Massive multiple input multiple output antenna array is crucial for the fifth generation wireless communication. Proper antenna array design can reduce interference among different signals and generate desirable beamforming. Sparse antenna array is able to form narrower beam with lower sidelobe than equally spaced antenna array given the same number of array elements. However, determining the p...

In this paper one optimization heuristic search technique, Hybrid Evolutionary Programming (HEP) is applied to the process of synthesizing three-ring Concentric Circular Antenna Array (CCAA) focused on maximum sidelobe-level reduction. This paper assumes non-uniform excitations and uniform spacing of excitation elements in each three-ring CCAA design. Experimental results reveal that the design...

We consider the ‘faint companion’ problem where substantial reduction of diffraction sidelobes is required in order to image a faint neighbour near a much brighter source. In addition to well-known pupil amplitude and shape apodization methods, we found that the required sidelobe reduction can be obtained by appropriate spatial phase modulations over an aperture. Here, our previous results on o...

This paper investigates the benefit of mutual coupling compensation via a method of moments (MoM) approach in a uniform circular antenna array operating at 1.8 GHz. This mutual coupling compensation technique is applied to a direction of arrival (DOA) study of up to two cochannel mobile users. Field measurements and computer simulations are examined to explore the assumptions of the technique a...

Schmidt proved in 2014 that if ε > 0, almost all binary sequences of length n have peak sidelobe level between ( √ 2 − ε)√n log n and ( √ 2 + ε) √ n log n. Because of the small gap between his upper and lower bounds, it is difficult to find improved upper bounds that hold for almost all binary sequences. In this note, we prove that if ε > 0, then almost all binary sequences of length n have pea...

The modulation technique of N -continuous orthogonal frequency division multiplexing (OFDM) has lower sidelobes than those of the original OFDM as a result of the continuous connection with higher-order derivatives between the OFDM symbols. Compared with the other sidelobe suppression schemes, for example, cancellation carrier insertion, and windowing, N continuous OFDM does not require an exte...

This paper proposes a two-channel adaptive microphone array with target tracking to reduce external noise in hands-free speech communications. The proposed microphone array has two processings, one of which is beamforming and the other is target tracking. The Frequency Domain Generalized Sidelobe Canceller (FDGSC), which is the frequency domain adaptive filter derived from the time domain adapt...

Sidelobes cancellation is challenging task in beamforming and beam steering in smart antenna systems. The high level of sidelobes can significantly degrade the system performance as well as antenna power efficiency. In this paper, we present the new decimal genetic algorithm to reduce the sidelobe and at the same time create the nulls toward interferers and jammers. This technique takes advanta...

Many kinds of microstrip array antennas have been developed in the millimeter-wave band. In order to avoid feeding loss and the decrease of antenna gain by beam shift due to frequency changes, center-fed array antennas are advantageous. In this case, the element spacing around the feeding circuit of the transition from the waveguide to two microstrip lines is larger than one wavelength. Therefo...

Adaptive arrays are of immense interest due to their ability to automatically steer nulls towards undesired interference sources, thereby reducing the output noise and enhancing the detection of desired signal. In active phased arrays, each antenna element is weighted for beamforming. These weights are estimated iteratively using different algorithms. Generalized sidelobe cancellers (GSC) are a...