Design Of A Low Profile Duplex Slot Antenna With Transmission Zero

In recent years,mobile communication technology has developed rapidly,and miniaturization and integration have gradually become a new trend in the development of communication systems.The design of the duplex antenna is not simply to cascade the antenna and the duplexer,but a joint design needs to be considered comprehensively.Different techniques can be used to achieve high transceiver port isolation.For example,by adding the frequency isolation structure like filter,defective ground structure can improve port isolation.Compared to a single antenna system,a duplex antenna structure is more compact and more integrated.Because of its low profile,light weight,simple structure,easy processing,low cost and easy conformity,the planar slot antenna has become one of the important research objects in wireless communication antenna design in recent years.The joint design of the two makes it possible to achieve a compact antenna structure and better performance.The slot in the antenna of this article is both a radiating element and a resonant element.The first two antennas successfully increase the isolation of the port by introducing a transmission zero point.The third antenna is a slot array,and the resonant mode within the passband is increased.It also serves to increase isolation.1.Highly isolated duplex slot antenna with transmission zero.The half-wavelength open path is used to stimulate the rectangular slot on the back of the floor,so that the transmit and receive frequency bands have second-order filtering characteristics.In order to improve the isolation of the receiving and sending ports,a quarter-wavelength open stub line is introduced in each of the transceiver network,resulting in a transmission zero near each transceiver band.In order to reduce the size of the antenna,the partial open route was bent.The final measured results prove the effectiveness of the design.2.Duplex "I-shaped" slot antenna.A common dual-mode resonator's even mode is used to couple the side of the "I-shaped" slot,and the feed is fed by the end-coupled feed.The second-order filtering characteristics are realized in the transmit-receive passband.The simulation results show that the isolation of the low-frequency passband is low.Therefore,a quarter-wavelength open-end stub line corresponding to the central frequency is introduced in the high-frequency feed network,and a transmission zero point is successfully introduced near the low-frequency passband.Increased isolation by nearly 10 d B.The final processing was performed.3.Duplex "I-shaped" slot antenna array.Based on the design of the "I-shaped" slot antenna,the dual-mode resonator's even-mode excitation of two "I-shaped slot" antenna units is also used,so that the power is equally divided to the unit,and the input impedance is improved by the end-coupled feeding method.The dual-mode resonator for performing power splitting has a resonant mode in itself,and the array antenna finally exhibits third-order filtering characteristics in the operating frequency band.Finally,after a simple optimization in HFSS,a duplex "I-shaped" slot antenna array design was implemented.