CN106785290B - Filtering power divider based on quarter-mode substrate integrated waveguide circular cavity - Google Patents

Abstract

The invention discloses a filter power divider based on a quarter-mode substrate integrated waveguide circular cavity, which is formed by combining two quarter-mode substrate integrated waveguide circular cavities through a signal input microstrip line The quarter-mode substrate-integrated waveguide circular cavity is obtained by dividing the substrate-integrated waveguide circular cavity along any two mutually perpendicular magnetic walls, and along its two right-angled sides are respectively provided with signal input microstrip lines and signal The output microstrip line is provided with a field mode perturbation hole and a parasitic passband suppression mode perturbation hole; the signal input from the signal input end enters two quarter-mode substrate integrated waveguide circular cavities respectively, after filtering and power. After dividing, it is output by the signal output terminals of the two signal output microstrip lines. While the device size is obviously reduced, the invention combines the filter and the power divider to realize a highly integrated multifunctional passive device, which is suitable for filtering and power division of the local oscillator of a microwave and millimeter wave communication system.

Description

A Filtering Power Divider Based on Quarter-Mode Substrate Integrated Waveguide Circular Cavity

technical field

The invention relates to a filter power divider based on a quarter-mode substrate integrated waveguide circular cavity, which belongs to the technical field of microwave passive devices.

Background technique

With the rapid development and maturity of modern wireless communication systems, filters and power dividers as their important components have also attracted extensive attention and research. In traditional low frequency designs, microstrip filters and power dividers are very common. However, in the millimeter-wave frequency band, the passive structure of the microstrip structure has problems such as large insertion loss and difficult processing; while the traditional low-loss metal waveguide structure has problems such as complex structure, difficult design, large size, and inability to integrate planarly. Therefore, the advantages of substrate-integrated waveguide technology in the millimeter-wave frequency band have attracted widespread attention.

Substrate integrated waveguide technology is a new type of waveguide device with low insertion loss, high quality factor, and high power capacity that has appeared in the past decade. Various substrate integrated waveguide passive and active based on PCB and LTCC processes It has both the advantages of traditional metal waveguides and planar circuits, and has unparalleled advantages in production cost and design complexity in the microwave and millimeter wave frequency bands.

At present, the 5G millimeter wave communication system that has attracted widespread attention, especially the massive MIMO system, the millimeter wave front-end module puts forward higher requirements on the loss, size and processing accuracy of the circuit. Therefore, highly integrated devices or modules have become an important research focus. Among them, the inventor mainly considers how to improve the integration degree from two aspects: one is how to reduce the size from the substrate integrated waveguide structure itself, and the other is that the multifunctional passive device can realize a more compact structure in the wireless communication system . In many traditional communication systems, the filter and the power divider are usually designed separately and finally cascaded to realize the functions of filtering and power division. The problem with this design method is that the area of the circuit is large and the loss is large. Therefore, the inventor considers designing a filter and a power divider in combination, so as to realize a small-sized, multi-functional, and highly integrated passive device.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a filter power divider based on a quarter-mode substrate integrated waveguide circular cavity, which is used to solve the problem of the large size of passive devices in a millimeter wave communication system. , The technical problems of large loss and poor integration.

Technical scheme: In order to realize the above-mentioned purpose, the technical scheme adopted in the present invention is:

A filter power splitter based on a quarter-mode substrate-integrated waveguide circular cavity, comprising two quarter-mode substrate-integrated waveguide circular cavities;

Wherein, the quarter-mode substrate-integrated-waveguide circular cavity is obtained by dividing the substrate-integrated-waveguide circular cavity along any two mutually perpendicular magnetic walls, and signal input microstrips are respectively provided along its two right-angle sides. line and signal output microstrip line; the substrate-integrated waveguide circular cavity includes a dielectric substrate whose upper and lower surfaces are covered with metal conductive layers, and metal through holes penetrating the upper and lower metal conductive layers are uniformly distributed on the dielectric substrate along the circumferential direction ;

A field mode perturbation hole is arranged in the right-angle area of the quarter-mode substrate-integrated waveguide circular cavity, and a parasitic passband suppression mode is arranged on the quarter-mode substrate-integrated waveguide circular cavity inside the metal through hole. perturbation holes, and both the field mode perturbation holes and the parasitic passband suppression mode perturbation holes are metal holes penetrating the dielectric substrate and the upper and lower metal conductive layers;

Two quarter-mode substrate-integrated waveguide circular cavities are combined through a signal input microstrip line, that is, the two signal input microstrip lines are connected as a whole to form the signal input end of the filter power divider; from the signal input end The input signal enters two quarter-mode substrate integrated waveguide circular cavities respectively, and after filtering and power division, it is output from the signal output ends of the signal output microstrip lines on both sides.

