JP4868117B2 - Wireless sensor receiver and wireless sensor device - Google Patents

Description

  The present invention relates to a wireless sensor receiver and a wireless sensor device.

  A wireless sensor device that transmits data such as temperature and humidity detected by a sensor to a wireless sensor receiving device arranged at a remote location by a wireless sensor transmission device is known from, for example, Patent Document 1.

  This type of wireless sensor device spatially separates the wireless sensor transmission device from equipment that uses measured values of temperature, humidity, or illuminance, and sends data obtained by the wireless sensor transmission device to the wireless sensor reception device. Thus, the measurement values can be centrally managed, and the wireless sensor transmission device can be moved and carried, and can be used in various forms.

  In the wireless sensor receiver, a signal wirelessly communicated from the wireless sensor transmitter must be detected, but the lower limit value of the detectable signal level depends on the reception sensitivity characteristics of the reception antenna unit and the reception circuit unit. For this reason, when the reception sensitivity characteristic is poor, the lower limit value of the detectable signal level becomes a larger level, and it becomes difficult to detect a weaker signal level. The reception sensitivity characteristics affect the distance (communication distance) between the wireless sensor transmitter and the wireless sensor receiver and the noise resistance environment around the wireless sensor receiver. Environmental properties will deteriorate.

  Thus, in this type of wireless sensor device, how to improve reception sensitivity is an important issue. Among the receiving circuit unit and the receiving antenna unit that affect the receiving sensitivity, the receiving circuit unit can cope with the improvement of the receiving sensitivity by devising the circuit configuration. Because of physical constraints, it cannot always be used in an ideal state.

  For example, if the receiving antenna unit is a monopole type with a length close to 1/2 or 1/4 wavelength of the radio frequency and standing vertically, assuming that the radio frequency f is set to 300 MHz, it is 250 mm at 1/4 wavelength. For a half wavelength, an antenna with a length of 500 mm is required. Even when the radio frequency f is increased to 1000 MHz, a length of 75 mm is required for the 1/4 wavelength and 150 mm is required for the 1/2 wavelength, so that there is a limit to the reduction in size and thickness of the wireless sensor receiver.

In addition, when the receiving antenna unit is configured by a monopole type, in order to maximize the characteristics of the antenna, such as reception sensitivity and antenna gain, the ground electrode area has a radius of 1 / of the radio frequency around the antenna. The area of a circle corresponding to two wavelengths is required. If such an ideal monopole antenna can be constructed, the reception sensitivity characteristics of the antenna can be fully demonstrated. However, in reality, the wireless sensor receiver is installed inside the air conditioning equipment, etc. Often installed and installed in For this reason, the area of the ground electrode has to depend on the arrangement and area of the ground electrode of the wireless sensor receiver and the component mounting board, and the area of the ground electrode necessary to ensure various characteristics of the monopole type. It is difficult to secure.

  Also, even if the antenna is configured with the monopole type in mind, the characteristics such as reception sensitivity and antenna gain must be maximized unless there is a major revision of the installed equipment. It must be influenced by the surroundings of the installed equipment.

  In addition, since the antenna part has a form that protrudes 1/4 wavelength or 1/2 wavelength from the wireless sensor receiver, it is not only affected by installed equipment but also easily affected by passersby, etc. The antenna characteristics may be further deteriorated.

Similar problems occur when a dipole antenna is used instead of the monopole antenna.
JP 2002-14072 A

  The object of the present invention is to reduce the shape and thickness of the receiving antenna section without being affected by the revision of the installed equipment side or the surroundings, and without degrading various characteristics such as the reception sensitivity of the wireless sensor receiver. It is an object of the present invention to provide a wireless sensor receiver capable of achieving the above and a wireless sensor device using the same.

  In order to solve the problems described above, a wireless sensor receiver according to the present invention includes a component mounting board, a receiving circuit unit, a signal processing unit, and an antenna unit. The component mounting board has the receiving circuit unit, the signal processing unit, and the antenna unit on one surface, and a ground electrode on a part of the other surface. The receiving circuit unit and the signal processing unit are provided in a region facing the ground electrode. The antenna unit includes a plurality of the antenna elements, and each of the antenna elements is disposed in a region not facing the ground electrode and connected in series.

