X-band SIW Magnetron Directional Coupler

From the birth of 1G in 1980 s to the current 5G era,with the continuous development of mobile communication technology,wireless communication system is developing towards miniaturization,high frequency and high power.In this context,"reconfigurable directional couplers" or "tuning directional couplers" based on substrate integrated waveguides(SIW)have a wide range of applications.SIW is a kind of planar transmission line with waveguide-like structure proposed at the beginning of the 20 th century,which is easy to integrate with planar circuits and is very suitable for high-frequency and high-power scenarios.The existing mechanical reconfigurable directional couplers have the problem of slow adjustment speed,so electronically controlled reconfigurable directional couplers can not be applied to highfrequency and high-power scenarios.In order to solve the above problems,combined with the existing magnetically controlled reconfigurable antennas and filters,the tunability of the parameters of the directional coupler is realized by loading the ferrite junction in the SIW directional coupler and changing the external bias magnetic field.The research is as follows.1.Firstly,the X-band SIW transmission line is designed;on the basis of the SIW transmission line,three SIW porous directional couplers coupled with 20 d Bmag10 d B SIW directional couplers are designed.The three SIW porous directional couplers are all full band and the directivity is more than 24 d B.According to the SIW transmission line,the SIW short slit directional coupler is designed,the central frequency is 10 GHz,and the20 d B directional bandwidth is 1.07 GHz.Then the SIW short-slit directional coupler is designed,the center frequency is 10 GHz,and the directional bandwidth of 20 d B is1.07 GHz.2.Based on three kinds of SIW porous directional couplers loading ferrite at appropriate position,three magnetron coupling coefficient adjustable SIW directional couplers with different coupling degree are designed.By changing the external bias magnetic field,under different coupling degrees,the coupling degree adjustment of the three devices is larger than that of 1.5d B,and the external bias magnetic field has little influence on the isolation and standing wave.3.Based on the ferrite junction loaded at the appropriate position of the SIW short slit directional coupler,the magnetically controlled frequency adjustable SIW directional coupler is designed.Under the premise that the directional bandwidth of the 20 d B is1 GHz,the center frequency shifts 200 MHz under the change of the external bias magnetic field.The above work provides two ways to realize magnetically reconfigurable directional couplers.This type of adjustable directional couplers has potential application value in the context of miniaturization,high frequency and high power development of wireless communication.