TW201824644A - Active array antenna system with hierarchical modularized mechanism comprising an array antenna and a simplified backbone beamforming circuit - Google Patents

Abstract

The present invention provides an active array antenna system with hierarchical modularized mechanism, comprising: an array antenna and a beam forming circuit. The array antenna includes a plurality of antenna units that are arranged in an array manner and have the number N. The beam forming circuit receives a plurality of input signals and a plurality of phase control signals, and the beam forming circuit includes a hierarchical circuit structure based on phase shifters, wherein the hierarchical circuit structure outputs a plurality of signals based on the phase control signals, the corresponding plurality of phase values and superposition of the phase values, and the output signals are respectively coupled to the antenna units to produce a radiation pattern.

Description

   Hierarchical modular active array antenna system   

The invention relates to an array antenna system, and more particularly to a hierarchical modular active periodic array antenna system.

In the structure of the signal processing system, a set of transmitting / receiving modules and phase shifters are connected to the rear end of each antenna. The transmitting / receiving module includes a low noise amplifier (LNA) and a power amplifier. (PA, power amplifier) and RF attenuators such as power attenuators. The function of the transmitting / receiving module is to provide power, and the role of the array antenna and phase shifter is to form a beam, in which reducing the number of components of the transmitting / receiving module, phase shifter, etc. is a very important factor in the system cost; The traditional design architecture is to connect each antenna with a transmitting / receiving module. However, this architecture is not economical. The reasons are as follows: RF components are controlled in a digital manner. Each component in a traditional periodic array antenna system All must correspond to a set of control lines. If the element is composed of N antenna units, the antenna structure requires N groups of control lines and N control units; if each antenna is connected to M radio frequency components, the antenna The structure will require a total of N × M control lines and N × M group controllers. Such a large number of control lines and control modules will not only consume manufacturing costs, but also increase substrate space. In addition, excessive control lines and RF components may also cause mutual interference between signals, causing energy loss and increasing difficulties in reducing process size. degree.

In addition, if the period of an array antenna is too long, sidelobe waves will often be generated, and the sidelobe wave will consume the energy of the main beam, making the performance of the array antenna worse. This is also the most important factor when designing an array antenna. Common difficulties encountered.

In view of the disadvantages of the above-mentioned conventional technologies, the main object of the present invention is to provide an array antenna system whose architecture can simplify the control circuit of the back-end circuit module.

To achieve the above object, the present invention provides a hierarchical modular active array antenna system, which includes: an array antenna and a beamforming circuit. The array antenna includes a plurality of antenna elements, which are arranged in an array and the number is N. The beamforming circuit receives a plurality of input signals and a plurality of phase control signals. The beamforming circuit includes a hierarchical circuit structure based on a phase shifter, and the hierarchical circuit structure is based on a plurality of corresponding phase control signals. The phase value and the superposition of the phase values are used to output a plurality of output signals based on the input signals. The output signals are respectively coupled to the antenna units to generate a radiation field pattern. The number of the phase control signals is T, T <N, where , , MP T M, Ni (i = 1 to P), M, P are positive integers, P 3, Ni 2.

In an embodiment of the present invention, the hierarchical circuit structure includes: a phase shifter hierarchical circuit for receiving the input signals to output the output signals, and including a plurality of layers coupled in a hierarchical manner to P layers. Phase shifters, the P-level phase shifters receive the P group of phase control signals divided by the phase control signals, and the k-th phase shifters of the phase shifters receive the phase control signals respectively Nk phase control signals in the k-th group, of which 1 k P.

In an embodiment of the present invention, the hierarchical circuit structure includes an adder hierarchical circuit and a plurality of phase shifters. An adder hierarchical circuit is used to generate a plurality of output phase control signals according to a plurality of phase values corresponding to the phase control signals and a superposition of the phase values. The adder hierarchical circuit includes a hierarchical coupling as P- Multiple adders for 1 level. A plurality of phase shifters are coupled to the adder hierarchical circuit and are used to output the output signals according to the input signals and the output phase control signals.