  The feature of the wireless sensor receiver according to the present invention described above is the relative positional relationship between the antenna unit and the ground electrode. That is, the antenna unit includes a plurality of antenna elements, and each of the antenna elements is arranged in a region not facing the ground electrode and connected in series.

  According to the above configuration, a dipole antenna can be configured by the electrical length of the antenna elements connected in series and the electrical length of the ground electrode that is not opposed to the antenna elements. In this case, the antenna portion constituted by the antenna element and the ground electrode is planar using one surface and the other surface of the component mounting board. Therefore, unlike the conventional columnar monopole type or dipole type antenna, the antenna does not protrude in the height direction, so that it is not easily affected by the surroundings of the facility where the wireless sensor receiver is installed. In addition, since it is not a monopole type, the reception sensitivity characteristics and the like are not restricted such that the antenna portion must be arranged at the center of the ground electrode area.

  Furthermore, since the antenna unit is configured by arranging a plurality of antenna elements on the component mounting surface side of the board, the area for arranging the antenna elements and the area of the ground electrode formed on the back surface can be arbitrarily set. Can be adjusted. In addition, the arrangement relationship with the surrounding equipment, the size of the entire wireless sensor receiver, and the external dimensions of the component mounting board can be arbitrarily adjusted.

  In the end, according to the present invention, compared to the conventional case, the installation of the antenna unit is affected without being affected by the revision of the installed equipment and the surroundings, and without degrading various characteristics such as the reception sensitivity of the wireless sensor receiver. Miniaturization and thinning can be achieved.

  Preferably, the plurality of antenna elements are arranged so that at least two antenna elements constitute an outward path and a return path. This arrangement is simply a U-shaped arrangement. According to such an arrangement, it is possible to effectively use the area of one surface of the limited component mounting board and to increase the electrical length of the antenna unit.

  More preferably, each of the antenna elements includes a dielectric base and an antenna conductor film, and the dielectric base is made of a dielectric material having a dielectric constant higher than that of the material constituting the component mounting board. The conductor film is supported by a dielectric substrate. According to such a configuration, the antenna characteristics are imparted to the dielectric base having a high dielectric constant, and the mechanical strength of the entire device is ensured by the component mounting substrate having a low dielectric constant and excellent mechanical strength. be able to.

  The wireless sensor receiver according to the present invention is combined with a wireless sensor transmitter to constitute a wireless sensor device. The wireless sensor transmission device detects a physical quantity by a sensor, processes a detection signal output from the sensor by a signal processing unit, supplies a signal supplied from the signal processing unit to an antenna unit by a transmission circuit unit, and in the air Since it can radiate, the physical quantity detected by the sensor can be received by the wireless sensor receiver. Physical quantities to be measured include various quantities such as temperature, humidity, illuminance, acceleration, and impact.

  Other features of the present invention and the operational effects thereof will be described in more detail by way of examples with reference to the accompanying drawings.

1. Wireless Sensor Receiver and Wireless Sensor Device FIG. 1 is a block diagram of a wireless sensor device that combines a wireless sensor transmitter 10 and a wireless sensor receiver 8 according to the present invention. The wireless sensor transmission device 10 detects a physical quantity by a plurality of sensors 21 to 2n provided in the sensor unit 2, processes a detection signal output from the sensors 21 to 2n by the signal processing unit 4, and outputs a signal from the signal processing unit 4. The supplied signal is supplied to the antenna unit 6 by the transmission circuit unit 5 and radiated into the air. In the sensors 21 to 2n, physical quantities to be measured include various quantities such as temperature, humidity, illuminance, acceleration, and impact. The number and type of sensors 21 to 2n are prepared according to the physical quantity to be measured. It is not necessary to provide all of them, and it is sufficient to measure some selected physical quantities.

