A frequency selection structure with adjustable wave-transmitting frequency

Abstract

The present invention discloses a frequency selective structure with tunable wave transmission frequency, which comprises m×n frequency selective units arranged in an m-row and n-column array. The frequency selective units in the same row are seamlessly spliced in sequence, and the frequency selective units in the same column are seamlessly spliced in sequence. Each frequency selective unit respectively includes a varactor diode and a first copper layer, a dielectric substrate layer and a second copper layer stacked in sequence from top to bottom. A first rectangular groove penetrating through the upper and lower surfaces is formed on the dielectric substrate layer. The first copper layer is attached to the upper surface of the dielectric substrate layer and is provided with a second rectangular groove penetrating through the upper and lower surfaces. The second copper layer is attached to the lower surface of the dielectric substrate layer and is provided with a third rectangular groove, a fourth rectangular groove, a fifth rectangular groove, a sixth rectangular groove, a seventh rectangular groove, an eighth rectangular groove, a ninth rectangular groove, a tenth rectangular groove and an eleventh rectangular groove all penetrating through the upper and lower surfaces. The advantages are fast tuning speed, large tuning range, small size and low insertion loss.

Description

Technical Field

[0001] The present invention relates to a frequency selection structure, and more particularly to a frequency selection structure with adjustable wave-transmitting frequency. Background Art

[0002] The frequency selection structure has the characteristic of spatial filtering and is widely used in radar and satellite communications. The frequency selection structure plays a decisive role in modern high-tech warfare and also greatly improves the communication of aircraft and ships. On the one hand, the frequency selection structure can reduce the radar scattering characteristics of its own targets to achieve low detectability, and on the other hand, it can improve the information exchange between its own targets to achieve high communication capabilities. The main technical approach of the frequency selection structure is to reflect the out-of-band electromagnetic wave energy incident on the surface of the equipment, which can reduce the monostatic radar cross-section. Secondly, it allows the in-band electromagnetic wave energy to pass through to ensure that the electromagnetic signals within the working frequency band of the antenna can be normally transmitted to achieve communication between its own targets.

[0003] In recent years, the frequency selection structure has been widely used in antenna design as the reflector or radome of the antenna to achieve the purposes of anti-electromagnetic interference, enhancing or regulating the radiation performance of the antenna, or reducing the radar cross-section of the antenna. One of the typical functional requirements is the out-of-band reflection and in-band wave-transmitting characteristics, and the wave-transmitting frequency can be changed. The traditional frequency selection structure reflects out of band and transmits in band, and its transmission frequency is fixed. The electromagnetic transmission frequency is often related to the equivalent parasitic capacitance and inductance generated by the periodic structure, and its resonance frequency is the electromagnetic wave transmission frequency.

