Stabilized Long-distance Superluminal Propagation Based on Polarization-matched Low-noise Brillouin Lasing Resonance

Abstract Internet of Things (IoT) based automation has provided sophisticated research and developments in the field of agriculture. In agriculture field production, using environmental and deployment sensors like DHT11, soil moisture, soil temperature, and so on, IoT has been utilised to monitor field conditions and automation in precision agriculture. The environmental parameters, field evaluation, deployment parameters, and shortage of water has become an unresolved task for agriculture monitoring. All of this leads to insufficient production of the agricultural crop. To eradicate the above-mentioned problems, we proposed a system in the using an architectural manner. This system uses an NRF24L01 module with in-built power and low noise amplifiers to enable a long-distance communication for transmission of the field information about the current crop situation to the farmers. This work is investigating an appropriate, reasonable, and applied IoT technology for precision agriculture by considering various applications of agriculture and experiments. The proposed system reduces power consumption, and improves operational efficiency. The proposed system reduces human efforts and also evaluates heat index measurement to monitor the environment. Based on the experiments, the current consumption and life expectancy of the AWMU are determined to be 0.02819 A and 3 days 20 hours 13 minutes and 47 seconds, respectively. Furthermore, the maximum transmission of AWMU is in an environmental location is 200 meters line of sight from the router.

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Design of Amplifying Circuit for Receiving Weak Signal for Laser Fuze

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.300-301.1012 ◽

2013 ◽

Vol 300-301 ◽

pp. 1012-1017

Author(s):

Bing Ting Zha ◽

He Zhang ◽

Jun Hong Wang ◽

Jing Guo

Keyword(s):

Small Volume ◽

Avalanche Photodiode ◽

High Gain ◽

Low Noise ◽

Weak Signal ◽

Echo Signal ◽

Long Distance ◽

Detection Range ◽

Simulation And Experiment ◽

Processing Circuit

The echo signal received by laser fuze was very weak when the detection range increased. In order to expand the operating range of fuze, the reception capacity of fuze for weak signal should be improved. According to the requirements of long-range laser fuze receiving system as small volume, low-power, low-noise, high-gain, the amplifying circuit of the receiving system was analyzed and designed. To improve the ability of laser fuze for detecting weak signal, the high-sensitive, low-noise, inner-gain avalanche photodiode (APD) was used as a photodetector in the system, and the low-noise preamplifier and voltage amplifying circuit was designed. The noise and frequency response of the amplifying circuit was researched and analyzed by simulation and experiment. The results show that the design is effective and feasible, which can meet the requirements of processing circuit as receiving weak signal from long-distance.

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Photodetection Technology Based on Laser Coding Emission

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.3745 ◽

2011 ◽

Vol 189-193 ◽

pp. 3745-3749 ◽

Cited By ~ 1

Author(s):

Jing Guo ◽

He Zhang ◽

Xiang Jin Zhang ◽

Xiao Feng Wang

Keyword(s):

High Sensitivity ◽

Avalanche Photodiode ◽

High Gain ◽

Low Noise ◽

High Signal ◽

Weak Signal ◽

Echo Signal ◽

Long Distance ◽

The Poor ◽

Theory And Experiment

For the extremely weak echo signal and the poor anti-interference ability of the long-distance laser fuze, the high signal noise ratio (SNR) receiving system based on laser coding mode was designed. In order to improve the weak signal receiving ability, the avalanche photodiode (APD) with high sensitivity, low noise and high gain was adopted. And the optimum multiplication factor of APD when the system obtains the highest SNR was analyzed and calculated. Then, the amplifying circuit optimum matching with APD and the decoding circuit were designed, and validated by the experiments. The theory and experiment results indicate that the design is efficiency and capable to the long distance laser fuze, the system can exactly decode the weak laser coding signals received and export the ignition signal.

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A low-noise single-photon detector for long-distance free-space quantum communication

EPJ Quantum Technology ◽

10.1140/epjqt/s40507-021-00111-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Elena Anisimova ◽

Dmitri Nikulov ◽

Simeng Simone Hu ◽

Mark Bourgon ◽

Sebastian Philipp Neumann ◽

...

Keyword(s):

Free Space ◽

Quantum Communication ◽

Detection Efficiency ◽

Single Photon ◽

Avalanche Photodiode ◽

Low Noise ◽

Photon Detector ◽

Single Photon Detector ◽

Long Distance ◽

Communication Links

AbstractWe build and test a single-photon detector based on a Si avalanche photodiode Excelitas 30902SH thermoelectrically cooled to −100∘C. Our detector has dark count rate below 1 Hz, $500\ \mu\mathrm{m}$ 500 μ m diameter photosensitive area, photon detection efficiency around 50%, afterpulsing less than 0.35%, and timing jitter under 1 ns. These characteristics make it suitable for long-distance free-space quantum communication links, which we briefly discuss. We also report an improved method that we call long-time afterpulsing analysis, used to determine and visualise long trap lifetimes at different temperatures.

