Flat topped radiation pattern synthesis based on FIR filter concept

A Zero Placement Algorithm for Synthesis of Flat Top Beam Pattern With Low Sidelobe Level

“…Both methods are used in this simulation for comparison. It shows clearly that while FIR algorithm used in [5] does make a flat-top beam pattern, the synthesized SLL is around -52.7dB. In contrast, the proposed ZPFT algorithm by beamwidth gives a much lower SLL of around -75dB with the same broadened flat-top main beam width of 25 • , the same null to null beamwidth of 60 • and a negligible ripple of 0.25dB as shown from the zoomed view of the flat top pattern in Fig.…”

“…In the first simulation, ZPFT is compared with window method based on FIR and Dolph-Chebyshev to demonstrate that ZPFT is able to deliver the same main beam as the window methods but with much lower SLL or narrower null to null beamwidth. A 7 elements ULA with flat-top beam pattern with -52dB SLL as designed in [5] is used for comparison for FIR based algorithm. The design parameter is listed below in Table (1).…”

“…Various robust algorithms [2]- [4] have been proposed to cater for the mismatch of DOA by putting in constraints to broaden the main beam. The Flat Top shaped beam pattern [5]- [9] is thus increasingly attractive due to its flat response to large DOA mismatch especially in high mobility scenario when the DOA changes more rapidly.…”

“…To get flat-top beam pattern, Finite Impulse Response (FIR) based algorithms and various numerical optimization algorithms over an objective or cost function could be used. Window method [5] based on FIR algorithm is popular due to its robustness and easy for implementation. But due to its extra constraints of the same level of ripples in pass band and stop band, it is not optimum for the filter order [21].…”

A Generalized Flat-Topped Beam Synthesis Approach for Uniform Linear Array With Arbitrary Beam Directions

“…The sector beam array design is introduced as an example of the Fourier series method with windowing, demonstrating that the broadside and oblique FTB synthesis can be performed using a low-pass FIR filter with a frequency shifting [31]. In our previous work, the FTB synthesis based on the FIR filter concept has been exemplified for broadside FTBs [32].…”