CN207117635U - Antenna array calibration network - Google Patents

Abstract

The utility model discloses an antenna array calibration network, include: the first layer of dielectric substrate and the second layer of dielectric substrate are arranged in a stacked mode; a strip line circuit is arranged between the first layer of dielectric substrate and the second layer of dielectric substrate, a microstrip line circuit is arranged on the surface of one side of the first layer of dielectric substrate, which is far away from the second layer of dielectric substrate, the number of the strip line circuits and the number of the microstrip line circuits are the same and more than one, and the strip line circuit and the microstrip line circuit are connected to form a calibration circuit; in each calibration circuit, the strip line circuit comprises a power combiner and more than two directional couplers, the microstrip line circuit comprises more than two amplitude modulators with the same quantity as the directional couplers, and each amplitude modulator is respectively connected between the coupling end of one directional coupler and one input end of the power combiner. Through the implementation mode, the calibration network can adjust the amplitude from each radiation port to the calibration port, the amplitude adjustment range is large, and the adjustment precision is high.

Description

Antenna Array Calibration Network

technical field

The utility model relates to the technical field of mobile communication base stations, in particular to an antenna array calibration network.

Background technique

Faced with the explosive growth of users' data demand for mobile communication networks, especially wireless applications that require real-time transmission of large amounts of data, the network capacity of 1000 times that of 4G LTE systems and the massive MIMO antenna array with extremely low delay of 1 millisecond The system is considered to be the most potential transmission technology for 5G.

The feeding network of massive MIMO antenna array includes power dividing network and calibration network. The function of the calibration network is to extract a part of the RF signal input to each radiation port, and monitor the extracted signal to determine whether the amplitude and phase of the signal input to each radiation port are stable.

The RF signals extracted from each radiation port need to be cascaded through a power combiner to form a calibration port, and the maximum amplitude deviation between each radiation port in the calibration network and the calibration port is required to be less than 0.5dB. At present, the circuit of the calibration network is formed by processing the PCB circuit board, and the processing accuracy and the crosstalk between each circuit line all affect the amplitude from each radiation port to the calibration port. The deviation of the calibration amplitude is too large to make an accurate judgment on the stability of the signal, and after the calibration network processing is completed, the calibration amplitude of each channel cannot be adjusted. Therefore, it brings great difficulties to the performance design and debugging of the calibration network.

Utility model content

The utility model provides an antenna array calibration network for solving the above technical problems, the calibration network can adjust the amplitude from each radiation port to the calibration port, the amplitude adjustment range is large, and the adjustment accuracy is high.

In order to solve the above technical problems, the utility model provides an antenna array calibration network, comprising: a first layer dielectric substrate and a second layer dielectric substrate stacked; There is a stripline line, and the surface of the first layer of dielectric substrate away from the second layer of dielectric substrate is provided with a microstrip line line, and the number of the stripline line and the microstrip line line is the same and there are more than one. The stripline line and a microstrip line are connected to form a calibration line; in each of the calibration lines, the stripline line includes a power combiner and more than two directional couplers, and the microstrip line The line includes more than two amplitude modulators with the same quantity as the directional coupler, and each of the amplitude modulators is connected between a coupling end of a directional coupler and an input end of a power combiner.

Further, the input end of each amplitude modulator is connected to the coupling end of a directional coupler through a metallized via hole, and the output end is connected to an input end of the power combiner through a metallized via hole.

Further, in each of the calibration lines, the stripline line includes a first directional coupler and a second directional coupler, and the microstrip line includes a first amplitude modulator and a second amplitude modulator; The first amplitude modulator is connected between the coupling end of the first directional coupler and the first input end of the power combiner, and the second amplitude modulator is connected between the coupling end of the second directional coupler and the first input end of the power combiner. between the two inputs.

Further, among all the calibration circuits, a plurality of power combiners having the same number as the calibration circuits are cascaded and connected to form a total output terminal.

Further, a metal ground is provided on the surface of the second-layer dielectric substrate away from the first-layer dielectric substrate; each of the directional couplers is a parallel coupled line directional coupler.

