Research On Duplexing Filtering Antenna Arrays Based On Multilayer Stacked Microstrip Patches

With the rapid development of mobile communications,especially the development of modern mobile communication devices such as handheld,vehicular,airborne and spaceborne equipment,the integrated and miniaturized design of the system has gradually become a new trend of development,and has been paid more and more attention by the academia and the industry.In recent years,the continuous innovation of the joint design method of devices has made it possible to integrate and miniaturize the system.The integrated design of the front-end system has become the focus of research.The integration of the antenna and the transceiver has not only realized the miniaturization of the system,but also improved the performance to some extent.This paper begins with the research of filtering antenna,which the antenna and filter are jointly designed with filter theory.Compared with the antenna cascaded the filter,the bandwidth and frequency selectivity of the filtering antenna are improved.Then based on the filtering antenna,the FDD(Frequency Division Duplex)duplex antenna is designed.The duplex antenna employs the integration of design of the antenna and duplexers or filter.The operating bandwidth and isolation characteristics of the duplex antenna are enhanced.Based on the integration design of antennas,the arrays of filtering antennas and duplexing antennas have been proposed in this paper.The works are summarized as follow:1?A filtering antenna array based on SLR(stub-loaded resonator)is proposed.The working principle of the two-layers stacked microstrip patches and SLR are firstly analyzed.Using the joint design method,the antenna serves as the last stage of the filter.A two element filtering antenna array rending a fourth-order filtering response is designed.Due to the introduction of transmission zeros by filter,the broadside gain has a radiating zero outside the low and high frequency bands,which improves the frequency selectivity and out-of-band suppression.On the basis,a five-order filtering 2x2 filtering antenna array is designed by changing the feeding method,which expands the bandwidth and improves the frequency selectivity.2?A FDD filtering antenna array based on a duplex network with asymmetric transmission zeros is proposed.By combining the dual-mode SLR filter with the design of power distribution network,a six port duplex power distribution network is designed to realize the isolation between the transmitting and receiving channels,and each channel has the function of filtering,power distribution and 180 degree phase shift.The transmitting and receiving channel of the antenna can enhance the isolation between the transmitting and receiving port by the transmission zero generated by the SLR filter in the other operating band.The duplex antenna employs the joint design of the antenna and duplexer.By integrating the dual-frequency two-layers stacked microstrip patches with a six-port duplex filter network,a duplexing filtering antenna array is designed.The antenna patches serve as the last stage of the duplexing network,so that each channel has a third-order filtering response.The ratio of the operating band to the guard band of the transmitting and receiving channels is 0.85 and 1.2,respectively.3?A FDD filtering antenna array based on SLR filtering power divider network is proposed.The element of the antenna array adopts a novel two-layers stacked microstrip patches,in which short circuit column is loaded on the driving patch,in order to reduce the mutual interference between the transceiver channels.Then,the transmitting and receiving filtering antenna arrays are designed based on the filter synthesis theory.The theory is consistent with the simulation results.Finally,the two filtering antennas are integrated to complete the design of the duplex filter antenna.