JP4337728B2 - Method for designing antenna arrangement and electronic device using the same - Google Patents

Description

  The present invention relates to a design method for arrangement of a plurality of antennas mounted on an electronic apparatus having a plurality of systems and functions, and an electronic apparatus using the same.

As for the arrangement of antennas used for modules having cellular and GPS communication functions, those described in Non-Patent Document 1 are known. This non-patent document 1 describes a method for roughly determining the arrangement of cellular antennas and GPS antennas.
Hitachi Metals Technique Vol. 20 (2004)

  However, considerable time is required to optimize the arrangement of the conventional cellular antenna and GPS antenna. Further, when a communication module having an FM function is mounted in addition to these, components having considerably different frequencies are mixed. A design time is required to make them distracted when trying to design them in an optimal arrangement while taking into account interference between radio waves. Even if ten antenna placement candidates are fixed, there are 10 × 9 × 8 = 720 combinations for arranging three types of antennas. In addition, the characteristics of the antenna vary greatly depending on the position of the board to which it is attached. Therefore, it is difficult to establish design guidelines that maintain the excellent characteristics of the antenna itself and also reduce the interference between radio waves. It has a problem of requiring a long time.

  SUMMARY OF THE INVENTION The present invention solves the above-described problem, and a design method that significantly shortens the time required for optimal design of antenna arrangement in an electronic device incorporating a plurality of antennas, and an electronic device equipped with an antenna designed using this design method. The purpose is to provide equipment.

In order to achieve this object, according to the first aspect of the present invention, the arrangement of a plurality of antennas mounted on an electronic device having a plurality of systems and functions is determined based on at least reflection characteristics and transmission characteristics of each antenna. A method of designing antenna arrangement that is determined based on the antenna characteristics to be obtained, in which a plurality of antenna shapes are fixed and antenna numbers are assigned, and the size and arrangement of a predetermined analysis area including each antenna are determined and arranged A first step of assigning a number, a second step of determining a bit length based on the number of arrangements of candidate antennas, and a section constituted by the bit length determined in the second step. comprising the steps of generating a bit string information group having a plurality of bit string information comprising side by side only, for each antenna number, contrary to the case where the antenna was simplex arrangement to all placement candidate The arrangement number indicating the arrangement characteristic is reduced to generate a constraint information obtained by converting the binary bit length, a constrained bit string information of the same length as the bit string information, restrictions on the section corresponding to the antenna number A third step of inserting information, generating constrained bit string information in which the constraint information and the random number are combined so that the other sections are random numbers, and generating a bit string information group in which the constrained bit string information is arranged at a higher level; A fourth step of calculating the antenna characteristics of each antenna by performing an electromagnetic field simulation of antenna arrangement based on the bit string information generated in the third step, and the antenna characteristics and A fifth step of calculating the fitness based on the antenna characteristics of each antenna calculated by the electromagnetic field simulation in the step 4, and a determination in the fifth step. The sixth step of determining whether the convergence condition is satisfied based on the fitness and the sixth step when the convergence condition is satisfied, and when the convergence condition is not satisfied, A seventh step of performing a predetermined operation based on a genetic algorithm in consideration of the fitness, and repeating the fourth to seventh steps until the convergence condition is satisfied. This is a design method, and since it is possible to automatically and optimally design when there are a plurality of antennas for which it has been difficult to establish conventional design guidelines, there is an effect that the time required for optimal design can be significantly shortened. In addition, by increasing the probability that genetic information that maintains the results of the most important evaluation items as the characteristics of a single antenna will remain, it is possible to determine the optimal arrangement that satisfies the favorable characteristics of multiple antennas in a shorter period of time. Has the effect of being able to.

The invention according to claim 2 is the invention according to claim 1 , wherein the number of rankings is equal to or greater than the number of antennas, so that the best place in one antenna is the best place candidate in the other antenna. In this case, an effective initial value can be set without fail.

The invention according to claim 3 is a step of optimizing the arrangement of the plurality of antennas using a local search method with the optimum arrangement of the plurality of antennas determined using the design method of claim 1 as an initial value. This is an antenna arrangement design method having the function and effect that a value closer to the optimum solution can be obtained.