Further, each of the amplitude modulators is a phase compensation amplitude modulator.

Further, the phase compensation amplitude modulator is formed by cascading a microstrip power divider and a microstrip power combiner, wherein one branch of the microstrip power divider is provided with a phase shifter.

Further, the phase shifter is composed of a plurality of microstrip line segments of different lengths, and the microstrip line segments of different lengths correspond to different phases, and then the amplitudes of different values are adjusted by conducting the microstrip line segments of different lengths.

Further, the dielectric constants of the first dielectric substrate and the second dielectric substrate range from 2.2 to 10.2; the total thickness of the first dielectric substrate and the second dielectric substrate ranges from 0.76mm to 2.70mm.

Further, the antenna array calibration network is a massive MIMO antenna array calibration network.

The antenna array calibration network of the utility model has the following beneficial effects:

By setting the amplitude modulator in the microstrip line, setting the directional coupler and the power combiner in the strip line line, and connecting each amplitude modulator between the coupling end of a directional coupler and an input end of the power combiner The amplitude from each radiation port to the calibration port can be adjusted, and the amplitude adjustment range is large, and the adjustment accuracy is high;

Moreover, the amplitude modulator adopts the form of microstrip line, and the directional coupler and power combiner adopt the form of strip line, which are easy to integrate and low in cost;

In addition, the amplitude modulator, the directional coupler and the power combiner are respectively integrated on each layer of dielectric substrate, and the structure is compact.

Description of drawings

Fig. 1 is a schematic cross-sectional structural diagram of the antenna array calibration network of the present invention.

FIG. 2 is a schematic structural diagram of the circuit connection of the antenna array calibration network shown in FIG. 1 .

FIG. 3 is a schematic structural diagram of an embodiment of an amplitude modulator in the antenna array calibration network shown in FIG. 1 .

FIG. 4 is a graph showing the relationship between the amplitude adjustment value of the amplitude modulator and the phase value in the antenna array calibration network shown in FIG. 1 .

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to FIG. 1 to FIG. 2 , the utility model provides an antenna array calibration network. The antenna array calibration network includes: a first-layer dielectric substrate 1 and a second-layer dielectric substrate 2, and the first-layer dielectric substrate 1 and the second-layer dielectric substrate 2 are stacked.

Wherein, the dielectric constant ranges of the first layer dielectric substrate 1 and the second layer dielectric substrate 2 can be 2.2-10.2 respectively; the total thickness range of the first layer dielectric substrate 1 and the second layer dielectric substrate 2 is 0.76mm~ 2.70mm.

For example, Rogers RO4730JXR can be selected as the plate material of the first dielectric substrate 1 and the second dielectric substrate 2 . Preferably, the dielectric constants of the first dielectric substrate 1 and the second dielectric substrate 2 are both 3.0, and the thicknesses of the first dielectric substrate 1 and the second dielectric substrate 2 are both 0.78 mm.

In a specific embodiment, a stripline line 3 is provided between the first layer dielectric substrate 1 and the second layer dielectric substrate 2, and the surface of the first layer dielectric substrate 1 away from the second layer dielectric substrate 2 is provided with micro Strip line 4. The stripline lines 3 and the microstrip line lines 4 have the same number and more than one. Wherein, a stripline line 3 and a microstrip line 4 are connected to form a calibration line.

Wherein, in each calibration line, the stripline line 3 includes a power combiner 33 and more than two directional couplers 31, 32; the microstrip line 4 includes the same number of directional couplers as in the stripline line 3 More than two amplitude modulators 41, 42. Wherein, each amplitude modulator 41 (42) is respectively connected between the coupling end 311 (321) of one of the directional couplers 31 (32) and an input end 331 (332) of the power combiner 33, that is, different The amplitude modulator 41 ( 42 ) is connected between the coupling ends 311 ( 321 ) of different directional couplers 31 ( 32 ) and different input ends 331 ( 332 ) of the same power combiner 33 . Preferably, the input end 411 (421) of each amplitude modulator 41 (42) is connected to the coupling end 311 (321) of one of the directional couplers 31 (32) through a metallized via hole 6, and the output end 412 ( 422 ) and an input terminal 331 ( 332 ) of the power combiner 33 are conducted through another metallized via hole 6 .

