| In recent years, microelectronic technique and process technology have experienced rapid development. Millimeter-wave (MMW) solid-state devices have matured, and monolithic microwave integrated circuit (MMC) has developed to high frequency and has been applied in MMW band, all of which have laid a good foundation of development of MMW integrated system. With the improvement of MMW system continuously, increasing demands are put forward to antennas, which speed MMW antennas' development enormously. Novel structure and high performance antennas are presented constantly, and most of them have been applied to MMW system successfully.Combined with the international development and application of MMW radar, research background of the thesis is introduced, and innovation and importance of researching the compact MMW radar system based on MMIC technology is presented at the beginning. The thesis also collects the state of arts and the development trend of MMW microstrip array antenna during last ten years.Following the introdution of basic theory, classical analysis method and feeding structure of microstrip antenna, and configuration, characteristics and feeding network of microstrip array antenna, the thesis discusses design method and performance of the rectangular microstrip antenna, and gives calculation formulas available in MMW band. Based on the results of theoretical calculation, influence of antenna patch dimensions and feed point positions upon input impedance and return loss with different feeding ways is investigated with the aid of HFSS9.0. Optimized parameters are achieved which correspond to the theoretical ones.According to the project demand of radar front-end, eight MMW microstrip array antennas are designed, fabricated and measured. Two of them are double-antenna arrays designed for MMW radar front-end. Good isolations are proved, and both double-antenna arrays have been applied to compact radar front-end successfully. The other six microstrip array antennas are designed for radar front-end worked with single antenna. Three of them are formed by traditional sub-arrays including a 64-element antenna array fed from radiating edge, a 64-element antenna array fed from non-radiating edge and a 256-element antenna array fed from non-radiating edge. The left three are designed with hybrid feeding of series and parallel including a 16-element antenna array, a 144-element antenna array and an improved 144-element antenna array with broadband. The hybrid feeding network has several parallel branches and a group of antenna elements are fed in turn in each branch. This feeding network makes antenna element number of square array more flexible. An effective multi-resonance method is presented to enhance bandwidth of the 144-element antenna array. By designing dimensions of each patch and length of quarter wavelength transformer in parallel branches, close resonant frequencies can be obtained and matched well simultaneously which widen bandwidth nearly four times with the radiation pattern almost unchanged.As the background of the MMW array antennas, MMW radar front-end based on MMIC technology is introduced in detail. Circuit of the radar front-end is hybrid integration of MMIC barechips and microstrip components with MCM technology. The whole circuit is fabricated on substrate with the same dimension as the antenna and connected with antenna by coaxial probe or hole coupling from back to back. Two compact radar front-ends operate at 36.5GHz are mainly introduced. They work with single antenna and double-antenna respectively, and they are integrated in metal boxes with 25mm and 30mm diameters individually. System integration, major qualifications, allocation of objectives and integration technique are presented in the thesis. Measurement results of MMW radar front-end employed the double-antenna array are given which show perfect performance.At the end of the thesis, fabrication technique and measurement method of microstrip antenna are discussed. Detailed fabrication process and measurement procedure of S parameters and radiation pattern are introduced. The thesis also describes prospects of application of microstrip antenna in MMW wireless communication field.
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