CN114899594B - A Broadband Filtering Patch Antenna Based on Dual-loop Slot Structure Coupling Feed - Google Patents

Abstract

The invention discloses a broadband filter patch antenna based on double-ring slot structure coupled feeding, which includes four layers of dielectric substrates from bottom to top, the first layer of dielectric substrates is made of all-metal aluminum; the upper surface of the second layer of dielectric substrates is printed The first square metal patch with a double-ring gap structure, the lower surface is printed with L-shaped feed microstrip lines, which together form the antenna feeding structure; the second square metal patch is printed on the upper surface of the third layer of dielectric substrate; the fourth layer A third rectangular metal patch is printed on the upper surface of the dielectric substrate. The first layer of all-metal aluminum dielectric substrate is used as the metal ground of the antenna, the second layer structure is the feeding network of the antenna, the third layer structure is the main radiation part of the antenna, and the fourth layer structure is the antenna part of the parasitic radiation. By using a double-ring slot structure, two radiation zero points are generated, and the band-pass filter radiation function is integrated into the antenna. Compared with other filter antennas, the structure is simple and no filter circuit is required.

Description

A Broadband Filtering Patch Antenna Based on Double Ring Slot Structure Coupling Feed

technical field

The invention relates to the technical field of radio frequency communication, in particular to a broadband filtering patch antenna based on double-ring slot structure coupled feeding.

Background technique

In the RF front-end circuit, in order to suppress clutter interference in other frequency bands, the previous stage of the antenna is usually cascaded with a filter. The filter not only occupies additional circuit size, but also introduces a certain insertion loss, which reduces the radiation efficiency of the antenna. In recent years, filter antennas, as the name suggests, are antennas with filtering performance. Because of their small size and low loss, they have become a research hotspot in academia and industry. There are roughly two types of traditional filter antenna design methods. One is to replace the last resonator of the filter circuit with an antenna radiation unit such as a dipole antenna, a monopole antenna, a patch antenna, etc.; Parasitic filter devices such as half-wavelength resonators, patches, etc. are implanted in the radiator and feed structure of the antenna, and the filtering effect of out-of-band radiation suppression is realized by introducing a non-radiative resonant mode outside the band of the antenna. Although the first method achieves the miniaturization of the device and does not require cables connecting the filter and the antenna, the filter resonant circuit still has unavoidable insertion loss; the second method not only achieves miniaturization but also reduces the loss. However, parasitic filter components increase the complexity of filter antenna design.

Based on this, a filter antenna without any filter structure and simultaneously realizing miniaturization, low loss, and simple structure has potential application value in systems such as base stations, terminals, and satellites.

Contents of the invention

The technical problem to be solved by the present invention is to provide a broadband filter patch antenna based on double-ring slot structure coupled feed, the antenna can achieve high roll-off band-pass filter radiation performance, has three frequency-controllable radiation zero points, and The unconventional band-pass filter radiation performance is realized through the conventional antenna structure without introducing an additional filter circuit.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A broadband filter patch antenna based on double-ring slot structure coupled feed, including a first layer of dielectric substrate, a second layer of dielectric substrate, a third layer of dielectric substrate and a fourth layer of dielectric substrate, the first layer The dielectric substrate is the metal ground structure of the antenna, the upper and lower surfaces of the second layer of dielectric substrate are printed with slot coupling feeding structure, the upper surface of the third layer of dielectric substrate is printed with the main radiation patch structure of the antenna, and the fourth layer of dielectric substrate is The parasitic radiation patch structure of the printed antenna on the upper surface.

The first layer of dielectric substrate is an all-metal aluminum plate structure, the upper surface of the second layer of dielectric substrate is printed with a first square metal patch with a double-ring gap structure, and the lower surface is printed with an L-shaped feed microstrip line; The second square metal patch is printed on the upper surface of the third layer dielectric substrate; the third square metal patch is printed on the upper surface of the fourth layer dielectric substrate;

The first layer of dielectric substrate is provided with a plurality of through holes, and a plurality of nylon columns are uniformly installed on the through holes, and the first layer of dielectric substrate, the second layer of dielectric substrate, the third layer of dielectric substrate and the fourth layer of dielectric substrate The dielectric substrates are provided with a plurality of through holes, and a plurality of nylon posts are uniformly installed on the through holes, and the four-layer dielectric substrate is fixed and installed on the plurality of nylon posts through nylon nuts.