Specifically, the first amplitude modulator 41 is connected between the coupling end 311 of the first directional coupler 31 and the first input end 331 of the power combiner 33, and the second amplitude modulator 42 is connected to the second directional coupler 32 between the coupling end 321 of the power combiner 33 and the second input end 332 of the power combiner 33 .

Further, the coupling end 311 of the first directional coupler 31 is connected to the input end 411 of the first amplitude modulator 41 through a metallized via hole 61, and the coupling end 321 of the second directional coupler 32 is connected to the input end 411 of the second amplitude modulator. The input terminal 421 of 42 is connected through a metallized via 62 .

Furthermore, the output end 412 of the first amplitude modulator 41 is connected to the first input end 331 of the power combiner 33 through a metallized via hole 63; the output end 422 of the second amplitude modulator 42 is connected to the second input end of the power combiner 33 Terminal 332 is connected through a metallized via 64 .

In a preferred embodiment, the surface of the second dielectric substrate 2 away from the first dielectric substrate 1 is provided with a metal ground 5 . The arrangement of the metal ground 5 can replace the metal reflector in the traditional antenna array, reduce the number of components of the antenna array, and greatly reduce the volume and weight of the antenna array, while ensuring reliable electrical performance.

In a specific embodiment, when there are two or more stripline lines 3 and microstrip line lines 4 respectively, and correspondingly connected to form more than two calibration lines, among all the calibration lines, the same number of calibration lines Multiple power combiners 33 are cascaded and connected to form a total output terminal 333 as a calibration port.

Preferably, each directional coupler 31, 32 can be a parallel coupled line directional coupler.

In a preferred embodiment, each amplitude modulator 41, 42 can be a phase compensation amplitude modulator, and the phase compensation microstrip amplitude modulator can be used to adjust the amplitude by adjusting the phase difference. The amplitude adjustment method is simple and feasible, and the adjustment range, adjustment Higher precision.

Specifically, as shown in FIG. 3, the phase compensation amplitude modulator is formed by cascading a microstrip power divider 413 and a microstrip power combiner 414. The microstrip power divider 413 may be a one-to-two power divider. The microstrip power combiner 414 may be the two-in-one power combiner 33 , wherein one branch of the microstrip power divider 413 is provided with a phase shifter 415 . The splitting side of the microstrip power divider 413 serves as the input end of the phase compensation modulator, and the combining side of the microstrip power combiner 414 serves as the output end of the phase compensation modulator.

Wherein, the phase shifter 415 can usually be composed of a plurality of microstrip line segments of different lengths, and the microstrip line segments of different lengths correspond to different phases, and then the amplitudes of different values can be adjusted by conducting the microstrip line segments of different lengths. In actual use, one of the microstrip line segments can be turned on as needed.

For example, the phase shifter 415 can be composed of five microstrip line segments with different lengths, and each microstrip line segment is turned on sequentially according to the length from short to long, and the phase adjustment is 10°, 15°, 20°, 25° in sequence , 30°, the corresponding amplitude adjustments are 0.3dB, 0.45dB, 0.65dB, 0.86dB, 1.15dB. Of course, in other embodiments, more or fewer microstrip line segments of different lengths can be set as required. Of course, the length of the microstrip line segment can also be set as required to achieve different phase adjustments, and then different amplitude adjustments .

Please refer to FIG. 4 , which is a graph showing the relationship between the amplitude adjustment value and the phase value of the aforementioned phase compensation amplitude modulator. The abscissa is the frequency, the frequency range is 2.575GHz to 2.635GHz; the ordinate is the amplitude adjustment amount; when the phase adjustment is 10°, 15°, 20°, 25°, 30°, the amplitude adjustment is 0.3dB, 0.45dB, 0.65dB, 0.86 dB, 1.15dB.

In the foregoing embodiments, the antenna array calibration network may and preferably is a massive MIMO antenna array calibration network.

The utility model also provides an antenna array, and the antenna array includes the antenna array calibration network as described in any one of the above embodiments.

