Simplified Tightly-Coupled Cross-Dipole Arrangement for Base Station Applications

The electromagnetic fundamentals that govern the performance characteristics of dual-polarized tightly coupled cross-dipoles that are widely used in cellular base station applications are investigated. The mutual coupling effects and their impact on standard performance indices are stressed. A model is developed that considers this type of cross-dipole as an array. Links between the physical dimensions of the components of these model and key radiation characteristics, including directivity, half-power-beam width, and cross polarization discrimination levels, are established. The model guides the introduction and optimization of a simplified cross-dipole structure that exhibits excellent performance. A prototype was fabricated, assembled, and tested. The measured results are in good agreement with their simulated values, validating the model, and its governing principles.