[0004] The currently existing frequency selection structures with adjustable wave-transmitting frequency are mainly divided into three categories: mechanical adjustable, magnetic adjustable, and electric adjustable. The mechanical adjustable frequency selection structure is achieved by changing the shape of the device, which can be a solid or a liquid. The magnetic adjustable frequency selection structure is achieved by using a ferrite substrate, and the magnetic permeability of the ferrite substrate can be changed by applying an external bias magnetic field. However, the tuning speed of these two frequency selection structures is slow and the tuning range is small, which is very fatal in modern communications. The electric adjustable frequency selection structure is achieved by loading active semiconductor devices in the structure design; the active semiconductor devices are varactor diodes, PIN diodes, or barium strontium titanate (BST) varactor diodes. The electric adjustable frequency selection structure has the advantages of fast tuning speed, large tuning range, and small size, but there is a coupling effect between adjacent structures within it, and the parasitic resistance in the selected varactor diode is relatively large, resulting in a relatively large insertion loss. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a frequency selection structure with adjustable wave-transmitting frequency that has a fast tuning speed, a large tuning range, a small size, and a low insertion loss.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows: A frequency selection structure with adjustable wave-transmitting frequency, including m×n frequency selection units, where m is an integer greater than or equal to 1, n is an integer greater than or equal to 1, and the m×n frequency selection units are arranged in an m-row and n-column array. The frequency selection units in the same row are seamlessly spliced in sequence, and the frequency selection units in the same column are seamlessly spliced in sequence. Each of the frequency selection units respectively includes a varactor diode and a first copper layer, a dielectric substrate layer, and a second copper layer stacked in sequence from top to bottom. The dielectric substrate layer is a rectangular plate, and a first rectangular groove penetrating up and down is formed on the dielectric substrate layer. The center of the first rectangular groove coincides with the center of the dielectric substrate layer. The front end face of the first rectangular groove is parallel to the front end face of the dielectric substrate layer. The left end face of the first rectangular groove is parallel to the left end face of the dielectric substrate layer. The upper end face of the first rectangular groove is in the same plane as the upper end face of the dielectric substrate layer. The lower end face of the first rectangular groove is in the same plane as the lower end face of the dielectric substrate layer. The front end face, rear end face, left end face, and right end face of the dielectric substrate layer are completely covered by the copper layer. The first copper layer is rectangular and is attached to the upper surface of the dielectric substrate layer. The front end face of the first copper layer is flush with the front end face of the dielectric substrate layer. The rear end face of the first copper layer is flush with the rear end face of the dielectric substrate layer. The left end face of the first copper layer is flush with the left end face of the dielectric substrate layer. The right end face of the first copper layer is flush with the right end face of the dielectric substrate layer. A second rectangular groove penetrating up and down is provided on the first copper layer. The front end face of the second rectangular groove is flush with the front end face of the first rectangular groove. The rear end face of the second rectangular groove is flush with the rear end face of the first rectangular groove. The left end face of the second rectangular groove is flush with the left end face of the first rectangular groove. The right end face of the second rectangular groove is flush with the right end face of the first rectangular groove.The second copper metal layer is rectangular and is attached to the lower surface of the dielectric substrate layer. The front end face of the second copper metal layer is flush with the front end face of the dielectric substrate layer, the rear end face of the second copper metal layer is flush with the rear end face of the dielectric substrate layer, the left end face of the second copper metal layer is flush with the left end face of the dielectric substrate layer, and the right end face of the second copper metal layer is flush with the right end face of the dielectric substrate layer. Third rectangular grooves, fourth rectangular grooves, fifth rectangular grooves, sixth rectangular grooves, seventh rectangular grooves, eighth rectangular grooves, ninth rectangular grooves, tenth rectangular grooves, and eleventh rectangular grooves that penetrate up and down are formed in the second copper metal layer. The center of the third rectangular groove coincides with the center of the second copper metal layer. The front end face of the third rectangular groove is flush with the front end face of the first rectangular groove, the rear end face of the third rectangular groove is flush with the rear end face of the first rectangular groove, the left end face of the third rectangular groove is flush with the left end face of the first rectangular groove, and the right end face of the third rectangular groove is flush with the right end face of the first rectangular groove. The fourth rectangular groove is located on the front side of the third rectangular groove. The left end face of the third rectangular groove is flush with the left end face of the second copper metal layer. The front end face of the third rectangular groove is located on the rear side of the second copper metal layer. The right end face of the third rectangular groove is located on the left side of the symmetry line of the second copper metal layer along the front-rear direction. The fifth rectangular groove is located between the third rectangular groove and the fourth rectangular groove. The front end face of the fifth rectangular groove is in contact with the rear end face of the fourth rectangular groove. The right end face of the fifth rectangular groove is flush with the right end face of the fourth rectangular groove. The rear end face of the fifth rectangular groove is in contact with the front end face of the third rectangular groove. The left end face of the fifth rectangular groove is located on the right side of the plane where the left end face of the third rectangular groove is located. The sixth rectangular groove is located on the rear side of the third rectangular groove and is symmetric front and back with respect to the symmetry line of the second copper metal layer along the left-right direction with the fourth rectangular groove. The seventh rectangular groove is located between the third rectangular groove and the sixth rectangular groove and is symmetric front and back with respect to the symmetry line of the second copper metal layer along the left-right direction with the fifth rectangular groove. The eighth rectangular groove is located on the right side of the fourth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the fourth rectangular groove. The ninth rectangular groove is located on the right side of the fifth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the fifth rectangular groove. The tenth rectangular groove is located on the right side of the sixth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the sixth rectangular groove. The eleventh rectangular groove is located on the right side of the seventh rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the seventh rectangular groove;The varactor diode is disposed at the center of the third rectangular groove. One end of the varactor diode is connected to the portion of the second copper layer located between the third rectangular groove, the fifth rectangular groove, and the ninth rectangular groove, and the other end of the varactor diode is connected to the portion of the second copper layer located between the third rectangular groove, the seventh rectangular groove, and the eleventh rectangular groove.