The antenna array and the antenna array calibration network of the present invention have the following beneficial effects:

By setting the amplitude modulators 41, 42 in the microstrip line 4, setting the directional couplers 31, 32 and the power combiner 33 in the strip line 3, and connecting each amplitude modulator 41 (42) to a directional coupling Between the coupling end 311 (321) of the power combiner 31 (32) and an input end 331 (332) of the power combiner 33, the amplitude from each radiation port to the calibration port can be adjusted, and the amplitude adjustment range is large and the adjustment accuracy is high;

In addition, the amplitude modulators 41 and 42 are in the form of microstrip lines, and the directional couplers 31 and 32 and the power combiner 33 are in the form of striplines, which are easy to integrate and low in cost;

In addition, the amplitude modulators 41, 42, the directional couplers 31, 32 and the power combiner 33 are respectively integrated on the dielectric substrates 1, 2 of each layer, and the structure is compact.

The above are only embodiments of the present utility model, and are not intended to limit the patent scope of the present utility model. Any equivalent structure or equivalent process conversion made by using the description of the utility model and the contents of the accompanying drawings, or directly or indirectly used in other related Technical fields are all included in the scope of patent protection of the utility model in the same way.

Claims (10)

1. A kind of 1. antenna array calibration network, it is characterised in that including：

   The first layer medium substrate and second layer medium substrate being stacked；

   Strip line circuit, the first layer medium substrate are provided between the first layer medium substrate and second layer medium substrate Surface away from second layer medium substrate side is provided with microstrip line circuit, strip line circuit and microstrip line the number of, lines phase Together and it is more than one, a strip line circuit and a microstrip line connection form a calibration circuit；

   In each calibration circuit, the strip line circuit includes a work(clutch and more than two directional couplers, institute Stating microstrip line circuit includes each connecting with the more than two modulators of directional coupler quantity identical, each modulator Between the coupled end of a directional coupler and an input of work(clutch.
2. 2. antenna array calibration network according to claim 1, it is characterised in that：

   The input of each modulator is turned on the coupled end of a directional coupler by a metallization VIA, output end with One input of work(clutch is turned on by a metallization VIA.
3. 3. antenna array calibration network according to claim 1, it is characterised in that：

   In each calibration circuit, the strip line circuit includes the first directional coupler and the second directional coupler, institute Stating microstrip line circuit includes the first modulator and the second modulator；First modulator is connected to the coupling of the first directional coupler Close between end and the first input end of work(clutch, second modulator is connected to the coupled end of the second directional coupler and work(closes Between second input of device.
4. 4. antenna array calibration network according to claim 1, it is characterised in that：

   All in the calibration circuit, cascade and be connected to form one always with the calibration multiple work(clutchs of number of, lines identical Output end.
5. 5. antenna array calibration network according to claim 1, it is characterised in that：

   Surface of the second layer medium substrate away from the first layer medium substrate side is with being provided with metal；

   Each directional coupler is parallel coupled line directional coupler.
6. 6. antenna array calibration network according to claim 1, it is characterised in that：

   Each modulator is Amplitude Modulator with Phase Compensation.
7. 7. antenna array calibration network according to claim 6, it is characterised in that：

   The Amplitude Modulator with Phase Compensation is that microstrip power divider cascades to be formed with micro-strip work(clutch, wherein the one of the microstrip power divider Road branch is provided with phase shifter.
8. 8. antenna array calibration network according to claim 7, it is characterised in that：

   The phase shifter is made up of the different micro-strip line segment of a plurality of length, and the micro-strip line segment of different length corresponds to different phases Position, and then the amplitude of the different numerical value of micro-strip line segment adjustment by turning on different length.
9. 9. antenna array calibration network according to claim 1, it is characterised in that：

   The dielectric constant range of the first layer medium substrate and second layer medium substrate is respectively 2.2~10.2；Described first Layer medium substrate and the total thickness range of the second layer medium substrate are 0.76mm~2.70mm.
10. 10. antenna array calibration network according to claim 1, it is characterised in that：

    The antenna array calibration network is extensive mimo antenna array calibration network.