Communication device

Abstract

The present technology relates to a communication device that enables stable communication even for an antenna of reduced electrical size. The communication device includes: a circularly polarized antenna configured from a first antenna element and a second antenna element arranged orthogonally to the first antenna element; and a phase shifter composed of a capacitor connected to the first antenna element and an inductor connected to the second antenna element. The impedance of the antenna is represented by R + jX, the capacitance of the capacitor is a value calculated from C = 1 / {pi f (R + X)}, and the inductance of the inductor is a value calculated from L = (R-X) / (4pi f), where R is the resistance, j is an imaginary unit, X is the reactance, f is the center frequency of the antenna, C is the capacitance, and L is the inductance. The present technology can be applied, for example, to a communication device installed in seawater.

Description

Technical Field

[0001] The present technology relates to a communication device, and, for example, to a communication device suitable for communication in a liquid. Background Art

[0002] In recent years, wireless communication such as wireless local area network (LAN) and contactless communication has become widespread. Patent document 1 proposes a communication device that communicates with a communication device isolated underwater.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-21874 Summary of the invention

[0006] Problems to be solved by the present invention

[0007] In water, such as seawater, the attenuation of electromagnetic waves increases due to high conductivity, so frequencies equal to or lower than the MHz band are generally selected as communication frequencies. In addition, since it is difficult for an antenna to resonate in a medium with a high dielectric constant, there are challenges in designing a resonant antenna based on the premise of using it in such a medium. For this reason, in the case where a general resonant antenna such as a half-wave dipole antenna is used as an antenna for implementing communication in seawater, the length of one wavelength is, for example, on the order of several meters, which increases the size of the antenna and leads to challenges in antenna design.

[0008] Even in a medium having high conductivity such as seawater, it is desirable to achieve stable communication with an antenna having a small electrical size.

[0009] The present technology has been proposed in view of such circumstances, and realizes stable communication even with an antenna of a small electrical size.

[0010] Solutions to the Problem

[0011] According to a certain aspect of the present technology, a first communication device includes: a circularly polarized antenna, including a first antenna element and a second antenna element arranged orthogonally to the first antenna element; and a phase shifter, including a capacitor connected to the first antenna element and an inductor connected to the second antenna element, wherein when the resistance is marked by R, the imaginary unit is marked by j, the reactance is marked by X, the center frequency of the antenna is marked by f, the capacitance is marked by C, and the inductance is marked by L, the impedance of the antenna is represented by R+jX, the capacitance of the capacitor is a value calculated by C=1 / {πf(R+X)}, and the inductance of the inductor is a value calculated by L=(RX) / (4πf).

[0012] According to a certain aspect of the present technology, a second communication device includes: a circularly polarized antenna, including a first antenna element and a second antenna element with orthogonal linear polarizations; and a phase shifter, including a capacitor connected to the first antenna element and an inductor connected to the second antenna element, wherein when the resistance is marked by R, the imaginary unit is marked by j, the reactance is marked by X, the center frequency of the antenna is marked by f, the capacitance is marked by C and the inductance is marked by L, the impedance of the antenna is represented by R+jX, the capacitance of the capacitor is a value calculated by C=1 / {2πf(R+X)}, and the inductance of the inductor is a value calculated by L=(RX) / (2πf).

[0013] A first communication device according to the aspect of the present technology is provided with: a circularly polarized antenna including a first antenna element and a second antenna element arranged orthogonally to the first antenna element; and a phase shifter including a capacitor connected to the first antenna element and an inductor connected to the second antenna element. Where resistance is denoted by R, imaginary unit is denoted by j, reactance is denoted by X, the center frequency of the antenna is denoted by f, capacitance is denoted by C, and inductance is denoted by L, the impedance of the antenna is represented by R+jX, the capacitance of the capacitor is a value calculated by C=1 / {πf(R+X)}, and the inductance of the inductor is a value calculated by L=(RX) / (4πf).

[0014] The second communication device according to the aspect of the present technology is provided with: a circularly polarized antenna including a first antenna element and a second antenna element of orthogonal linear polarization; and a phase shifter including a capacitor connected to the first antenna element and an inductor connected to the second antenna element. Where the resistance is indicated by R, the imaginary unit is indicated by j, the reactance is indicated by X, the center frequency of the antenna is indicated by f, the capacitance is indicated by C, and the inductance is indicated by L, the impedance of the antenna is represented by R+jX, the capacitance of the capacitor is a value calculated by C=1 / {2πf(R+X)}, and the inductance of the inductor is a value calculated by L=(RX) / (2πf).

[0015] It should be noted that the communication device may be an independent device or an internal block constituting one device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a diagram showing the configuration of an embodiment of a communication system to which the present technology is applied.

[0017] Figure 2 is a diagram showing the configuration of another embodiment of a communication system to which the present technology is applied.

[0018] Figure 3 is a diagram showing the configuration of another embodiment of a communication system to which the present technology is applied.