10, 20, 20A, 30, 30A‧‧‧ array antenna system

110, 110A, 210‧‧‧ array antenna

120, 220, 220A‧‧‧ Beamforming circuit

320, 220A‧‧‧Beamforming circuit

CS1 ~ CST‧‧‧phase control signal

SI‧‧‧ input signal

AS1 ~ ASN‧‧‧Output signal

G1, G2, G3 ‧‧‧ sub arrays

41,42,51,52,61,62‧‧‧ curves

Figure 1 is a schematic diagram of a conventional rotational speed measurement system.

Figure 2 is a schematic diagram of a conventional speed correction system.

FIG. 3 is a schematic diagram of a calibration system of a rotational speed measuring device according to the present invention.

FIG. 4 is a schematic diagram of the steps of a calibration method of a rotational speed measuring device according to the present invention.

The following is a description of specific embodiments of the present invention. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification.

Please refer to FIG. 1, which is a schematic structural diagram of a hierarchical modular active periodic array antenna system (hereinafter referred to as an array antenna system) according to an embodiment of the present invention. As shown in FIG. 1, the array antenna system 10 includes an array antenna 110 and a beam forming circuit 120. The array antenna 110 includes a plurality of antenna elements. The antenna elements are arranged in an array and the number is N. The beam forming circuit 120 receives or couples a plurality of input signals SI and a plurality of phase control signals CS1 to CST signals, wherein each phase control signal can be a digital serial signal or a digital parallel signal. The beamforming circuit 120 includes a hierarchical circuit structure based on a phase shifter. The hierarchical circuit structure outputs a plurality of phase values corresponding to the phase control signals and a superposition of the phase values based on the input signals. A plurality of output signals AS1 ~ ASN are respectively coupled to the antenna units to generate a radiation field pattern. The number of these phase control signals CS1 ~ CST is T, where T is less than N, and T and N are positive integers.

In this embodiment, in order to simplify the control lines corresponding to the control signals in the array antenna system 10, the number of phase control signals received by the hierarchical circuit structure of the beam forming circuit 120 is smaller than the number of antenna units. The hierarchical circuit structure is implemented based on the concept of “hierarchical modularization” and based on the number and arrangement of antenna elements in the array antenna 110. The implementation of the hierarchical circuit structure will be described in the following embodiments.

The following first explains the meaning of the concept of "hierarchical modularization" in the beam forming of an array antenna. Please refer to FIG. 2A. For a one-dimensional array antenna 110A, hierarchical modularization refers to grouping in the following manner: N1 (such as N1 = 2) antenna units are used as a group of antennas of the array antenna 110A. The unit is divided into a plurality of sub-arrays G1, and is referred to as a level 1 or a level 1 antenna unit. Next, for the sub-array G1 of the layer 1, the N2 (for example, N2 = 2) sub-arrays G1 as a group is divided into a plurality of sub-arrays G2, and it is called an antenna unit of the layer 2 or the second layer. By analogy, until the last level P, the sub-array GP-1 of level P-1 is divided into sub-arrays GP with NP (such as NP = 3) sub-arrays GP-1 as a group, and is called the level P or the first level. P-level antenna elements; where P is an integer greater than or equal to three.

Please note that the hierarchy generated after the above-mentioned "hierarchical modularization" is a logical classification and the array antenna 110A has not been physically changed. In addition, when implementing a back-end circuit such as the beamforming circuit 120, the designer can use the same level of sub-arrays to share a set of control signals to control the corresponding back-end circuit components (such as Shifter, or adder, or attenuator, etc.), and then the superposition generated by the hierarchical structure of the back-end circuit elements is used to generate the signals required by each antenna unit of the array antenna 110A, thereby achieving beamforming. For example, as shown in FIG. 2A, the beamforming circuit 120 may be implemented as follows: using N1 (such as N1 = 2) phase control signals to control the phase values of the transmission signals fed to the sub-array G1 of the layer 1 respectively; N2 (such as N2 = 2) phase control signals to control the phase values of the transmission signals fed to the sub-array G2 of level 2; and N3 (such as N3 = 3) phase control signals to control the sub-feeds of level 3 children Phase value of the transmission signal of the array G3. In this way, based on the hierarchy shown in FIG. 2A, when implementing a back-end circuit such as the beamforming circuit 120, T = N1 + N2 + N3 = 7 phase control signals can be used to control the 12 antenna elements required by the 12 antenna units. 12 phase values of the transmitted signal. Compared with the conventional beamforming circuit of an array antenna, which uses 12 phase control signals to achieve the same purpose, the embodiment of the present invention can reduce the use of 5 phase control signals; if a digital with a resolution of 5 bits is used In the case of a phase shifter, the above-mentioned conventional method requires 60 signal lines to connect the phaser and the control unit. According to the embodiment of the present invention, it can be reduced to 35 signal lines.