Specifically, two quarter-mode substrate-integrated waveguide circular cavities are symmetrically distributed about the connected signal input microstrip line, and the signal input microstrip line and the signal output microstrip line are both 50 ohm microstrip lines. , and the signal output microstrip line achieves the direction consistency of the signal input end and the signal output end through a 90° rotation angle.

Specifically, the line connecting the center of the parasitic passband suppression mode perturbation hole and the right-angle end of the quarter-mode substrate integrated waveguide circular cavity where it is located is at a right angle to the quarter-mode substrate integrated waveguide circular cavity where it is located. The sides are at an angle of 45°.

Specifically, a thin slit separating the two field mode perturbation holes is disposed between the two quarter-mode substrate-integrated waveguide circular cavities, and the slit has a width of 0.2 mm.

Beneficial effects: The filter power splitter based on a quarter-mode substrate integrated waveguide circular cavity provided by the present invention has the following advantages compared to the prior art:

(1) Small size: the present invention adopts a quarter-mode circular substrate-integrated waveguide structure, which reduces the size by 75% compared to the conventional substrate-integrated waveguide circular structure;

(2) High integration degree: the present invention adopts the idea of integrated design of filter and power divider, and integrates two independent passive devices on a passive structure, which greatly improves the integration degree while reducing the size;

(3) Simple implementation: Compared with other design schemes adopting a multi-layer structure, the present invention does not require a multi-layer structure, and can be realized only by using an ordinary PCB processing technology and adding metal through-hole perturbation;

(4) Small loss: Compared with the design of using an independent filter and a power divider, the filter power divider of the present invention integrates the functions of the two at the same time, and its loss is less than the sum of the two independently generated, which is beneficial to reduce the circuit losses incurred.

Description of drawings

1 is a schematic diagram of the result of the substrate integrated waveguide circular cavity in the present invention;

2 is a schematic structural diagram of a quarter-mode substrate integrated waveguide circular cavity in the present invention;

Fig. 3 is the overall structure schematic diagram of the present invention;

Fig. 4 is the frequency response curve diagram of the filter power divider in the embodiment of the present invention;

The figure includes: 1. Substrate integrated waveguide circular cavity, 2. Metal through hole, 3. Quarter-mode substrate integrated waveguide circular cavity, 4. Signal input microstrip line, 5. Signal output microstrip line , 6, the field mode perturbation hole, 7, the parasitic passband suppression mode perturbation hole, 8, the signal input, 9, the signal output.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in FIG. 3, a filter power splitter based on a quarter-mode substrate-integrated waveguide circular cavity includes two quarter-mode substrate-integrated waveguide circular cavities 3;

The quarter-mode substrate-integrated-waveguide circular cavity 3 is obtained by dividing the substrate-integrated-waveguide circular cavity 1 along any two mutually perpendicular magnetic walls, and signal inputs are respectively provided along its two right-angle sides. Microstrip line 4 and signal output microstrip line 5; as shown in Figure 1, the substrate-integrated waveguide circular cavity 1 includes a dielectric substrate whose upper and lower surfaces are covered with metal conductive layers, and the dielectric substrate is uniform along the circumferential direction Distributed metal through holes 2 penetrating the upper and lower metal conductive layers;

As shown in FIG. 2 , a field mode perturbation hole 6 is provided in the right-angle area of the quarter-mode substrate-integrated waveguide circular cavity 3 , and the quarter-mode substrate-integrated waveguide circular cavity inside the metal through hole 2 The cavity 3 is provided with a parasitic passband suppression mode perturbation hole 7, and the field mode perturbation hole 6 and the parasitic passband suppression mode perturbation hole 7 are both metal holes penetrating the dielectric substrate and the upper and lower metal conductive layers;

The two quarter-mode substrate-integrated waveguide circular cavities 3 are combined through the signal input microstrip line 4, that is, the two signal input microstrip lines 4 are connected as a whole to form the signal input end 8 of the filter power divider; The signal input from the signal input terminal 8 enters the two quarter-mode substrate integrated waveguide circular cavities 3 respectively, and is output from the signal output terminal 9 of the two signal output microstrip lines 5 after filtering and power division.

