Antenna system with radio frequency antenna configured with EBG structure and matched with annular coupler

Abstract

The utility model discloses a radio frequency antenna equipped with an EBG structure and an antenna system matched with an annular coupler, which comprises a top copper plate, an upper dielectric layer, a curing plate, a lower dielectric layer and a bottom copper plate which are sequentially arranged from top to bottom, and a signal transmission layer is arranged between the upper dielectric layer and the curing plate; an annular coupler is arranged on the signal transmission layer, a branch knot of the annular coupler is connected with a balance port, a transmitting port, an antenna port and a receiving port through an impedance conversion branch knot, a radio frequency antenna is arranged at the antenna port, and two EBG structures are arranged around the radio frequency antenna. According to the antenna system in which the radio frequency antenna configured with the EBG structure is matched with the annular coupler, energy power division and signal isolation of a transmitting port and a receiving port are realized, so that the signal-to-noise ratio is improved; the EBG structure is configured around the radio frequency antenna, so that the propagation of reflected waves and plane waves is suppressed, the radiation gain of the antenna is increased, and the overall stability of the system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of wireless communication, in particular to an antenna system configured with an EBG structured radio frequency antenna and a matching ring coupler. Background Art

[0002] With the rapid development of wireless communication technology, the interaction technology between RF antennas and PCBs is also constantly integrating and innovating. New antenna technologies such as MIMO (multiple-input, multiple-output) antennas and phased array antennas are being closely integrated with PCB design. By optimizing the antenna structure and PCB layout, more compact and efficient RF systems can be achieved, meeting the miniaturization and lightweight requirements of modern electronic equipment.

[0003] Current general antenna system designs are subject to significant signal reflections, surface wave propagation, and edge radiation. The interaction between RF signals and PCBs ensures that the majority of the signal is radiated by the TX antenna according to the designed radiation pattern. However, general antenna system designs have the following drawbacks:

[0004] 1) There is a GND plane on the PCB surface: This will easily cause partial destructive interference to the initial radiation signal, resulting in a decrease in the maximum gain of the boresight and a reduction in the antenna's radiation range;

[0005] 2) Simply removing the GND plane on the PCB surface: This improves the antenna's radiation performance to a certain extent. However, using this method to optimize antenna gain may require customizing the PCB layer stack and understanding the dielectric properties of the substrate material at RF frequencies. However, the effects of surface wave propagation and edge radiation are not improved.

[0006] In PCB design, the layout and routing of various components and antennas are susceptible to reradiation of the feed signal from surface wave propagation, affecting the final radiation pattern of the entire system. This can cause serious deviations from the initial antenna radiation pattern at multiple angles, resulting in ripples and notches in the generated radiation pattern. Summary of the Invention

[0007] The purpose of the utility model is to provide an antenna system in which a radio frequency antenna configured with an EBG structure is matched with a ring coupler. The ring coupler located in the middle is connected to four ports through impedance transformation branches to achieve energy power division and signal isolation between the transmitting port and the receiving port, thereby improving the signal-to-noise ratio; the EBG structure is configured around the radio frequency antenna to suppress the propagation of reflected waves and plane waves, increase the radiation gain of the antenna, and improve the stability of the system.

[0008] To achieve the above objectives, the present invention provides an antenna system configured with an EBG structure radio frequency antenna and a ring coupler matching antenna system, comprising a top copper plate, an upper dielectric layer, a solidified plate, a lower dielectric layer, and a bottom copper plate arranged in sequence from top to bottom, wherein a signal transmission layer is provided between the upper dielectric layer and the solidified plate;

[0009] A ring coupler is provided on the signal transmission layer, and the branches of the ring coupler are connected to a balanced port, a transmitting port, an antenna port and a receiving port through impedance transformation branches. A radio frequency antenna is provided at the antenna port, and two EBG structures are provided around the radio frequency antenna.

[0010] Preferably, the angles between the balancing port and the receiving port, between the receiving port and the antenna port, and between the antenna port and the transmitting port are all 60°.

[0011] Preferably, two rows of evenly distributed metal vias extend from the center position of the signal transmission layer to the ends of the balanced port, the transmitting port, the antenna port and the receiving port.

[0012] Preferably, the receiving port, the transmitting port and the balanced port are all provided with microstrip lines, and the microstrip lines are connected to the strip lines of the signal transmission layer through blind holes.

[0013] Preferably, the EBG structure includes three copper pillars arranged in a 7-shape and a copper sheet arranged above the copper pillars. The shape of the copper sheet is 7-shaped, and the position of the copper sheet is higher than the radio frequency antenna.

[0014] Preferably, the radio frequency antenna is a microstrip antenna or a probe antenna.

[0015] Preferably, the radio frequency antenna is electrically connected to a waveguide horn.

[0016] Preferably, the transmitting port is connected to a transmitting pin of an external chip, the receiving port is connected to a receiving pin of an external chip, and the balanced port is connected to an impedance matching resistor.

