Research On Low Profile Microwave Millimeter Wave Guide Attenuator And Load

With the exploration of microwave millimeter wave circuits,the study of circuit miniaturization has become an important part of it,so the substrate integrated waveguide as an easily integrated and low-cost transmission line has gradually become a structure that research scholars are keen to study.In this thesis,the substrate integrated waveguide is used as an intermediate transition structure to transition electromagnetic waves into the dielectric substrate under the premise of using waveguide ports,thus making the circuit effectively miniaturized by using a dielectric substrate with high loss angle tangent to consume the electromagnetic waves in the dielectric substrate,and thus proposing the following two circuits:1.two types of waveguide port low-profile attenuators based on a lossy transmission line are proposed.One is a waveguide port low-profile single-plate coupled attenuator and the other is a waveguide port low-profile double-plate traveling wave attenuator.Both attenuators are based on the waveguide-SIW transition structure,the electromagnetic wave energy in the resonant cavity of the SIW for consumption,and finally part of the energy from the output port,so as to achieve the purpose of energy attenuation.After testing: S11 of waveguide port low-profile single-plate coupled attenuator is basically under-16.5d B between 29.6GHz-31.2GHz,S21 can maintain a flatness of about 1d B between 29.2GHz-31 GHz,with a relative bandwidth of 6%;for the low-profile double-layer traveling-wave attenuator with waveguide ports,the flatness of S11 is basically below-16.5d B between 31GHz-33 GHz,S21 reaches16.6d B-17.6d B between 31.2GHz and 32.6GHz,with flatness within 1d B.2.three types of waveguide port low-profile matching loads based on a consumed transmission line are proposed.The first one is waveguide-SIW-microstrip line waveguide port low-profile matching load,the second one is multimode consumptive resonant cavity SIW waveguide based matching load,and the third one is high power hybrid SIW aggregate resistive waveguide port low-profile matching load.All three matching loads use the waveguide-SIW transition,and tolerance analysis was performed on the waveguide-SIW-microstrip line waveguide port low-profile matching load.After testing: the waveguide-SIW-microstrip line waveguide port low-profile matching load in the frequency range below-19 d B is 45.3GHz-53 GHz,with a relative bandwidth of 15.67%;the S11 based on multimode consumptive resonant cavity SIW waveguide matching load is less than-15 d B in the frequency range of 31GHz-35.6GHz,with a relative bandwidth of 13.8%;the high power The S11 of the low-profile matching load of the hybrid SIW aggregate resistive waveguide port is under-20 d B in the frequency range of 7.98GHz-9GHz,with a relative bandwidth of 12%.