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Design of Microwave LNA Based on Ladder Matching Networks for WiMAX Applications

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v6i4.9877 ◽

2016 ◽

Vol 6 (4) ◽

pp. 1717

Author(s):

Abu Bakar Ibrahim ◽

Ahmad Zamzuri Mohamad Ali

Keyword(s):

High Performance ◽

Noise Figure ◽

Low Noise ◽

Low Noise Amplifier ◽

Long Distance ◽

High Data ◽

Receiver System ◽

Noise Amplifier ◽

Increasing Demand ◽

Technology Transformation

Advancement in the wireless industry, internet access without borders and increasing demand for high data rate wireless digital communication moving us toward the optimal development of communication technology. Wireless communication is a technology that plays an important role in current technology transformation. Broadband communication is a method of telecommunication that are available for transmitting large amounts of data, voice and video over long distance using different frequencies. Specifically, Low Noise Amplifier which is located at the first block of receiver system, makes it one of the important element in improving signal transmition. This study was aimed to design a microwave Low Noise Amplifier for wireless application that will work at 5.8 GHz using high-performance low noise superHEMT transistor FHX76LP manufactured by Eudyna Technologies. The low noise amplifier (LNA) produced gain of 16.8 dB and noise figure (NF) of 1.20 dB. The input reflection (S11) and output return loss (S22) are -10.5 dB and -13.3 dB respectively. The bandwidth of the amplifier recorded is 1.2 GHz. The input sensitivity is compliant with the IEEE 802.16 standards.

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Insight into skywave theory and breakthrough applications in resource exploration

National Science Review ◽

10.1093/nsr/nwab046 ◽

2021 ◽

Author(s):

Qingyun Di ◽

Changmin Fu ◽

Guoqiang Xue ◽

Miaoyue Wang ◽

Zhiguo An ◽

...

Keyword(s):

Oil And Gas ◽

Parallel Line ◽

Low Noise ◽

Ore Deposits ◽

Guided Wave ◽

Central China ◽

Seismic Exploration ◽

Gas Reservoirs ◽

Long Distance ◽

Biyang Depression

Abstract Skywave refers to the electromagnetic wave reflected or refracted from the ionosphere and propagate in the form of a guided wave between the ionosphere and the Earth's surface. Since the skywave can propagate over large distances, it has been widely used in long-distance communication. This paper explores and demonstrates the feasibility of skywave for deep resource and energy exploration at depths up to 10 km. Theoretical and technical advancements were accomplished in furthering the skywave applications. A new solution method based on Green's function has been developed to study skywave propagation in a fully coupled lithosphere-air-ionosphere full space model. The model allows one, for the first time, to study skywave distribution characteristics in the lithosphere containing inhomogeneity such as ore deposits or oil and gas reservoirs. This model also lays a foundation for skywave data processing and interpretation. On a parallel line, we have developed a multi-channel, broadband, low-noise, portable data acquisition system suitable for receiving skywave signals. Using the skywave field excited by a high-power fixed source located in the central China, actual field surveys have been carried out in some areas in China including the Biyang depression of Henan Province. The initial results appear encouraging – The interpreted resistivity models prove to be consistent with those of seismic exploration and known geological information, and the exploration cost is only about 1/4 to 1/10 of seismic surveys. These initial successful applications of the skywave theory lay a solid foundation for further verification of the new method.

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Экспериментальные исследования возможности регистрации шумоизлучения морского объекта в неблагоприятных гидрологических условиях при использовании адаптивной фильтрации помех

MORSKIE INTELLEKTUAL`NYE TEHNOLOGII ◽

10.37220/mit.2020.47.1.065 ◽

2020 ◽

Author(s):

R.V. Viktorov ◽

M.V. Dyagilev ◽

A.V. Krupenkov

Keyword(s):

Kalman Filter ◽

Detection System ◽

Experimental Studies ◽

Low Noise ◽

Noise Emission ◽

Adaptive Kalman Filter ◽

Long Distance ◽

Signal Noise ◽

Adverse Conditions ◽

Underwater Object

В настоящее время при всплытии подводного объекта, особенно в неблагоприятных гидрологоакустических условиях не обеспечивается его безопасность от столкновения с морскими целями. Показано, что для решения этой проблемы возможно применение в типовом тракте гидроакустической системы обнаружения использование линейного фильтра Калмана. Представлены результаты имитационного моделирования показывающие принципиальную возможность регистрации малошумных объектов в неблагоприятных условиях, при обеспечении всплытия подводного объекта. Приведены результаты морских экспериментальных исследований, которые показывают, что применение в гидроакустическом тракте обнаружения линейного фильтра Калмана позволяет подавить фоновую помеху моря, гидродинамические шумы и шумы дальнего судоходства на приемном устройстве и выделить сигналы шумоизлучения морского объекта при низких входных отношениях сигнал/помеха. Показано, что применение в тракте обработки адаптивного фильтра Калмана позволяет повысить выходное отношение сигнал/помеха, а также существенно увеличить время наблюдения за надводным объектом.For the ascent of the underwater object, especially in adverse conditions gidroakusticheskikh not ensured his safety from collision with the sea objectives. It is shown that to solve this problem it is possible to use a linear Kalman filter in a typical path of a hydroacoustic detection system. The results of simulation showing the principal possibility of registration of low-noise objects in adverse conditions, while ensuring the surfacing of an underwater object. The results of marine experimental studies, which show that the use of a linear Kalman filter in the sonar detection path allows to suppress background noise of the sea, hydrodynamic noise and noise of long-distance navigation at the receiver and to highlight the noise emission signals of the marine object at low input signal/noise ratios, are presented. It is shown that the use of an adaptive Kalman filter in the processing path can increase the output signal / noise ratio, as well as significantly increase the time of observation of the surface object.

