CN205900780U - Compact multifrequency base station antenna array - Google Patents

Abstract

The utility model discloses a compact multi-frequency base station antenna array, which comprises a first sub-array and a second sub-array arranged on a substrate, the first sub-array works in the first frequency band, and the second sub-array works in the In a second frequency band different from the first frequency band, the first sub-array includes at least one first filter antenna element without an external loss circuit, and the second sub-array includes at least one second filter antenna element without an external loss circuit. Antenna unit. In the embodiment provided by the utility model, by using the filter antenna unit with no external loss circuit as the element of the multi-frequency base station antenna array, its filter characteristics can be used to reduce the mutual coupling between multiple sub-arrays with similar working frequency bands; no need to design duplex The device or decoupling network reduces the complexity of designing the duplexer or decoupling network, the circuit structure is simple, the design is simple, and it can be processed by cheap PCB technology, and the cost is low.

Description

A compact multi-frequency base station antenna array

technical field

The utility model relates to the field of mobile communication, in particular to a compact multi-frequency base station antenna array.

Background technique

With the rapid development of mobile communication technology, it is often required in the construction of base station antennas that the array antenna not only covers multiple frequency bands, but also supports multiple wireless system systems. When designing dual-frequency or multi-frequency base station array antennas, if the frequency intervals of different frequency bands are large, such as the GSM frequency band (820-960MHz) and the 3G frequency band (1710-2170MHz), at this time, two columns are commonly used to work in the corresponding frequency bands. The sub-arrays are arranged together to design an array antenna. However, once the frequency interval of the two wireless frequency bands is very close, such as the DCS frequency band (1710-1880MHz) and the WCDMA frequency band (1920-2170MHz), the mutual coupling between the sub-arrays is very large, which can only be achieved by increasing the frequency between the two sub-arrays. spacing to reduce mutual coupling and increase port isolation. Increasing the spacing between sub-arrays means increasing the volume of the array antenna.

In engineering applications, there are two commonly used methods for designing dual-frequency base station arrays with small frequency intervals such as DCS (1710-1880MHz) and WCDMA (1920-2170MHz) frequency bands. One is to use one column to cover the entire frequency band of DCS and WCDMA (1710MHz) -2170MHz) antenna units form an array, and a duplexer is cascaded at the front end, and the decoupling between the working frequency bands is carried out by designing a high-isolation duplexer. .-Q.Yang, H.-W.Liu, and L.-Zhu, “Compact and high isolation diplexer using dual-mode stub-loaded resonators”, IEEE Microw.Wireless Compon.Lett.vol.24, no.6, pp.385-387, Jun.2014". However, the duplexer will inevitably bring cascade loss, which will affect the gain of the antenna, and because the frequency band is very close, it is very challenging to design a duplexer with low insertion loss and high isolation. In addition, this solution only uses one array, so it is impossible to independently adjust the downtilt angle for each frequency band during the WLAN optimization process. The second method is to use two sub-arrays covering the entire frequency band (1710-2710MHz) to arrange in parallel, and add a decoupling network between the two sub-arrays to achieve the decoupling effect. These decoupling networks include electromagnetic walls (references such as "R.-I.Eva, Q.-T.Oscar, and I.-S.Luis, "Mutual coupling reduction in patch antenna arrays by using aplanar EBG structure and a multilayer dielectric substrate," IEEETrans.Antennas Propag., vol.56, no.6, pp.1648-1655, Jun.2008"), defect structure (references such as "N.-H.Noordin, A.Rayis, N. .Haridas, B.Flynn, A.Erdogan, and T.Arslan, "Triangular lattices for mutual coupling reduction in patch antenna arrays," in Proc.Loughborough.Conf.Antennas Propag,2011,pp.1-4》), with Anti-resonance unit (references such as "C.-Y.Chiu, C.-H.Cheng, R.-D.Murch, and Corbett R.Rowell, "Reduction of mutual coupling between closely-packed antenna elements," IEEE Trans. Antennas Propag., vol.55, no.6, pp.1732-1738, Jun.2007") and so on. However, these decoupling networks will increase the width of the antenna array and also affect the radiation performance of the antenna such as radiation efficiency, front-to-back ratio, gain, etc.

