Research On Technologies Of Antenna For Small Wirelss Devices And Directional Antenna On Chip

With the development of the wireless communications, antenna has become an important part of the wireless devices. In the meantime,with the volume of wireless devices constantly decreasing, it has brought challenges for antenna design. These challenges appear in three aspects. The first is the small antenna design. From the half wavelength antenna to the quarter wavelength and eighth wavelength antenna, from the whip antenna to the low-profile antenna, from the free space antenna to the high dielectric antenna, the antenna volume is constantly shrinking. The second is the wide band antenna design. As the channel capacity of wireless application increasing constantly, the antenna bandwidth grows from several MHz to several GHz. The last is the high gain antenna design. In order to expand the scope of antenna radiation, the high gain antenna array has been developed rapidly. In addition to the antenna design, the wireless device has also brought some problems, such as the cell phone antenna can't be selected in a late design, but as an integrated part that must be designed along with the entire layout of the mobile design. And the antenna of the wireless interconnect on chip must has small interference to the chip circuit. In considering the above problems, this dissertation has finished the following research.An antenna with the finite ground is presented. The fold type and sliding type mobile phone has two ground planes. A comprehensive investigation into the performance of two ground planes with various angle and ration was performed. Results from numerical simulation and measurement on prototype hardware are presented to show the influence of angle and ratio on resonant frequency, bandwidth, return loss of centre frequency, gain, and radiation patterns. It is found the Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS) of the mobile phone satisfy the Cellular Telecommunications and Internet Association (CTIA) certification. For studying how to integrate several antennas in a finite ground, a dual Subscriber Identity Module (SIM) mobile phone which integrates a planar inverted-F antenna (PIFA), a monopole and an inverted-F antenna (IFA) was designed. The main circuit board has a dimension of 105 mm×45 mm. By reasonably positioning the antennas and adjusting the gap and angle of the antennas, good isolation of the three antennas can be obtained. The PIFA and monopole support the GSM (Global System for Mobile) communications applications. The TRP and TIS of them reach the requirements of the CTIA certification. The gain of the IFA which enables the Bluetooth function is 3.79 dBi. The presented ways are very useful for design of the dual SIM mobile phone. A new dual frequency series feeding coaxial collinear antenna array is developed. It consists of the first frequency radiation section, the double frequency radiation section, and the end adjusting section. For the effect of double frequency, there should be an even number of the double frequency radiation sections. The antenna gain of the dual frequency bands can be adjusted separately. A dual frequency COCO (coaxial collinear) antenna array which operated at 900 MHz and 1800 MHz was fabricated for experimentation. It has the S11 of -24.8 dB and -14.3 dB at 900 MHz and 1800 MHz respectively, as well as the -5 dB S11 impedance bandwidths of 830-1020 MHz and 1700-1970 MHz. Furthermore it has better omni-directivity in the horizontal plane. For its low cost and structural simplicity, the antenna array is suitable for small repeater of mobile communication system to support GSM900/DCS1800.A new compact 24-GHz ladder reflector antenna on chip is presented. It has been developed using the standard 0.18 um six metal layers CMOS process. The antenna consists of an active dipole and a ladder reflector array. Through adjusting the number, gap, and arm width of the reflectors, the ladder reflector array successfully adjusts the radiation direction of the active dipole and effectively suppresses the interference of the active dipole to chip circuit. The measured results show that the ladder reflector antenna has a 6.25 dBdc gain at 24 GHz and a -6 dB S11 impedance bandwidth of 19.92-27.60 GHz. The design method is quite straightforward, and can be used to develop antenna on chip for wireless interconnect for inter-chip communications.