Evaluation Of High-Gain Optical Processors For LPI Surveillance And Communications Systems

1977 ◽  
Author(s):  
David W. Walsh
Keyword(s):  
High Gain ◽  
Communications Systems

scholarly journals Design and Fabrication of a Printed Tri-Band Antenna for 5G Applications Operating Across Ka-, and V-Band Spectrums

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2674
Author(s):  
Musa Hussain ◽  
Syed Muhammad Rizvi Jarchavi ◽  
Syeda Iffat Naqvi ◽  
Usama Gulzar ◽  
Salahuddin Khan ◽  
...  
Keyword(s):  
Patch Antenna ◽  
State Of The Art ◽  
High Gain ◽  
Potential Candidate ◽  
Operational Mode ◽  
Multiple Frequency ◽  
Wide Bandwidth ◽  
V Band ◽  
Communications Systems ◽  
Compact Size

In this paper, an umbrella-shaped patch antenna for future millimeter-wave applications for the 5G frequency band is presented. The proposed antenna resonates at multiple frequency bands, i.e., 28 GHz, 38 GHz, and 55 GHz (V-band) that have been globally allocated for 5G communications systems. The proposed antenna is designed using Rogers RT/duroid 5870, with a relative permittivity, loss tangent and thickness of 2.33 mm, 0.0012 mm and 0.79 mm, respectively. The antenna has an overall size of 8 mm × 8 mm which correspond to 0.7 λ × 0.7 λ, where λ is free space wavelength at the lowest resonance. Moreover, the wide bandwidth, high gain and tri band operational mode is achieved by introducing two stubs to the initial design. The antenna prototype was fabricated and validated experimentally. The comparison of the simulated and measured results demonstrates a good correlation. Additionally, the comparative analysis with state of the art work demonstrates that the proposed antenna offers compact size, simple geometrical configuration, wide bandwidth, high gain, and radiation efficiency which makes the proposed antenna a potential candidate for compact smart 5G devices.

scholarly journals A design of lens antenna with high gain

2021 ◽  
Vol 336 ◽  
pp. 01005
Author(s):  
Darong Gao
Keyword(s):  
Wireless Communications ◽  
Microstrip Antenna ◽  
Return Loss ◽  
High Gain ◽  
Impedance Bandwidth ◽  
Lens Antenna ◽  
Communications Systems ◽  
Dielectric Lens ◽  
Wireless Communications Systems ◽  
Peak Gain

In this paper, A lens antenna with high gain is proposed. The antenna is composed of the microstrip antenna and the hemisphere dielectric lens, and the lens is loaded on the top. The polyethylene is used to fabricated the hemisphere dielectric lens. The antenna has dimensions of 47.58 mm × 47.58 mm × 24.79 mm, which is corresponding to the electrical size of 1.586λ0×1.586λ0×0.826λ0, where λ0 is the free-space wavelength at 10GHz. The impedance bandwidth (return loss<-10dB) is 12.7%(9.24 GHz-10.51 GHz), and the peak gain is 9.06 dBi. The hemisphere dielectric lens can improve the gain of the microstrip antenna. The proposed lens antenna is suitable for wireless communications systems.

A simple method to simultaneously increase the gain and bandwidth of wearable antennas for application in medical/communications systems

2020 ◽  
pp. 1-7 ◽  
Author(s):  
Farzad Khajeh-Khalili ◽  
Ali Shahriari ◽  
Fatemeh Haghshenas
Keyword(s):  
Transmission Lines ◽  
Efficient Method ◽  
High Gain ◽  
Dual Band ◽  
Medical Systems ◽  
Simple Method ◽  
High Gain Antenna ◽  
Wearable Antennas ◽  
Communications Systems ◽  
Simulation Results

Abstract In this paper, a simple and efficient method to increase the gain and bandwidth of the wearable antennas used in several medical/communications systems is presented. To increase the gain and bandwidth simultaneously, the triple transmission lines (TTLs) method has been used. With this method, the frequency ranges of 1.7–2.5 and 5.4–5.95 GHz are covered with dual-band responses. Also, the simulated maximum gain at 2 and 5.8 GHz is equal to 8.26 and 9.86 dB, respectively. Using the TTLs method, the second frequency band (5.4–5.95 GHz) is achieved. Also, the gain improvement in operating frequencies is more than 4 dB compared to the conventional antenna. The dimensions of the proposed wearable high-gain antenna are 80 × 92 × 2 mm3 or 0.57 × 0.67 × 0.01 λg3 at 2 GHz. Finally, a dual-band sample antenna for use in medical systems was fabricated with a flexible felt substrate and its characteristics were measured. There is a good fit between the measurement and simulation results.

Effect of energy filtering on micro-diffraction in the SEM

1994 ◽  
Vol 52 ◽  
pp. 604-605
Author(s):  
James F. Mancuso ◽  
Leo A. Fama ◽  
William B. Maxwell ◽  
Jerry L. Lehman ◽  
Hasso Weiland ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Ccd Camera ◽  
High Gain ◽  
Microchannel Plate ◽  
Electrostatic Energy ◽  
Energy Filtering ◽  
Electron Channelling ◽  
Low Energy Electrons ◽  
Low Sensitivity ◽  
Angular Field Of View

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.

Equivalent Noise Dose Obtained Through Hearing Aids in the Classrooms of Hearing-Impaired Children

1990 ◽  
Vol 21 (3) ◽  
pp. 147-150
Author(s):  
Ronald A. Wilde
Keyword(s):  
Hearing Aids ◽  
High Gain ◽  
Hearing Impaired ◽  
Deaf Children ◽  
Impaired Children ◽  
Very High ◽  
Hearing Impaired Children

A commercial noise dose meter was used to estimate the equivalent noise dose received through high-gain hearing aids worn in a school for deaf children. There were no significant differences among nominal SSPL settings and all SSPL settings produced very high equivalent noise doses, although these are within the parameters of previous projections.

EXPERIENCES, FRUSTRATIONS, AND BARRIERS, OF IPAD USAGE IN THE SPECIAL EDUCATION: LIFE SKILLS CLASSROOM FROM EDUCATORS PERSPECTIVE

2018 ◽  
pp. 61-67
Author(s):  
D. J. Sullivan ◽  
S. Labby ◽  
A. Koptelov ◽  
S. L. Sullivan
Keyword(s):  
Special Education ◽  
Mixed Methods ◽  
Communication Systems ◽  
Life Skills ◽  
Mixed Methods Study ◽  
Educational Tool ◽  
Special Educator ◽  
Communications Systems ◽  
Communication Device ◽  
Communication Devices

The purpose of this mixed methods study was to determine the barriers that special educator teachers encounter when using iPads within the Life Skills classroom. The research investigates the experiences, frustrations, and barriers through educators’ perceptions of iPad implementation. The influence of these issues suggests why iPad usage is not a device that special education classrooms are using in a widespread daily manner. Exploration of iPads as an educational tool and as a communication device is also discussed, along with considerations of other communications systems such as Picture Exchange Communication Systems and Alternative and Augmented Communication Devices is considered. Recommendations for further possible research are also discussed.

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