[0017] Therefore, the present invention adopts the above-mentioned antenna system in which the radio frequency antenna configured with the EBG structure is matched with the ring coupler, and the beneficial effects are as follows:

[0018] (1) Suppression of reflection: Within the operating frequency band, the surface impedance of the EBG provided by the present invention to the RF signal is very high. The EBG reflection behavior of electromagnetic waves incident close to 0 degrees is very similar to that of a continuous conductive surface, but there is one major difference: the reflection on the continuous conductive surface will introduce a 180-degree phase shift, while the reflection on the EBG surface will not introduce additional phase shift, and there is only a small phase difference between the reflected signal and the initial radiation signal.

[0019] 2) Suppression of plane wave propagation and edge radiation:

[0020] The high surface impedance achieved by the EBG provided in the present invention strongly suppresses the propagation of surface currents, thereby suppressing the propagation of surface waves. In addition, the EBG will not re-radiate RF signals. Therefore, the RF signal coupling from the antenna to the PCB is limited to a small area around the antenna, and the re-radiation of RF signals from the edge of the package or any other PCB structure will be greatly reduced.

[0021] (3) When an EBG design is used on the PCB surrounding the antenna, the degree to which the radiation characteristics deviate due to re-radiation from the PCB is significantly reduced, and is generally less dependent on the PCB shape, PCB size, and PCB layout that is not directly adjacent to the sensor area; as long as the EBG structure remains unchanged, changes in the PCB layout will not have a significant impact on the radiation pattern, and can also be used to obtain more consistent radiation performance on different custom PCB layouts.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of an antenna system embodiment of the utility model, which is a radio frequency antenna configured with an EBG structure and matched with a ring coupler;

[0024] Figure 2 This is a cross-sectional view of a signal transmission layer of an antenna system embodiment of the utility model, in which a radio frequency antenna configured with an EBG structure is matched with a ring coupler;

[0025] Figure 3 This is a schematic diagram of the EBG structure of an antenna system embodiment of the utility model, in which a radio frequency antenna configured with an EBG structure is matched with a ring coupler;

[0026] Figure 4 This is a schematic diagram of the EBG structure position of an antenna system embodiment of the utility model, in which a radio frequency antenna configured with an EBG structure is matched with a ring coupler;

[0027] Figure 5 This is a schematic diagram of the operating principle of an antenna system embodiment of the utility model, which is a radio frequency antenna configured with an EBG structure and matched with a ring coupler;

[0028] Figure 6 This is a full-wave electromagnetic simulation result of the port reflection coefficient of an antenna system embodiment of the utility model, which is a radio frequency antenna configured with an EBG structure and matched with a ring coupler.

[0029] Reference numerals

[0030] 1. Top copper plate; 2. Upper dielectric layer; 3. Signal transmission layer; 4. Curing board; 5. Lower dielectric layer; 6. Bottom copper plate; 7. Ring coupler; 8. Impedance transformation branch; 9. Balanced port; 10. Transmitting port; 11. Antenna port; 12. Receiving port; 13. Metal via; 14. RF antenna; 15. EBG structure; 16. Copper pillar; 17. Copper sheet. DETAILED DESCRIPTION

[0031] The technical solution of the present utility model is further described below through the accompanying drawings and embodiments.

[0032] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the usual meanings understood by persons of ordinary skill in the field to which this utility model belongs. The words "first", "second" and similar terms used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0033] like Figure 1 As shown, an antenna system with an EBG structure radio frequency antenna and a ring coupler is provided, including a top copper plate 1, an upper dielectric layer 2, a curing plate 4, a lower dielectric layer 5 and a bottom copper plate 6 arranged in order from top to bottom. The upper dielectric layer 2 and the lower dielectric layer 5 can be Rogers 4835 plates. A signal transmission layer 3 is provided between the upper dielectric layer 2 and the curing plate 4. The signal transmission layer 3 is a copper plate.

[0034] like Figure 2 As shown, a ring coupler 7 is provided on the signal transmission layer 3, and the branches of the ring coupler 7 are connected to the balanced port 9, the transmitting port 10, the antenna port 11 and the receiving port 12 through the impedance transformation branch 8. The angles between the balanced port 9 and the receiving port 12, between the receiving port 12 and the antenna port 11, and between the antenna port 11 and the transmitting port 10 are all 60°.

[0035] Two rows of evenly distributed metal vias 13 extend from the center of the signal transmission layer 3 toward the ends of the balanced port 9, transmit port 10, antenna port 11, and receive port 12. Microstrip lines are provided for the receive port 12, transmit port 10, and balanced port 9, and these lines are connected to the stripline of the signal transmission layer 3 via blind vias. An RF antenna 14 is located at the antenna port 11, surrounded by two EBG structures 15.