[0007] The dielectric substrate layer is made of F4B material with a dielectric constant of 2.55 and a loss tangent value of 0.001. The length of the dielectric substrate layer in the left-right direction is 20 mm, the length in the front-back direction is 6.4 mm, and the thickness is 0.3 mm. The length of the first rectangular groove in the left-right direction is 19.2, and the length in the front-back direction is 0.8 mm. The length of the third rectangular groove in the left-right direction is 19.2 mm, and the length in the front-back direction is 0.8 mm. The length of the fourth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the fifth rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the sixth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the seventh rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the eighth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the ninth rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the tenth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the eleventh rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm.

[0008] The varactor diode used is the MA46H120 varactor diode from MA / COM. By applying a voltage of 16 - 0V to the varactor diode, the capacitance value of the varactor diode changes from 0.12 - 1 pF. In this structure, the parasitic resistance of the varactor diode is extremely small, and the tuning speed is fast. Within the adjustable capacitance value range, the tuned transmission frequency is 2.1 - 5.5 GHz, and the tuning range is large, enabling multi-band communication transmission.

[0009] Compared with the prior art, the advantages of the present invention are as follows: in each frequency selection unit, the first copper layer is completely attached to the upper surface of the dielectric substrate layer, and the first copper layers of m×n frequency selection units are tightly connected. Electromagnetic waves can only be transmitted in the first rectangular groove. The second copper layers of m×n frequency selection units are tightly connected. In each of the m×n frequency selection units, the distribution of the third rectangular groove, the fourth rectangular groove, the fifth rectangular groove, the sixth rectangular groove, the seventh rectangular groove, the eighth rectangular groove, the ninth rectangular groove, the fourth rectangular groove, and the eleventh rectangular groove at the second copper layer can ensure that while a voltage is applied to the varactor diode, the capacitance value of the varactor diode operates within the normal tuning range. The overall thickness of the frequency selection structure of the present invention can be about 0.3 mm, which is only about 1 / 110 of the operating wavelength, having an extremely thin physical property. In the present invention, electromagnetic waves are transmitted in the first rectangular groove, so that the electromagnetic waves do not consume energy in the lossy medium during the propagation process, reducing unnecessary energy loss. At the same time, the varactor diode uses a varactor diode of model MA46H120 from MA / COM company, which has a small parasitic resistance. Therefore, the present invention has a fast tuning speed, a large tuning range, a small size, and a low insertion loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is the front view of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0011] Figure 2 is the splicing schematic diagram of the dielectric substrate layers of m×n frequency selection units of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0012] Figure 3 is the splicing schematic diagram of the first copper layers of m×n frequency selection units of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0013] Figure 4 is the splicing schematic diagram of the second copper layers of m×n frequency selection units of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0014] Figure 5 is the splicing schematic diagram of the second copper layer of the frequency selection unit of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0015] Figure 6 is the equivalent circuit diagram of the first rectangular groove of the frequency selection unit of the frequency selection structure with tunable wave transmission frequency of the present invention;

[0016] Figure 7 is the curve of the transmittance of the vertically incident electromagnetic wave varying with frequency under different capacitance values of the varactor diode of the frequency selection structure with tunable wave transmission frequency of the present invention.

[0017] Figure 8 This is the curve of the transmission characteristics of the electromagnetic wave incident vertically with respect to frequency when the frequency selection structure with tunable wave transmission frequency of the present invention is under different capacitance values of the varactor diode. Specific implementation mode

[0018] The present invention will be further described in detail below in conjunction with the embodiments in the accompanying drawings.