Utility model content

The technical problem to be solved by the utility model is to provide a compact multi-frequency base station antenna array, which overcomes the defects of large mutual coupling or complex structure of multi-frequency base stations in the prior art.

In order to solve the above technical problems, the utility model provides a compact multi-frequency base station antenna array, including a first sub-array and a second sub-array arranged on a substrate, the first sub-array works in the first frequency band, and the The second sub-array works in a second frequency band different from the first frequency band, the first sub-array includes at least one first filter antenna unit without an external loss circuit, and the second sub-array includes at least one Loss circuit for the second filter antenna element.

Wherein, the first filter antenna unit and the second filter antenna unit both include an upper dielectric substrate, a lower dielectric substrate, a parasitic radiation metal patch disposed on the upper surface of the upper dielectric substrate, and a parasitic radiation metal patch disposed on the lower dielectric substrate. The main radiating metal patch on the upper surface and the metal floor arranged on the lower surface of the lower dielectric substrate, the geometric center of the main radiating metal patch is provided with an asymmetrical E-shaped groove line, and the main radiating metal patch A metal short-circuit probe is connected between the patch and the metal floor.

Wherein, the middle groove line of the asymmetrical E-shaped groove line is the shortest, and the groove line on one side of the middle groove line is longer than the groove line on the other side.

Wherein, the first sub-array and the second sub-array are arranged in parallel and alternately.

Wherein, the distance between adjacent first filter antenna elements in the first subarray is equal to the distance between adjacent second filter antenna elements in the second subarray.

Wherein, the first filter antenna unit and the second filter antenna unit further include plastic support columns, and the upper dielectric substrate and the lower dielectric substrate are fixedly connected through the plastic support columns.

Wherein, the lower dielectric substrate is further provided with a feed port passing through the metal floor.

Wherein, the first sub-array includes 6 first filter antenna units without external loss circuits, and the second sub-array includes 6 second filter antenna units without external loss circuits.

Wherein, the first frequency band is a DCS frequency band, and the second frequency band is a WCDMA frequency band.

Wherein, metal baffles are arranged on both sides of the substrate.

The utility model has the following beneficial effects: by using the filter antenna unit with no external loss circuit as the element of the multi-frequency base station antenna array, it can realize efficient radiation in the band, effective suppression outside the band, and the edge of the gain passband rolls off quickly. Therefore, the use of this filtering characteristic can reduce the mutual coupling between multiple sub-arrays with similar working frequency bands; there is no need to design duplexers or decoupling networks, which reduces the complexity of designing duplexers or decoupling networks. The structure is simple, the design is convenient, and it can be processed by cheap PCB technology, and the cost is low.

Description of drawings

Figure 1 is a top view of a compact dual-frequency base station antenna array provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of the explosion structure of the filter antenna unit provided by the embodiment of the present invention;

Fig. 3 is a side view of the filter antenna unit shown in Fig. 2;

Fig. 4 is a top view of the filtering antenna unit shown in Fig. 2;

Fig. 5 is a bottom view of the filter antenna unit shown in Fig. 2;

Fig. 6 is the simulation result diagram of the reflection coefficient S11-frequency of the filtering antenna unit of the DCS frequency band without external loss circuit provided by an embodiment of the present invention;

Fig. 7 is the simulation result diagram of the gain curve-frequency of the filtering antenna unit of the filter antenna unit without external loss circuit working in the DCS frequency band provided by an embodiment of the present invention;

Fig. 8 is the simulation result diagram of the reflection coefficient S11-frequency of the filtering antenna unit of the WCDMA frequency band without external loss circuit provided by an embodiment of the present invention;

Fig. 9 is the simulation result diagram of the gain curve-frequency of the filtering antenna unit of the WCDMA frequency band without external loss circuit provided by an embodiment of the present invention;

Fig. 10 is a simulation result diagram of the reflection coefficient S11-frequency of the sub-array working in the DCS frequency band provided by an embodiment of the present invention;