In addition, the above-mentioned "hierarchical modularization" concept can be extended to three levels or more. For example, the number of antenna elements N of the array antenna 110 can be expressed as N = N1 × N2 × N3 ... × Np (that is, ), And the number T of these phase control signals can be expressed as T = M = N1 + N2 + N3 ... + Np (ie ), Where Ni (i = 1 ~ P, Ni The size of 2) can be determined according to the number of levels P set in the design of the array antenna system 10. Since N> M, in other words, in the case of a large number of antenna units N, the number of levels can be selected to be set, and the control signals and the number of signal lines of the back-end circuits required in the array antenna system 10 can cut back. In addition, the implementation of the present invention is not limited to the above examples, and the number of control signals and their signal lines can be further simplified so that the phase control signal T is less than M. For these simplified matters, embodiments will be described later.

Furthermore, when the "array modularization" is used to design the array antenna system 10, different beam division circuits can be generated for different layers. For example, compared to FIG. 2A, as shown in FIG. 2B, the same array antenna 110A is also divided into 3 levels. Level 1, Level 2, and Level 3 in FIG. 2B have: 4 sub-arrays G1, 2 Each of the sub-arrays G2 and G3 needs to use 3, 2, and 2 phase control signals to control the phase values of the transmission signals fed to the sub-arrays of the layer 1, layer 2, and layer 3, respectively. It can be seen that based on Ni (i = 1 ~ P, Ni Any natural number 2) can be used to implement the beamforming circuit 120, and these specific implementations are considered as embodiments of the present invention.

The following embodiments illustrate various implementation manners of the beamforming circuit 120 in the foregoing FIG. 1. The beamforming circuit includes a hierarchical circuit structure based on a phase shifter, and the hierarchical circuit structure is used to calculate the phase signals based on the plurality of phase values corresponding to the phase control signals and the superposition of the phase values based on the input signals. A plurality of output signals are output, and the output signals are respectively coupled to the antenna units to generate a radiation field pattern. For example, the hierarchical circuit structure can be implemented using a phase shifter hierarchical circuit or an adder hierarchical circuit.

First, the implementation of a beamforming circuit using a phase shifter hierarchy circuit will be described. In some embodiments, the hierarchical circuit structure includes: a phase shifter hierarchy circuit, the phase shifter hierarchy circuit is used to receive a plurality of input signals to output a plurality of output signals, and includes P coupled in a hierarchical manner. A plurality of phase shifters, where P 3. The P layers respectively receive the P group of phase control signals divided by the phase control signals, and the phase shifter of the kth layer in the phase shifters respectively receives a maximum of Nk phases of the kth group in the phase control signals Control signal, of which 1 k P.

Please refer to FIG. 3, which is a block diagram of an embodiment of a hierarchical modular array antenna system according to the present invention. As shown in the figure, the array antenna system 20 is based on the architecture of FIG. 1 and therefore includes an array antenna 210 and a beamforming circuit 220. The beamforming circuit 220 includes a hierarchical circuit structure based on a phase shifter and the hierarchical circuit structure. Contains phase shifter hierarchy circuits. In this embodiment, the array antenna 210 includes 12 antenna units, and the phase shifter hierarchy circuit in the beamforming circuit 120 is implemented according to the above-mentioned hierarchical modular concept of FIG. 2A, so that antennas of the same hierarchy The sub-arrays of the units share a set of control signals to control the corresponding phase shifters, and then the superposition effect generated by the hierarchical structure of the phase shifters is used to generate the signals required by each antenna unit of the array antenna 210, thereby Achieve beamforming.