[0019] Embodiment: As Figures 1 to 5As shown in the figure, a frequency selection structure with adjustable wave-transmitting frequency includes m×n frequency selection units 1, where m is an integer greater than or equal to 1, and n is an integer greater than or equal to 1. The m×n frequency selection units 1 are arranged in an m-row and n-column array. The frequency selection units 1 in the same row are seamlessly spliced in sequence, and the frequency selection units 1 in the same column are seamlessly spliced in sequence. Each frequency selection unit 1 respectively includes a varactor diode and a first copper layer 2, a dielectric substrate layer 3, and a second copper layer 4 that are stacked in sequence from top to bottom. The dielectric substrate layer 3 is a rectangular plate. A first rectangular groove 5 that penetrates up and down is formed on the dielectric substrate layer 3. The center of the first rectangular groove 5 coincides with the center of the dielectric substrate layer 3. The front end face of the first rectangular groove 5 is parallel to the front end face of the dielectric substrate layer 3. The left end face of the first rectangular groove 5 is parallel to the left end face of the dielectric substrate layer 3. The upper end face of the first rectangular groove 5 is in the same plane as the upper end face of the dielectric substrate layer 3. The lower end face of the first rectangular groove 5 is in the same plane as the lower end face of the dielectric substrate layer 3. The front end face, rear end face, left end face, and right end face of the dielectric substrate layer 3 are completely covered by the copper layer. The first copper layer 2 is rectangular and is attached to the upper surface of the dielectric substrate layer 3. The front end face of the first copper layer 2 is flush with the front end face of the dielectric substrate layer 3. The rear end face of the first copper layer 2 is flush with the rear end face of the dielectric substrate layer 3. The left end face of the first copper layer 2 is flush with the left end face of the dielectric substrate layer 3. The right end face of the first copper layer 2 is flush with the right end face of the dielectric substrate layer 3. A second rectangular groove 6 that penetrates up and down is provided on the first copper layer 2. The front end face of the second rectangular groove 6 is flush with the front end face of the first rectangular groove 5. The rear end face of the second rectangular groove 6 is flush with the rear end face of the first rectangular groove 5. The left end face of the second rectangular groove 6 is flush with the left end face of the first rectangular groove 5. The right end face of the second rectangular groove 6 is flush with the right end face of the first rectangular groove 5.The second copper metal layer 4 is rectangular and is attached to the lower surface of the dielectric substrate layer 3. The front end face of the second copper metal layer 4 is flush with the front end face of the dielectric substrate layer 3, the rear end face of the second copper metal layer 4 is flush with the rear end face of the dielectric substrate layer 3, the left end face of the second copper metal layer 4 is flush with the left end face of the dielectric substrate layer 3, and the right end face of the second copper metal layer 4 is flush with the right end face of the dielectric substrate layer 3. Third rectangular grooves 7, fourth rectangular grooves 8, fifth rectangular grooves 9, sixth rectangular grooves 10, seventh rectangular grooves 11, eighth rectangular grooves 12, ninth rectangular grooves 13, tenth rectangular grooves 14, and eleventh rectangular grooves 15 that penetrate up and down are formed in the second copper metal layer 4. The center of the third rectangular groove 7 coincides with the center of the second copper metal layer 4. The front end face of the third rectangular groove 7 is flush with the front end face of the first rectangular groove 5, the rear end face of the third rectangular groove 7 is flush with the rear end face of the first rectangular groove 5, the left end face of the third rectangular groove 7 is flush with the left end face of the first rectangular groove 5, and the right end face of the third rectangular groove 7 is flush with the right end face of the first rectangular groove 5. The fourth rectangular groove 8 is located on the front side of the third rectangular groove 7. The left end face of the third rectangular groove 7 is flush with the left end face of the second copper metal layer 4. The front end face of the third rectangular groove 7 is located on the rear side of the second copper metal layer 4. The right end face of the third rectangular groove 7 is located on the left side of the symmetry line of the second copper metal layer 4 in the front-back direction. The fifth rectangular groove 9 is located between the third rectangular groove 7 and the fourth rectangular groove 8. The front end face of the fifth rectangular groove 9 is in contact with the rear end face of the fourth rectangular groove 8. The right end face of the fifth rectangular groove 9 is flush with the right end face of the fourth rectangular groove 8. The rear end face of the fifth rectangular groove 9 is in contact with the front end face of the third rectangular groove 7. The left end face of the fifth rectangular groove 9 is located on the right side of the plane where the left end face of the third rectangular groove 7 is located. The sixth rectangular groove 10 is located on the rear side of the third rectangular groove 7 and is symmetric front and back with respect to the symmetry line of the second copper metal layer 4 in the left-right direction with the fourth rectangular groove 8. The seventh rectangular groove 11 is located between the third rectangular groove 7 and the sixth rectangular groove 10 and is symmetric front and back with respect to the symmetry line of the second copper metal layer 4 in the left-right direction with the fifth rectangular groove 9. The eighth rectangular groove 12 is located on the right side of the fourth rectangular groove 8 and is symmetric left and right with respect to the symmetry line of the second copper metal layer 4 in the front-back direction with the fourth rectangular groove 8. The ninth rectangular groove 13 is located on the right side of the fifth rectangular groove 9 and is symmetric left and right with respect to the symmetry line of the second copper metal layer 4 in the front-back direction with the fifth rectangular groove 9. The tenth rectangular groove 14 is located on the right side of the sixth rectangular groove 10 and is symmetric left and right with respect to the symmetry line of the second copper metal layer 4 in the front-back direction with the sixth rectangular groove 10. The eleventh rectangular groove 15 is located on the right side of the seventh rectangular groove 11 and is symmetric left and right with respect to the symmetry line of the second copper metal layer 4 in the front-back direction with the seventh rectangular groove 11. A varactor diode is disposed at the center of the third rectangular groove 7. One end of the varactor diode is connected to the portion of the second copper metal layer 4 between the third rectangular groove 7, the fifth rectangular groove 9, and the ninth rectangular groove 13. The other end of the varactor diode is connected to the portion of the second copper metal layer 4 between the third rectangular groove 7, the seventh rectangular groove 11, and the eleventh rectangular groove 15.

