CN108183297B

CN108183297B - Centralized parameter circulator

Info

Publication number: CN108183297B
Application number: CN201810105082.4A
Authority: CN
Inventors: 汪晓光; 刘水平; 肖宇; 张丽君; 刘曜铭; 刘天民; 刘源; 李民庆; 李冠亚; 朱廷学; 邓德琪; 艾万森; 陈良; 谢海岩; 梁迪飞
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2018-02-02
Filing date: 2018-02-02
Publication date: 2020-02-14
Anticipated expiration: 2038-02-02
Also published as: CN108183297A

Abstract

The invention relates to the technology of microwave circulators, in particular to a lumped parameter circulator. The invention increases the inductive coupling through the design of slotting the arc center conductor, thereby reducing the impedance imaginary part of the circulator, better realizing the impedance matching and widening the bandwidth.

Description

Centralized parameter circulator

Technical Field

The invention relates to the technology of microwave circulators, in particular to a lumped parameter circulator.

Background

With the development of science and the advancement of technology, miniaturization is becoming more and more a popular trend of modern products. However, as can be seen from the theory of the strip-line circulator, the radius R of the ferrite disk of the junction circulator is proportional to the wavelength λ, which means that the lower the frequency, the larger the radius R of the ferrite disk, the larger the size and the heavier the strip-line junction circulator. Therefore, to reduce the volume of junction circulators, lumped parameter circulators have been developed.

However, the existing lumped parameter circulators are magnetically or electrically coupled, and because the imaginary part of the impedance of the circulators is large, impedance matching is not easy to achieve, and further bandwidth cannot be achieved widely.

Disclosure of Invention

Aiming at the problems or the defects, the invention provides a lumped parameter circulator for solving the problem that the bandwidth of the traditional lumped parameter circulator is not wide enough, and the inductive coupling is increased to realize wider bandwidth.

The lumped parameter circulator is a hexagonal structure consisting of three parts, namely a filling medium, a central conductor and a ferrite disc.

The ferrite disc is divided into two layers with upper and lower surfaces parallel to each other and separated by a central conductor, the upper surface of the central conductor is attached to the lower surface of the upper ferrite disc, the lower surface of the central conductor is attached to the upper surface of the lower ferrite disc, and the upper and lower surfaces of the central conductor are parallel to the upper surface of the ferrite disc.

The center conductor is composed of three sections at 120 degrees to each other, each corresponding to three ports of the circulator, each section including one wide center conductor, two narrow center conductors, and two arc center conductors.

From the port to the central junction, the wide central conductor, the narrow central conductor and the arc central conductor are arranged in sequence. One end of the wide central conductor is a circulator port part, the other end of the wide central conductor is connected with two narrow central conductors which are parallel to the space, and the two arc central conductors are respectively and correspondingly connected with the two narrow central conductors. The left side surface of the wide central conductor is coplanar with the left side surface of the narrow central conductor, the right side surface of the wide central conductor is coplanar with the right side surface of the other narrow central conductor, and the wide central conductor and the narrow central conductor are cuboids; the upper and lower surfaces of the arc center conductor are parallel and are in consistent thickness and tangent connection with the narrow center conductor.

The upper surface of each port wide center conductor is coplanar with the upper surface of one of the narrow center conductor and the arc center conductor, and the lower surface thereof is coplanar with the lower surface of the other of the narrow center conductor and the arc center conductor.

The arc central conductor of each port is connected with the arc central conductors which are not coplanar and correspond to the other two ports through the metal cylinders so as to realize electric coupling, and finally, the three components of the central conductor and the components corresponding to the other two ports form 120-degree rotational symmetry about the Z axis respectively. Further, the metal cylinder is homogenous with the center conductor.

The arc central conductor is provided with a completely penetrating groove along the radian central line; the physical center of the groove is positioned on the central line of the radian, and the circle centers of the groove and the radian are the same circle center; impedance matching is carried out by controlling the size of the slot, once the impedance matching approaches to an ideal condition, the working bandwidth is widened, and the slot can change the internal capacitance-inductance structure of the central conductor, so that the mutual inductance coupling of the conductor is enhanced.

The invention increases the inductive coupling through the design of slotting the arc center conductor, thereby reducing the impedance imaginary part of the circulator, better realizing the impedance matching and widening the bandwidth.