In FIG. 3, the phase shifter hierarchy circuit is used to receive 3 input signals to output 12 output signals, and includes a plurality of phase shifters (221 that are hierarchically coupled into 3 (P = 3) levels) , 222, 223). The three-level phase shifters respectively receive three sets of phase control signals CS1 ~ CS2, CS3 ~ CS4, CS5 ~ CS7 divided by the phase control signals. In detail, the phase shifter 221 of the first stage receives the two phase control signals CS1 to CS2 of the first group, respectively. The phase shifter 222 of the second stage receives the two phase control signals CS3 to CS4 of the second group, respectively. The phase shifter 223 of the third layer receives three phase control signals CS5 to CS7 of the third group, respectively.

In addition, as shown in FIG. 3, in the phase shifter hierarchy circuit, one of the input signals SI (such as the input signal shown at the top in FIG. 3) is coupled to the phase shifter hierarchy circuit. One of the phase shifter branches, which includes: a phase shifter of each of the layers from the third layer to the first layer (such as the phase shifters 223, 222, and 221 shown at the top in FIG. 3) It is coupled in series with one of these antenna elements (such as the antenna element shown at the top in FIG. 3). In addition, in the phase shifter hierarchical circuit, the input signal SI can also be coupled to different antenna units through different phase shifter branches. As a result, the phase shifter hierarchy circuit uses a superposition of the phases of the signals to generate the signals required by each antenna unit of the array antenna 210, thereby achieving beamforming.

In addition, for signal distribution, when implemented according to the embodiment of FIG. 3, the hierarchical circuit structure may further include a plurality of power distributors 250, and the power distributors are coupled between the layers. Pick up. However, the implementation of the present invention is not limited by this example; in implementation, when a power divider or other circuit elements can be used in the system to generate the signals required by the antenna.

FIG. 4 is a schematic diagram of an embodiment in which the beam forming circuit in FIG. 3 superimposes a phase value corresponding to a phase control signal. As shown in the table shown in FIG. 4, each field in row 401 indicates that the phase shifter 221 in the first layer in FIG. 3 receives the phase values corresponding to the first two phase control signals CS1 to CS2, respectively. Each field in row 402 indicates that the phase shifter 222 at the second level in FIG. 3 receives the phase values corresponding to the two phase control signals CS3 to CS4 in the second group, respectively. Each field in row 403 indicates that the phase shifter 223 at the third level in FIG. 3 receives the phase values corresponding to the three phase control signals CS5 to CS7 of the third group, respectively. After the phase shifters overlap with each other, 12 phase values can be obtained as shown in column 400; therefore, the phase shifter hierarchy circuit finally generates the signals required by the 12 antenna elements of the array antenna 210. This achieves beamforming.

Please look at Figures 3 and 4 again. In an array antenna, because the beam scanning requires the phase difference between the antenna elements, that is, the phases are relative; therefore, the array antenna 210 of Figure 3 can be The phase of the first antenna element is considered as the reference, so the phase provided by the first phase shifter can be 0 degrees. Similarly, for the hierarchy of other antenna units, the phase reference can also be defined in order, and the relative phase difference for this hierarchy is provided. Therefore, as in the embodiment shown in FIG. 4, some phase shifters corresponding to the phase value to be generated are zero.

In conclusion, the concept of phase reference can be further applied to the above embodiments of the present invention to achieve further simplification of circuit components and control signals. For example, in the embodiment shown in FIG. 3, the phase shifter in the hierarchy corresponding to the antenna unit in each layer of the array antenna 210 as the phase reference is omitted to reduce the required phase shifter and control signal. number. For example, please refer to Figures 3, 4, and 5 again. In Figure 3, there are 21 phase shifters corresponding to the three levels, and there is a phase in the sub-array of the antenna unit of each level. The reference, that is, the fourth figure indicates that the field with a phase of 0 degrees is required to be provided, so the phase shifter corresponding to the position of the field can be selectively omitted to achieve a simplified effect. As shown in FIG. 5, in the beam forming circuit 220A of the array antenna system 20A, the phase shifter hierarchy circuit is obtained by omitting the phase shifter whose phase reference is 0 degrees according to FIGS. 3 and 4. An embodiment.

