FDA-MIMO Beampattern Synthesis with Hamming Window Weighted Linear Frequency Increments

Abstract

By utilizing a tiny frequency increment across the array elements, frequency diverse array (FDA) generates a beampattern possessing the property of range-angle-dependent. However, the beampattern of the conventional FDA is "S"-shaped, which means it is coupled in range-angle domains, resulting in low target indication accuracy and poor jamming suppression ability. In this paper, taking advantage of multiple-input multiple-output (MIMO) technique and multiple matched filters, a new FDA framework using Hamming window weighted linear frequency increments is proposed. Correct FDA-MIMO framework and multiple matched filters are used to remove the influence of the time parameter. A range-angle-decoupled beampattern with sharp pencil-shaped mainlobe and low sidelobe levels can be produced. Comparing with the existing FDA-decoupled transmit beampattern design methods, a more focusing beampattern can be achieved. Simulation results validate the superiority of the proposed system.

Joint optimisation of transmit beamspace and receive filter in frequency diversity array‐multi‐input multi‐output radar

“…One is located at ð20°; 20 kmÞ and the other is located at ð40°; 40 kmÞ. We use the Hamming window weighting method to set the frequency offset value, and the frequency offset is [10]:…”

“…However, the beam pattern of the FDA radar is range-angle coupled. To overcome this problem, many scholars have proposed non-linear frequency offset methods such as: logarithmically increasing frequency offset, hamming window-based non-uniform frequency offset, random frequency diverse array and hamming window weighted linear frequency increments [7][8][9][10]. Furthermore, the authors in Ref.…”

FDA-MIMO Beampattern Synthesis with an Analytical Method

“…Many scholars have explored this to form a better beam. Logarithmically increasing frequency offset (Log_FDA) [14], Hamming window-based frequency offset (Ham_ FDA) [16], and Hamming window weighted linear frequency increments (HL_FDA) [18] have been proposed. The proposed frequency offset scheme in our work is analytical method (AM_FDA).…”

“…And they did not consider the influence of time parameters. Considering the influence of time parameters [11], a method of increasing frequency combined with window function is proposed in [18]. It is still a numerical solution.…”

“…(2) In FDA-MIMO radar, the mathematical relationship between frequency offset and range-angle beampattern has not been clarified, such as [18]. Through the simplified approximation of the pattern, we get that the spot beam formed by the FDA-MIMO radar is a quadratic curve related to the frequency offset, which mathematically explains how the frequency offset affects the performance of the beampattern…”