Drawings

FIG. 1 is a top view of an embodiment of a lumped parameter circulator prior to being unslotted;

FIG. 2 is a top view of a slotted lumped parameter circulator of an embodiment;

FIG. 3 is a schematic diagram of a slotted lumped parameter circulator of an embodiment;

FIG. 4 is a simulation result of S-parameters of the lumped parameter circulator before slotting in the embodiment;

FIG. 5 is a Smith chart simulation of a lumped parameter circulator before being slopped of an embodiment;

FIG. 6 is a simulation result of S-parameters of the slotted lumped parameter circulator of the embodiment;

FIG. 7 is a Smith chart simulation of a slotted lumped parameter circulator of an embodiment;

reference numerals: 1-filling medium, 2-ferrite disk, 3-wide central conductor, 4-narrow central conductor, 5-arc central conductor and 6-groove.

Detailed Description

The technical scheme of the invention is detailed below by combining the accompanying drawings and the embodiment.

As shown in fig. 1, is a lumped parameter circulator before slotting, with a center frequency of 750 MHz. Conventional lumped parameter circulators operate at this frequency and do not operate very wide in bandwidth.

The ferrite disk of the lumped parameter circulator has the radius of 7.2mm, the thickness of 1.8mm, the saturation magnetic moment 930Gauss, the relative dielectric constant of 15 and the resonance line width of 50 oersted.

The central conductor is copper, the width of the wide central conductor is 9.3mm, the thickness is 0.42mm, and the length is 11.5 mm; the narrow center conductor has a width of 1.02mm, a thickness of 0.2mm and a length of 6 mm. The filled medium is polytetrafluoroethylene resin. The circulator realizes magnetic coupling at the intersection of the upper and lower narrow central conductors and electric coupling at the connection of the arc central conductors. A fully penetrating slot of arc 30 degrees is spaced along the centre of the centre conductor of the arc, the width of the slot is 0.2mm and the radius of the arc inside the centre conductor of the arc corresponds to 5.71 mm.

The result of the S parameter of the circulator before slotting and final simulation is shown in figure 4, and the smith chart is shown in figure 5. When the conductor segments are separated by a slot at the center of the arc, the simulated S-parameter results are shown in fig. 6 and the smith chart is shown in fig. 7. Comparing fig. 4 and 5, it can be seen that the bandwidth is increased from 306M to 327M, which shows that the working bandwidth can be widened by performing the slotting process at the arc center conductor of the circulator, thereby improving the practical result.

Claims

1. The utility model provides a lumped parameter circulator, is the hexagonal body structure that three parts of filling medium, central conductor and ferrite disc constitute, its characterized in that:

the ferrite disc is divided into two layers with upper and lower surfaces parallel to each other and separated by a central conductor, the upper surface of the central conductor is attached to the lower surface of the upper ferrite disc, the lower surface of the central conductor is attached to the upper surface of the lower ferrite disc, and the upper and lower surfaces of the central conductor are parallel to the upper surface of the ferrite disc;

the central conductor is composed of three parts which form 120 degrees with each other, each part corresponds to three ports of the circulator, and each part comprises a wide central conductor, two narrow central conductors and two arc central conductors;

the wide central conductor, the narrow central conductor and the arc central conductor are sequentially arranged from the port to the central junction; one end of the wide central conductor is a circulator port part, the other end of the wide central conductor is connected with two narrow central conductors which are parallel in space, and the two arc central conductors are respectively and correspondingly connected with the two narrow central conductors; the left side surface of the wide central conductor is coplanar with the left side surface of the narrow central conductor, the right side surface of the wide central conductor is coplanar with the right side surface of the other narrow central conductor, and the wide central conductor and the narrow central conductor are cuboids; the upper surface and the lower surface of the arc central conductor are parallel and are in consistent thickness with the narrow central conductor and are in tangent connection;

the upper surface of each port wide central conductor is coplanar with the upper surface of one narrow central conductor and the upper surface of one arc central conductor, and the lower surface of each port wide central conductor is coplanar with the lower surfaces of the other narrow central conductor and the other arc central conductor;

the arc central conductor of each port is connected with the non-coplanar arc central conductors corresponding to the other two ports through the metal cylinders to realize electric coupling, and finally, the three components of the central conductor and the components corresponding to the other two ports form 120-degree rotational symmetry about the Z axis respectively;

the arc central conductor is also provided with a completely penetrated groove along the radian central line; the physical center of the groove is positioned on the central line of the radian, and the circle centers of the groove and the radian are the same.

2. The lumped-parameter circulator as recited in claim 1, further comprising: the metal cylinder is homogenous with the central conductor.