Fig. 11 is the simulation result diagram of the gain curve-frequency of the sub-array working in the DCS frequency band provided by an embodiment of the present invention;

Fig. 12 is the simulation result diagram of the reflection coefficient S11-frequency of the subarray working in the WCDMA frequency band provided by an embodiment of the present invention;

Fig. 13 is the simulation result diagram of the gain curve-frequency of the subarray working in the WCDMA frequency band provided by an embodiment of the present invention;

Fig. 14 is an isolation curve S12-frequency simulation diagram of the two sub-array ports of the compact dual-frequency base station antenna array provided by an embodiment of the present invention;

Fig. 15 is the main polarization and cross polarization radiation patterns of the E-plane at 1.8 GHz for the compact dual-frequency base station antenna array provided by an embodiment of the present invention;

Fig. 16 is the main polarization and cross polarization radiation patterns of the H-plane at 1.8 GHz for the compact dual-frequency base station antenna array provided by an embodiment of the present invention;

Figure 17 is the main polarization and cross polarization radiation patterns of the E-plane at 2.06 GHz for the compact dual-frequency base station antenna array provided by an embodiment of the present invention;

Fig. 18 is a radiation pattern of main polarization and cross polarization of the H-plane at 2.06 GHz of the compact dual-frequency base station antenna array provided by an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The embodiment of the utility model provides a compact multi-frequency base station antenna array, including multiple sub-arrays arranged on the substrate, such as the first sub-array, the second sub-array...the Nth sub-array (N≥2, N is Natural number). Wherein the first sub-array works in the first frequency band, the second sub-array works in the second frequency band, ..., the Nth sub-array works in the Nth frequency band, and the first frequency band, the second frequency band ... the Nth frequency band are similar but not same. The first sub-array contains at least one first filter antenna unit without an external loss circuit, the second sub-array contains at least one second filter antenna unit without an external loss circuit, ..., the Nth sub-array contains at least one filter antenna unit without an external loss circuit. The Nth filter antenna element of the loss circuit. By using the filter antenna unit with no external loss circuit as the element of the antenna array of the multi-frequency base station, it can realize high-efficiency radiation in the band, effective suppression outside the band, and the edge of the passband of the gain rolls off quickly, so this filtering feature can be used Reduce the mutual coupling between multiple sub-arrays with similar working frequency bands; there is no need to design duplexers or decoupling networks, which reduces the complexity of designing duplexers or decoupling networks. The circuit structure is simple and easy to design, and can It is processed by cheap PCB technology, and the cost is low.

For ease of description, the following and accompanying drawings will take the dual-frequency base station antenna array as an example to illustrate the mechanism of the antenna array provided by the embodiment of the utility model. It should be understood that the embodiment of the utility model is not limited to the dual-frequency base station antenna array , but should include all multi-frequency base station antenna arrays with the features of the present invention.

Please refer to FIG. 1 , which is a top view of a compact dual-frequency base station antenna array provided by an embodiment of the present invention. The antenna array includes a first sub-array 2 and a second sub-array 3 arranged on the substrate 4, the first sub-array 2 works in the first frequency band, and the second sub-array 3 works in the second frequency band, wherein the first frequency band and The second frequency band is similar but different. For example, the first frequency band is the DCS frequency band (1710-1880MHz), and the second frequency band is the WCDMA frequency band (1920-2170MHz). Of course, these two frequency bands are listed only for illustration and not for limitation. The first sub-array 2 includes at least one first filter antenna unit without an external loss circuit, and the second sub-array 3 includes at least one second filter antenna unit without an external loss circuit, and the filtering characteristics of the filter antenna unit itself make Mutual coupling between two columns of subarrays is greatly reduced. Due to different operating frequencies, the sizes of the first filter antenna unit and the second filter antenna unit are also different. In the embodiment shown in FIG. DCS frequency band), the small-sized second filter antenna unit works in the second frequency band with higher frequency (for example, WCDMA frequency band). The size of the substrate 4 can also be set according to the number and scale of the sub-arrays. For example, in the embodiment of the dual-frequency base station antenna array shown in FIG. Substrate, the metal floor is formed by printing copper on the bottom surface of the PCB dielectric substrate and tinning it to prevent oxidation. The PCB dielectric substrate can be processed from a material with a relative permittivity εr=2.65 and a thickness of 2-4mm.