[0020] In this embodiment, the dielectric substrate layer 3 is made of F4B material with a dielectric constant of 2.55 and a loss tangent value of 0.001. The length of the dielectric substrate layer 3 in the left-right direction is 20 mm, the length in the front-back direction is 6.4 mm, and the thickness is 0.3 mm; the thickness of the first copper layer 2 is 0.017 mm, the thickness of the second copper layer 4 is 0.017 mm, the length of the first rectangular groove 5 in the left-right direction is 19.2, and the length in the front-back direction is 0.8 mm; the length of the third rectangular groove 7 in the left-right direction is 19.2 mm, and the length in the front-back direction is 0.8 mm; the length of the fourth rectangular groove 8 in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm; the length of the fifth rectangular groove 9 in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm; the length of the sixth rectangular groove 10 in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm; the length of the seventh rectangular groove 11 in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm; the length of the eighth rectangular groove 12 in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm; the length of the ninth rectangular groove 13 in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm; the length of the tenth rectangular groove 14 in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm; the length of the eleventh rectangular groove 15 in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm.

[0021] In this embodiment, the varactor diode is a varactor diode of model MA46H120 from MA / COM. By applying a voltage of 16 - 0V to the varactor diode, the capacitance value of the varactor diode changes from 0.12 - 1 pF.

[0022] The equivalent circuit diagram of the first rectangular groove of the frequency selection unit of the frequency selection structure with adjustable wave - transmission frequency of the present invention is as Figure 6 shown, Z 0fsr is the input impedance of the metal rectangular groove to the vertically incident electromagnetic wave. L1 and C1 are the parasitic inductance and parasitic capacitance of the metal rectangular groove respectively. Z W is the propagation constant β of the electromagnetic wave in the metal rectangular groove and the characteristic impedance of the thickness t. C p represents the capacitance value of the varactor diode, R s represents the parasitic resistance of the varactor diode. The inductance L2 represents the part of the second copper layer connected to the varactor diode. When a bias voltage is applied across the varactor diode, the capacitance value of the varactor diode changes, thereby realizing the dynamic adjustment of the wave - transmission frequency of this structure.