  The wireless sensor receiver 8 receives a physical quantity signal radiated from the antenna 6. The wireless sensor reception device 8 receives the wireless signal transmitted from the wireless sensor transmission device 10 by the reception antenna unit 81 and the reception circuit unit 82, and processes them by the signal processing unit 83. Then, the processing result is transmitted to the central management device or the like. Thereby, the physical quantity measured at the remote place can be received by the wireless sensor receiver 8 and the control for the device can be executed.

  FIG. 2 is a block diagram showing another configuration of the wireless sensor device according to the present invention. In the figure, portions corresponding to the components shown in FIG. 1 are denoted by the same reference numerals. In this embodiment, m wireless sensor receivers 8 are provided for one wireless sensor transmitter 10. These shall be arrange | positioned in a mutually different position. The number m (m = 1, 2,...) Of the wireless sensor receivers 8 may be arbitrary.

  Each of the wireless sensor reception devices 8 receives the wireless signal transmitted from the wireless sensor transmission device 10 by the reception antenna unit 81 and the reception circuit unit 82 and processes them by the signal processing unit 83. Then, the processing result is transmitted to the central management device or the like. Thereby, the physical quantity measured in the remote place can be individually received by the wireless sensor receiver 8 installed in different places, and the control of the device can be executed.

  Next, details of the wireless sensor receiver will be described. 3 is a plan view of the wireless sensor receiver, and FIG. 4 is a front view of the wireless sensor receiver shown in FIG.

  The component mounting board 80 includes an antenna unit 81, a receiving circuit unit 82, and a signal processing unit 83 on one surface (component mounting surface). These are sequentially connected in the state shown in FIGS. On the back surface of the component mounting surface of the component mounting substrate 80, a solid pattern ground electrode GND is formed at a location other than the area where the antenna portion 81 is formed. However, a solid pattern is not essential, and a partially missing pattern may be used.

  The antenna unit 81 includes three antenna elements 811 to 813 connected in series. However, the number of antenna elements 811 to 813 is not limited to three and may be larger than that. Among the antenna elements 811 to 813, the antenna element 811 constitutes the forward path, and the antenna element 813 constitutes the return path. That is, it has a U-shaped arrangement. The antenna element 812 is disposed on one end side of the antenna elements 811 and 813, and both ends thereof are connected to one end side of the antenna elements 811 and 813 by conductor patterns 814 and 815. The other end of the antenna element 813 constituting the return path is connected to a conductor pattern 816 led to the input end of the receiving circuit unit 82.

  However, part or all of the conductor patterns 814 to 816 can be omitted. Even with such a configuration, it functions sufficiently as an antenna in a high-frequency region. The illustrated antenna elements 811 to 813 have, for example, a shape of (vertical) 8 × (horizontal) 3 × (thickness) 2 mm, and are arranged while changing directions such as a horizontal direction, a vertical direction, and a horizontal direction. Has been.

  The ground electrode GND is not provided on the back side facing the antenna elements 811 to 813. In the illustrated embodiment, the ground electrode GND is not provided on the back side facing the area occupied by the antenna elements 811 to 813 and the region surrounded by the antenna elements 811 to 813.

  Regarding the planar shape of the antenna elements 811 to 813, the optimum design is made within the area of the component mounting board 80. An example thereof is shown in FIGS. FIG. 5 is a plan view of the antenna elements 811 to 813, and FIG. 6 is a front view of the antenna elements 811 to 813 shown in FIG.

  Each of the antenna elements 811 to 813 includes a dielectric base 84 and an antenna conductor film 85, and is disposed on one surface of the component mounting board 80. The dielectric base 84 is made of a dielectric material having a dielectric constant higher than that of the material constituting the component mounting board 80. Specifically, the component mounting board 80 is made of a board material, for example, FR4, which has a high degree of freedom in its outer dimensions and is also effective in a degree of freedom in mounting in the facility. Its relative dielectric constant is 4-5. On the other hand, the dielectric substrate 84 is made of, for example, a high dielectric constant ceramic material in the range of a relative dielectric constant of 7 to 8. The dielectric base 84 is configured in a form (8 × 3 × 2 mm) that can be easily placed on the component mounting board 80 because the degree of freedom in terms of external dimensions and mountability is limited as compared with the FR4.

