Investigation Of Millimeter Wave Multilayer Substrate Intergrated Array Antenna

In a wireless communication system, antenna is the key component for transmitting and receiving of signal. In recent years, the millimeter wave antenna arrays become a hot research area. Because of the huge available spectrum and lightweight spectrum license, E-band(71~76 GHz and 81~86 GHz) is increasingly becoming a hot point in the wireless communication market. E-band are widely used in high-capacity point-to-point communication system, wireless backhaul systems and broadband metropolitan network, requiring array antenna the high-gain and wideband/dual-band features at the same time. Ka-band are widely used in access control and security system, remote sensing and imaging system, industrial nondestructive testing, point-to-point communication and energy transiting, requiring array antenna the beam-focusing characteristic.High-gain array Antennas, such as slot arrays and patch arrays have relative narrow bandwidth because of restriction of the electrical characteristics. Beam-focusing antennas, for example, patch arrays, achieve focusing characteristic by adjusting phase of antenna unit, that is, through tuning length of feeding microstrip line of antenna unit with respect to its location in the array. Though realizing focusing characteristic and convenient of integration, it is hard to realize miniaturization.With the development of substrate integrated waveguide technology and multilayer processing technology, array antennas based on multilayer structure become one of the main solutions to these problems.This paper contains three parts and the main concerns are applications of multilayer structure for high-gain antenna and beam-focusing antenna.Firstly, key technologies and structures involved in the design of multilayer structure array antennas are introduced, including the two layer transition structure, the wideband coupling structure, the waveguide-SIW transition and the waveguide phase shifter, and these studies lay the foundation for design of large arrays.Secondly, the two layer dual-slot feed antenna unit and dual-resonance phenomenon are introduced and the bandwidth and gain are studied, as well as the influence of other parameters. Two E-band substrate integrated antenna array, the 16×16 high-gain wideband array and 8×8 high-gain dual-band array, are designed and tested, respectively. The measured results coincide well with the simulated ones, indicating excellent properties of two antenna arrays that the structure can obtain high-gain and wide bandwidth or dual bandwidth at the same time in design of large-scale arrays.Finally, the minimum-scale beam-focusing array, as such the 4×4 array is studied for its focal distance and 3 dB focal spot. Then an X-band 4×4 beam-focusing array feed by single slot and a Ka-band 8×8 beam-focusing array feed by dual-slot are designed based on multilayer structure. The measured and simulated results of the 4×4 agree well with each other and the array achieves beam-focusing characteristics. The simulated results of Ka-band 8×8 array show its good properties in reflection coefficient and wideband focusing characteristics.