Conventional vs. Convolutional Windows for Reduction of Side Lobes

Convolutional windows analysis and performance comparison with traditional windows is main intent of the present paper. Convolutional windows are formed by convoluting the window by itself. These new class of windows are applied to a pseudo-LFM signal designed by using two stage piece wise linear frequency functions. Simulations were performed for the designed LFM signal with both the traditional and convolutional window functions are is observed that the convolutional windows yield better peak to side lobe level ratio (PSLR) values compared to traditional windows.

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Convolutional Windows for Side Lobe Reduction

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.j9747.0881019 ◽

2019 ◽

Vol 8 (10) ◽

pp. 3526-3529

Keyword(s):

Frequency Modulation ◽

Pulse Compression ◽

Side Lobe ◽

Linear Frequency Modulation ◽

Side Lobe Level ◽

Chirp Signal ◽

Sidelobe Level ◽

Linear Frequency ◽

Radar Systems ◽

Window Functions

A lot of applications in radar systems necessitate low range side-lobe performance which is achieved by pulse compression processing. Linear Frequency Modulation (LFM) signal is mainly used chirp signal for this processing. The paramount drawback in LFM is the first side-lobe level of -13dB at the receiver side. In this paper, LFM signal is modified by using simple two-stage piece wise linear frequency modulation (PWLFM) functions. The autocorrelation function of this PWLFM signal exhibited low peak sidelobe level ratio (PSLR) value compared to its counterpart LFM signal. An attempt is made to further reduce the side lobe values by using novel Convolutional windows. The simulation results confirm a significant side lobe reduction by the LFM signal designed using PWLFM functions when a more flexible Power of Cosine window function is applied compared to all other window functions.

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Design and performance of a microstrip reflectarray on a uniaxial substrate

Canadian Journal of Physics ◽

10.1139/p01-079 ◽

2002 ◽

Vol 80 (1) ◽

pp. 7-17 ◽

Cited By ~ 2

Author(s):

A Iliadis ◽

K Siakavara

Keyword(s):

Electromagnetic Field ◽

Green's Function ◽

Method Of Moments ◽

Dielectric Substrate ◽

Side Lobe ◽

Side Lobe Level ◽

Dual Polarization ◽

Full Wave ◽

Wave Technique ◽

And Performance

A design formulation of microstrip reflectarrays is presented in this paper. Previous published articles, referring to this subject, present results for reflectarrays on a uniform dielectric substrate. In this work microstrip reflectarrays with offset feed, dual polarization, and side-lobe level under control, fabricated on a uniaxial substrate were studied. The method of moments, combined with the full-wave technique, and the corresponding dyadic Green's function is used for the specification of the electromagnetic field scattered by the array. PACS No.: 84.40B

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Encoded Hybrid PSK/FSK Waveform for LPI Radar

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.f8492.038620 ◽

2020 ◽

Vol 8 (6) ◽

pp. 2753-2760

Keyword(s):

Frequency Modulation ◽

Pulse Compression ◽

Average Power ◽

Side Lobe ◽

Linear Frequency Modulation ◽

Coincidence Detection ◽

Side Lobe Level ◽

Linear Frequency ◽

Non Linear ◽

Radar Waveforms

Since the advantage of pulse compression radar, the pseudo random codes and poly time codes and non linear frequency modulation has been mostly widely used low probability intercept (LPI) radar waveforms. By changing frequencies time to time in frequency modulation known as non-linear frequency modulation (frequency hopping (FH)), peak to side lobe ratio (PSLR) can be achieved to make less severe the covering effect of nearby targets and to improve the useful dynamic range. Adding an appropriate binary encoded ternary phase shift signal (PSK) as form as Binary encoded Hybrid-PSK/FSK (BEH PSK/FSK), the peak side lobe ratios are obtained very low values (e.g., PSLR<-70dB), similar to the antenna side lobes. In advanced microwave power amplifier technology, now a day’s using low peak to average power modules requires them to be amalgamated at the radio frequency (RF) stage in that way to obtain the required emitted radiated power. The deterministic waveforms are represents Noise waveform radar technology is a valid alternative. The pseudorandom waveform-realization of a noise process, the higher its bandwidth-time (or BT) product, the lower the (numerical) peak side lobe ratio. With practical Bandwidth-time values, the achievable peak side lobe using pure random is not sufficient the generated pseudorandom waveforms undergoes optimized genetic algorithm Hamming Scan (HS) to achieve optimized pseudo random (OBC), in order to achieve the desired side lobe level. This manuscript proposes a general analysis of the two modes of radar waveforms, i.e., Ternary and Binary alphabetic waveforms of coincidence detection.

