CN205452493U - Coplane waveguide bandpass filter based on novel split ring resonator structure - Google Patents

Abstract

The utility model discloses a coplane waveguide bandpass filter based on novel split ring resonator structure, gap structure in dielectric substrate, central conduction band, central conduction band, the metal grounding plate of central conduction band both sides, the ribbon metallic who connects both sides metal grounding plate, the split ring resonator structure that corresponds with each gap structure, the metal throuth hole of being connected split ring resonator structure and metal grounding plate. Wherein, the gap structural formation stop band of co -planar waveguide center conduction band, the ribbon metallic who connects both sides metal grounding plate is used for restrain tank drawing die formula, and the split ring resonator structure is used for producing the passband, and the metal throuth hole is used for deepening the passband and the outer frequency selection nature of elevator belt. The utility model discloses an in central conduction band loading gap structure to pass gap structural connection both sides metal grounding plate through ribbon metallic, further reduced the electric size of split ring resonator structure, possess better outband characteristic.

Description

Coplanar waveguide bandpass filter based on a novel split resonator structure

technical field

The utility model relates to a coplanar waveguide bandpass filter based on a novel split resonant ring structure, which belongs to the field of microwave technology.

Background technique

The traditional split resonant ring structure has a smaller electrical size and a higher quality factor, so this structure has attracted attention as soon as it was proposed, and it is widely used in the field of constructing miniaturized bandpass filters. When the split resonant ring structure is combined with the coplanar waveguide, the bandpass filter is usually implemented by conducting a series capacitor or parallel inductor in the center of the coplanar waveguide, but due to the existence of the parasitic passband, the out-of-band performance needs to be improved.

Utility model content

The technical problem to be solved by the utility model is: to provide a coplanar waveguide bandpass filter based on a novel split resonant ring structure, introduce a gap structure into the central conduction band of the coplanar waveguide, and use strip metal to connect the metal junctions on both sides. The floor suppresses the slot line mode, thereby forming a stop band, and loading a new split resonant ring structure with a smaller electrical size. When the resonant ring is working, a narrow passband is generated near the resonant frequency, thereby realizing miniaturization bandpass filter.

The utility model adopts the following technical solutions for solving the above-mentioned technical problems:

A coplanar waveguide bandpass filter based on a new split resonant ring structure, including a dielectric substrate, a central conduction band is arranged in the middle of the upper surface of the dielectric substrate, and the two ends of the central conduction band extend to the edges of a pair of opposite sides of the dielectric substrate respectively , and the central conduction band is perpendicular to the pair of opposite sides of the aforementioned dielectric substrate; the central conduction band is provided with two slit structures parallel to the pair of opposite sides of the aforementioned dielectric substrate, and the two sides of the central conduction band are also provided with metal Grounding plate, the metal grounding plates on both sides of the central conductive strip are connected by two strips of metal passing through the two gap structures respectively;

A centrally symmetrical split resonant ring structure is provided on the lower surface of the dielectric substrate directly below each slit structure. The split resonant ring structure includes first to seventh metal strips connected end to end in sequence, wherein the second, fourth and sixth The metal strips are parallel to each other and the distance between adjacent two is equal, the first and third metal strips are perpendicular to the second metal strip, the fifth and seventh metal strips are perpendicular to the sixth metal strip, and the 1. The fifth metal strip is on the same straight line, the third and seventh metal strips are on the same straight line, the length of the first and seventh metal strips is the same and less than the length between the second and fourth metal strips The spacing of the split resonator ring structure is symmetrical about the bifold line parallel to the direction of the central conduction band of the dielectric substrate; metal through holes are provided at the two ends of the split resonator ring structure to connect the split resonator ring structure and the metal on the upper surface of the dielectric substrate ground plane.

As a preferred solution of the present invention, the two slot structures are symmetrical about the center of the central conduction band, and the distance between the two slot structures is a quarter of the waveguide wavelength.

As a preferred solution of the present invention, the lengths of the second, fourth and sixth metal strips are the same.

As a preferred solution of the present invention, the characteristic impedance of the coplanar waveguide on the upper surface of the dielectric substrate is 50 ohms.

As a preferred solution of the present invention, the dielectric substrate is a Rogers4003 dielectric plate.

As a preferred solution of the present invention, the dielectric substrate is rectangular.

Compared with the prior art by adopting the above technical scheme, the utility model has the following technical effects:

1. When realizing the coplanar waveguide bandpass filter, the utility model loads the gap structure on the central conduction band, introduces capacitance, and enhances the attenuation of the low-frequency end outside the passband; connects the metal grounding plates on both sides through the gap structure through the strip metal , to ensure that the potentials on both sides are consistent during work, thereby achieving the effect of suppressing the groove line mode, avoiding the use of traditional air bridges, and making the process easier.

2. The utility model adopts a new split resonant ring structure. Compared with the traditional split resonant ring, the new structure has a lower working frequency under the same physical size, so it has a smaller electrical size and meets the requirements of miniaturization; The operating frequency can be changed by adjusting the physical size of the new split resonant ring structure, and the adjustability is strong; the bandwidth of the filter can be widened by increasing the number of the new split resonant ring structure.

3. By introducing metal through holes, the utility model solves the disadvantage of weak coupling due to the thick dielectric substrate when the traditional split resonator ring is combined with the coplanar waveguide, and improves the performance of the structure as a whole; the new split resonator ring structure is combined with the coplanar waveguide The metal ground plate of the waveguide is connected, and at the operating frequency, a strong resonance is generated, which improves the passband performance; improves the out-of-band performance, and improves the frequency selectivity of the filter.

Description of drawings

Fig. 1 is a three-dimensional layered schematic diagram of the coplanar waveguide bandpass filter based on the novel split resonant ring structure of the present invention.

