A Pattern Shaping Method for Focused Antenna Arrays

In this letter, the extended method of maximum power transmission efficiency (EMMPTE) is applied to the design of the antenna array to generate desired field patterns in the target region. By introducing different weighted constraints, the EMMPTE ensures the high electric field intensity in the target region while its distribution pattern can be flexibly controlled. Once the weighted matrix is determined, a focused electric field pattern with the desired shape can be generated by the antenna array with the optimized distribution of excitations obtained from solving the weighted constrained problem. To verify the validity of the proposed method, a 6 x 6 microstrip antenna array operating at 2.45 GHz is designed and fabricated to produce four different focused near-field patterns-a square, a circle, a triangle and a heart-shaped pattern. Measurement results show a good agreement with simulations.