Electromagnetic interference mitigation by using a spread-spectrum approach

2002 ◽  
Vol 44 (2) ◽  
pp. 380-385 ◽  
Author(s):  
Yoonjae Lee ◽  
R. Mittra
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Interference Mitigation

scholarly journals FDTD Computation of Space/Time Integrated Electromagnetic Lagrangian: New Insights on Mutually Coupled Wide-band Antenna Design

2021 ◽  
Author(s):  
Debdeep Sarkar ◽  
Yahia Antar
Keyword(s):  
Electromagnetic Interference ◽  
Interference Mitigation ◽  
Near Field ◽  
Time Integration ◽  
Wide Band ◽  
Space Time ◽  
Ultra Wideband ◽  
Mimo Antennas ◽  
Electric And Magnetic Fields ◽  
Spatio Temporal

In this paper, we develop a formalism based on either spatially or temporally integrated electromagnetic (EM) Lagrangian, which provides new insights about the near-field reactive energy around generic antennas for arbitrary spatio-temporal excitation signals. Using electric and magnetic fields calculated via FDTD technique and interpolation routines, we compute and plot the normalized values of space/time integrated EM Lagrangian around antennas. While the time-integration of EM Lagrangian sheds light onto the spatial distribution of inductive/capacitive reactive energy, time-variation of spatially integrated EM Lagrangian can help in design of ultra-wideband (UWB) MIMO antennas with low mutual coupling. The EM Lagrangian approach can assist in design of energy harvesting and wireless power transfer systems, as well as for electromagnetic interference mitigation applications.

scholarly journals A Low EMI DC-DC Buck Converter with a Triangular Spread-Spectrum Mechanism

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 856
Author(s):  
Jing-Yuan Lin ◽  
Yi-Chieh Hsu ◽  
Yo-Da Lin
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Output Voltage ◽  
Buck Converter ◽  
Circuit Board ◽  
System Stability ◽  
Maximum Efficiency ◽  
Load Current ◽  
Voltage Range ◽  
Switching Regulators

In this paper, a triangular spread-spectrum mechanism is proposed to suppress the electromagnetic interference (EMI) of a DC-DC buck converter. The proposed triangular spread-spectrum mechanism, which is implemented in the chip, can avoid modifying the printed circuit board of switching regulators. In addition, a lower ripple of output voltage of switching regulators and a better system stability can be realized by the inductive DC resistance (DCR) current sensing circuit. The chip is fabricated by using TSMC 0.18-μm 1P6M CMOS technology. The chip area including PADs is 1.2 × 1.15 mm2. The input voltage range is 2.7~3.3 V and the output voltage is 1.8 V. The maximum load current is 700 mA. The off-chip inductor and capacitor are 3.3 μH and 10 μF, respectively. The experimental results demonstrate that the maximum spur of the proposed DC-DC buck converter with the triangular spread-spectrum mechanism improves to 14dBm. Moreover, the transient recovery time of step-up and step-down loads are both 5 μs. The measured maximum efficiency is 94% when the load current is 200 mA.

Spread Spectrum Microwave Power Generation for Improving Efficiency

1996 ◽  
Vol 430 ◽  
Author(s):  
W. M. Van Loock
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Frequency Modulation ◽  
Power Supply ◽  
Microwave Power ◽  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Frequency Bands ◽  
Ism Band ◽  
Microwave Generators

AbstractMicrowave power for heating applications is normally generated in the designated ISM frequency bands which occupy a band of 4%. Actual microwave generators, such as are used in domestic ovens utilise only a small fraction of this bandwidth. It is being demonstrated that spreading the power uniformly over the full ISM band by controlled frequency modulation dramatically reduces all levels of potential electromagnetic interference. With such controlled modulation telecommunication channels can operate within the ISM bands without serious problems because the leakage levels are reduced by 20 to 30 dB with no additional shielding costs. One simple (though not optimum) modulating waveform is a large ripple voltage on the magnetron power supply. Frequency modulation that spreads the energy over the full ISM band also improves the overall energy efficiency in multimode heating applications.

scholarly journals Design of double ring lock ring in extensible frequency clock generator chip

2021 ◽  
Vol 2137 (1) ◽  
pp. 012041
Author(s):  
Chao Xu ◽  
Yumeng Xie ◽  
Yuan Zhou
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Phase Locked Loop ◽  
Center Frequency ◽  
Good Effect ◽  
Clock Generator ◽  
Clock Frequency ◽  
Noise Interference ◽  
Main Loop ◽  
Secondary Loop

Abstract With the continuous development of computer technology and the continuous improvement of interface data rate, the clock frequency has reached the demand of several gigahertz, which makes the electromagnetic interference problem very serious. Spread spectrum clock is an effective method to reduce electromagnetic interference of digital chips. Therefore, this paper designs a double-loop phase-locked loop that can spread spectrum and has strong anti-electromagnetic noise interference ability. The designed dual-loop phase-locked loop can be used in the clock generator chip. The overall structure of the circuit consists of a main loop and a secondary loop. The main loop is an adjustable phase-locked loop circuit that can provide an output with a center frequency of 500MHz. The secondary loop can realize the spread spectrum function by charging and discharging the filter capacitor of the main loop loop, and at the same time, the spreading depth can be set by the feedback based on the frequency division. The dual-loop phase-locked loop designed in this paper has a good effect in spread spectrum and anti-electromagnetic interference noise.