As a preferred embodiment of the present invention, a first square metal patch is printed on the upper surface of the second dielectric substrate in the present invention, and the first square metal patch is etched with a first slit groove line and a second The slot line, the first slot line and the second slot line are arranged directly above the L-shaped feeding microstrip line on the lower surface.

As a preferred embodiment of the present invention, the first slot line and the second slot line in the present invention are both square annular slot lines, the first slot line is inside the second slot line, The L-shaped feeding microstrip line is connected to the external cable test element as the 50Ω input port of the antenna.

As a preferred embodiment of the present invention, the first slot line and the second slot line in the present invention are both square annular slot lines, and the first slot line, the second slot line, the L-shaped The feeding microstrip line and the cable test components together form the feeding structure of the antenna. The feeding structure is a dual-function structure, which realizes the broadband impedance matching of the antenna, that is, the feeding function and produces two radiation zero.

As a preferred embodiment of the present invention, the double-ring slot line on the upper surface of the second layer dielectric substrate of the present invention enables the antenna to generate a radiation zero point with a very low gain in the upper and lower frequency sidebands of the working frequency band. By controlling the double-ring slot structure The size and location of the two radiation nulls are used to independently control the frequency of the two radiation nulls to achieve band-pass filtered radiation performance.

As a preferred embodiment of the present invention, the L-shaped feeding microstrip line printed on the lower surface of the second dielectric substrate in the present invention is used to couple the input signal of the antenna to the first The slot line of the slot and the slot line of the second slot are coupled to the main radiation patch of the upper third layer dielectric substrate and the parasitic radiation patch of the fourth layer dielectric substrate.

As a preferred embodiment of the present invention, the parasitic radiation patch on the upper surface of the fourth dielectric substrate in the present invention is used to increase the radiation gain of the antenna and generate a frequency-controllable radiation zero point outside the high-frequency band.

As a preferred embodiment of the present invention, the second square metal patch is printed on the upper surface of the third layer dielectric substrate of the present invention, and the second square metal patch is the main radiation structure of the antenna. The carrier signal is transmitted into the wireless space through the input port.

As a preferred embodiment of the present invention, the number of through holes in each layer of the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate in the present invention is four, and the nylon The corresponding number of columns is 12, and the nylon columns are installed on the corresponding through holes.

Compared with the prior art, the present invention has the following advantages and effects:

1. The present invention discloses the dual-loop slot coupling feeding technology for the first time. This structure has two functions: one is to realize the broadband impedance matching of the antenna, and the other is to integrate the response of band-pass filter radiation on the antenna.

2. A wideband filter patch antenna based on double-ring slot structure coupling feeding that the present invention relates to has three controllable radiation zero points: by changing the perimeter of the two slot line structures, it is possible to introduce two A radiation zero point outside the high-frequency band can be introduced by changing the parasitic radiation patch located on the fourth layer.

3. The present invention has a simple structure, realizes a high roll-off filtering effect without introducing an additional filter circuit, and does not introduce additional loss, ensuring that the radiation performance of the antenna in the working frequency band is not affected.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is a top view structural schematic diagram of the first layer dielectric plate of the present invention;

Fig. 3 is a schematic diagram of a top perspective structure view of a second layer dielectric plate of the present invention;

Fig. 4 is a top view structural schematic diagram of a third-layer dielectric plate of the present invention;

Fig. 5 is a top view structural schematic diagram of the fourth layer dielectric plate of the present invention;

Fig. 6 is the result figure of the antenna reflection coefficient S11-frequency of simulation and test of the present invention;

Fig. 7 is the result figure of the antenna gain-frequency of simulation and test of the present invention;

Fig. 8 is the result figure of the antenna efficiency-frequency of simulation and test of the present invention;

Fig. 9 is the direction diagram of the present invention on the YOZ plane, that is, the direction diagram of the E plane;

Fig. 10 is the direction diagram of the present invention on the XOZ plane, that is, the direction diagram of the H plane.

