Low-profile circular array of equilateral triangular patches for angular diversity

The design of a planar circular antenna array of 6-triangular patches radiating away from broadside and intended for angular diversity at 5.1 GHz (HIPERLAN) is presented. This work is a contribution to the size reduction effort to integrate smart antennas on laptop computers. Each patch within the array is excited in its TM₁₁ mode (endfire radiation) on a high permittivity substrate (10.2). The thickness of the array is ∼1.4 mm. The 3 dB beamwidth in azimuth is about 60°. The return loss bandwidth is about 2% (VSWR<2), and the radiation pattern bandwidth is slightly less than 0.5%. Details of the antenna design and experimental results are presented for a fixed beam configuration.