Wide-band high frequency signals from Poldhu? The propagating spectrum and terminal equipment revisited

1995 ◽  
Author(s):  
J.C.B. MacKeand
Keyword(s):  
High Frequency ◽  
Wide Band ◽  
Terminal Equipment

scholarly journals Band notched self complementaryultra wideband antenna for wireless applications

2018 ◽  
Vol 7 (2.8) ◽  
pp. 529 ◽  
Author(s):  
Ch Ramakrishna ◽  
G A.E.Satish Kumar ◽  
P Chandra Sekhar Reddy
Keyword(s):  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Relative Dielectric Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Wireless Applications ◽  
Patch Edge

This paper presents a band notched WLAN self complementaryultra wide band antenna for wireless applications. The proposed antenna encounters a return loss (RL) less than -10dB for entire ultra wideband frequency range except band notched frequency. This paper proposes a hexagon shape patch, edge feeding, self complementary technique and defective ground structure. The antenna has an overall dimensionof 28.3mm × 40mm × 2mm, builton  substrate FR4 with a relative dielectric permittivity 4.4. And framework is simulated finite element method with help of high frequency structured simulator HFSSv17.2.the proposed antenna achieves a impedance bandwidth of 8.6GHz,  band rejected WLAN frequency range 5.6-6.5 GHz with  vswr is less than 2.

scholarly journals Research and Fabrication of High-Frequency Broadband and Omnidirectional Transmitting Transducer

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2347 ◽  
Author(s):  
Shaohua Hao ◽  
Hongwei Wang ◽  
Chao Zhong ◽  
Likun Wang ◽  
Hao Zhang
Keyword(s):  
Composite Material ◽  
High Frequency ◽  
Wide Band ◽  
Simulation Software ◽  
Piezoelectric Composite ◽  
Voltage Response ◽  
Forming Process ◽  
Composite Ring ◽  
Matching Layer ◽  
Acoustic Transducer

A wide-band cylindrical transducer was developed by using the wide band of the composite material and the matched matching layer for multimode coupling. Firstly, the structure size of the transducer’s sensitive component was designed by using ANSYS simulation software. Secondly, the piezoelectric composite ring-shaped sensitive component was fabricated by the piezoelectric composite curved-surface forming process, and the matching layer was coated on the periphery of the ring-shaped piezoelectric composite material. Finally, it was encapsulated and the electrodes were drawn out to make a high-frequency broadband horizontal omnidirectional water acoustic transducer prototype. After testing, the working frequency range of the transducer was 230–380 kHz, and the maximum transmission voltage response was 168 dB in the water.

A new high frequency wide band 180� differential power splitter

1996 ◽  
Vol 11 (3) ◽  
Author(s):  
Javier Gonzalez ◽  
Andres Guerrero ◽  
Isabelle Telliez
Keyword(s):  
High Frequency ◽  
Wide Band ◽  
Power Splitter

High Frequency Modeling of Smart Sensor for Precise Power Quality Assessment Using Fuzzy Logic

2016 ◽  
Vol 25 (06) ◽  
pp. 1650056 ◽  
Author(s):  
G. Sudha ◽  
K. R. Valluvan
Keyword(s):  
Fuzzy Logic ◽  
Quality Assessment ◽  
Power Quality ◽  
High Frequency ◽  
Wide Band ◽  
Electrical Equipment ◽  
Distribution Networks ◽  
Accurate Method ◽  
Energy Difference ◽  
Critical Issue

Power Quality Assessment (PQA) is a critical issue both in transmission and distribution networks. Therefore, it is necessary to precisely classify the disturbances in shortest possible time to prevent the malfunction or increase of losses in the electrical equipment through appropriate remedial techniques. This paper proposes a highly accurate method of PQA through data acquisition using smart sensors, the Rogowski coils (RCs). RCs with wide band width and linear characteristics allow faithful reproduction of high-frequency (HF) signals. In the proposed method, simulated disturbance signals are applied to RC. The output signals are subjected to multilevel wavelet decomposition and then computation of the energy difference in the detailed components between the disturbance signal and the pure sinusoidal waveform is performed to design a fuzzy logic Power Quality Classifier. The classifier is tested by varying the magnitude, frequency and duration of the disturbance and found to be accurate to 98.38%. The classification accuracy depends mainly on the performance of sensors at HFs. Thus, with RCs as sensors instead of conventional instrument transformers, it is found that the precision of power quality classification is greatly improved.

scholarly journals A Novel Wineglass Shaped Wide Band Antenna for TV White Space Communication

2018 ◽  
Vol 7 (4.5) ◽  
pp. 324
Author(s):  
Ghulam Ahmad Raza ◽  
Garima Saini ◽  
Naveen Kumar
Keyword(s):  
Patch Antenna ◽  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Vector Network Analyzer ◽  
Network Analyzer ◽  
White Space ◽  
Good Match ◽  
Space Communication ◽  
Tv White Space

This paper presents a novel patch antenna for TV white spaces applications. The shape of the proposed antenna is based on the shape of a wineglass. The dimension of the proposed antenna is 170 mm x 120 mm x 1.6 mm. After simulation, the proposed antenna resonates at 703 MHz with a return loss of -21.97 dB and covering a bandwidth from 495 MHz to 1540 MHz. Overall bandwidth coverage is 1045 MHz. So the proposed antenna is a wide band antenna covering almost the entire TV Ultra High Frequency (UHF) range. Simulated VSWR obtained at 703 MHz is 1.38 dB and simulated gain is 2.32 dB. The proposed antenna is fabricated using FR4 substrate and tested on Vector Network Analyzer (VNA). The measured return loss of fabricated antenna is -20.20 dB at 596 MHz. Proposed antenna shows the simulated radiation efficiency of 95%. Simulated and measured results showed good match between them. Proposed design is compared with few designs available in literature to validate its novelty and advantages. 

scholarly journals A New Impedance Matching Method for an Ultra-Wide Band and Dual Circularly Polarised Feed

2016 ◽  
Vol 33 ◽  
Author(s):  
Sha Li ◽  
Yi Hua Yan ◽  
Wei Wang ◽  
Zhi Jun Chen ◽  
Dong Hao Liu ◽  
...  
Keyword(s):  
High Frequency ◽  
Near Field ◽  
Impedance Matching ◽  
Axial Ratio ◽  
Wide Band ◽  
Beam Width ◽  
Metal Ring ◽  
Field Radiation ◽  
Fixed Phase ◽  
Strip Lines

AbstractIn traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz.

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