In the figure: Among them: 1. The first layer of dielectric substrate; 2. The second layer of dielectric substrate; 3. The third layer of dielectric substrate; 4. The fourth layer of dielectric substrate; 5. The first slot line; 6. The second gap Slot line; 7. The first square metal patch; 8. L-shaped feed microstrip line; 9. Cable test components; 10. The second square metal patch; 11. The third square metal patch; 12. Nylon column; 13, nylon nut; 14, through hole.

Detailed ways

The present invention will be described in further detail below through examples, and the following examples are explanations of the present invention and the present invention is not limited to the following examples.

A broadband filter patch antenna based on double-ring slot structure coupled feed, as shown in Figure 1, includes a first layer of dielectric substrate 1, a second layer of dielectric substrate 2, a third layer of dielectric substrate 3 and a fourth layer of dielectric substrate from bottom to top A layer of dielectric substrate 4, the first layer of dielectric substrate 1 is the metal ground structure of the antenna, the upper and lower surfaces of the second layer of dielectric substrate 2 are printed with slot coupling feeding structures, and the upper surface of the third layer of dielectric substrate 3 is printed with the structure of the antenna. The main radiation patch structure, the parasitic radiation patch structure of the printed antenna on the surface of the fourth dielectric substrate 4;

The first layer of dielectric substrate 1 is an all-metal aluminum plate structure, the upper surface of the second layer of dielectric substrate 2 is printed with a first square metal patch 7 with a double-ring gap structure, and the lower surface is printed with an L-shaped feed microstrip Line 8; a second square metal patch 10 is printed on the upper surface of the third layer dielectric substrate 3; a third square metal patch 11 is printed on the upper surface of the fourth layer dielectric substrate 4;

The first layer of dielectric substrate 1 is provided with a plurality of through holes 14, and a plurality of nylon posts 12 are uniformly installed on the through holes 14. The first layer of dielectric substrate 1, the second layer of dielectric substrate 2, the third layer of dielectric substrate Both the dielectric substrate 3 and the fourth-layer dielectric substrate 4 are provided with a plurality of through holes 14, and a plurality of nylon posts 12 are uniformly installed on the through holes 14, and the four-layer dielectric substrate is fixedly installed on the plurality of nylon posts 12 through nylon nuts 13. .

Among them, as shown in Figure 1-2 of the present invention, the first layer of dielectric substrate 1 is made of all-metal aluminum, the first layer of all-metal aluminum dielectric substrate is used as the metal ground of the antenna, the second layer structure is the feed network of the antenna, and the second layer structure is the antenna feed network. The three-layer structure is the main radiation part of the antenna, and the fourth layer structure is the parasitic radiation part of the antenna; the first layer of dielectric substrate 1 is provided with four through holes 14 for installing nylon posts 12, and the main layer of the first layer of dielectric substrate 1 The function is to reflect the electromagnetic wave leaked to the bottom of the first slot line 5 and the second slot line 6 to the main radiation direction of the antenna, that is, directly above, thereby improving the front-to-back ratio index of the antenna; by using the double-ring slot coupling feeding structure, a Two radiation zeros integrate the bandpass filter radiation function into the antenna. Compared with other filter antennas, this structure has two functions: one is to realize the broadband impedance matching of the antenna, and the other is to integrate the bandpass filter on the antenna Radiation response: by changing the perimeter of the two slot line structures, two radiation zeros at the edge of the antenna's working frequency band can be introduced, and by changing the parasitic radiation patch located on the fourth layer, a radiation zero outside the high frequency band can be introduced The present invention has a simple structure, realizes a high roll-off filtering effect without introducing an additional filter circuit, and does not introduce additional loss, ensuring that the radiation performance of the antenna in the working frequency band is not affected, and does not require any filter circuit.