Table 1 shows the simplified results of the beamforming circuit in the embodiment of FIG. 5 compared with the phase shifter circuit of the conventional array antenna. As can be seen from Table 1, compared to the many phase control signals and phase control signal lines used in the conventional circuit, the number of phase control signals (or phase control signal lines) required in this embodiment is the number used in the conventional circuit. It is only 1/3 of the demand. This will greatly facilitate the circuit simplification of the overall system. In addition, the implementation of back-end control circuits such as the control unit 230 can be further simplified.

As shown in FIG. 5, the phase control signals of each group in the original FIG. 3 are also omitted due to simplification, and the phase control signals CS1, CS3, and CS5 in FIG. 3 are omitted in FIG. 5. Therefore, the number of the phase control signals required in the phase shifters in FIG. 5 is T = M-P = 7-3 = 4.

In addition, due to the simplification, in the phase shifter hierarchy circuit shown in FIG. 5, one of the input signals (such as the uppermost input signal SI in FIG. 5) is coupled to the phase shifter. A phase shifter branch of one of the hierarchical circuits is coupled to one of the antenna units (such as the uppermost antenna unit in FIG. 5). Furthermore, in the phase shifter hierarchy circuit, one of the input signals (such as the uppermost input signal SI in FIG. 5) is coupled to a phase shifter branch of the phase shifter hierarchy circuit. The phase shifter branch includes: q phase shifters from the P (eg, P = 3) level to the first level, the q phase shifters are connected in series with one of the antenna units Coupling (other than the top antenna unit in Figure 5), where 1 q P.

It is true that the implementation of the present invention is not limited to the example in FIG. 5; for example, the antenna unit used as the reference may be any other antenna unit, or the phase of the reference may be defined as 0 or a different value, or retained after simplification. For some phase shifters, etc., any possible changes mentioned above are considered as embodiments of the present invention.

FIG. 6 is a radiation field pattern obtained by the hierarchical modular array antenna system of FIGS. 3 and 5 according to the phase values in FIG. 4, and the array antenna 210 generates a beam with an offset angle of 10 degrees. Forming effect.

The following describes the implementation of a beamforming circuit using an adder hierarchical circuit. In some embodiments, the hierarchical circuit structure includes: an adder hierarchical circuit and a plurality of phase shifters. The adder hierarchical circuit is configured to generate a plurality of output phase control signals according to a plurality of phase values corresponding to the phase control signals and a superposition of the phase values. The adder hierarchical circuit includes a hierarchical coupling to P Multiple adders for -1 levels. The phase shifters are coupled to the adder-level circuit to output the output signals according to the input signals and the output phase control signals, where P 3.

Please refer to FIG. 7, which is a block diagram of another embodiment of the hierarchical modular array antenna system of the present invention. As shown in FIG. 7, the array antenna system 30 is based on the architecture of FIG. 1 and includes an array antenna 210 and a beam forming circuit 320. The phase-shifter-based hierarchical circuit structure of the beamforming circuit 320 includes: an adder-level circuit and a plurality of phase-shifters 321. The adder-level circuit includes a hierarchical coupling to P-1 (P = 3) A plurality of adders 331, 332 of each hierarchy. In this embodiment, the beam forming circuit 320 is also implemented according to the hierarchical modular concept of the above FIG. 2A, and the sub-arrays of antenna units of the same level share a set of control signals to control the corresponding ones. The adder, and then the superposition effect generated by the hierarchical structure of the adder, is used to control the phase shifter, thereby generating the signals required by each antenna unit of the array antenna 210, thereby achieving beamforming.