The invention described in claim 4 is an electronic device equipped with the antenna designed using the antenna arrangement design method described in claim 1 , and maintains excellent characteristics of each antenna inside the electronic device. In addition, there is an effect of optimizing a plurality of excellent communication environments.

According to the antenna arrangement design method of the present invention, an antenna that determines the arrangement of a plurality of antennas mounted on an electronic apparatus having a plurality of systems and functions based on antenna characteristics including at least reflection characteristics and pass characteristics of each antenna. A first step of fixing the shape of a plurality of antennas and assigning antenna numbers , determining a size and arrangement of a predetermined analysis region including each antenna, and assigning the arrangement numbers ; A second step of determining the bit length based on the number of candidate antenna arrangements, and a plurality of pieces of bit string information in which sections configured by the bit length determined in the second step are arranged by the number of antennas. a process of generating a bit string information group for each antenna number, arrangement reflection properties when the antenna was simplex arrangement to all placement candidate becomes smaller Generates the restriction information obtained by converting the arrangement numbers shown in binary bit length, a constrained bit string information of the same length as the bit string information, inserts the constraint information in the section corresponding to the antenna number, other A third step of generating constrained bit string information obtained by combining the constrained information and the random number so that the section of FIG. 1 becomes a random number, and generating a bit string information group in which the constrained bit string information is arranged at a higher level, A fourth step of calculating the antenna characteristics of each antenna by performing an electromagnetic field simulation of the antenna arrangement based on the generated bit string information, and the target antenna characteristics of each antenna and the electromagnetic field in the fourth step A fifth step of calculating the fitness based on the antenna characteristics of each antenna calculated by the simulation, and a convergence condition based on the fitness obtained in the fifth step. The sixth step of determining whether the condition is satisfied, and the sixth step if the convergence condition is satisfied, and if the convergence condition is not satisfied, consider the fitness in consideration of genetics A design method of antenna arrangement, further comprising a seventh step of performing a predetermined operation based on an algorithm, and repeating the fourth to seventh steps until a convergence condition is satisfied. Since it is possible to automatically and optimally design when there are a plurality of antennas that are difficult to stand up, the time required for the optimal design can be significantly shortened.

  In addition, since the electronic device of the present invention is equipped with an antenna designed using the antenna arrangement design method, the excellent characteristics of each antenna are maintained inside the electronic device, and a plurality of excellent communication devices are provided. The environment can be optimized.

  An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a process diagram for explaining a design method of antenna arrangement in Embodiment 1 of the present invention, and FIG. 2 is a conceptual diagram of a predetermined analysis region including an antenna in the first step (S1) of the process diagram. 3 is a conceptual diagram for explaining antenna arrangement candidates in the first step (S1) of the process diagram, FIG. 4 is a conceptual diagram for explaining number assignment to the antenna arrangement shown in FIG. 3, and FIG. The conceptual diagram of the arrangement | sequence prepared with each antenna for determining bit length in the 2nd process (S2) of a process diagram, FIG. 6 synthesize | combines each arrangement | sequence shown in FIG. FIG. 7 is a conceptual diagram for explaining a method for generating bit string information in the third step (S3) of the same process diagram.

  2 to 4, reference numeral 1 denotes a cellular antenna, 2 denotes an analysis region, and 3 denotes a circuit board built in a mobile phone as an electronic device.

