A novel phase-only excitation law for omnidirectional arrays

A new class of excitation sequences (PAT Codes) for feeding large linear omnidirectional arrays is presented. The use of PAT Codes succeeds in overcoming the problem, typical of previously proposed excitations (e.g., Kuttruff-Quadt, Huffman-Type, Huffman Codes), of obtaining Radiation Patterns with excellent omnidirectional characteristics and avoiding, at the same time, power utilization inefficiencies due to amplitude tapering. This attractive feature derives from the innovative PAT Code generation method named Spectral Domain Synthesis (SDS) which acts directly on Code Spectrum and leads to define a simple code generation formula. Thanks to SDS, PAT Code-fed arrays succeed in controlling Radiation Pattern omnidirectionality both on average and locally, avoiding the presence of deep dips or peaks typical of other feeding sequences (e.g., Frank Codes). Due to their systematic generation algorithm, PAT Codes may be easily employed in large array applications and might also represent an optimum starting point for numerical optimization techniques aiming at further performance improvements.