Compensation type helix microstrip resonant unit and branch line coupler

Abstract

The invention discloses a compensation type spiral microstrip resonance unit which includes an input port, an output port, a spiral microstrip line and a central microstrip line, wherein the spiral microstrip line is symmetrically disposed taking the central microstrip line as symmetrical line, and the spiral microstrip line is led out from the center of the central microstrip line and is a spiral microstrip open circuit line, one end of which is folded inwards; the invention further includes a long annular belt shaped open circuit compensation microstrip line and a short annular belt shaped open circuit compensation microstrip line which are led from the center of the central microstrip line, and which are disposed at the same side of the central microstrip line. The invention further discloses a branch-line coupler based on the compensation type spiral microstrip resonance unit. The resonance unit is transmission line at fundamental frequency, and has strong restraining effect on the transmitted signal at the second order and the third order harmonic position. The branch-line coupler comprised by the compensation type spiral microstrip resonance unit has advantages of harmonic suppression, small circuit area, low insertion loss and so on.

Description

Technical field: [0001] The invention belongs to the technical field of microwave branch line couplers, in particular to a compensation type spiral microstrip resonant unit and a branch line coupler based on the microstrip resonant unit. Background technique: [0002] Branch line couplers are widely used in microwave integrated circuits, especially -3dB couplers with equal power. ICs such as registers, phase shifters, and switches. The output signals of the two output ports of the branch line coupler have a theoretical phase difference of 90 degrees at the center frequency. [0003] Figure 1 shows the structural diagram of a traditional branch line coupler. It can be seen from the figure that there are four microstrip lines inside the coupler, of which the characteristic impedance of the two lateral microstrip lines is 35Ω, and the vertical two microstrip lines The characteristic impedance of the microstrip line is 50Ω, and the length of each microstrip line is a quarter w...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a compensation-type spiral microstrip resonator unit with small overall size and strong harmonic suppression effect and a branch line coupler made of it, so as to overcome the problems of large volume and cost in the prior art. High, passive filters have defects such as differential loss and poor system performance

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