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Simulation of multi-rotor powered urban aerial mobility noise for environmental assessment

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-2541 ◽

2021 ◽

Vol 263 (3) ◽

pp. 3854-3860

Author(s):

Qichen Tan ◽

Haoyu Bian ◽

Siyang Zhong ◽

Xin Zhang

Keyword(s):

High Performance ◽

Prediction Models ◽

Atmospheric Condition ◽

Human Perception ◽

Low Noise ◽

Noise Sources ◽

Long Distance ◽

Noise Impact ◽

User Friendly ◽

High Performance Computers

The operation of the rapidly growing unmanned aerial vehicles (UAV) and the promising urban aerial mobility (UAM) could have a significant noise impact on the environment. In this work, we developed a cloud-based noise simulator to efficiently assess the environmental impact of UAM and UAV. The noise sources and long-distance propagation are computed by the propeller noise prediction models and an advanced Gaussian beam tracing method, respectively, in local high-performance computers. Users can define the working conditions and vehicle layer through a platform with a user-friendly graphical interface. In addition, the noise level distribution at the observers of interest such as the buildings can be visualized. By employing advanced interpolation methods or autonomous learning algorithms, the computations are efficiently accelerated such that the noise distributions are simultaneously displayed during flights of the vehicles. To better measure the noise impact on human perception, various noise metrics will be output for further analysis. By conducting the virtual flights using the simulator, the noise impact in each flight state and atmospheric condition of different vehicles can be predicted, which will then facilitate the low-noise flights for both UAV and UAM.

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A Hybrid and Efficient Low-noise assessment Platform for Urban aerial mobility (HELPU)

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-2509 ◽

2021 ◽

Vol 263 (3) ◽

pp. 3756-3768

Author(s):

Siyang Zhong ◽

Peng Zhou ◽

Yi Fang ◽

Xin Zhang

Keyword(s):

Prediction Models ◽

Noise Pollution ◽

Control Device ◽

Low Noise ◽

Long Distance ◽

Flight Planning ◽

High Efficient ◽

Noise Assessment ◽

Complex Boundary ◽

The Impact

Urban aerial mobility (UAM) is a promising approach to improve the traffic situation in gigantic cities, which, however, may encounter significant noise pollution issues. An integrated research platform, which is being established at HKUST, to include noise generation, long-distance propagation, and perception at the observers is timely to assess the environmental impact of UAM noise and to develop low-noise designs and flight planning. A high-quality test rig in the anechoic aerodynamic facility at HKUST is employed to measure the propeller aeroacoustics and aerodynamics, and to enable the innovative noise control device and design studies. The measurements and high-fidelity simulations using an in-house computational aeroacoustics solver can lead to comprehensive databases to facilitate and validate the development of physics-oriented noise prediction models. Also, high-efficient implementation of the boundary element method is conducted to account for the noise scattering due to the fuselage and then to evaluate the impact of UAM layout on the directivity patterns, which will then be efficiently projected to the far-field observers using the advanced Gaussian beam tracing with the effects due to moving source, atmospheric attenuation, and refraction, complex boundary absorption and reflection incorporated. Low-noise flight planning is then be made accordingly.

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Experimental quantum conference key agreement

Science Advances ◽

10.1126/sciadv.abe0395 ◽

2021 ◽

Vol 7 (23) ◽

pp. eabe0395

Author(s):

Massimiliano Proietti ◽

Joseph Ho ◽

Federico Grasselli ◽

Peter Barrow ◽

Mehul Malik ◽

...

Keyword(s):

Secure Communication ◽

Key Agreement ◽

Quantum Communication ◽

Quantum Information Processing ◽

Global Scale ◽

Low Noise ◽

Long Distance ◽

Quantum Networks ◽

High Brightness ◽

Ghz States

Quantum networks will provide multinode entanglement enabling secure communication on a global scale. Traditional quantum communication protocols consume pair-wise entanglement, which is suboptimal for distributed tasks involving more than two users. Here, we demonstrate quantum conference key agreement, a cryptography protocol leveraging multipartite entanglement to efficiently create identical keys between N users with up to N-1 rate advantage in constrained networks. We distribute four-photon Greenberger-Horne-Zeilinger (GHZ) states, generated by high-brightness telecom photon-pair sources, over optical fiber with combined lengths of up to 50 km and then perform multiuser error correction and privacy amplification. Under finite-key analysis, we establish 1.5 × 106 bits of secure key, which are used to encrypt and securely share an image between four users in a conference transmission. Our work highlights a previously unexplored protocol tailored for multinode networks leveraging low-noise, long-distance transmission of GHZ states that will pave the way for future multiparty quantum information processing applications.

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