scholarly journals Design selective band antenna using coupling sidewall and multi resonator for wireless communications

2020 ◽  
Vol 9 (5) ◽  
pp. 2206-2212
Author(s):  
Ali Khalid Jassim ◽  
Malik Jasim Farhan ◽  
Alaa Fadhil Fahad
Keyword(s):  
Center Frequency ◽  
Frequency Selection ◽  
Bandwidth Requirement ◽  
Cylinder Length ◽  
Cylindrical Antenna ◽  
Sharp Edges ◽  
Ideal Filter ◽  
Cylindrical Resonators ◽  
Edge Band ◽  
Selection Of

Design and simulation of antenna with performance operating at bandwidth (4.5-6.5) GHz, with center frequency 5.5 GHz. This antenna constriction from two cylindrical antenna shapes and four cylindrical resonators with include iris to matching impedance, to enhancement sharp edge band and four tuned between coupling sidewall to removed distortions. Improving the frequency selection of the bandwidth requirement antenna is by adjusting the cylinder length of the antenna The proposed antenna is operating ideal filter because the edge of the band rejection is matched the edge of the bandwidth requirement which makes it perform well including broad edges for the band rejection and sharp edges of the bandwidth requirement together with a little insertion between two types and good return loss of the bandwidth requirement. CST software used to investigate and simulated results.

A Skywave OTHR Adaptive Frequency Selection Method Based on Preliminary Criterion and Weighted Criterion

2014 ◽  
Vol 1061-1062 ◽  
pp. 974-977
Author(s):  
Shi Hua Liu ◽  
Xian Gang Liu ◽  
Zhi Jian Sun
Keyword(s):  
Selection Criterion ◽  
Selection Method ◽  
Frequency Selection ◽  
Selection Of

A skywave radar adaptive frequency selection method based on the preliminary criterion and the weighted criterion is presented. In this method, according to the various operational tasks, the frequency selection criterion is divided into the preliminary criterion and the weighted criterion based on the characteristic of the targets. The adaptive frequency selection of the skywave radar is achieved by the weighted computed of the frequency selection criterion. The feasibility and availability is demonstrated by an example.

Research on Frequency Selection of Triple Frequency in Earth Capacitance Measurement

energyo ◽  
2019 ◽  
Author(s):  
Qiukuan Zhou ◽  
Jun Yao ◽  
Yan Liu ◽  
Yi Tan ◽  
Yang Zou ◽  
...  
Keyword(s):  
Capacitance Measurement ◽  
Frequency Selection ◽  
Triple Frequency ◽  
Selection Of

scholarly journals Distinct fast and slow processes contribute to the selection of preferred step frequency during human walking

2011 ◽  
Vol 110 (6) ◽  
pp. 1682-1690 ◽  
Author(s):  
Mark Snaterse ◽  
Robert Ton ◽  
Arthur D. Kuo ◽  
J. Maxwell Donelan
Keyword(s):  
Energy Expenditure ◽  
Closed Loop ◽  
Walking Speed ◽  
Prior Experience ◽  
Step Frequency ◽  
Total Change ◽  
Direct Optimization ◽  
Frequency Selection ◽  
Fine Tune ◽  
Selection Of

Humans spontaneously select a step frequency that minimizes the energy expenditure of walking. This selection might be embedded within the neural circuits that generate gait so that the optimum is pre-programmed for a given walking speed. Or perhaps step frequency is directly optimized, based on sensed feedback of energy expenditure. Direct optimization is expected to be slow due to the compounded effect of delays and iteration, whereas a pre-programmed mechanism presumably allows for faster step frequency selection, albeit dependent on prior experience. To test for both pre-programmed selection and direct optimization, we applied perturbations to treadmill walking to elicit transient changes in step frequency. We found that human step frequency adjustments ( n = 7) occurred with two components, the first dominating the response (66 ± 10% of total amplitude change; mean ± SD) and occurring quite quickly (1.44 ± 1.14 s to complete 95% of total change). The other component was of smaller amplitude (35 ± 10% of total change) and took tens of seconds (27.56 ± 16.18 s for 95% completion). The fast process appeared to be too fast for direct optimization and more indicative of a pre-programmed response. It also persisted even with unusual closed-loop perturbations that conflicted with prior experience and rendered the response energetically suboptimal. The slow process was more consistent with the timing expected for direct optimization. Our interpretation of these results is that humans may rely heavily on pre-programmed gaits to rapidly select their preferred step frequency and then gradually fine-tune that selection with direct optimization.