In FIG. 7, the P-1 (eg, P = 3) levels respectively receive the phase control signals from the first group to the P-1 group of the phase control signals of the P group, where the k-th layer of the adders The adder (such as the adder 331 of the first layer) respectively receives a maximum of Nk phase control signals of the kth group of the phase control signals (such as the phase control signals CS1 ~ CS2 of the first group), of which 1 k P-1. In addition, as shown in FIG. 7, the adder of the P-1 level (such as the adder 332 of the second level) receives the maximum NP phase control signals of the P group in the phase control signals (such as the 3 sets of phase control signals CS5 ~ CS7).

In addition, in FIG. 7, in the adder hierarchical circuit, one of the phase control signals of the P group (such as CS5 in the third group) is coupled to one of the adder hierarchical circuits. Adder branch, the adder branch includes: one of the adders from the P-1 level to the first level (such as the adders 332 and 331 of each level from the second level to the first level), which It is coupled in series to one of the phase shifters (such as the uppermost phase shifter 321 in FIG. 7).

The concept of the phase reference can be further applied to the above-mentioned embodiment of the present invention based on FIG. 7 and its representative to achieve further simplification of circuit components and control signals. FIG. 8 is a block diagram of a simplified embodiment of the hierarchical modular array antenna system of FIG. 7. Figure 7 is also based on the superposition of the phase, so it can also be controlled by the embodiment shown in Figure 4. Therefore, Figure 7 can be simplified according to the method discussed in the previous embodiment of Figure 5. Since the adder in FIG. 7 is omitted, the circuit structure shown in FIG. 8 is achieved.

For example, in the array antenna system 30A in FIG. 8 and the adder layer circuit of the beam forming circuit 320A, one of the phase control signals of the P group (such as CS6 in FIG. 8) is the phase control signal. One of the adder hierarchical circuits is coupled to an adder branch, and the other adder branch is coupled to one of the phase shifters (such as the fourth phase shifter in FIG. 8).

For another example, in the array antenna system 30A in FIG. 8, in the adder hierarchical circuit, one of the phase control signals in the P group (such as CS6 in FIG. 8) may be coupled to An adder branch of one of the adder hierarchical circuits, the adder branch includes: q adders from the P-1 level to the first level, the q adders are coupled in series to these One of the phase shifters second, where 1 q <P-1.

Compared with a conventional back-end circuit module to an antenna unit, the array antenna system according to the embodiment of the present invention can achieve the effect of simplifying the number of back-end circuit modules. Such circuit modules should not be limited to phase shifters, but should be understood by those with the same knowledge in the technical field to which the present invention pertains. All radio frequency components that can be replaced should be included in the present invention, such as low noise. Radio frequency components such as signal amplifiers, power amplifiers and power attenuators, or various combinations of these radio frequency components, can also be controlled using control signals that are smaller than the number of antenna units, thereby simplifying the overall circuit. In addition, according to the foregoing embodiment using P = 3 as an example, it can be extended to the case where P> 3 or more. For example, when N = 60, because N = 5 * 3 * 2 * 2, 4 can also be used to achieve The beam forming circuit corresponding to the hierarchical antenna unit is implemented by a phase shifter hierarchical circuit or an adder hierarchical circuit. For example, when N = 72, since N = 3 * 3 * 2 * 2 * 2, it is also possible to use a beamforming circuit corresponding to an antenna unit of 5 levels.

In addition, in some embodiments, the hierarchical modular active periodic array antenna system further includes a processing unit 230, and the aforementioned beamforming circuit is controlled digitally by the processing unit. . The control unit 230 may use, for example, a processor, a digital signal processor, or a programmable integrated circuit such as a microcontroller, a Field Programmable Gate Array (FPGA), or a special application integrated circuit. (application specific integrated circuit, ASIC), or a dedicated circuit or module.