  In FIG. 1, the overall steps of the antenna layout design method are outlined below. In FIG. 1, all steps are fixed based on the first step (S1) of fixing the antenna shape and determining the size and position of a predetermined analysis region including this antenna, and the number of arrangements of candidate antennas. A second step (S2) for determining the length, a third step (S3) for generating random bit sequence information within a range that falls within the bit length determined in the second step, and the third step ( A fourth step (S4) of calculating antenna characteristics of each antenna by performing electromagnetic field simulation based on the bit string information generated in S3), and a fourth step ( The fifth step (S5) for calculating the fitness based on the antenna characteristics of each antenna calculated by the electromagnetic field simulation in S4), and the convergence condition based on the fitness obtained in the fifth step (S5) Is met And in that either determining a sixth step (S6), when a convergence condition is met consists first algorithm consisting in the step (F1) ending in the sixth step (S6). If the convergence condition is not satisfied in the sixth step (S6) for determining whether the convergence condition is satisfied based on the fitness obtained in the fifth step (S5), the fitness is The seventh step (S7) for performing a predetermined operation based on the genetic algorithm in consideration of the above, and performing the predetermined operation in the seventh step (S7), exceeding the preset number of generations The eighth step (S8) for determining whether or not the second step is satisfied and if this determination condition is satisfied, the fourth step (S4) to the seventh step (S7) are repeated, and the sixth step (S6) is repeated. It is determined whether or not the convergence condition shown in FIG. 5 is satisfied, and if satisfied, the process has a step (F1) to end, and if the convergence condition is not satisfied, a seventh step (S7) is further performed. When the number of generations shown in the eighth step (S8) is exceeded (ie, It exceeds a predetermined calculation time required for proper design) is composed of a second algorithm consisting in the step of terminating the calculation (F2).

  Next, each step will be described in detail below. First, as shown in FIG. 2, the first step (S1) includes a cellular antenna 1 (referred to as antenna 1), a GPS antenna (not shown, referred to as antenna 2), and an FM antenna (shown in FIG. 2). The size of the predetermined analysis region 2 is determined for each of the antenna 1, the antenna 2, the antenna 2 (not shown), and the antenna 3 while maintaining the determined size of the analysis region 2. All placement candidates for (not shown) are determined (shown in FIG. 3). In this example, 16 placement candidates are set. Next, the numbers from (0) to (15) are sequentially assigned in decimal numbers to the 16 antenna arrangement candidates shown in FIG. 3 (shown in FIG. 4).

  Next, in the second step (S2), a bit consisting of 4 digits for each antenna so that the arrangement from (0) to (15) expressed in decimal number shown in FIG. 4 is re-expressed in binary number. The length is determined (see FIG. 5). Furthermore, a combined arrangement of 4 bits of bit length / antenna × number of antennas (3 in this example) = 12 digits of bit length is prepared (see FIG. 6). Here, a 4-digit bit length is referred to as a section. In this way, by setting the number of antenna arrangement candidates to a power of 2, as described later, no extra bit string information is generated, so that the calculation efficiency can be improved.

  Next, in a third step (S3), random bit string information is generated using random numbers within a range that fits in the combined 12 arrays shown in FIG. 6 (see FIG. 7). Here, when the same bit string information exists in different sections, it means that a plurality of antennas exist in the same place. Therefore, when generating bit string information, the bit strings of all the sections. Make the information different.

  Next, in the fourth step (S4), an electromagnetic field simulation is performed based on the bit string information generated in the third step (S3).

Next, in the fifth step (S5), the antenna characteristics of the target antennas 1, 2, 3 and the antennas of the antennas 1, 2, 3 calculated by the electromagnetic field simulation in the fourth step (S4). Based on the characteristics, fitness is calculated. Here, in order to calculate the fitness, it is necessary to prepare an fitness function corresponding to the problem. It is necessary to create an objective function prior to creating the fitness function. The objective function includes characteristics to be evaluated, but here, attention is paid to S parameters in a certain frequency band. The present invention aims to be able to design an optimum arrangement of each antenna 1, 2, 3 in a short period of time so that each antenna 1, 2, 3 has good individual characteristics and is not easily influenced by other antennas. Yes. Accordingly, it is desirable that the reflection characteristics S ₁₁ , S ₂₂ , and S _{33 of} each of the antennas 1, 2, and 3 are small and the passing characteristics S ₁₂ , S ₁₃ , and S ₂₃ are small. From this point of view, an objective function including all of S ₁₁ , S ₂₂ , S ₃₃ , S ₁₂ , S ₁₃ , and S ₂₃ is created, and the objective function may be negative. f (g) the fitness function using a ^{= 1 / (1 + e g} ) ...... ( equation 1)
g: An objective function is set, and fitness is calculated based on this.