  The antenna conductor film 85 is supported by the dielectric substrate 84. More specifically, the first conductor pieces 851 are formed on one surface of the component mounting board 80 at a predetermined interval in one direction, and on the other surface at the same pitch as the first conductor pieces 851. A second conductor piece 852 is formed in the direction. The end portions of the first conductor piece 851 and the second conductor piece 852 are helically connected by the third conductor piece 853 and the fourth conductor piece 854 penetrating the dielectric substrate 84 in the thickness direction. Are connected in sequence. Thus, an opening surrounded by the first conductor piece 851, the third conductor piece 853, the second conductor piece 852, and the fourth conductor piece 854 is generated. The area of the opening is approximately the product XY of the effective length X of the first conductor piece 851 and the second conductor piece 852 and the effective length Y of the third conductor piece 853 and the fourth conductor piece 854. Determined.

  In order to adjust the resonance point of the impedance to the frequency for wireless transmission, the opening area, the number of turns, and the dielectric constant of the substrate material may be adjusted. The lower the radio transmission frequency, the higher the aperture area, the number of turns, or the dielectric constant. In order to increase the opening area, the thickness of the dielectric substrate 84 or the floor area of the antenna forming portion may be increased. However, the shape of the antenna forming portion increases and the device shape also increases.

  On the other hand, if the number of turns and the dielectric constant of the substrate material are increased, the impedance can be lowered without increasing the device shape. Increasing the number of turns increases the pattern length and therefore increases the conductor loss due to the pattern. However, if the relative permittivity (εr) of the material constituting the dielectric substrate 84 is increased, the number of turns can be reduced. Thereby, the conductor loss by a pattern can be reduced and a shape can be reduced in size, without the loss as the antenna part 6 increasing.

  FIG. 7 is a circuit diagram of an antenna circuit by connecting the antenna elements 811 to 813. As shown in the figure, the antenna element 811 has an inductor L11 with an antenna conductor 85, and is expressed as a π-type circuit in which capacitors C11 and C12 are connected to both ends of the inductor L11. The antenna element 812 also has an inductor L21 with an antenna conductor 85, and is expressed as a π-type circuit in which capacitors C21 and C22 are connected to both ends of the inductor L21. Further, the antenna element 813 also has an inductor L31 formed of an antenna conductor 85, and is represented as a π-type circuit in which capacitors C31 and C32 are connected to both ends of the inductor L31. The capacitors C11, C12, C21, C22, C31, and C32 are generally not provided as a lumped constant on the dielectric base 84, but between the antenna conductor 85 of the antenna elements 811 to 813 and the ground electrode GND. It is a generated capacitor.

  In connection of the antenna elements 811 to 813, first, one end side of the antenna element 811 is expressed as a circuit grounded through a series connection circuit of an inductor L41 and a capacitor C41. On the other end side of the antenna element 811, the antenna element 811 and one end of the antenna element 812 are connected by a series capacitor C42, and the other end side of the antenna element 811 is expressed as a circuit grounded through the inductor L42. On the other end side of the antenna element 812, the antenna element 812 and one end of the antenna element 813 are connected by a series inductor L43, and the connection side of the antenna element 812 of both ends of the inductor L43 is grounded by a capacitor C43. This is expressed as a circuit in which the connection side of the antenna element 813 is grounded through the inductor L44.

  Furthermore, the other end of the antenna element 813 is guided to the receiving circuit unit through the inductor L45, and the receiving circuit unit side of the inductor L45 is expressed as a circuit grounded through the capacitor C44. However, FIG. 7 is merely an example and is not intended to be limited to this.

  As described above, the antenna unit 81 includes a plurality of antenna elements 811 to 813, and each of the antenna elements 811 to 813 is arranged in a region not facing the ground electrode GND and connected in series. According to the above configuration, a dipole antenna can be configured by the electrical length of the antenna elements 811 to 813 connected in series and the electrical length of the ground electrode GND that is not opposed to the antenna elements 811 to 813. . In this case, the antenna portion constituted by the antenna elements 811 to 813 and the ground electrode GND is planar using one surface and the other surface of the component mounting board 80. Therefore, unlike the conventional columnar monopole type or dipole type antenna, the antenna does not protrude in the height direction, so that it is not easily affected by the surroundings of the facility where the wireless sensor receiver is installed.