Preferably, as shown in FIG. 1 , metal baffles 1 are provided on both sides of the substrate 4 , and the metal baffles 1 can be made of metal aluminum plates. In the example shown in FIG. 1 , the first sub-array 2 and the second sub-array 3 work in the DCS frequency band and the WCDMA frequency band respectively, and the height of the metal baffle 1 is 8 mm.

Preferably, as shown in FIG. 1 , the first sub-arrays 2 and the second sub-arrays 3 are arranged in parallel and alternately. Specifically, as shown in FIG. 1, the first sub-array 2 and the second sub-array 3 are parallel to each other in the first direction, and interlaced with each other in the second direction perpendicular to the first direction. The parallel alignment arrangement can increase the distance between the first sub-array 2 and the second sub-array 3, thereby further reducing the mutual coupling between the sub-arrays and obtaining a better isolation effect.

Preferably, as shown in FIG. 1 , the distance A between adjacent first filter antenna elements in the first subarray 2 and the distance B between adjacent second filter antenna elements in the second subarray 3 Equal, for example, when the operating frequency bands of the first filtering antenna unit and the second filtering antenna unit are DCS frequency band and WCDMA frequency band respectively, A=B=130mm.

Preferably, as shown in FIG. 1 , the first sub-array 2 includes 6 first filter antenna units, and the second sub-array 3 includes 6 second filter antenna units.

The structures of the first filter antenna unit and the second filter antenna unit will be described in detail below with reference to FIGS. 2-5 . The first filter antenna unit and the second filter antenna unit are basically the same in structure except for the different sizes. For convenience of description, in the following illustrations with reference to FIGS. 2-5 , filter antenna units are collectively used to represent the first filter antenna unit and the second filter antenna unit.

As shown in FIGS. 2 and 3 , each filter antenna unit includes an upper dielectric substrate 6 , a lower dielectric substrate 11 and a connecting mechanism for connecting the upper dielectric substrate 6 and the lower dielectric substrate 11 . The upper surface of the upper dielectric substrate 6 is provided with a parasitic radiation metal patch 7, the upper surface of the lower dielectric substrate 11 is provided with a main radiation metal patch 10, the lower surface of the lower dielectric substrate 11 is provided with a metal floor 14, and the parasitic radiation The metal patch 7, the main radiation metal patch 10 and the metal floor 14 are all metal plating. A metal short-circuit probe 12 is connected between the main radiation metal patch 10 and the metal floor 14 . Specifically, as shown in Figures 2, 3 and 5, three metal probes 12 are provided with a diameter of 1 mm. An asymmetrical E-shaped slot line 13 is provided at the geometric center of the main radiating metal patch 10 . Specifically, as shown in Figures 2, 3, and 5, the middle groove line of the asymmetric E-shaped groove line is the shortest, and the groove line on one side of the middle groove line is longer than the groove line on the other side. The slot line creates a radiating null at the low frequency edge of the passband of the gain curve.

Preferably, as shown in FIGS. 2-5 , the filter antenna unit includes a plastic support column 8 through which the upper dielectric substrate 6 and the lower dielectric substrate 11 are connected and fixed into an upper and lower layer structure. Specifically, as shown in FIG. 3 , there are four plastic support columns 8 , and four via holes 5 are provided at the four corners of the upper dielectric substrate 6 and the lower dielectric substrate 11 for connecting the plastic support columns 8 . The upper dielectric substrate 6 is fixed on the lower dielectric substrate through plastic support columns 8 to form a certain interval. Properly adjusting the interval can generate a high-frequency radiation zero point on the right side of the passband. In this way, there is a radiation zero point at the high and low frequency sides of the passband, which ensures the bandpass characteristic of the filter antenna.

Preferably, the lower dielectric substrate 11 is further provided with a feed port 9 passing through the metal floor 14 .

