Analysis and design of wideband wide-scan phased array with controllable sidelobe level based on log-periodic dipole antenna

Wideband wide-scan phased arrays (WWPAs) are crucial for radar and communication systems. The log-periodic dipole antenna (LPDA) can achieve a very wide bandwidth, but its large physical size at low frequencies often forces the element spacing to exceed the half-wavelength limit, leading to grating lobes in E-plane scanning arrays. This paper proposes an analytical design method for LPDA–based phased arrays with a design target of ± 30° scanning range, large inter element spacing (up to 0.72λ), and controllable sidelobe level (SLL). The E-plane pattern is approximated by a cos m ( θ /2) function. By combining pattern multiplication with structural non-overlap constraints, a maximum allowable spacing and a scanning bandwidth upper bound are derived. Furthermore, a closed-form relation linking SLL, beamwidth factor m, spacing d, and scan angle θ 0 . is established, enabling direct synthesis of the required element beamwidth. A systematic design procedure is then developed to determine all array parameters from system specifications. An eight-element linear array operating over 200–300 MHz is designed and validated through full-wave simulations and a 3:1 scaled model (600–900 MHz), achieving an SLL of − 10 dB and good agreement between theory, simulation, and measurement.