Research And Design Of Four-phase Quadrature Coupler Based On LTCC Technology

The four-phase quadrature coupler,as a new type of passive device that can equally divide the incident signal into four orthogonal signals,is of great significance to the polarization of the antenna.The development of 5G commercialization from the coexistence of non-independent networking(NSA)and independent networking(SA)to completely independent networking(SA)has put forward higher requirements for the anti-interference ability and selectivity of space signals.The phase quadrature coupler not only satisfies the signal isolation,but also reduces the number of antennas.With its unique multi-layer three-dimensional structure,short-period design and embedded passive components,LTCC technology is more and more widely used in the production design of RF side.In this paper,under the support of LTCC technology,the existing power divider,phase shifter,coupler,and balun are improved and innovated.According to the characteristics of these passive components,four types of four-phase quadrature structures are studied Coupler,the research results are as follows:(1)The power divider and phase shifter are cascaded to design two types of four-phase quadrature couplers with lumped structure and distributed structure.For the lumped structure,the article introduces the principle of the high-and low-pass phase shifter in detail,and innovatively uses a jumper capacitor to adjust the phase balance of the 90-degree high-and low-pass phase shifter,and then uses a capacitor-loaded lumped structure to design the power divider.The size is 6.4mm × 4.8mm × 0.9mm.For distributed structure,the article analyzes the principle of open-circuit stub-loaded phase shifter,selects stripline for design,and creatively adopts upper,middle,and lower layers for layout.The dimensions are 16 mm ×15mm × 5.5mm.(2)By combining the directional coupler and the delay line,an improved distributed four-phase quadrature coupler is designed.Analyze the couplers of different routing methods,and design a 180-degree coupler with a helical symmetrical structure and two couplers with a serpentine wiring structure,and distribute them symmetrically up and down to reduce the size.The final design size is only It is 6mm × 8mm × 2.3mm,and its processing test,the test result shows that the design scheme is feasible.(3)A three-wire improved Marchand balun and multi-section cross-interconnected broadband coupler cascade are used to design a broadband four-phase quadrature coupler.The design differences of the balun in the case of different material dielectric constants and wiring methods are analyzed in detail,and then the symmetrical multi-section structure and cross-interconnection structure of the coupler are analyzed.The broadband balun and coupler are designed according to the theory.A broadband four-phase quadrature coupler with a relative bandwidth of 66.7% and a size of 10.8mm × 9mm × 1mm is designed.