scholarly journals Reduction of Spurious Signal Upconversion in Frequency Multipliers

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1126
Author(s):  
Zenon Szczepaniak ◽  
Tomasz Rogala
Keyword(s):  
Power Level ◽  
Frequency Synthesizers ◽  
Frequency Multiplier ◽  
Frequency Multipliers ◽  
Direct Digital Synthesis ◽  
Frequency Multiplication ◽  
Spurious Signal ◽  
Baseband Signal ◽  
Digital Synthesis ◽  
Spurious Signals

Usually many applications of radar transceivers and heterodyne frequency synthesizers assume a spurious signal power level below −60 dBc. In the case of modern synthesizers using direct digital synthesis (DDS) systems, the number of emerging spurious signal frequencies is very large, and spectral purity within −60 dBc can only be obtained in the relatively narrow tuning band of the DDS unit. For the purposes of widening this useful frequency range, the frequency multiplying operation is applied commonly. Then, during the process of frequency multiplication of the baseband signal containing inband spurious signals, the effect of the upconversion of spurious signals occurs. The paper contains an analysis of the undesirable effects of the conversion of spurious signal frequencies accompanying the process of frequency multiplication. A method of reducing the level of upconverted spurious signals is proposed. The numerical calculations and measurement results are provided. For the case of a frequency multiplier with a multiplying factor equal to N, the power ratio between the desired output signal and upconverted spurious signal drops by an additional 1/N2. It has been found that the application of the presented method during the design process of the frequency multiplier allows this ratio to be improved by 6 dB.

scholarly journals Industrial frequency multiplier based on a transformer with a rotating field

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Evgenij Koptjaev ◽  
Vyacheslav Balashevich ◽  
Pavel Atrashkevich
Keyword(s):  
Electromagnetic Compatibility ◽  
Pulse Width Modulation ◽  
Large Mass ◽  
Frequency Multiplier ◽  
Frequency Multipliers ◽  
Frequency Multiplication ◽  
Additional Degree ◽  
Industrial Energy ◽  
Low Efficiency ◽  
Rotating Field

The disadvantage of domestic static converters past generations are the worst dimensions in comparison with rotating converters. Modern inverters use pulse width modulation, which causes problems with electromagnetic compatibility. Imposed by the EU and US sanctions have caused on the agenda of the replacement of imported parts and components, including the search for new ways to develop domestic technology. Known ferromagnetic frequency multipliers have not received applications in industrial energy due to the large mass and low efficiency. Proposed in the article a new method of frequency multiplication solve the above issues, allowing you to implement a simple and reliable converter without the use of imported components. The output voltage of high frequency multiplier is formed by the use of magnetic flux transformer with a rotating field, which has an additional degree of freedom, which is a new solution. Perhaps multiplication with different coefficients of frequency multiplication, including 8 times to provide voltage with a frequency of 400 Hz.

An Improved Doppler Shift Simulation Method Based on Third-Order DDS

2014 ◽  
Vol 614 ◽  
pp. 356-362 ◽  
Author(s):  
Rui Li ◽  
Yuan Long Cai ◽  
Xin Bei Bai ◽  
Ming Quan Lu
Keyword(s):  
Doppler Shift ◽  
Dynamic Range ◽  
Doppler Frequency ◽  
Simulation Method ◽  
Global Navigation Satellite Systems ◽  
Direct Digital Synthesis ◽  
Third Order ◽  
Satellite Systems ◽  
Digital Synthesis ◽  
Global Navigation Satellite

A method to simulate the Doppler frequency shift of high dynamic signals of Global Navigation Satellite Systems (GNSS) is provided in this paper. The methodology of the method based on third-order Direct Digital Synthesis (DDS) is introduced and the efficient implementation architecture is proposed. The design criteria of the DDS are investigated according to the precision and dynamic range of the Doppler shift. The simulation results are also demonstrated, which indicate that the method is available for the high precision Doppler shift simulation of GNSS signals.

Simulation of Stepped-Frequency LFM Radar Echo Based on FPGA

2012 ◽  
Vol 198-199 ◽  
pp. 948-953
Author(s):  
Jian Ping Ou ◽  
Sheng Qi Liu ◽  
Wei Niu
Keyword(s):  
Moving Target ◽  
Direct Digital Synthesis ◽  
Implementation Framework ◽  
Radar Echoes ◽  
Radar Echo ◽  
Digital Synthesis ◽  
Physical Simulations ◽  
Stepped Frequency ◽  
Logic Resource

An implementation framework of stepped-frequency LFM (SF-LFM) radar echoes simulator is presented in the paper based on the decomposition and calculation of SF-LFM radar echoes of a moving target. The proposed method can be implemented conveniently with direct digital synthesis (DDS) logic resource. The feasibility of this resolution is verified with computer and semi-physical simulations experiments.

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