Kaiser Window Based Side Lobe Level Suppression in 3D Beamforming for Massive MIMO Structure

2020 ◽  
Author(s):  
Tanmoy Kundu ◽  
Arijeet Ghosh ◽  
Iti Saha Misra ◽  
Salil Kumar Sanyal
Keyword(s):  
Massive Mimo ◽  
Side Lobe ◽  
Side Lobe Level ◽  
3D Beamforming ◽  
Kaiser Window

scholarly journals Proposing a new variable window for better side lobe reduction

2019 ◽  
Vol 8 (9) ◽  
pp. 1107-1112
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Power Loss ◽  
Finite Impulse Response ◽  
Variable Parameter ◽  
Digital Signal ◽  
Side Lobe ◽  
Fir Filter ◽  
Side Lobe Level ◽  
Kaiser Window

Digital signal processing is most widely used to process the signal. In digital signal processing filters are used to remove some unwanted constituents from aspired signal. Windowing is a scheme of finite impulse response filters. Present paper proposes a new versatile window function. It has two variable parameters first one is window span N and another changeable parameter is r. when the value of variable parameter r increases width of major lobe of window also increases with better side lobe reduction and vice versa. Gaussian window and Kaiser window are the well-known variable windows. This paper shows that the proposed window has more desirable results in comparison of Gaussian and Kaiser window with low power loss and better side lobe reduction. To achieve minimum power loss peak side lobe level should have to minimum. Proposed window has low peak side lobe level (-17.681dB) in comparison of Gaussian (-11.836dB) and Kaiser window (-6.9704dB). Proposed work shows that the proposed window has finer spectral characteristic then Gaussian and Kaiser window. FIR filter formed by applying proposed window has narrow -3dB bandwidth (2π×0.320 rad/sample) corresponding to FIR filter formed by using Gaussian and Kaiser window. Ripple ratio of FIR filter plotted by applying proposed window (-144.321dB) is less corresponding to FIR filter delineated by using Gaussian and Kaiser which indicates that the proposed window will give better side lobe rejection and reduce the aliasing problem. In the biomedical field noise present in ECG signal can also reduce by using proposed window.

scholarly journals A Design Approach of Optical Phased Array with Low Side Lobe Level and Wide Angle Steering Range

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 63
Author(s):  
Xinyu He ◽  
Tao Dong ◽  
Jingwen He ◽  
Yue Xu
Keyword(s):  
Phased Array ◽  
Phase Distribution ◽  
Beam Steering ◽  
Side Lobe ◽  
Design Approach ◽  
Optical Antennas ◽  
Side Lobe Level ◽  
Wide Angle ◽  
Spacing Distribution ◽  
Optical Phased Array

In this paper, a new design approach of optical phased array (OPA) with low side lobe level (SLL) and wide angle steering range is proposed. This approach consists of two steps. Firstly, a nonuniform antenna array is designed by optimizing the antenna spacing distribution with particle swarm optimization (PSO). Secondly, on the basis of the optimized antenna spacing distribution, PSO is further used to optimize the phase distribution of the optical antennas when the beam steers for realizing lower SLL. Based on the approach we mentioned, we design a nonuniform OPA which has 1024 optical antennas to achieve the steering range of ±60°. When the beam steering angle is 0°, 20°, 30°, 45° and 60°, the SLL obtained by optimizing phase distribution is −21.35, −18.79, −17.91, −18.46 and −18.51 dB, respectively. This kind of OPA with low SLL and wide angle steering range has broad application prospects in laser communication and lidar system.

scholarly journals Ka-Band Lightweight High-Efficiency Wideband 3D Printed Reflector Antenna

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Zhai ◽  
Ding Xu ◽  
Yan Zhang
Keyword(s):  
High Efficiency ◽  
Near Field ◽  
Side Lobe ◽  
High Gain ◽  
Reflector Antenna ◽  
Field Analysis ◽  
Side Lobe Level ◽  
Ka Band ◽  
3D Printed ◽  
Reflecting Surface

This paper presents a lightweight, cost-efficient, wideband, and high-gain 3D printed parabolic reflector antenna in the Ka-band. A 10 λ reflector is printed with polylactic acid- (PLA-) based material that is a biodegradable type of plastic, preferred in 3D printing. The reflecting surface is made up of multiple stacked layers of copper tape, thick enough to function as a reflecting surface (which is found 4 mm). A conical horn is used for the incident field. A center-fed method has been used to converge the energy in the broadside direction. The proposed antenna results measured a gain of 27.8 dBi, a side lobe level (SLL) of −22 dB, and a maximum of 61.2% aperture efficiency (at 30 GHz). A near-field analysis in terms of amplitude and phase has also been presented which authenticates the accurate spherical to planar wavefront transformation in the scattered field.

Circular aerial arrays for radio astronomy

1961 ◽  
Vol 262 (1308) ◽  
pp. 84-99 ◽  
Keyword(s):  
Radio Astronomy ◽  
Side Lobe ◽  
Correction Function ◽  
Side Lobe Level ◽  
Circular Aperture ◽  
Circular Array ◽  
Polar Diagram ◽  
Beam Shape ◽  
Correction Process ◽  
Dimensional Distribution

A new type of aerial array suitable for high-resolution observations in radio astronomy is explored theoretically. The array consists of a large number of aerial elements equally Spaced round a circle and electrically connected in phase. The power polar diagram is calculated for the cases when the circle is effectively continuous, and when the separation between adjacent elements is appreciable. In both cases the side-lobe level is rather high for most radio astronomical purposes, for which a process of aerial correction is required. The function of the correction process is to readjust the relative weights of the different spatial Fourier components to provide a suitable beam shape. A general method of aerial correction is developed in which the two dimensional distribution of brightness directly recorded by scanning is cross-correlated with a circularly symmetrical correction function , a process which is desirably performed in the instrument itself. The correction process allows one to convert the polar diagram of a ring-shaped array into (for example) the diagram of a uniform circular aperture of the same radius. The principal theoretical characteristics of the circular array are briefly compared with those of the Mills cross. It is found that while the process of aerial correction or ‘tapering’ is technically more straightforward in the cross, the circular array has the following advantages: (1) the length of transmission line (and hence attenuation) between each element and receiver is halved; (2) the number of elements required to gain the same information is reduced, approximately in the ratio 4: π ; (3) the beam possesses circular or elliptical symmetry; and (4) the system offers the possibility of direct phase and amplitude calibration with the aid of a transmitter situated on a central tower.

scholarly journals Null Steering in Failed Antenna Arrays

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Om Prakash Acharya ◽  
Amalendu Patnaik ◽  
Sachendra N. Sinha
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Correction Procedure ◽  
Swarm Optimization ◽  
Array Pattern ◽  
Null Steering ◽  
Simulation Results ◽  
Pattern Simulation

Antenna array pattern nulling is desirable in order to suppress the interfering signals. But in large antenna arrays, there is always a possibility of failure of some elements, which may degrade the radiation pattern with an increase in side lobe level (SLL) and removal of the nulls from desired position. In this paper a correction procedure is introduced based on Particle Swarm Optimization (PSO) which maintains the nulling performance of the failed antenna array. Considering the faulty elements as nonradiating elements, PSO reoptimizes the weights of the remaining radiating elements to reshape the pattern. Simulation results for a Chebyshev array with imposed single, multiple, and broad nulls with failed antenna array are presented.

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