In an exemplary embodiment of the present invention, there are two filter antenna units whose working frequency bands are respectively DCS frequency band and WCDMA frequency band without additional loss circuit, and these two filter antenna units all adopt the circuit structure shown in Fig. 2, Due to the different working frequency bands, the specific circuit dimensions are different. The corresponding circuit design dimensions of the filter antenna unit without external loss circuit are shown in Table 1 below:

Table 1 Circuit dimensions of DCS frequency band and WCDMA frequency band filter antenna unit

In this embodiment, the frequency intervals between the working frequency bands 1710-1880MHz and 1920-2170MHz of the two sub-arrays are very small, and the sub-arrays in the DCS frequency band radiate efficiently in their working frequency bands 1710-1880MHz. 2170MHz) to suppress radiation; at the same time, the sub-arrays in the WCDMA frequency band radiate efficiently within its working frequency band 1920-2170MHz, and suppress radiation outside the band, that is, the DCS frequency band (1710-1880MHz). Therefore, the radiation between the two sub-arrays does not interfere with each other, thereby reducing mutual interference and achieving higher port isolation.

As shown in Fig. 6-7, it is a simulation result diagram of reflection coefficient S11-frequency and gain curve-frequency of the filter antenna unit working in the DCS frequency band without external loss circuit provided by an embodiment of the present invention. It can be seen that there are three resonance modes in the working frequency band of 1710-1880MHz. In the S11-frequency curve, S11 is lower than -10dB in the DCS frequency band. In the gain curve, the gains at the two radiation zero points are all below -22dBi. At the same time, it has a bandpass filter characteristic with good squareness, steep passband edge, obvious sideband suppression, good frequency selectivity, and flat gain in the band. Nearly 9dBi at 1.8GHz.

As shown in Fig. 8-9, it is a simulation result diagram of the reflection coefficient S11-frequency and gain curve-frequency of the filter antenna unit working in the WCDMA frequency band without external loss circuit provided by an embodiment of the present invention. It can be seen that there are three resonance modes in the working frequency band of 1920-2170MHz. In the S11-frequency curve, S11 is lower than -10dB in the DCS frequency band. In the gain curve, the gains at the two radiation zero points are both below -20dBi. At the same time, it has a bandpass filter characteristic with good squareness, steep passband edge, obvious sideband suppression, good frequency selectivity, and flat gain in the band. Nearly 9dBi at 2.0GHz.

As shown in Fig. 10-11, it is a simulation result diagram of reflection coefficient S11-frequency and gain curve-frequency of a subarray working in the DCS frequency band provided by an embodiment of the present invention. It can be seen that there are three resonance modes in the working frequency band of 1710-1880MHz. In the S11-frequency curve, S11 is lower than -10dB in the DCS frequency band. In the gain curve, the gain has a bandpass filter characteristic with good rectangularity, steep passband edge, obvious sideband suppression, good frequency selectivity, and flat gain in the band, which is close to 14.6dBi at 1.8GHz.

As shown in Fig. 12-13, it is a simulation result diagram of the reflection coefficient S11-frequency and the gain curve-frequency of the sub-array working in the WCDMA frequency band provided by an embodiment of the present invention. It can be seen that there are three resonance modes in the working frequency band of 1920-2170MHz. In the S11-frequency curve, S11 is lower than -10dB in the WCDMA frequency band. In the gain curve, the gain has a bandpass filter characteristic with good rectangularity, steep passband edge, obvious sideband suppression, good frequency selectivity, and flat gain in the band, which is close to 15dBi at 2.06GHz.

As shown in FIG. 14 , it is an isolation curve S12-frequency simulation diagram of two sub-array ports of a compact dual-frequency base station antenna array provided by an embodiment of the present invention. It can be seen that in the entire frequency band 1.5GHZ-2.5GHz, the port isolation factor S12 of the array is lower than 35dB, indicating that the mutual coupling between the sub-arrays of the antenna array is very small and the port isolation is very high. Figures 15-18 respectively show the main polarization and cross-polarization radiation patterns of the H-plane and E-plane of the antenna array at 1.8GHz and 2.06GHz, which also shows that the antenna array has a stable radiation pattern.

