| With the fast development of wireless communication technology, higher and higher demands have been put forward for various antennas. On one hand, the rise of the indoor high-speed wireless data access technology calls for the ultra-wideband antennas. Meanwhile, to avoid the interference between ultra-wideband (UWB) system and some other existing communication systems, such as WLAN and WiMAX, the UWB antennas should be band-notched.Phased array antenna is responsive, sensitive, accurate and can detect, identify and track multiple targets, so it is a very advanced multi-functional integrated antenna. It can be used almost in all of the military radar system, in addition to the air traffic control, weather forecasting in civilian areas.Continuous transverse stub (CTS) has many advantages as a new antenna, it has a vast arena.The dissertation makes deeply insight to UWB antennas, phased array antenna system and CTS antenna. The author’s major contributions are as follows:1. The design and realization of a type of UWB antenna and three UWB double band-notched antennas are presented. A crescent microstrip-fed printed UWB antenna is proposed. By adjusting the parameters of the antenna, the antenna yields ideal impedance bandwidth. Based on this UWB antenna, three types of double band-notched UWB antenna are designed through etching U-shaped slot in the radiation plane or defected ground structure (DGS), the influence of their parameters on band-notched characteristic is analyzed. Finally, all the antennas mentioned above are fabricated and measured. The measured results agree well with simulated ones.2. A conformal low side-lobe passive phased array antenna system has been studied. A simple and wideband printed dipole is designed, then a linear array is also presented based on this element, and the low sidelobe and beam scanning is realized. A fractal microstrip antenna is proposed to reduce the antenna size. A novel and compact power divider is presented by introducing microstrip open-ended and short-ended stubs to reduce the size and suppress the harmonics. A type of microstrip band-pass filter with DGS is designed to suppress the parasitic pass-band and the measured results agree well with the simulated ones. Then the design of digital phase shifter and attenuator applied in feeding work is given, the measured results are well. At last, the phased array antenna is measured in the anechoic chamber, and the results could meet the design requirements.3. A Ku band low profile and compact phased array antenna system has been studied. A double H-slot aperture-coupled microstrip antenna is presented and the measured results meet the requirements. A new aperture-coupled wideband micristrip element is proposed and the simulation results show it has wider bandwidth and higher isolation. Two types of microstrip divider are designed and fabricated, the measured results show their own advantages and disadvantages. Then the digital phase shifter and attenuator used in feeding network are designed and measured, the measured results are well. And an effective active variable polarization method is put forward to solve the problem of polarization mismatch, it can achieve polarization tracking and decrease the polarization mismatch by controlling the antenna element amplitude of the two ports, and the method is verified by the experiment. Finally, the array synthesis is done according to the specification, the array radiation pattern and the scanning characteristic is given.4. A type of CTS antenna is presented. The antenna can realize miniaturization, low profile, low cost, conformal properties and it is a very promising candidate phased array antenna element. The antenna characteristic is analyzed by changing its parameters. Then a 5 element array is designed and the parameters of the CTS element are synthesized to achieve low side-lobe. Based on the former synthesized array, the array realizes scanning by virtue of ferroelectric material. At last, a 5×5 CTS array achieves good dual linear polarization and circular polarization. |
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