  In addition, since it is not a monopole type, there is no restriction that the antenna section must be arranged at the center of the GND area with respect to the reception sensitivity characteristics and the like.

  Furthermore, since the antenna section is configured by arranging a plurality of antenna elements 811 to 813 on the component mounting surface side of the component mounting board 80, the antenna element 811 to 813 is formed on the back surface. The area of the ground electrode GND can be arbitrarily adjusted. The arrangement relationship with surrounding equipment and the overall size of the wireless sensor receiver 8 can be adjusted according to the external dimensions of the component mounting board 80.

  Ultimately, according to the present invention, the antenna unit is not affected by revisions on the installed equipment side and the influence from the surroundings and without degrading various characteristics such as reception sensitivity of the wireless sensor receiver 8 as compared with the prior art. The shape can be made smaller and thinner.

  Further, since the antenna elements are divided into a plurality of antenna elements 811 to 813, the individual antenna elements 811 to 813 can be individually selected and used so as to obtain necessary characteristics without causing warping or cracking. . In addition, since the dielectric base 84 that supports the antenna conductor film 85 is made of a dielectric material having a higher dielectric constant than the material constituting the component mounting substrate 80, the antenna characteristics can be improved by using a dielectric base having a high dielectric constant. 84, the mechanical strength of the entire device can be secured by the component mounting substrate 80 having excellent mechanical strength.

  However, FIG. 5 and FIG. 6 merely show an example of an antenna element structure that can be adopted, and the present invention is not intended to be limited to such a structure. For example, a structure in which the dielectric substrate 84 is built in as a conductor pattern can be employed. Or as shown in FIG. 8, the antenna part 81 can also be comprised by the conductor pattern which has the pattern parts 811-813.

  The wireless sensor receiver according to the present invention includes a transmission circuit in addition to transmitting the data generated by the signal processing unit 83 to the outside by a wired method, and the data obtained by the signal processing circuit is transmitted by the transmission circuit. It can also be configured to transmit. An example is shown in FIGS.

  First, in the example of FIG. 9, the input side of the reception circuit unit 821 and the output side of the transmission circuit unit 822 are guided to the common antenna unit 81 via the switch unit 823.

  When the switch unit 823 is switched in the direction of the reception circuit unit 821, the detection signal from the wireless sensor transmission device 10 (see FIGS. 1 and 2) is received by the reception circuit unit 821 and processed by the signal processing unit 83. The data processed and generated by the signal processing unit 83 is supplied to the transmission circuit unit 822, and is transmitted from the antenna 81 to the outside (such as a central management device) by switching the switch unit 823 to the transmission circuit unit 822 side. The

  In the example of FIG. 10, the input side of the reception circuit unit 821 and the output side of the transmission circuit unit 822 are led to different antenna units 811 and 812, respectively. Therefore, in this example, the signal from the wireless sensor transmission device is received by the reception circuit unit 821 without being switched by the switch unit, processed by the signal processing unit 83, and the generated data is transmitted to the transmission circuit unit 822 and The antenna unit 812 can transmit to the outside.

2. 11 is a plan view of the wireless sensor transmitter 10, FIG. 12 is a front view of the wireless sensor transmitter 10 shown in FIG. 11, and FIG. 13 is a diagram of the wireless sensor transmitter 10 shown in FIGS. FIG. 14 is a bottom view of the wireless sensor transmitter 10 shown in FIGS. The illustrated wireless sensor transmission device 10 is modularized, and includes a dielectric substrate 1, sensors 21 to 2n, sensor circuits 31 to 33, a signal processing unit 4, a transmission circuit unit 5, and an antenna unit 6. And a battery 91.

  The dielectric substrate 1 may be made of an insulating material, and any of an organic insulating material, an inorganic insulating material, or a composite insulating material may be used. Moreover, the whole may be comprised with the dielectric material, and the combination of a dielectric material layer and a magnetic material layer may be sufficient.