Embodiments of the utility model have the following advantages:

1. Integrated filtering characteristics and radiation characteristics, the antenna array itself has filtering performance, the edge of the passband is steep, the sideband suppression is obvious, and it has good frequency selection characteristics. The disadvantages of large loss and large volume are easily caused by the device or decoupling network;

2. The antenna array is suitable for DCS frequency bands and WCDMA frequency bands with close frequency intervals. Without the need for decoupling circuits, it achieves high port isolation, suppresses adjacent frequency interference, and improves the performance of base station transceivers;

3. The sub-arrays are arranged in parallel with each other, and are staggered by a certain distance in the vertical direction, so as to further reduce the mutual coupling between the sub-arrays;

4. The whole structure is mainly composed of metal patches, metalized vias, dielectric plate through holes and U-shaped grooves. The structure is simple, the design is simple, and it can be processed by cheap PCB technology.

The embodiment provided by the utility model is applicable to the field of wireless mobile communication base stations, and can be applied to receiving and transmitting equipment of various wireless communication systems. Due to the filtering characteristics of the utility model, it is especially suitable for communication in open and complex multi-frequency bands and multi-standards In the scenario, a base station antenna working in the 4G-LTE D-band (2.3-2.7GHz), and a large-scale wireless local area network WLAN 2.4GHz AP. At the same time benefiting from the integration of filtering characteristics and radiation characteristics, the utility model is also suitable for the integration and integration of wireless mobile communication system equipment, reduces design requirements, and improves the ability of communication equipment to resist adjacent frequency interference.

What is disclosed above is only a preferred embodiment of the present utility model, and of course it cannot limit the scope of rights of the present utility model. Those of ordinary skill in the art can understand all or part of the process of realizing the above-mentioned embodiment, and according to this Equivalent changes made to the claims of the utility model still fall within the scope of the utility model.

Claims (10)

1. a kind of compact multifrequency base-station antenna array it is characterised in that include is arranged at the first subarray on substrate and the Two subarrays, described first subarray works in the first frequency range, and described second subarray works in different from described first frequency range The second frequency range, described first subarray comprises the first filter antenna unit of at least one no additional losser circuit, described Two subarrays comprise the second filter antenna unit of at least one no additional losser circuit.

2. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that described first filter antenna unit Identical with the structure of described second filter antenna unit, all include medium substrate, lower medium substrate, be arranged at described upper medium The parasitic radiation metal patch of upper surface of base plate, be arranged at described lower medium substrate upper surface primary radiation metal patch and It is arranged at the metal floor of described lower medium substrate lower surface, be provided with the geometric center position of described primary radiation metal patch The asymmetrical e font line of rabbet joint, is connected with short circuit metal probe between described primary radiation metal patch and described metal floor.

3. compact multifrequency base-station antenna array as claimed in claim 2 is it is characterised in that described asymmetrical e font groove The middle line of rabbet joint of line is the shortest, and the line of rabbet joint positioned at described middle line of rabbet joint side is longer than the line of rabbet joint of opposite side.

4. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that described first subarray and described Second subarray is parallel to be staggered.

5. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that phase in described first subarray Between the first adjacent filter antenna unit the spacing distance second filter antenna unit adjacent with described second subarray it Between spacing distance equal.

6. compact multifrequency base-station antenna array as claimed in claim 2 is it is characterised in that described first filter antenna unit Also include plastic support post with described second filter antenna unit, described upper medium substrate and described lower medium substrate are by described Plastic support post is fixedly connected.

7. compact multifrequency base-station antenna array as claimed in claim 2 is it is characterised in that also set on described lower medium substrate There is the feed port through described metal floor.

8. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that described first subarray comprises 6 First filter antenna unit of individual no additional losser circuit, described second subarray comprises the second of 6 no additional losser circuits Filter antenna unit.

9. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that described first frequency range is dcs frequency Section, described second frequency range is wcdma frequency range.

10. compact multifrequency base-station antenna array as claimed in claim 1 is it is characterised in that described substrate both sides are provided with Metal baffle.