| With the development of wireless communication technology,receiver and radar sensor system play an important role in different fields.The six-port network can provide multiple selectable vector channels,and has been widely used in microwave measurement applications.Since the 1990 s,it has been used in direct conversion receivers and radars sensor.And due to its natural advantages,the six-port receiver technology has been developed rapidly,and various high-frequency,multi-channel,broadband,and multifunctional radar receiver systems have been realized.Substrate integrated suspension line(SISL)is a new circuit design platform,which is firstly proposed by Ma Kaixue team.Using multilayer printed circuit technology,SISL not only has advantages of traditional suspension line like low loss and high Q,but also overcomes the drawbacks of traditional waveguide suspension lines like high cost,low integration,large size and high weight.At present,there are many active and passive devices such as low-noise amplifiers,power amplifiers,VCOs,switches,multiplexers,high-gain antennas,and couplers have implemented and verified on SISL platform.In this thesis,a new six-port network based on SISL platform is firstly designed.Using the technology of hollowing out the substrate,double-metal layer and electromagnetic shielding environment formed by the upper and lower ground planes and the surrounding metalized vias shielding wall,the circuit loss is significantly reduced in the three aspects of dielectric loss,conductor loss and radiation loss.And according to the design concept and method of bionic honeycomb,three SISL patch couplers and a SISL rat-race coupler are integrated on the SISL platform to implement the new SISL six-port junction.Every component is set in an independent closed cavity,which can reduce the parasitic effect between the adjacent components effectively and improves the integration efficiency of the system circuit.The designed SISL six-port junction circuit operates in the 24 GHz frequency band,and is integrated with the SISL diode detector and differential operational amplifier on the same SISL platform to constitute the SISL six-port network.The overall circuit is processed using standard PCB technology with high system integration,and has advantages of low loss,low cost and self-packaging.In this thesis,a transition scheme in the stacked-SISL structure is proposed,which can realize the vertical integration of SISL and improve the integration of the system.In addition,the interconnection structure between the cavities in the honeycomb concept is introduced,which can reduce the parasitic effects greatly.Subsequently,a Ka-band vertical power divider based on stacked-SISL is designed and applied to the feeding network of SISL-based Vivaldi antenna 2×2 array,which verifies the application value of the stacked-SISL platform. |