Fig. 2 is a schematic diagram of the upper surface of the dielectric substrate in the utility model.

Fig. 3 is a schematic diagram of the structure of the split resonant ring in the utility model.

Among them, 1 is a dielectric substrate, 2 is a central conduction band, 3 is a slot structure, 4 is a strip metal, 5 is a metal ground plate, 6 is a split resonant ring structure, and 7 is a metal through hole.

Fig. 4 is a simulation S-parameter diagram of the embodiment of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary, and are only used to explain the present invention, and cannot be construed as limiting the present invention.

The utility model is based on a coplanar waveguide bandpass filter with a novel split resonant ring structure, as shown in FIG. 1 , including a dielectric substrate. As shown in Figure 2, a central conductive strip is arranged in the middle of the upper surface of the dielectric substrate, and a gap structure is loaded in the middle of the central conductive strip, and the metal grounding plates on both sides of the central conductive strip are connected by a band-shaped metal passing through the gap structure; the central conductive strip The two ends of the strip extend to the edge of a pair of opposite sides of the dielectric substrate respectively, and the central conductive strip is perpendicular to the aforementioned pair of opposite sides of the dielectric substrate; both sides of the central conductive strip are also provided with metal grounding plates. The distance between the two slot structures is a quarter of the waveguide wavelength, the distance from the left slot structure to the left side of the dielectric substrate is a quarter of the waveguide wavelength, and the right slot structure to the right side of the dielectric substrate The distance is one quarter of the waveguide wavelength.

The lower surface of the dielectric substrate is located below each slit structure and is provided with a centrally symmetrical split resonant ring structure. As shown in FIG. , The fourth and sixth metal strips are parallel to each other and the distance between adjacent two is equal, the first and third metal strips are perpendicular to the second metal strip, and the fifth and seventh metal strips are both perpendicular to the sixth The metal strips are vertical, the first and fifth metal strips are on the same straight line, the third and seventh metal strips are on the same straight line, the first and seventh metal strips have the same length and are shorter than the second and seventh metal strips The spacing between the four metal strips; the structure of the split resonator ring is symmetrical about the bifold line in the direction of the long side of the dielectric substrate; metal through holes are provided at the two ends of the split resonator ring to connect the split resonator ring and the upper surface of the dielectric substrate metal ground plate.

In the embodiment of the present invention, the dielectric substrate adopts Rogers4003 dielectric board, the dielectric constant is 3.55, and the thickness is 0.8 mm. As shown in Figure 4, the horizontal axis Frequency represents the frequency (GHz), and the vertical axis S-parameter represents the S parameter (dB). The bandpass filter performance of the present embodiment is good, the central operating frequency is 4.8GHz, and the 3dB bandwidth is 4.65GHz -4.9GHz, within the stop band, the stop band suppression at low frequencies is below -40dB. It can be seen that the coplanar waveguide bandpass filter based on the novel split resonant ring structure of the present invention is a successful combination of the coplanar waveguide and the split resonator ring structure, and has the characteristics of miniaturization and high performance. It has great reference value in the planar circuit design and application.

The above embodiments are only to illustrate the technical ideas of the utility model, and can not limit the protection scope of the utility model with this. All technical ideas proposed according to the utility model, any changes made on the basis of the technical solution, all fall into the scope of the utility model. within the scope of the new protection.

Claims (6)

1. A coplanar waveguide bandpass filter based on a novel split resonant ring structure, including a dielectric substrate, characterized in that a central conduction band is arranged in the middle of the upper surface of the dielectric substrate, and the two ends of the central conduction band extend to the dielectric substrate respectively A pair of opposite edges, and the central conduction band is perpendicular to the pair of opposite sides of the aforementioned dielectric substrate; the central conduction band is provided with two slit structures parallel to the pair of opposite sides of the aforementioned dielectric substrate, and the central conduction band There are also metal grounding plates on both sides, and the metal grounding plates on both sides of the central conductive strip are connected by two strip metals passing through the two gap structures respectively; A centrally symmetrical split resonant ring structure is provided on the lower surface of the dielectric substrate directly below each slit structure. The split resonant ring structure includes first to seventh metal strips connected end to end in sequence, wherein the second, fourth and sixth The metal strips are parallel to each other and the distance between adjacent two is equal, the first and third metal strips are perpendicular to the second metal strip, the fifth and seventh metal strips are perpendicular to the sixth metal strip, and the 1. The fifth metal strip is on the same straight line, the third and seventh metal strips are on the same straight line, the length of the first and seventh metal strips is the same and less than the length between the second and fourth metal strips The spacing of the split resonator ring structure is symmetrical about the bifold line parallel to the direction of the central conduction band of the dielectric substrate; metal through holes are provided at the two ends of the split resonator ring structure to connect the split resonator ring structure and the metal on the upper surface of the dielectric substrate ground plane. 2. The coplanar waveguide bandpass filter based on the novel split resonant ring structure according to claim 1, wherein the two slot structures are symmetrical about the center of the central conduction band, and the distance between the two slot structures is a quarter of the waveguide wavelength. 3 . The coplanar waveguide bandpass filter based on the novel split resonant ring structure according to claim 1 , wherein the lengths of the second, fourth and sixth metal strips are the same. 4. The coplanar waveguide bandpass filter based on the novel split resonant ring structure according to claim 1, wherein the characteristic impedance of the coplanar waveguide on the upper surface of the dielectric substrate is 50 ohms. 5. The coplanar waveguide bandpass filter based on the novel split resonant ring structure according to claim 1, wherein the dielectric substrate is a Rogers4003 dielectric plate. 6. The coplanar waveguide bandpass filter based on the novel split resonant ring structure according to claim 1, wherein the dielectric substrate is rectangular.