19 patients at both admission to and discharge from one of the Padua University Hospital Intensive Care Units (ICU). LUS was performed using a low frequency probe on six different areas per each hemithorax. A specific pattern for each area was assigned, depending on the prevalence of A-lines (A), non-coalescent B-lines (B1), coalescent B-lines (B2), consolidations (C). A LUS score (LUSS) was calculated after assigning to each area a defined pattern. Results Out of 28 patients, 18 survived, were stabilized and then referred to other units. The prevalence of C pattern was 58.9% on admission and 61.3% at discharge. Type B2 (19.3%) and B1 (6.5%) patterns were found in 25.8% of the videos recorded on admission and 27.1% (17.3% B2; 9.8% B1) on discharge. The A pattern was prevalent in the anterosuperior regions and was present in 15.2% of videos on admission and 11.6% at discharge. The median LUSS on admission was 27.5 [21–32.25], while on discharge was 31 [17.5–32.75] and 30.5 [27–32.75] in respectively survived and non-survived patients. On admission the median LUSS was equally distributed on the right hemithorax (13; 10.75–16) and the left hemithorax (15; 10.75–17). Conclusions LUS collected in COVID-19 patients with acute respiratory failure at ICU admission and discharge appears to be characterized by predominantly lateral and posterior non-translobar C pattern and B2 pattern. The calculated LUSS remained elevated at discharge without significant difference from admission in both groups of survived and non-survived patients.

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The Research into the Key Problem of Multi-Channel Video Acquisition and Display System Based on FPGA

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.433-440.5611 ◽

2012 ◽

Vol 433-440 ◽

pp. 5611-5615

Author(s):

Jian Sheng Hu

Keyword(s):

Power Consumption ◽

Low Cost ◽

Time Sequence ◽

Good Effect ◽

Low Power Consumption ◽

Display System ◽

Reading And Writing ◽

Video Acquisition ◽

System A ◽

Time Division

Aimed at the problem of the embedded multi-channel video acquisition and display system, a new one based on FPGA is put forward. The configuration of the system is given. The principle and key issue is analyzed. Using of the state shift mechanism, t the controlling time sequence signals of TFT-LCD are produced; The synchronization among multi-channel video acquisition is realized by using time-division multiplexing technology; The problem of conflict between reading and writing frame cache is solved through the two SRAM switch; The frames composition technology is applied to accomplish the change from interlaced scanning to progressive scanning. The result of project application shows the virtues of system, such as good effect of acquisition and display, low cost and low power consumption.

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