A PEAK ENERGY CRITERION (P. E.) FOR THE SELECTION OF RESONANCE BANDS IN COMPLEX SHIFTED MORLET WAVELET (CSMW) BASED DEMODULATION OF DEFECTIVE ROLLING ELEMENT BEARINGS VIBRATION RESPONSE

2009 ◽  
Vol 07 (04) ◽  
pp. 387-410 ◽  
Author(s):  
KONSTANTINOS C. GRYLLIAS ◽  
IOANNIS ANTONIADIS
Keyword(s):  
Energy Criterion ◽  
Vibration Response ◽  
Frequency Resolution ◽  
Center Frequency ◽  
Index Number ◽  
Rolling Element Bearings ◽  
Time Frequency ◽  
Peak Energy ◽  
Rolling Element ◽  
Selection Of

Complex Shifted Morlet Wavelets (CSMW) present a number of advantages when used for the demodulation of the vibration response of defective rolling element bearings: (A) They present the optimally located window simultaneously in the time and in the frequency domains; (B) They allow for the maximal time-frequency resolution; (C) The magnitudes of the complex wavelet coefficients in the time domain lead directly to the required envelope; (D) They allow for the optimal selection of both the center frequency and the bandwidth of the requested filter. A Peak Energy criterion (P. E.) is proposed in this paper for the simultaneous automatic selection of both the center frequency and the bandwidth of the relevant wavelet window to be used. As shown in a number of application cases, this criterion presents a more effective behavior than other criteria used (Crest Factor, Kurtosis, Smoothness Index, Number of Peaks), since it combines the advantages of energy based criteria, with criteria characterizing the spikiness of the response.

scholarly journals Simulation of an Adaptive Method of Improving the Accuracy and Extending the Range of Frequency Signal Processing in a Frequency-to-Code Converter

2021 ◽  
Vol 11 (21) ◽  
pp. 10341
Author(s):  
Piotr Warda
Keyword(s):  
Signal Processing ◽  
Adaptive Method ◽  
Variable Frequency ◽  
Frequency Change ◽  
Clock Signal ◽  
Frequency Signal ◽  
Frequency Selection ◽  
Processing Error ◽  
Simulation Results ◽  
Selection Of

The article discusses the modification of one of the basic methods of converting successive periods of a variable frequency signal into numerical values representing them. The method performs the adaptive frequency selection of the clock signal in the system processing the consecutive periods of input signal. The signal processing error is analyzed on an ongoing basis, and the frequency change factor is selected. Algorithms describing the operation of the method are included. The program of the simulator of the measurement channel operation with a frequency carrier of information is described, which allows for the verification of the proposed method. Examples of the simulation results are included.

scholarly journals Латеральный спин-волновой транспорт в системе неидентичных магнонно-кристаллических микроволноводов

2021 ◽  
Vol 63 (9) ◽  
pp. 1330
Author(s):  
В.А. Губанов ◽  
С.Е. Шешукова ◽  
А.В. Садовников
Keyword(s):  
Signal Processing ◽  
Bragg Resonance ◽  
Brillouin Spectroscopy ◽  
Power Dividers ◽  
Frequency Selection ◽  
Waveguide Modes ◽  
Micromagnetic Modeling ◽  
Magnonic Crystals ◽  
Magnonic Crystal ◽  
Selection Of

The control regimes of dipole coupling in the lateral system of non-identical magnonic crystals are investigated by the method of Mandelstam-Brillouin spectroscopy and by the method of micromagnetic modeling. The modes of spatial and frequency selection of the spin-wave signal near the frequency of the band gap zone of the magnonic crystal are revealed. The influence of changes in geometric parameters on the properties of waveguide modes near the frequency of the Bragg resonance is investigated. The results obtained can be used to create microwave signal processing devices, such as demultiplexers, power dividers, couplers.

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