Design of integrated stripline multibeam antenna arrays fed by compact butler matrices

The design of the fully integrated four-beam antenna array has been presented. A stripline technique has been selected which allows for achieving good properties of the feeding network which is a key issue to obtain good parameters of the antenna array and at same time ensures reliable mechanical properties. The compensated 3 dB/90deg coupled-line directional coupler is used as a basic element of our compact broadband Butler matrix. In order to ensure proper connection of the radiating elements and the feeding network in the integrated structure the compensated crossover is applied. As radiating elements stripline-fed aperture coupled patch antennas have been used. The four-beam integrated antenna array operating within 2.4 GHz band has been designed, manufactured and measured. Measurement results confirm good properties of the presented antenna.