  The sensors 21 to 2n are mounted on one surface of the dielectric substrate 1. Physical quantities to be measured include various quantities such as temperature, humidity, illuminance, acceleration, and impact. Various sensors may be used in combination, or may be configured as a kind of sensor.

  The signal processing unit 4 and the transmission circuit unit 5 are mounted on one surface of the dielectric substrate 1. A ground electrode 7 is provided on the other surface of the dielectric substrate 1. The ground electrode 7 is a so-called “solid coating” (wide area pattern), but is not formed in a portion located below the antenna unit 6.

  The battery 91 supplies power to the sensors 21 to 2n, the signal processing unit 4, and the transmission circuit unit 5, and is assembled to the other surface of the dielectric substrate 1, that is, the side where the ground electrode 7 is provided. In the illustrated embodiment, the battery 91 is a so-called “coin type” having a circular outer periphery, and the outer peripheral surface is provided on the other surface of the dielectric substrate 1 so as not to go outside. . More specifically, it is arranged inside a holder 92 made of an insulating synthetic resin or the like. One surface of the holder 92 is attached to the surface of the ground electrode 7 provided on the other surface of the dielectric substrate 1 by means such as adhesion. Inside the holder 92, terminals 93 and 94 that are in contact with the anode and electrode of the battery 91 are provided.

  The antenna unit 6 is assembled to the dielectric substrate 1. The illustrated antenna unit 6 is provided on the periphery of one surface of the dielectric substrate 1. The illustrated dielectric substrate 1 has, for example, a quadrangular outer shape, and the antenna unit 6 is disposed at one corner.

  The antenna unit 6 can basically have the structure illustrated in FIGS. 5 and 6. That is, it has a helical axis and has a winding axis in a direction parallel to the surface in the thickness direction of the dielectric substrate 1. The antenna unit 6 is assembled to the dielectric substrate 1 at the side of the arrangement area of the sensor circuits 31 to 33, the sensors 21 to 2n, the signal processing unit 4 and the transmission circuit unit 5.

  In the case of the illustrated embodiment, since the ground electrode 7 and the battery 9 are provided on the other surface of the dielectric substrate 1, the electromagnetic field radiated from the antenna unit 6 is absorbed and attenuated by the ground electrode 7 and the battery 9. Affected. For this reason, the antenna directivity is further sharpened.

  The antenna directivity depends not only on the structure of the antenna unit 6 itself but also on the position of the antenna unit 6 on the dielectric substrate 1. Therefore, the antenna directivity can be arbitrarily adjusted to some extent by selecting the position of the antenna unit 6 on the dielectric substrate 1. For example, it can be maximized in the direction intersecting the direction of the winding axis, or can be maximized in the direction of the winding axis.

  Furthermore, the antenna unit 6 is configured in a helical manner using the same structure as the receiving antenna described with reference to FIGS. 5 and 6, that is, using an antenna conductor. According to this configuration, the overall length of the antenna unit 6 can be remarkably shortened by the shape effect. For this reason, it is possible to provide the wireless sensor transmission device 10 whose shape is significantly reduced.

  Further, since the antenna conductor advances in one direction parallel to the surface of the dielectric substrate 1 in the thickness direction, the component penetrating the ground electrode in the high-frequency current magnetic field flowing through the antenna unit 6 is remarkably reduced, and the high-frequency current is reduced. Generation of eddy current due to a magnetic field can be suppressed. Further, it is possible to avoid the electromagnetic noise from getting on the antenna unit 6 in spite of the miniaturization of the whole.

  In addition, the illustrated wireless sensor transmission device 10 includes a battery 91, and the battery 91 supplies power to the sensors 21 to 2 n, the signal processing unit 4, and the transmission circuit unit 5. Therefore, when newly installing the wireless sensor transmission device 10 and when moving to an arbitrary place after installation, there is no restriction on the installation environment for securing the power supply, and it is free to an environment without an AC power supply. It can be installed and used. That is, there is no restriction on the installation environment.