[0023] The polarization direction of the frequency selective structure with tunable transmission frequency of the present invention is the direction of varactor diode loading, and the transmission effect is achieved in the polarization direction. Therefore, the frequency selective structure of the present invention can achieve the effect of tunable transmission frequency only by adjusting the bias voltage applied to the varactor diode. Simulating the frequency selective structure with tunable transmission frequency of the present invention, the curves of the transmittance of the frequency selective structure with tunable transmission frequency of the present invention varying with frequency for perpendicularly incident electromagnetic waves under different capacitance values of the varactor diode are as Figure 7 shown. The curves of the transmission characteristics of the frequency selective structure with tunable transmission frequency of the present invention varying with frequency for perpendicularly incident electromagnetic waves under different capacitance values of the varactor diode are as Figure 8 shown. Analyzing Figure 7 and Figure 8 it can be known that by loading a bias voltage to change the capacitance value of the varactor diode, the transmittance of the frequency selective structure with tunable transmission frequency of the present invention can always be greater than 90% at frequencies from 2.1 to 5.5 GHz, so that the insertion loss of the electromagnetic wave at 2.1 - 5.5 GHz is less than 1 dB; the tunable ratio of the frequency selective structure with tunable transmission frequency of the present invention reaches more than 2.6, realizing the function of wide-range tunable transmission. The frequency selective structure with tunable transmission frequency of the present invention has a fast tuning speed and wide-range tuning, and at the same time, the whole structure is relatively thin (about 0.3 mm), and this thickness is only about 1 / 110 of the working wavelength, having an extremely thin physical property.