Next, in the sixth step (S6), the calculation is terminated if the preset convergence condition is satisfied (F1 in FIG. 1), and if not, the seventh step (the next step) ( The process proceeds to S7). Here, when the calculation is terminated by this conditional branch, it means that the optimum solution has been obtained. The convergence conditions shown in S6 can be considered as follows: • Maximum fitness in individual population> threshold value • Average fitness of individual population> threshold value. Here, the larger the threshold value, the higher the probability that an optimum solution can be obtained, but the calculation time increases.

  Next, in a seventh step (S7), an operation based on a genetic algorithm (including selection operation, crossover operation, mutation operation) is performed, and the population is updated. Here, as in the case of the third step (S3), when generating bit string information, the bit string information of all sections is set to be different. Here, when the operation of the seventh step (S7) is completed, the generation is advanced by one generation.

  Next, in the eighth step (S8), if the number of generations set in advance is exceeded, the calculation is terminated (F2 in FIG. 1), and if not, the process returns to the fourth step (S4). Return and repeat the same operation.

  Accordingly, it is possible to realize an electronic device in which excellent characteristics of each antenna are maintained inside the electronic device and a plurality of excellent communication environments are optimized.

  In the present embodiment, an example in which attention is paid to the S parameter in the antenna characteristic has been described. However, the present invention is not limited to this, and it is also possible to calculate the fitness by setting the radiation characteristic as a target. By doing so, it is possible to reduce the time required for optimization while considering the directivity of the antenna.

  In this embodiment, an example of a mobile phone as an electronic device has been described. However, the present invention is not limited to this and can be applied to various electronic devices.

(Embodiment 2)
FIG. 8 is a process diagram for explaining a design method of antenna arrangement according to Embodiment 2 of the present invention, and FIG. 9 is a tenth process (S10) based on the electromagnetic field simulation shown in the ninth process (S9) of the process diagram. ) For explaining the ranking of the reflection characteristics of the antennas in FIG. 10, FIG. 10 is for generating bit string information based on the result of ranking of the reflection characteristics of the antennas shown in the tenth step (S10). FIG. 11 is an explanatory diagram for explaining a step of generating final bit string information using random numbers for the constraint information shown in FIG. 10. In the present embodiment, the same steps as those in the process diagram for explaining the antenna layout design method shown in FIG. 1 are denoted by the same reference numerals, detailed description thereof is omitted, and only different process portions are described in detail. .

  In the ninth step (S9) shown in FIG. 8, an electromagnetic field simulation is performed when the antenna 1 is present at all positions (0) to (15) shown in FIG. Similarly, an electromagnetic field simulation is performed when the antenna 2 or the antenna 3 is present in all the arrangements of numbers (0) to (15) shown in FIG. That is, in this example, a total of 48 types of electromagnetic field simulations are performed.

  Next, in the tenth step (S10), ranking is performed based on the result of the electromagnetic field simulation performed in the ninth step (S9). Here, ranking is performed in descending order of reflection characteristics at a desired frequency. Here, the number of top-level genetic information that is preferentially created is the same as or more than the number of candidate antennas so that there is no problem even if there is a top-level arrangement for all antennas. Is desirable. In this case, since there are three types of antennas, the top three pieces of information are recorded as shown in FIG.

  Next, in the third step (S3), bit string information is generated within a range that fits in the array prepared in the second step (S2). Here, the number of individuals of the first generation is 100. Here, when creating bit string information, bit string information including the higher ranks of those ranked in the tenth step (S10) is preferentially generated. Specifically, the arrangement number that is the higher rank of each antenna 1, 2, 3 is converted into a binary number, and is inserted as constraint information in a section corresponding to each antenna 1, 2, 3 as shown in FIG. Further, with respect to portions other than the constraint information shown in FIG. 10, final bit string information is generated using random numbers as shown in FIG. In the example shown in FIG. 11, five types of bit string information are generated for one constraint condition. That is, 5 × 9 = 45 types of bit string information are generated. As described above, since the number of individuals of the first generation is 100, the remaining 55 individuals are generated using random numbers without giving constraint information. Here, when the same bit string information exists in different sections, it means that a plurality of antennas exist in the same place. Therefore, when generating bit string information, the bit strings of all the sections. Make the information different.

