Digital Beamforming Antenna Beam Switching Antenna

Antenna have found many applications and are rapidly advancing as the development of radar, communication, mobile TV reception in both commercial and military applications. Some researches on the Digital Beam-forming antenna and beam controlled antenna have been proposed in this thesis. The main contents are listed below:Part 1:Study the DBF antenna array.1.Design a DBF antenna array. First, a microstrip antenna element is designed. Based on the element, an sub-array is simulated. Then 100 array have been manufactured and measured. From the measured results, the bandwidth of the antenna is about 1 GHz and the peak gain is 16.5dB.The gain is more than 15.8dB in the bandwidth. The error of the radiation patterns is less than 0.5dB.2. The concept and results of investigation of grating lobe reduction through superstrate is presented in this paper. Through the superstrate, the radiation pattern of element antenna has been optimized. As a result, the grating lobe level is reduced for the radiation is depressed at the position of the grating lobe.The uniform distribution 1×10 microstrip antenna array has been manufactured. The experiment results show that the grating lobe is reduced by 5dB through the superstrate.Part 2:Study the beam controlled antenna.1. A novel U-slot patch antenna with electromagnetic band-gap (EBG) structure is presented. From the measured results, the peak radiation of the antenna is shifted at 22°and the gain is 7.55dBi at the working frequency 5.5GHz. The parametric studies have been given. As a result, the beam is shifted with the arrangement of the EBG structure. It is shown that the beam can be shifted at 16°,22°nd 31°with the arrangement of EBG structure.2. A novel aperture coupled antenna with artificial magnetic conductor (AMC) structure is presented. From the simulated results, the peak radiation of the antenna is shifted at 21°and the gain is 6.4dB at the working frequency 5.5GHz. Furthermore, the parametric studies have been given. As a result, the beam is shifted with the arrangement of the AMC structure. It is shown that the beam can be shifted at 11°with the one arrangement of AMC structure. Base on the antenna element, a 1×2 antenna array is presented. The advantage of array antenna with AMC structure is higher gain and bandwidth, controlled beam performances. The array is shifted at 26°and the gain is 8.47dB at the working frequency 5.5GHz.3. Three different of novel U-slot radiation pattern reconfigurable patch antennas with electromagnetic band-gap (EBG) structure are presented. As a result, the beam is shifted with the arrangement of the EBG structure. Base on the property, a radiation reconfigurable antenna is presented. By controlling the states of switches installed on EBG, several modes are obtained. The advantage of pattern reconfigurable antenna with EBG structure is low-profile, controlled beam performances.