Research On Multilayer Microwave Circuit Based On Broadside-coupled Structure

Compared with the traditional planar microstrip structure circuit,the multi-layer microwave circuit is not only easy to obtain the tight coupling of the circuit,but also easy to realize the miniaturization of the circuit.This thesis proposes a curved T-shape microstrip patch based on the microstrip-slot broadside coupling structure,and have designed an ultra-wideband(UWB)with an excellent performance and small size,a wideband filter and a wideband filter with a notched band;a multi-layer millimeter wave power divider is designed using a curved T-shaped structure;a curved T-shape coupled transition interconnection structure is proposed for the multi-layer interconnection problem of millimeter wave circuits,and the interconnection frequency can reach above 80 GHz,which makes the multilayer circuit integration more flexible.The main contents of this thesis include:(1)The SIR resonator is introduced.The working principle and resonance characteristics of the quarter-wavelength and half-wavelength SIR are analyzed,respectively.The theory and methods of the miniaturization of the circuit and using the impedance ratio to control the parasitic passband are analyzed.(2)Introduced the basic type of broadside coupling structure transmission lines,and mainly introduced the the microstrip-slotline broadside coupling structure.By establishing the odd-even mode equivalent circuit model,the transmission characteristics of the microstrip-slotline coupling structure are analyzed,and the calculation method of the circuit coupling coefficient is given.(3)A microstrip-slotline broadside coupling resonator with a curved T-shaped structure is designed and it has two transmission poles in the band.The resonant characteristics and circuit performance of the resonator are also analyzed.Based on the curved T-shaped resonator structure,a new UWB filter with multiple transmission poles,a wideband filter and a wideband filter with wide notch characteristics were designed,respectively.The transmission characteristics and the parameter selection of cascaded coupling units are mainly studied in UWB filter.In the design of wideband filter,the circuit bandwidth is controlled by the coupling coefficient adjustment,and the method of suppressing the out-of-band harmonics frequence by using half-wavelength SIR to improve the bandwidth of the upper stopband is studied.The thesis researched the design and implementation of the wideband filter with a notched band desiged using the curved T-shaped structure,and the controlled method of the notch frequency is given by the analysis of the equivalent circuit.(4)A 5G millimeter wave one-two-type power divider is designed by using a curved T-shaped microstrip-slotline broadside coupling structure.The power divider can work at 24.5-25.5 GHz and achieve equal power distribution through the analysis of equivalent circuits.The design method of equal power distribution and unequal power distribution is given by the analysis of equivalent circuit,which embodies the advantages of multi-layer structure in circuit miniaturization design,and it embodies the advantages of multi-layer structure in circuit miniaturization design.(5)Introduced the vertical via interconnect and vertical strip interconnect structure based on traditional microwave integrated circuits,and proposed a microstrip interconnection method with a curved T-shaped structure that can work in the 5G millimeter wave band,And gives a detailed performance analysis In this thesis,the design process and performance analysis of each microwave device are introduced in detail,and the wideband filter and notch filter are physically produced and tested,and compared with the simulation results to verify the feasibility of the design method.