In this embodiment, two quarter-mode substrate-integrated waveguide circular cavities 3 are symmetrically distributed with respect to the integrated signal input microstrip line 4, and the signal input microstrip line 4 and the signal output microstrip line 5 are both A 50-ohm microstrip line is used, and the signal output microstrip line 5 is rotated by 90° to achieve the direction consistency of the signal input end 8 and the signal output end 9 .

In this embodiment, the line connecting the center of the parasitic passband suppression mode perturbation hole 7 and the right-angle end of the quarter-mode substrate integrated waveguide circular cavity 3 where it is located is connected to the quarter-mode substrate integrated waveguide circle where it is located. The right-angled sides of the cavity 3 are at an included angle of 45°; a slit separating the two field mode perturbation holes 6 is arranged between the two quarter-mode substrate-integrated waveguide circular cavities 3, and The slit has a width of 0.2 mm.

In this embodiment, the relative permittivity of the selected dielectric substrate is 10.2, and the thickness of the dielectric is 1.27mm; and the geometrical parameters in FIG. 3 are: L1=8.5mm, L2=4mm, L3=6.8mm, L4=3.3 mm, g1=0.6mm, g2=0.3mm, D1=2mm, D2=2mm, D3=1.2mm, the overall plane size including the input and output microstrip lines is 35mm*15mm.

Fig. 4 is the frequency response curve of the filter power divider in the embodiment of the present invention, wherein the three curves are test results, wherein the center frequency of the filter power divider is 9.1GHz, the bandwidth is 600MHz, and the insertion loss in the passband is better than 1.7 dB, the return loss in the passband is better than 15dB, and the two power division output ports have good consistency.

The specific embodiments of the present invention are as follows:

The signal enters from the signal input end 8 of the filter power divider. Since there is a quarter-mode substrate integrated waveguide circular resonator filter on the left and right of the structure, the input signal is first divided into two paths, and then Filtered by band-pass filters composed of quarter-mode substrate integrated waveguide circular cavity 3 and perturbed metal holes, and finally output signals of equal amplitude and in-phase from two signal output ends 9 respectively.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (1)

1. A filter power splitter based on a quarter-mode substrate integrated waveguide circular cavity, characterized in that it comprises two quarter-mode substrate integrated waveguide circular cavities (3); Wherein, the quarter-mode substrate-integrated-waveguide circular cavity (3) is obtained by dividing the substrate-integrated-waveguide circular cavity (1) along any two mutually perpendicular magnetic walls, and along its two right-angle sides, respectively A signal input microstrip line (4) and a signal output microstrip line (5) are provided; the substrate-integrated waveguide circular cavity (1) includes a dielectric substrate whose upper and lower surfaces are covered with metal conductive layers, and the dielectric substrate is Metal through holes (2) penetrating the upper and lower metal conductive layers are evenly distributed along the circumferential direction; A field mode perturbation hole (6) is arranged in the right-angle region of the quarter-mode substrate-integrated waveguide circular cavity (3), and the quarter-mode substrate-integrated waveguide circular cavity (2) is provided inside the metal through hole (2). The cavity (3) is provided with a parasitic passband suppression mode perturbation hole (7), and the field mode perturbation hole (6) and the parasitic passband suppression mode perturbation hole (7) are both metal penetrating the dielectric substrate and the upper and lower metal conductive layers hole; The two quarter-mode substrate-integrated waveguide circular cavities (3) are combined through a signal input microstrip line (4), that is, the two signal input microstrip lines (4) are connected as a whole to form the filter power divider The signal input terminal (8); the signal input from the signal input terminal (8) enters the two quarter-mode substrate integrated waveguide circular cavities (3) respectively, and after filtering and power division, the two signal output micro The signal output terminal (9) on the strip line (5) is output; Two quarter-mode substrate-integrated waveguide circular cavities (3) are symmetrically distributed with respect to the integrated signal input microstrip line (4), the signal input microstrip line (4) and the signal output microstrip line ( 5) 50 ohm microstrip lines are used, and the signal output microstrip line (5) realizes the direction consistency of the signal input end (8) and the signal output end (9) through a rotation angle of 90°; The line connecting the center of the parasitic passband suppression mode perturbation hole (7) and the right-angle end of the quarter-mode substrate integrated waveguide circular cavity (3) where it is located is connected to the quarter-mode substrate integrated waveguide circular cavity where it is located The right-angled sides of the cavity (3) form an included angle of 45°; A thin slit separating the two field mode perturbation holes (6) is provided between the two quarter-mode substrate-integrated waveguide circular cavities (3), and the slit has a width of 0.2 mm .

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