In practice, any beamforming algorithm can be used to construct the desired radiation field pattern according to the aforementioned hierarchical modular concept, and can optionally cooperate with the optimized algorithm, such as particle swarm algorithm. Either method, differential algorithm, dynamic difference algorithm, electromagnetic-like algorithm, or genetic algorithm to calculate the parameters such as the phase and / or amplitude of the antenna elements in the optimal array antenna and store them in a table in advance. Or downloaded from the outside into the control unit 230 or the memory unit of the control unit 230. Therefore, when the array antenna system according to the present invention operates, the control unit 230 can obtain parameters such as phase and / or amplitude to control each antenna unit in a table lookup manner, so as to generate corresponding control signals such as the aforementioned phase control. Signal to form the required beam. However, the implementation of the present invention is not limited by this example. For example, in another embodiment, the control unit 230 may also calculate the desired radiation field type according to the foregoing hierarchical modular concept through calculation, and generate the phase and / or amplitude of each antenna unit accordingly. And other parameters in order to generate corresponding control signals such as the aforementioned phase control signals to form the required beam. For example, genetic algorithms are used for optimization, but other algorithms can achieve the same purpose. When the genetic algorithm is optimized, the parameters are converted into chromosomes expressed in bits, and a table is created for comparison. Therefore, this method just corresponds to digital elements, so it can be directly brought into the genetic algorithm to calculate the most The parameters needed to meet the desired beam field pattern are used to control the attenuator and phase shifter for beamforming in the array antenna system.

The following example illustrates the application of the hierarchical modularization theory of the array antenna unit to the two-dimensional array antenna system. If a two-dimensional planar array antenna is taken as an example, the number of antenna units is N = Nx × Ny, which can be divided into three levels. For example, the two-dimensional array antenna shown in Figure 9, N = 64 = 8 × 8, Nx = 8, Ny = 8, can be divided into three levels, such as the sub-array G1 of the first level and the sub-array G2 of the second level, The third-level sub-array G3, but the present invention is not limited thereto. The sum of the antenna modules formed by the array antenna units can be expressed as: among them Expressed as the radiation of each antenna unit, versus Representing the excitation amplitude and phase of nm ^th respectively, “0” represents the 0 ^th layer, and the array antenna element can be expressed as: If Expressed as the antenna radiation of the array unit at the origin of the coordinates, then formula (1) can be expressed as: among them Is the array factor (AF, array factor), θ and Orientation "in visible space".

The antenna module in the first layer can be expressed as: The antenna module in the second layer can be expressed as: Using formulas (4) to (5), the required phase can be derived as:

Therefore, according to the above formula (6), the phase required for beamforming in a two-dimensional array antenna system can be obtained; accordingly, a processing unit can be used to control the phase shifter or adder of the back-end circuit. In the embodiment, the array antenna is driven according to formula (6) in different levels.

For example, if an array antenna uses a 5-bit digital step attenuator and phase shifter as the back-end circuit, the digital step attenuator can adjust the input energy of the array antenna in this embodiment. Proportional mode control, in which 5 bits means 25 = 32 variations, so the power can be divided into 0 ~ -32dB; and the phase shifter in this embodiment can adjust the input phase control of the array antenna, where 5 bits means 25 = 32 variations. Therefore, for any embodiment of the above-mentioned hierarchical modular active periodic array antenna system, the processing unit can be used to digitally control the back-end circuit module to achieve various beamforming operations. However, the implementation of the present invention is not limited by components such as a phase shifter. For example, a serially controlled digital phase shifter can also be used in the embodiment of the present invention.

Please refer to FIG. 10, which is a first result comparison diagram of a hierarchical modular array antenna according to the second embodiment of the present invention, where curve 41 is an embodiment using the above-mentioned array antenna system of the present invention (the number of antenna elements N = 36) The gene calculation is used as the array factor for beamforming, and curve 42 is the array factor for the traditional Tschebyscheff Taper formed by 36 attenuators. Among them, Figure 10 is not only reducing the control signal line of the back-end phaser from 36 sets of traditional architecture to 10 sets (T = M = 10) or 6 sets (T = MP = 4) by adjusting the input energy proportion of the antenna unit. ; P = 4), to achieve better suppression of beams beside array antennas.