scholarly journals A RAKE RECEIVER DESIGN FOR ULTRA WIDE BAND APPLICATION

2014 ◽  
pp. 257-262
Author(s):  
SURAJIT DEKA ◽  
MANASH PRATIM SARMA ◽  
Kandarpa Kumar Sarma
Keyword(s):  
Spread Spectrum ◽  
Interference Mitigation ◽  
Signal To Noise Ratio ◽  
Rake Receiver ◽  
Wide Band ◽  
Multipath Fading ◽  
Ultra Wide Band ◽  
Receiver Design ◽  
Sequence Generator ◽  
Spread Spectrum Modulation

In this paper, we describe the design and implementation of a rake receiver for use with ultra wide band (UWB) systems. The rake receiver uses spread spectrum modulation (SSM) aided by kasami sequence generator. The combination is found to be effective in dealing with multipath fading and signal to noise ratio. The design is initially simulated using MATLAB 7.10 and is implemented using a HDL coder. The design is also implemented in a FPGA kit and is found to be effective in interference mitigation as part of a CDMA framework.

scholarly journals Inter-Relay Interference Mitigation for Chirp-Based Two-Path Successive Relaying Protocol

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3346 ◽  
Author(s):  
Kwang-Yul Kim ◽  
Yoan Shin
Keyword(s):  
Spectral Efficiency ◽  
Spread Spectrum ◽  
Cross Correlation ◽  
Interference Mitigation ◽  
Data Rate ◽  
Transmission Performance ◽  
High Data ◽  
Single Relay ◽  
The Internet Of Things ◽  
Degree Of Similarity

Since the chirp spread spectrum (CSS) system is considered as a communication technology for the Internet of things (IoT), long-range communication and a high data rate are required. In wireless communications, in order to increase spectral efficiency and to extend transmission coverage, a two-path successive relaying (TPSR) protocol has been proposed. Thus, in order to improve transmission performance of the CSS system, in this paper we apply the TPSR protocol to the CSS system. However, since the TPSR protocol is successively relaying data, the spectral efficiency may be limited due to inter-relay interference (IRI). Hence, we propose a multiple linear chirp-based IRI mitigation method for the CSS-based TPSR protocol. In the proposed scheme, the cross-correlation coefficient (CCC) has been derived mathematically according to a separating bandwidth in a given total bandwidth. Then, one separating bandwidth that guarantees the transmission performance is allocated to the primary relay by considering a single relay CCC (SR-CCC) and another separating bandwidth that guarantees the orthogonality from the primary relay is allocated to the secondary relay by considering the inter-relay CCC (IR-CCC). Since the IR-CCC means a degree of similarity between these two relays, it is possible to mitigate the IRI effect within the same bandwidth by allocating orthogonal separating bandwidths to each relay. Simulation results show that the proposed scheme can improve the transmission performance by mitigating the IRI effect even in high IRI environments. Consequently, we expect that the proposed scheme can extend the transmission coverage and increase the data rate of the CSS system.

Magnetic and structural characterization of polyaniline/Cu0.5Zn0.5Fe2O4 composites for electromagnetic interference mitigation

2020 ◽  
Author(s):  
Mathdh Gurusiddesh ◽  
Beedimane Jayanna Madhu ◽  
Gowdra Jayadevappa Shankaramurthy ◽  
Hosahallypata Ramaiah Venkatesha
Keyword(s):  
Structural Characterization ◽  
Electromagnetic Interference ◽  
Interference Mitigation

scholarly journals An Anti-Interference Scheme for UAV Data Links in Air–Ground Integrated Vehicular Networks

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4742 ◽  
Author(s):  
Yixin He ◽  
Daosen Zhai ◽  
Ruonan Zhang ◽  
Xiaojiang Du ◽  
Mohsen Guizani
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Vehicular Networks ◽  
Ad Hoc ◽  
Intelligent Transportation System ◽  
Multiple Input Multiple Output ◽  
Signal Spectrum ◽  
Spectrum Utilization ◽  
Communication Performance ◽  
Data Links

As one of the main applications of the Internet of things (IoT), the vehicular ad-hoc network (VANET) is the core of the intelligent transportation system (ITS). Air–ground integrated vehicular networks (AGIVNs) assisted by unmanned aerial vehicles (UAVs) have the advantages of wide coverage and flexible configuration, which outperform the ground-based VANET in terms of communication quality. However, the complex electromagnetic interference (EMI) severely degrades the communication performance of UAV sensors. Therefore, it is meaningful and challenging to design an efficient anti-interference scheme for UAV data links in AGIVNs. In this paper, we propose an anti-interference scheme, named as Mary-MCM, for UAV data links in AGIVNs based on multi-ary (M-ary) spread spectrum and multi-carrier modulation (MCM). Specifically, the Mary-MCM disperses the interference power by expanding the signal spectrum, such that the anti-interference ability of AGIVNs is enhanced. Besides, by using MCM and multiple-input multiple-output (MIMO) technologies, the Mary-MCM improves the spectrum utilization effectively while ensuring system performance. The simulation results verify that the Mary-MCM achieves excellent anti-interference performance under different EMI combinations.

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