[0036] like Figure 3 、 Figure 4 As shown, EBG structure 15 includes three copper pillars 16 arranged in a figure-7 shape and a copper plate 17 disposed above copper pillars 16. Copper plate 17 is shaped like a figure-7. Three copper pillars 16 are connected from bottom copper plate 6 to the copper plate of signal transmission layer 3. Copper plate 17 is positioned above RF antenna 14. RF antenna 14 is in the form of a microstrip antenna or a probe antenna and is electrically connected to a waveguide horn.

[0037] The above structure can suppress the propagation of reflected waves and plane waves. The ring coupler 7 located in the middle is connected to the four ports through the impedance transformation branch 8 to achieve energy power division and signal isolation between the transmitting port 10 and the receiving port 12, thereby improving the signal-to-noise ratio and stability. The EBG structure 15 is configured around the RF antenna 14 to suppress the propagation of reflected waves and plane waves, increase the antenna's radiation gain, and improve the stability of the system.

[0038] The operating principle of this utility model is as follows Figure 5 As shown:

[0039] By connecting the transmitting port 10 to the transmitting pin of an external chip (the form of the external chip is not limited, that is, it can be connected to a variety of processing chips), the chip's transmitting signal is transmitted to the ring coupler 7 and further transmitted through the RF antenna 14; the RF antenna 14 is used to couple the chip's transmitting signal to the waveguide horn, and at the same time receive the reflected signal, and send it to the receiving port 12 through the ring coupler 7; the receiving port 12 is connected to the receiving pin of the external chip, and sends the signal received by the RF antenna 14 to the chip; the balanced port 9 is connected to an impedance matching resistor to maintain system impedance matching.

[0040] The EBG structure 15 is a periodic structure placed on the PCB surrounding the antenna. The goal is to utilize the unique electromagnetic properties of the EBG structure 15 to reduce the impact of the actual PCB design on the antenna radiation pattern, thereby improving antenna performance. Both reflection and plane wave propagation can be addressed by the EBG structure 15.

[0041] In addition, the present invention also performs full-wave electromagnetic simulation of the reflection coefficient of the antenna transceiver system, such as Figure 6 The following is the full-wave electromagnetic simulation result of the port reflection coefficient. Figure 6 The simulation of the input port's reflection coefficient shows that it is below -10dB within the required bandwidth. A good reflection coefficient can reduce echo reflections at the port, lower system noise, and improve the signal-to-noise ratio.

[0042] Therefore, the present invention adopts the above-mentioned antenna system of the RF antenna configured with the EBG structure and matched with the ring coupler, and configures the EBG structure around the RF antenna to suppress the propagation of reflected waves and plane waves, increase the radiation gain of the antenna, and improve the overall stability of the system.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An antenna system configured with an EBG structure radio frequency antenna and a ring coupler matching antenna, characterized by: It includes a top copper plate, an upper dielectric layer, a curing plate, a lower dielectric layer and a bottom copper plate arranged in sequence from top to bottom, and a signal transmission layer is arranged between the upper dielectric layer and the curing plate; A ring coupler is provided on the signal transmission layer, and the branches of the ring coupler are connected to a balanced port, a transmitting port, an antenna port and a receiving port through impedance transformation branches. A radio frequency antenna is provided at the antenna port, and two EBG structures are provided around the radio frequency antenna.

2. The antenna system according to claim 1, wherein: The angles between the balanced port and the receiving port, between the receiving port and the antenna port, and between the antenna port and the transmitting port are all 60°.

3. The antenna system according to claim 2, wherein the EBG structured radio frequency antenna is matched with a ring coupler, wherein: Two rows of evenly distributed metal vias extend from the center of the signal transmission layer to the ends of the balanced port, the transmitting port, the antenna port and the receiving port.

4. The antenna system according to claim 3, wherein: The receiving port, the transmitting port and the balanced port are all provided with microstrip lines, and the microstrip lines are connected to the strip lines of the signal transmission layer through blind holes.

5. The antenna system according to claim 4, wherein the EBG structured radio frequency antenna is matched with a ring coupler, wherein: The EBG structure includes three copper pillars arranged in a 7-shape and a copper sheet arranged above the copper pillars. The copper sheet is in a 7-shape and is positioned higher than the radio frequency antenna.

6. The antenna system according to claim 5, wherein the EBG structured radio frequency antenna is matched with a ring coupler, wherein: The radio frequency antenna is a microstrip antenna or a probe antenna.

7. The antenna system according to claim 6, wherein the EBG structured radio frequency antenna is matched with a ring coupler, wherein: The radio frequency antenna is electrically connected to a waveguide horn.

8. The antenna system according to claim 7, wherein the EBG structured radio frequency antenna is matched with a ring coupler, wherein: The transmitting port is connected to a transmitting pin of an external chip, the receiving port is connected to a receiving pin of an external chip, and the balanced port is connected to an impedance matching resistor.

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