Uniform impedance stub-loaded microstrip combiner

Abstract

A uniform impedance stub loaded microstrip combiner provided by the invention comprises a low-pass filter circuit, a high-pass filter circuit and a combining circuit, and is characterized in that the low-pass filter circuit comprises two cascaded [pi]1-type structural units, each [pi]1-type structural unit is provided with a main transmission line and two uniform impedance open circuit stubs arranged at the two ends of the main transmission line, the pole of the [pi]1-type structural unit is positioned on the left side of two zero points of the [pi]1-type structural unit; and the high-pass filter circuit comprises two cascaded [pi]2-type structural units, each [pi]2-type structural unit is provided with a main transmission line and two uniform impedance open-circuit branches arranged at the two ends of the main transmission line, and the pole of each [pi]2-type structural unit is located between the two zero points of the [pi]2-type structural unit. The combiner has the beneficial effects that the position of a zero pole can be flexibly regulated and controlled by adjusting parameter values of the structure units, so that a good roll-off characteristic is generated; in the design, unequal-length branch knot loading is used, so that the size of the circuit can be reduced, and the circuit is simpler and lighter.

Description

technical field [0001] The invention relates to the technical field of combiners, in particular to a microstrip combiner loaded with uniform impedance stubs. Background technique [0002] At present, the known microstrip combiners loaded with open stubs of radio frequency signals have mostly the same width as the stubs and the main line, and the wiring area is relatively large, which is not suitable for the miniaturization of combiners in the base stations of most mobile communication systems. , based on this, a miniaturized microstrip combiner loaded with unequal-length open stubs is proposed. [0003] After searching, it is found that the patent CN 204348876 U discloses a built-in microstrip combiner for an ultra-wideband dual-frequency dual-polarization base station antenna, including high-frequency branching, low-frequency branching and high-low frequency combining. The high-frequency branching has two Open stubs, the low frequency shunt has three open stubs. The micro...

AI Technical Summary

Problems solved by technology

However, its disadvantages are: the branch adopts step impedance transformation line segment, the design is relatively complicated; the length difference of the main line between the branches is very small, and the purpose of further reducing the circuit volume cannot be achieved.

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