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Design of 1 + 1 / 2 counter rotating centrifugal turbine and performance comparison with two-stage centrifugal turbine

Energy ◽

10.1016/j.energy.2020.118628 ◽

2020 ◽

Vol 211 ◽

pp. 118628

Author(s):

Dan Luo ◽

Xiaojing Sun ◽

Diangui Huang

Keyword(s):

Performance Comparison ◽

Two Stage ◽

And Performance

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Modified PWNLFM Signal for Side-Lobe Reduction

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.20.22110 ◽

2018 ◽

Vol 7 (4.20) ◽

pp. 4

Author(s):

N. Adithya valli ◽

Dr. D. Elizabath Rani

Keyword(s):

Linear Function ◽

Frequency Modulation ◽

Pulse Compression ◽

Weighting Function ◽

Side Lobe ◽

Linear Frequency Modulation ◽

Side Lobe Level ◽

Chirp Signal ◽

Linear Frequency ◽

Non Linear

Many applications in radar systems require low range side-lobe performance which is achieved by pulse compression processing. Most used chirp signal for this processing is linear frequency modulation (LFM) signal but with a presence of first high side-lobe level. Suppression of this side-lobe requires weighting function causing the reduction in signal to noise ratio at the receiver owing to mismatch loss. Non-linear chirp signals are introduced as a solution and became most practiced signals aimed at reducing side-lobes. In this paper, an overall piece wise non-linear frequency modulation chirp signal is designed by merging two stages, one with linear function and the other with a tangent based non-linear function. Simulation results show significant reduction in the sidelobe level of autocorrelation function when NLFM is generated in this method.

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Antenna Array Weight Synthesis for Low Side Lobe Levels using Window Functions

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a1664.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 3074-3081

Keyword(s):

Antenna Array ◽

Radiation Pattern ◽

Antenna Arrays ◽

Side Lobe ◽

Optimization Techniques ◽

Side Lobe Level ◽

Linear Antenna ◽

Window Functions ◽

Linear Antenna Arrays ◽

Array Weight

A lot of research is being carried out to reduce side lobe levels (SSLs) in the radiation pattern of antenna arrays. A number of novel optimization techniques have been developed over the years and adapted for this purpose. In this paper, a number of window functions are applied to suppress the maximum side lobe level (MSLL) in linear antenna arrays. The window functions Bartlett, Taylor, Hanning, Barthann, Hamming, Gaussian, Blackman, Chebyshev, Blackman-Harris and Kaiser are considered in the simulation. The optimized pattern for a 10 element linear antenna array and corresponding normalized window tappers for every window are presented. Finally the efficiency of all windows is compared in terms of their computed parameters.

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Assessment of Various Window Functions in Spectral Identification of Passive Intermodulation

Electronics ◽

10.3390/electronics10091034 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1034

Author(s):

Khaled Gharaibeh

Keyword(s):

Spectral Density ◽

Low Power ◽

Power Spectral Density ◽

Side Lobe ◽

Frequency Separation ◽

Side Lobe Level ◽

Spectral Leakage ◽

Window Functions ◽

Power Spectral ◽

Passive Intermodulation

Passive Intermodulation (PIM) distortion is a major problem in wireless communications which limits cell coverage and data rates. Passive nonlinearities result in weak intermodulation (IMD) products that are very difficult to diagnose, troubleshoot and model. To predict PIM, behavioral models are used where spectral components of PIM are estimated from the power spectral density at the output of the model. The primary goal of this paper is to study the effect of window functions on the capability of the power spectral density computed from the periodogram of signal realizations to predict low power PIM components in a wideband multichannel communication system. Different window functions are analyzed and it is shown that windows with high side-lobe level fail to predict PIM components which are close to the main channels due to their high spectral leakage; while window functions with low roll-off rate of the side lobes fail to predict low power higher order PIM components especially when the frequency separation between the main carriers is high. These results are supported by simulations of the power spectral density computed using signal realizations of an LTE carrier aggregated system.

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