  In the illustrated wireless sensor transmitter 10, the battery 91 is assembled on the other surface (ground electrode side) of the dielectric substrate 1. That is, the sensors 21 to 2n, the signal processing unit 4 and the transmission circuit unit 5 are arranged on one side of the dielectric substrate 1, and the battery 91 is arranged on the other side. Therefore, the small, thin, and lightweight wireless sensor transmission device 10 can be realized.

  The battery 91 preferably has a circular outer periphery and is in the plane of the dielectric substrate 1. According to such a configuration, the overall planar outer dimension can be reduced to a shape determined solely by the plane area of the dielectric substrate 1 without being affected by the outer diameter of the battery 91.

  By the way, when the wireless sensor transmission device 10 is driven by a battery, it is technically difficult to satisfy both the request for miniaturization of the wireless sensor transmission device 10 and the request for reduction of current consumption. For example, if the shape of the antenna unit 6 is reduced due to the demand for size reduction, thickness reduction, and weight reduction, the current consumption required for the wireless sensor transmission device 10 increases, so the battery life is It may cause inconvenience that it ends in a short period of six months to one year.

  Of course, the battery life can be maintained for a long period of time by increasing the capacity and size of the battery, such as creating a 3.0V power supply using two AA batteries, but it is downsized. Therefore, it becomes impossible to sufficiently meet the demands for thickness reduction and weight reduction.

  Furthermore, in order to realize both the request for downsizing of the wireless sensor transmission device 10 itself and the request for reduction in current consumption, the communication distance cannot be increased with lower input power to the antenna unit 6. Don't be. For this purpose, it is necessary to reduce the loss of the antenna unit 6 and increase the radiation efficiency of the electromagnetic field.

  With respect to the above requirement, the antenna conductor advances in one direction parallel to the surface of the dielectric substrate 1, so that the component penetrating the ground electrode 7 in the high-frequency current magnetic field flowing through the antenna section 6 is remarkably reduced, and the high-frequency current magnetic field The generation of eddy current due to can be suppressed. Further, it is possible to avoid the electromagnetic noise from getting on the antenna unit 6 in spite of the miniaturization of the whole.

  Moreover, since the antenna section 6 is helical and the thickness of the dielectric substrate 1 is two sides of the opening, the antenna gain can be improved by controlling the area of the opening.

  As a result, it is possible to achieve both a request for downsizing of the wireless sensor transmission device 10 itself and a request for reduction in current consumption, thereby achieving a reduction in the loss of the antenna unit 6 and an improvement in the radiation efficiency of the electromagnetic field. it can. That is, with a lower input power to the antenna unit 6, the communication distance is increased, the power consumption of the circuit unit provided in the front stage of the antenna unit 6 is reduced, and the current consumption of the entire wireless sensor device is reduced. Longer battery life and continuous operation time can be achieved.

  The antenna unit 6 is preferably provided outside the mounting area of the battery 91. In addition, it is preferable that an electrical element other than the antenna unit 6, for example, a conductor pattern or other components is not disposed in the occupied area of the antenna unit 6. According to such a configuration, it is possible to avoid interference of electric signals and electromagnetic fields with respect to the antenna unit 6 to suppress the generation of noise, and to reduce eddy current leakage and improve antenna gain.

  15 is a plan view showing still another example of the wireless sensor transmitter 10, FIG. 16 is a partial cross-sectional view of the wireless sensor transmitter 10 shown in FIG. 15, and FIG. 17 is a wireless sensor transmitter shown in FIGS. 2 is a bottom view of the device 10. FIG. The feature of this example is that the antenna portion 6 is provided over almost the entire length along one side of the dielectric substrate 1. The antenna unit 6 is provided directly on the dielectric substrate 1. The ground electrode 7 is not provided in a portion corresponding to the antenna unit 6.

  Although the contents of the present invention have been specifically described above with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.

