Design Of A Microstrip Array Conformal To Conical And A Broadband Slot Antenna

The research works with scientific projects include three parts in this thesis. The engineering samples of a microstrip array conformal to conical surface with the given radiation pattern are made in the first part, the engineering sample of high gain directional circularly polarized microstrip antenna array with the given radiation pattern is made in the second part, and the engineering sample of a broadband CPW-fed T-shape slot antenna is developed is the last part.Firstly, the design methods of the microstrip conformal array antenna are discussed. The design methods of the microstrip array conformal to conical surface with the given radiation pattern and five engineering samples are presented.The design method of the microstrip array conformal to conical surface with the given direction pattern is presented based on the theories of conformal array antenna and the theories microstrip antenna. Five different frequency conical conformal array engineering samples are described based on the design method, and experimental results are presented. The measured results show that the antenna not only has good impedance matched characteristic and omidirection pattern in H-plane, but also has its radiation moved to the underside of the cone in E-plane, and the design method is available and valid.Secondly, the design method of a high gain directional circularly polarized microstrip antenna array with the given radiation pattern is discussed. A sample antenna is made and measured. The measured results show that the VSWR of the antenna is 1.5, the AR of the antenna is 1.5 and the gain of the antenna is more than 20dB at the center frequency. It is available for this design method to be applied in engineering.Lastly, a novel broadband design of a coplanar waveguide (CPW) fed T-shape slot antenna is proposed and experimentally studied. The size of the proposed antenna is reduced by over 26% compared to the reported wide slot antenna. The obtained results show that the impedance bandwidth, determined by 10-dB return loss, of the proposed slot antenna can be greater than 120%. From the experimental results, the operation mode has an impedance bandwidth of about 5690MHz (1850-7540MHz) that covers the PCS band (1.85-1.99GHz), 3G band (1.92-2.17GHz), Bluetooth band (2.4-2.48GHz), DMB band (2.605-2.665GHz) and WLAN band (2.4/5.2/5.8GHz). It is available for this design method to be applied in engineering.