(Embodiment 3)
Furthermore, using the antenna arrangement design method described in the first and second embodiments, a step of satisfying the convergence condition of the sixth step (S6) shown in FIG. 1 or FIG. F3) using the optimal location of the three antennas obtained from F1) as an initial value and using a local search method (for example, maximum gradient method, optimal gradient method, conjugate gradient method, Newton-Raphson method, etc.) A value closer to the optimal solution can be obtained in a short time.

  INDUSTRIAL APPLICABILITY The present invention is useful as an antenna arrangement design method that significantly shortens the time required for optimal antenna arrangement design in an electronic apparatus incorporating a plurality of antennas, and an electronic apparatus equipped with an antenna arranged using this design method. It is.

Process drawing explaining the design method of arrangement | positioning of the antenna in Embodiment 1 of this invention Conceptual diagram of a predetermined analysis region including an antenna in the first step (S1) Conceptual diagram for explaining antenna arrangement candidates in the first step (S1) Conceptual diagram for explaining the assignment of numbers to the antenna arrangement shown in FIG. Conceptual diagram of the arrangement prepared for each antenna for determining the bit length in the second step (S2) FIG. 5 is a conceptual diagram for explaining a method of synthesizing the respective arrays shown in FIG. 5 to create an entire array. The conceptual diagram explaining the method to produce | generate the bit row | line information in a 3rd process (S3). Process drawing explaining the design method of the arrangement | positioning of the antenna in Embodiment 2 of this invention Explanatory diagram for explaining the ranking of the reflection characteristics of each antenna Explanatory drawing explaining the process of displaying the constraint information for producing | generating bit column information based on the result of ranking in binary number Explanatory drawing for demonstrating the process of producing | generating the last bit sequence information using a random number for the constraint information shown in FIG.

Explanation of symbols

1 Cellular antenna 2 Analysis area 3 Circuit board

Claims (4)

An antenna arrangement design method for determining an arrangement of a plurality of antennas mounted on an electronic device having a plurality of systems / functions based on antenna characteristics including at least reflection characteristics and pass characteristics of each antenna, A first step of assigning an antenna number while fixing the shape of the antenna, determining a size and arrangement of a predetermined analysis region including each antenna, and assigning the arrangement number ; A second step of determining the bit length based on the number, and a step of generating a bit string information group having a plurality of bit string information in which sections configured by the bit length determined in the second step are arranged by the number of antennas. there are, for each of the antenna number, the arrangement number indicating an arrangement in which the reflection characteristic when the antenna was simplex arrangement to all placement candidate becomes smaller Generates the restriction information obtained by converting the binary serial bit length, a the bit string information as long as constrained bit string information and, inserting the constraint information to the section corresponding to the antenna number, A third step of generating constrained bit string information obtained by combining the constraining information and the random number so that the other sections become random numbers, and generating a bit string information group in which the constrained bit string information is arranged at a higher level; A fourth step of calculating the antenna characteristics of each antenna by performing electromagnetic field simulation of antenna arrangement based on the bit sequence information generated in step 3, the antenna characteristics of each target antenna, and the first A fifth step of calculating the fitness based on the antenna characteristics of each antenna calculated by the electromagnetic field simulation in the step 4, and the fifth step A sixth step for determining whether the convergence condition is satisfied based on the fitness value obtained, and the sixth step when the convergence condition is satisfied, and the convergence condition is not satisfied In this case, the method further includes a seventh step of performing a predetermined operation based on a genetic algorithm in consideration of fitness, and repeating the fourth to seventh steps until the convergence condition is satisfied. Design method of antenna arrangement. The antenna layout design method according to claim 1 , wherein the number of rankings is equal to or greater than the number of antennas. An antenna arrangement design method comprising a step of optimizing the arrangement of the plurality of antennas using a local search method with the optimum arrangement of the plurality of antennas determined using the design method of claim 1 as an initial value. . An electronic device equipped with an antenna designed using the antenna layout design method according to claim 1 .

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