| Summary: | 碩士 === 國立交通大學 === 電信工程系 === 87 === In this thesis, the design of a dual linearly polarized array antenna for base stations is presented. The antenna operates in the personnel-communication-system (PCS) band (1850MHz-1990MHz) with VSWR < 1.5. The two orthogonal polarizations are ±45°slanted. The array consists of several aperture-coupled microstrip patch elements fed by a microstrip corporate feeding network. A symmetrical feeding structure for each patch element is proposed and used to achieve good isolation (larger than 30dB) between the two orthogonal ports. In addition, to suppress the back radiation and increase the front-to-back ratio, a metal reflector is suitably placed behind the array antenna. Arrays with two, four, and eight antenna elements are fabricated and measured. Good performances have been achieved. Each array has a narrow beamwidth (depending on the element number) in the vertical direction and a beamwidth of about 65°in the horizontal direction.
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