In an optional implementation manner, as shown in FIG. 3 , the upper surface of the second dielectric substrate 2 of the present invention is printed with a first square metal patch 7 , and the first square metal patch 7 is etched with The first slot slot line 5 and the second slot slot line 6, the first slot slot line 5 and the second slot slot line 6 are arranged directly above the L-shaped feeding microstrip line 8 on the lower surface, and the first slot line The slot line 5 and the second slot slot line 6 are square annular slot lines, the first slot slot line 5 is inside the second slot slot line 6, and the L-shaped feed microstrip line 8 is connected to the external The cable test element 9 is connected as the 50Ω input port of the antenna, and the input signal is transmitted to the L-shaped feeding microstrip metal line 8 through the test element 9, and then the signal is coupled to the second square metal post above through the double-ring gap structure sheet 10 and the third square metal patch 11, and then radiate the carrier signal into the wireless space.

An optional embodiment, as shown in Figure 3, the first slot line 5 and the second slot line 6 in the present invention are both square annular slot lines, and the first slot line 5, The second slot line 6, the L-shaped feeding microstrip line 8 and the cable test element 9 jointly form the feeding structure of the antenna, and the feeding structure is a dual-function structure, which realizes the broadband impedance matching of the antenna, that is, the feeding function and Two radiation nulls are generated in the upper and lower sidebands of the antenna working frequency band.

Wherein, as shown in Figure 3, the first slot line 5, the second slot line 6, the L-shaped feeding microstrip line 8 and the cable test element 9 in the present invention jointly form the feeding structure of the antenna, input The signal is transmitted to the L-shaped feeding microstrip line 8 through the test element 9, and then the signal is coupled to the second square metal patch 10 and the third square metal patch 11 above through the double-ring gap structure, and then the carrier signal is radiated In the wireless space; the feed structure is a dual-function structure, the first function is to realize the broadband impedance matching of the antenna, that is, the feed function, and the second function is that the structure generates two gains in the upper and lower sidebands of the antenna working frequency band Very low radiated nulls, resulting in a bandpass filtered radiated response.

An optional implementation mode, the L-shaped feeding microstrip line 8 printed on the lower surface of the second dielectric substrate 2 in the present invention is used to couple the input signal of the antenna to the The first slot line 5 and the second slot line 6 are further coupled to the main radiation patch of the upper third dielectric substrate 3 and the parasitic radiation patch of the fourth dielectric substrate 4 .

An optional implementation, as shown in FIG. 5, the parasitic radiation patch on the upper surface of the fourth dielectric substrate 4 of the present invention increases the radiation gain of the antenna and generates a frequency-controllable radiation outside the high-frequency band. zero.

Wherein, the upper surface of the fourth dielectric substrate 4 of the present invention is printed with a third-shaped metal patch 11, the metal patch is the parasitic radiation structure of the antenna, on the one hand it acts as a director to increase the radiation gain of the antenna, on the other hand On the one hand, it can generate an out-of-band radiation zero point outside the high-frequency band, thereby ensuring the out-of-band suppression level of the antenna; similarly, the dielectric substrate also has four through holes 14 for installing nylon posts 12 .

In an optional implementation manner, as shown in FIG. 4 , a second square metal patch 10 is printed on the upper surface of the third dielectric substrate 3 of the present invention, and the second square metal patch 10 is the main radiation structure of the antenna. The carrier signal is transmitted from the input port to the wireless space through the half-wavelength resonant antenna principle, and there are also four through holes 14 on the dielectric substrate for installing nylon posts 12 .

An optional implementation mode, the number of through holes 14 in each layer of the first dielectric substrate 1, the second dielectric substrate 2, the third dielectric substrate 3 and the fourth dielectric substrate 4 in the present invention is four , the corresponding number of the nylon columns 12 is 12, and the nylon columns 12 are installed on the corresponding through holes 14 .