Claims

1. A frequency selective structure with tunable wave transmission frequency, characterized in that It includes m×n frequency selective units, where m is an integer greater than or equal to 1, and n is an integer greater than or equal to 1. The m×n frequency selective units are arranged in an m-row and n-column array. The frequency selective units in the same row are seamlessly spliced in sequence, and the frequency selective units in the same column are seamlessly spliced in sequence; Each of the frequency selective units respectively includes a varactor diode and a first copper layer, a dielectric substrate layer, and a second copper layer stacked in sequence from top to bottom. The dielectric substrate layer is a rectangular plate. A first rectangular groove penetrating through from top to bottom is formed on the dielectric substrate layer. The center of the first rectangular groove coincides with the center of the dielectric substrate layer. The front end face of the first rectangular groove is parallel to the front end face of the dielectric substrate layer. The left end face of the first rectangular groove is parallel to the left end face of the dielectric substrate layer. The upper end face of the first rectangular groove is in the same plane as the upper end face of the dielectric substrate layer. The lower end face of the first rectangular groove is in the same plane as the lower end face of the dielectric substrate layer. The front end face, rear end face, left end face, and right end face of the dielectric substrate layer are completely covered by the copper layer; The first copper layer is rectangular. The first copper layer is attached to the upper surface of the dielectric substrate layer. The front end face of the first copper layer is flush with the front end face of the dielectric substrate layer. The rear end face of the first copper layer is flush with the rear end face of the dielectric substrate layer. The left end face of the first copper layer is flush with the left end face of the dielectric substrate layer. The right end face of the first copper layer is flush with the right end face of the dielectric substrate layer. A second rectangular groove penetrating through from top to bottom is provided on the first copper layer. The front end face of the second rectangular groove is flush with the front end face of the first rectangular groove. The rear end face of the second rectangular groove is flush with the rear end face of the first rectangular groove. The left end face of the second rectangular groove is flush with the left end face of the first rectangular groove. The right end face of the second rectangular groove is flush with the right end face of the first rectangular groove; The second copper metal layer is rectangular, and the second copper metal layer is attached to the lower surface of the dielectric substrate layer. The front end face of the second copper metal layer is flush with the front end face of the dielectric substrate layer, the rear end face of the second copper metal layer is flush with the rear end face of the dielectric substrate layer, the left end face of the second copper metal layer is flush with the left end face of the dielectric substrate layer, and the right end face of the second copper metal layer is flush with the right end face of the dielectric substrate layer. A third rectangular groove, a fourth rectangular groove, a fifth rectangular groove, a sixth rectangular groove, a seventh rectangular groove, an eighth rectangular groove, a ninth rectangular groove, a tenth rectangular groove, and an eleventh rectangular groove that penetrate up and down are formed in the second copper metal layer. The center of the third rectangular groove coincides with the center of the second copper metal layer. The front end face of the third rectangular groove is flush with the front end face of the first rectangular groove, the rear end face of the third rectangular groove is flush with the rear end face of the first rectangular groove, the left end face of the third rectangular groove is flush with the left end face of the first rectangular groove, and the right end face of the third rectangular groove is flush with the right end face of the first rectangular groove. The fourth rectangular groove is located on the front side of the third rectangular groove. The left end face of the third rectangular groove is flush with the left end face of the second copper metal layer. The front end face of the third rectangular groove is located on the rear side of the second copper metal layer. The right end face of the third rectangular groove is located on the left side of the symmetry line of the second copper metal layer along the front-rear direction. The fifth rectangular groove is located between the third rectangular groove and the fourth rectangular groove. The front end face of the fifth rectangular groove is attached to the rear end face of the fourth rectangular groove. The right end face of the fifth rectangular groove is flush with the right end face of the fourth rectangular groove. The rear end face of the fifth rectangular groove is attached to the front end face of the third rectangular groove. The left end face of the fifth rectangular groove is located on the right side of the plane where the left end face of the third rectangular groove is located. The sixth rectangular groove is located on the rear side of the third rectangular groove and is symmetric front and back with respect to the symmetry line of the second copper metal layer along the left-right direction with the fourth rectangular groove. The seventh rectangular groove is located between the third rectangular groove and the sixth rectangular groove and is symmetric front and back with respect to the symmetry line of the second copper metal layer along the left-right direction with the fifth rectangular groove. The eighth rectangular groove is located on the right side of the fourth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the fourth rectangular groove. The ninth rectangular groove is located on the right side of the fifth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the fifth rectangular groove. The tenth rectangular groove is located on the right side of the sixth rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the sixth rectangular groove. The eleventh rectangular groove is located on the right side of the seventh rectangular groove and is symmetric left and right with respect to the symmetry line of the second copper metal layer along the front-rear direction with the seventh rectangular groove; The varactor diode is disposed at the center of the third rectangular groove. One end of the varactor diode is connected to the portion of the second copper layer located between the third rectangular groove, the fifth rectangular groove and the ninth rectangular groove, and the other end of the varactor diode is connected to the portion of the second copper layer located between the third rectangular groove, the seventh rectangular groove and the eleventh rectangular groove.

2. The frequency selection structure with adjustable wave transmission frequency according to claim 1, characterized in that The dielectric substrate layer is made of F4B material with a dielectric constant of 2.55 and a loss tangent value of 0.

001. The length of the dielectric substrate layer in the left-right direction is 20 mm, the length in the front-back direction is 6.4 mm, and the thickness is 0.3 mm. The length of the first rectangular groove in the left-right direction is 19.2, and the length in the front-back direction is 0.8 mm. The length of the third rectangular groove in the left-right direction is 19.2 mm, and the length in the front-back direction is 0.8 mm. The length of the fourth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the fifth rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the sixth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the seventh rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the eighth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the ninth rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm. The length of the tenth rectangular groove in the left-right direction is 9.8 mm, and the length in the front-back direction is 0.15 mm. The length of the eleventh rectangular groove in the left-right direction is 0.2 mm, and the length in the front-back direction is 2.45 mm.

3. The frequency selection structure with adjustable wave transmission frequency according to claim 1, characterized in that The varactor diode is a varactor diode of model MA46H120 from MA / COM. By applying a voltage of 16 - 0V to the varactor diode, the capacitance value of the varactor diode is changed from 0.12 - 1 pF.

Images