Please refer to FIG. 11, which is a comparison diagram of the second result of the hierarchical modular array antenna according to the second embodiment of the present invention, where curve 51 is an embodiment using the above-mentioned array antenna system of the present invention (the number of antenna elements N = 36) Gene calculation is used as the array factor for beamforming. Curve 52 is the traditional use of 36 phasers and the conjugation phase, so that the main beam of the antenna is scanned to θ (theta) at 20 degrees. The array factor. Among them, Figure 5 is to adjust the input phase of the antenna by a phase shifter to scan the main beam of radiation, not only reducing the control signal line of the back-end phaser from 36 groups of traditional architecture to 10 groups (T = M = 10) or 6 Group (T = MP = 4; P = 4), and achieve the effect of beam scanning, will also well suppress the side beam.

Please refer to FIG. 12, which is a comparison diagram of the third result of the hierarchical modular array antenna according to the second embodiment of the present invention, where curve 61 is an embodiment using the above-mentioned array antenna system of the present invention (the number of antenna elements N = 36) The genetic algorithm is used as the beamforming array factor, and curve 62 is the traditional use of 36 phasers and 36 attenuators to form a Tschebyscheff Taper and a conjugation phase to make the antenna The main beam scans to an array factor with θ (theta) of 20 degrees. Among them, Fig. 12 uses both an attenuator and a phase shifter to achieve beam scanning and side beam suppression. This structure not only greatly reduces the number of back-end components, but also points more precisely to the desired beam direction and obtains better side beams.

The above-mentioned embodiments are merely illustrative for describing the features and effects of the present invention, and are not intended to limit the scope of the essential technical content of the present invention. Anyone skilled in the art can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be listed in the scope of patent application described later.

Claims (10)

A hierarchical modular active array antenna system includes: an array antenna including a plurality of antenna units, which are arranged in an array and the number of which is N; and a beamforming circuit that receives a plurality of input signals, A plurality of phase control signals, the beamforming circuit includes: a hierarchical circuit structure based on a phase shifter, the hierarchical circuit structure is based on a plurality of phase values corresponding to the phase control signals and a superposition of the phase values based on the The input signals are output to output a plurality of output signals. The output signals are respectively coupled to the antenna units to generate a radiation field pattern. The number of the phase control signals is T, T <N, where , , MP T M, Ni (i = 1 to P), M, P are positive integers, P 3, Ni 2.     The calibration system of the rotational speed measuring device according to item 1 of the scope of patent application, wherein the signal generating unit is used to generate a specific frequency electrical signal.         The calibration system of the rotational speed measuring device according to item 1 of the scope of patent application, wherein the specific frequency is electrically connected to an atomic clock by a signal generator, and the original standard frequency is obtained through the atomic clock.         According to the calibration system of the rotational speed measuring device according to item 1 of the patent application scope, wherein the light emitting unit is an LED or a laser.         The correction system of the rotational speed measuring device according to item 1 of the scope of the patent application, wherein the specific frequency is used to simulate different rotational speed values.         A method for calibrating a rotational speed measuring device is a calibration system for a rotational speed device by using a comparison method. The method steps include: providing a specific frequency electrical signal; receiving the electrical signal to generate a specific frequency optical signal; receiving the optical signal, A tachometer indication value is generated, wherein the electric signal obtains a standard value of the tachometer through calculation, and the purpose of calibrating the tachometer device is achieved by comparing the difference between the standard value of the tachometer value and the tachometer value.         The method for calibrating the rotational speed measuring device according to item 6 of the scope of patent application, wherein the electrical signal of the specific frequency is generated by a signal generating unit.         The calibration method of the rotational speed measuring device according to item 6 of the scope of the patent application, wherein the specific frequency is electrically connected to an atomic clock by a signal generator, and the original standard frequency is obtained through the atomic clock.         The method for calibrating the rotational speed measuring device according to item 6 of the scope of patent application, wherein the optical signal is generated by using an LED or a laser.         The method for calibrating the rotational speed measuring device according to item 6 of the scope of patent application, wherein the specific frequency is used to simulate different rotational speed values.