Among them, 12 nylon columns 12 are evenly installed on the 4 through holes 14 of the present invention, and the four-layer dielectric substrate is fixedly installed on the 12 nylon columns 12 through nylon nuts 13 .

An optional implementation mode, as shown in Figure 6, provides the simulation and test result diagram of the reflection coefficient S11-frequency of the filter antenna involved in an embodiment of the present invention, the test and simulation results are in good agreement, and the impedance in the passband The matching is good, the impedance bandwidth is 1.4-2.1GHz, the relative bandwidth is 40%, and the return loss is below -10dB.

An optional implementation mode, as shown in Figure 7, provides a gain-frequency simulation and test result diagram of the filter antenna involved in an embodiment of the present invention, the test and simulation results are in good agreement, and the gain in the working frequency band is about It is 8.7dBi, and three radiation zero points are generated at frequencies of 1.32GHz, 2.2GHz, and 2.6GHz, which are respectively recorded as radiation zero point 1, radiation zero point 2, and radiation zero point 3. The radiation suppression level is better than 15dB, and the radiation suppression level in the high-frequency out-of-band frequency band from 2.2 to 2.8GHz exceeds 18dB. Among them, the radiation nulls 1 and 2 are produced by the double-ring slot structure on the upper surface of the second dielectric substrate 2 of the antenna, which ensures that the antenna gain has high frequency selectivity such as high roll-off of the band edge gain; the radiation zero 2 is generated by the fourth The third-party metal patch 11 is printed on the upper surface of the dielectric substrate 4 to ensure that the antenna has a high level of out-of-band radiation suppression outside the high-frequency band.

An optional embodiment, as shown in Figure 8, provides the efficiency-frequency simulation and test result diagram of the filter antenna involved in an embodiment of the present invention, the gain of the antenna is greater than 87% in the working frequency band, and the working frequency band The radiation efficiency outside is less than 5%.

An optional implementation, as shown in Figures 9 and 10, provides the directivity diagrams of the filter antenna involved in an embodiment of the present invention on the E plane of the YOZ plane and the H plane of the XOZ plane, and the data shows that the antenna of the present invention has good Directional radiation characteristics and its cross-polarization level is less than -15dB.

The filter antenna of the present invention has a simple structure, and achieves a high roll-off filter effect without introducing any additional filter circuit, and does not introduce additional loss; the innovative feeding method using a double-ring slot coupling structure can not only achieve a wider Impedance matching of frequency bands, in turn produces band-pass filtered radiation responses.

The embodiment provided by the present invention can adjust the size of the relevant structure according to the requirements to adapt to the receiving and transmitting equipment of the wireless communication system of different frequency bands. Since the antenna of the present invention can realize the filtering characteristics without a filter, it is especially suitable for the application In the communication environment where multi-band and multi-standard coexist, such as a new generation compatible with 5G/4G/3G multi-standard multi-band multi-band co-aperture antenna array; in this application scenario, antennas of multiple frequency bands are installed in a radome with limited size. The coupling between each other is very strong, and the traditional method of series filter circuit to achieve decoupling will bring problems such as high cost, many devices, compact space, and large loss. The filter antenna designed by the present invention can solve the above problems, and is a multi-band The communication system provides an effective decoupling technique.

The above content described in this specification is only an illustration of the present invention. Those skilled in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, as long as they do not deviate from the content of the present invention specification or exceed the scope defined in the claims, all should Belong to the protection scope of the present invention.

Claims (8)

