The Research Of Microstrip Array Antenna At K Band

As the indispensable part in radio systems, such as communication, navigation, radar, telecontrol and telemetering, the performance of antenna is very important. With the development of microwave integrating technology and new manufacturing technology, microstrip antenna has been improved dramatically. Compared with traditional antennas, microstrip antenna has many advantages, such as miniaturization, light weight, low profile, easily integrated, and low cost, suitable for mass production. Besides, it also can get diverse electrical performances. Except the common advantages, the microstrip array antenna at K band, which working between 18 GHz to 26 GHz, also has some excellent benefits, short wavelength, wide band, strong anti-interference, and good propagation characteristics. With such distinct advantages, the microstrip array antenna at K band has been widely used in military equipment and civilian applications. So, the research of microstrip array antenna at K band has very important value of applications.In the basis of radiation theory of microstrip antenna and the analysis and synthesis of array antenna, starting from the demand of projects and using electromagnetic simulation software, two pairs of microstrip array antennas at K band with different types and features were designed.1. Aimed at the automotive anti-collision radar, microstrip array antennas at K band,which adapted series parallel feed network and working at resonant mode. A pair of antenna included 8×6 elements and two pairs of antennas included 8×2 elements were designed. By taking the rectangular metal patch as the radiation element and by cutting a slot in the radial edge of rectangular patch, the linear array was standing-wave array with series-feeding. And by combing the linear arrays with parallel connection, the planar array antenna was realized. The feed network had advantages of compact structure, low microstrip loss and low stray radiation. To reduce the side-lobe level, the Taylor synthesis method was employed to realize unequal amplitude and in-phase incentive. By using the quarter wavelength transformer section, it was easy to realize current distribution and impedance matching. The feed network was flexible, and convenient to control current distribution, which was suitable for project. Test results showed that, the array antennas had the advantages of high gain, low side-lobe, narrow beam width, small size and easily integrated.2. A microstrip array antenna at K band with 8×8 elements and parallel feed network was designed. It adapted the rectangular metal patch with feeding in no-radial edge, and used the 2×2 subarray to makeup the 23×23 array. The feed network not only reduced the feeder length and the numbers of corners, but also made it flexible to restrain the cross polarization level. Compared with the traditional parallel feed network, it was simple and low loss. Besides, compared with the common array antennas with equal current and in-phase incentive, the test results showed that the array antennas had higher gain, lower side-lobe, narrower beam width and higher radiation efficiency,.Tests indicated that, the array antennas designed met the design index. To make further research on microstrip array antenna at K band, the expectation was made at the end in this paper.