An Effective Modification of Conventional Beamforming Methods Suitable for Realistic Linear Antenna Arrays

Abstract

Antenna array beamforming (BF) refers to a real-time procedure that aims at calculating the proper feeding weights applied to the array elements in order to create a main lobe and a number of nulls toward respective preassigned directions. Most of the research performed on BF has been based on a simplified mathematical model, which ignores the nonisotropic radiation pattern of the array elements and the element mutual coupling. This article introduces an innovative way to incorporate the actual radiation pattern of the array elements and the element coupling into two popular deterministic BF methods, thus making these methods applicable to realistic antenna arrays. These two modified methods are applied in several scenarios, where a desired signal and several interference signals with various directions of arrival are received by a realistic microstrip linear antenna array. The statistical analysis performed in every scenario demonstrates the validity and effectiveness of the proposed modification. Index Terms-Antenna array beamforming (BF), direction of arrival (DoA), microstrip arrays, minimum variance distortionless response (MVDR), mutual coupling, null steering beamforming (NSB). I. INTRODUCTION A NTENNA array beamforming (BF) is related to a particular problem that has to be solved in real time. It concerns the calculation of feeding weights applied by a proper feeding network to the elements of the antenna array in order to make the array create a main lobe and a number of radiation nulls toward respective preassigned directions [1]-[19]. In fact, the main lobe direction must coincide with the direction of Manuscript

Compact Multi-Wideband Array for Millimeter-Wave Communications Using Squint Beams

“…In this paper, we investigate wideband antenna arrays that employ spatial squint beams for cellular communications. Our research is based on overly idealistic assumptions and is in its infancy, both the non-isotropic pattern and the mutual coupling of the array elements should be considered for implementing a realistic antenna array [52]. The main contributions of the paper can be summarized as follows:…”

Development of beamforming techniques for antenna arrays

“…However, the lack of a fabricated array does not alter the conclusions of this research. This chapter is based on the publication [101], which was a result of this doctoral research.…”

“…In any case, these aforementioned methods manage to address the effects of the mutual coupling, but they still do not consider the non-isotropic patterns of the array elements. Moreover, the estimation of the coupling coefficients and the construction of the MCM require complex calculations that slow down the beamformer re- In this chapter, we present a new approach to construct the steering vectors [101]. In particular, we construct the steering vectors using the EEPs of the array elements [97][98][99][100].…”

“…Τα σήματα θορύβου επίσης προσομοιώνονται μέσω κανονικής κατανομής μέσης τιμής 0 και διακύμανσης: κριση του μορφοποιητή δέσμης. Σε αυτό το κεφάλαιο, παρουσιάζουμε μια νέα προσέγγιση για την κατασκευή των διανυσμάτων οδήγησης [101]. Συγκεκριμένα, κατασκευάζουμε τα διανύσματα οδήγησης χρησιμοποιώντας τα ΕΔΑ των στοιχείων της στοιχειοκεραίας [97--100].…”

“…Ωστόσο, η χρήση προσομοιωμένων δεδομένων δεν μεταβάλλει τα συμπεράσματα της έρευνας. Το συγκεκριμένο κεφάλαιο βασίζεται στη δημοσίευση [101], η οποία ήταν αποτέλεσμα αυτής της διδακτορικής έρευνας.…”