It is a block diagram of the wireless sensor apparatus which combined the wireless sensor receiver which concerns on this invention, and the wireless sensor transmitter. It is a block diagram which shows another structure of the wireless sensor apparatus which concerns on this invention. It is a top view of the wireless sensor receiver concerning the present invention. It is a front view of the wireless sensor receiver shown in FIG. It is a top view of an antenna element. FIG. 6 is a front view of the antenna element shown in FIG. 5. It is a circuit diagram of the antenna circuit by the connection of an antenna element. It is a top view which shows another example of the wireless sensor receiver which concerns on this invention. It is a block diagram which shows another example of the wireless sensor receiver which concerns on this invention. It is a block diagram which shows another example of the wireless sensor receiver which concerns on this invention. It is a top view of the wireless sensor transmitter concerning the present invention. It is a front view of the wireless sensor transmitter shown in FIG. FIG. 13 is a partially broken bottom view of the wireless sensor transmission device shown in FIGS. 11 and 12. It is a bottom view of the wireless sensor transmitter shown in FIGS. It is a top view which shows another example of a wireless sensor transmitter. It is a fragmentary sectional view of the wireless sensor transmitter shown in FIG. FIG. 17 is a bottom view of the wireless sensor transmission device shown in FIGS. 15 and 16.

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 Wireless sensor receiver 81 Antenna part 811-813 Antenna element 10 Wireless sensor transmitter GND Ground electrode

Claims (10)

A wireless sensor receiving device including a component mounting board, a receiving circuit unit, a signal processing unit, and an antenna unit,
The component mounting board has the receiving circuit unit, the signal processing unit, and the antenna unit on one surface, and a ground electrode on a part of the other surface,
The receiving circuit unit and the signal processing unit are provided in a region facing the ground electrode,
The antenna unit includes a plurality of the antenna elements, each of the antenna elements is disposed in a region not facing the ground electrode, and is connected in series with each other ,
A dipole antenna is constituted by the electrical length of the antenna elements connected in series and the electrical length of a ground electrode that is not opposed to the antenna elements,
The antenna element comprises a first antenna element, a second antenna element, and a third antenna element,
The first antenna element constitutes an outward path,
The third antenna element constitutes a return path;
The second antenna element is disposed on one end side of the first antenna element and the third antenna element, and both ends thereof are connected to the first antenna element 8 and the third antenna element. ,
The other end of the third antenna element constituting the return path is led to the input end of the receiving circuit unit.
Wireless sensor receiver. The wireless sensor receiver according to claim 1,
Each of the antenna elements includes a dielectric substrate and an antenna conductor film,
The dielectric substrate is made of a dielectric material having a higher dielectric constant than the material constituting the component mounting board.
The antenna conductor film is supported by the dielectric substrate.
Wireless sensor receiver.   3. The wireless sensor receiver according to claim 1, wherein the antenna conductor film includes an inductance element or an inductance element. 4.   4. The wireless sensor receiver according to claim 1, wherein the antenna conductor film includes a capacitance element or a capacitance element. 5.   5. The wireless sensor receiver according to claim 1, wherein the wireless sensor receiver includes a transmission circuit, and transmits data obtained by the signal processing circuit by the transmission circuit. 6.   6. The wireless sensor receiver according to claim 5, wherein an input side of the reception circuit unit and an output side of the transmission circuit are led to a common antenna unit via a switch unit. apparatus.   6. The wireless sensor receiver according to claim 5, wherein an input side of the reception circuit unit and an output side of the transmission circuit are respectively led to different antenna units. A wireless sensor device including a wireless sensor receiver and a wireless sensor transmitter,
The wireless sensor receiver is the one described in any one of claims 1 to 7,
The wireless sensor transmission device transmits a wireless sensor signal to the wireless sensor reception device.
Wireless sensor device. The wireless sensor device according to claim 8,
The wireless sensor transmission device includes a transmission component mounting substrate, a sensor unit, a sensor signal processing unit, a transmission circuit unit, and a transmission antenna unit.
The transmission component mounting board has the sensor unit, the sensor signal processing unit, and the transmission circuit unit on one surface,
The sensor unit detects a physical quantity,
The sensor signal processing unit is a circuit that processes a detection signal output from the sensor unit,
The transmission circuit unit is a circuit that transmits a signal supplied from the sensor signal processing unit,
The transmitting antenna portion is assembled to the transmitting component mounting board.
Wireless sensor device. The wireless sensor device according to claim 8, wherein the transmitting antenna unit includes a helical antenna conductor film.