1. A broadband filter patch antenna based on double-ring slot structure coupled feed, characterized in that: from bottom to top, it comprises a first layer of dielectric substrate (1), a second layer of dielectric substrate (2), a third layer of dielectric substrate (3) and the fourth layer of dielectric substrate (4), the first layer of dielectric substrate (1) is the metal ground structure of the antenna, and the upper and lower surfaces of the second layer of dielectric substrate (2) are printed with slot coupling feeding structure, so The main radiation patch structure of the printed antenna on the upper surface of the third layer dielectric substrate (3), and the parasitic radiation patch structure of the printed antenna on the upper surface of the fourth layer dielectric substrate (4); The first layer of dielectric substrate (1) is an all-metal aluminum plate structure, the upper surface of the second layer of dielectric substrate (2) is printed with a first square metal patch (7) with a double-ring gap structure, and the lower surface is printed with L-shaped feeding microstrip line (8); the upper surface of the third layer of dielectric substrate (3) is printed with a second square metal patch (10); the upper surface of the fourth layer of dielectric substrate (4) is printed with a third square metal patch (11); The first layer of dielectric substrate (1) is provided with a plurality of through holes (14), and a plurality of nylon columns (12) are uniformly installed on the through holes (14), and the first layer of dielectric substrate (1), The second layer of dielectric substrate (2), the third layer of dielectric substrate (3) and the fourth layer of dielectric substrate (4) are all provided with a plurality of through holes (14), and the through holes (14) are uniformly installed with a plurality of nylon Column (12), the four-layer dielectric substrate is fixedly installed on multiple nylon columns (12) through nylon nuts (13); The first slot line (5) and the second slot line (6) are etched on the first square metal patch (7), and the first slot line (5) and the second slot line ( 6) It is arranged directly above the L-shaped feeding microstrip line (8) on the lower surface; Both the first slot line (5) and the second slot line (6) are square annular slot lines, and the first slot line (5) is inside the second slot line (6) . 2. a kind of broadband filter patch antenna based on double-ring slot structure coupling feeding according to claim 1, is characterized in that: described L-shaped feeding microstrip line (8) and external cable test element (9 ) connected as the 50Ω input port of the antenna. 3. a kind of broadband filter patch antenna based on double-ring slot structure coupling feeding according to claim 1, is characterized in that: described first slot slot line (5), the second slot slot line (6), L Shaped feed microstrip line (8) and cable test element (9) jointly form the feed structure of the antenna, and the feed structure is a dual-function structure, which is used to realize the broadband impedance matching of the antenna, that is, the feed function and the feed function of the antenna. The upper and lower sidebands of the operating frequency band produce two radiation nulls. 4. A broadband filter patch antenna based on double-ring slot structure coupling feeding according to claim 1, characterized in that: the double-ring slot line on the upper surface of the second layer dielectric substrate (2) makes the antenna work The upper and lower frequency sidebands of the frequency band each generate a radiation zero point, which is used to independently control the frequency of the two radiation zero points by controlling the size and position of the double-ring slot structure to achieve band-pass filter radiation performance. 5. A broadband filter patch antenna based on double-ring slot structure coupling feeding according to claim 1, characterized in that: the L-shaped feeding microstrip line printed on the lower surface of the second layer dielectric substrate (2) (8), for coupling the input signal of the antenna to the first slot line (5) and the second slot line (6) through the L-shaped feeding microstrip line (8), and coupled to the upper third layer medium The main radiation patch of the substrate (3) and the parasitic radiation patch of the fourth dielectric substrate (4). 6. A kind of broadband filtering patch antenna based on double-ring slot structure coupling feeding according to claim 1, characterized in that: the parasitic radiation patch on the upper surface of the fourth layer of dielectric substrate (4) is used to increase The radiation gain of the antenna and the generation of a frequency-controllable radiation null outside the high-frequency band. 7. A broadband filter patch antenna based on double-ring slot structure coupling feeding according to claim 1, characterized in that: the second square metal patch (10) is printed on the upper surface of the third layer dielectric substrate (3) ), the second square metal patch (10) is the main radiation structure of the antenna, and is used to transmit the carrier signal from the input port to the wireless space through the half-wavelength resonant antenna principle. 8. A kind of broadband filter patch antenna based on double-loop slot structure coupling feeding according to claim 1, characterized in that: the first layer of dielectric substrate (1), the second layer of dielectric substrate (2), the second layer of dielectric substrate The number of through holes (14) in each layer of the three-layer dielectric substrate (3) and the fourth layer of dielectric substrate (4) is 4, and the corresponding number of the nylon columns (12) is 12, and the nylon columns ( 12) Install on the corresponding through hole (14).

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