[0019] Figure 4 is a diagram showing a configuration example of a master station.

[0020] Figure 5 is a diagram showing a configuration example of an antenna and a phase shifter.

[0021] Figure 6 is a diagram showing conditions related to the configuration of the phase shifter.

[0022] Figure 7 is a diagram showing a configuration example of a phase shifter.

[0023] Figure 8 is a diagram showing a configuration example of a phase shifter.

[0024] Fig. 9 : is a diagram showing a configuration example of a phase shifter to which a balun (balun) is added.

[0025] Fig.10 is a diagram showing a configuration example of a phase shifter to which a balun is added.

[0026] Fig.11 is a diagram showing a configuration example of a phase shifter to which a matching circuit is added.

[0027] Fig.12 is a diagram showing another configuration example of a phase shifter.

[0028] Fig.13 is a diagram showing another configuration example of a phase shifter.

[0029] Fig.14 is a diagram showing another configuration example of a phase shifter.

[0030] Fig.15 is a diagram showing another configuration example of a phase shifter.

[0031] Fig.16 is a diagram showing the shape of an antenna.

[0032] Fig.17 is a diagram showing the shape of an antenna.

[0033] Fig.18 is a diagram showing the shape of an antenna.

[0034] Fig.19 is a diagram showing a configuration example of an antenna.

[0035] Fig. 20 is a diagram showing a configuration example of an antenna.

[0036] Fig.21is a diagram showing a configuration example of an antenna. DETAILED DESCRIPTION

[0037] Hereinafter, a mode for carrying out the present technology (hereinafter referred to as an embodiment) will be described.

[0038] <Configuration of communication system>

[0039] Figure 1 : is a diagram showing the configuration of an embodiment of a communication system 1 to which the present technology is applied. Figure 1 The communication system 1 shown in FIG. 1 includes a master station 11, a communication station 12, a communication station 13, a satellite 14, slave stations 21-1 to 21-6, slave stations 31-1 and 31-2, and a repeater 32. In the following description, in the case where it is not necessary to distinguish the slave stations 21-1 to 21-6 individually, the slave stations 21-1 to 21-6 are simply described as 21. The same applies to other drawings.

[0040] The master station 11 and the communication station 12 implement communication using, for example, local 5G. The master station 11 and the communication station 13 implement communication using, for example, low power wide area (LPWA). The master station 11 can obtain location information from a satellite 14 using, for example, a global navigation satellite system (GNSS). Here, the description will continue with local 5G, LPWA, and GNSS as examples, but it is also possible to configure to implement communication using another communication network, such as a wireless local area network (WLAN), a satellite communication network, etc.

[0041] The master station 11 also communicates with the slave station 21. In the master station 11, the part communicating with the communication station 12, the communication station 13 and the satellite 14 described above is located in the air, and the part communicating with the slave station 21 is located in the sea water. The slave station 21 is located in the sea water.

[0042] It should be noted that the case where the environment in which the communication system 1 is installed is the ocean will be described as an example here, but the communication system 1 may also be installed in an environment such as a lake, a pond, a river, or a water tank. The present technology described below may be applied to installation in a medium (lossy medium) other than lossless air. Lossy media include the inside of a human body, a saltwater lake, and the other environments described above in addition to seawater.

[0043] A description will be given here assuming that one of the master stations 11 is located in the air (in gas) and the other is located in seawater (in liquid), but one master station 11 may be located on the seabed (in solid) or in a vacuum.

[0044] Figure 1 The configuration of the communication system 1 shown in FIG. 1 is an example and is not to be described as limiting. Figure 1The communication system 1 shown shows an example in which the master station 11 communicates with the communication station 12, the communication station 13, and the satellite 14, but the master station may also have the function of communicating with other devices other than these devices, or may not have the function of being able to communicate with all of these devices, or may be able to communicate with any one or two of them. The master station 11 may only have the function of communicating with the slave station 21, in other words, may not have the function of communicating with the communication station 12, the communication station 13, or the satellite 14.

[0045] The slave stations 21-1 to 21-6 each communicate with the master station 11. A so-called ad hoc network may be configured in which the respective slave stations 21 communicate with each other. The slave station 21 is provided with, for example, a seawater sensing sensor, and transmits the sensing data to the master station 11. The slave station 21 may have only a transmission function of transmitting data to the master station 11, or may have a transmission function and a reception function of transmitting and receiving data to / from the master station 11 and another slave station 21. The slave station 21 is installed, for example, within a depth range of 0 to 10 m from the sea surface.

[0046] Each of the slave stations 31-1 and 31-2 communicates with the repeater 32. The slave station 31 is provided with, for example, a seawater sensing sensor, and transmits sensing data to the repeater 32. The slave station 31 may have only a transmission function of transmitting data to the repeater 32, or may have a transmission function and a reception function of transmitting and receiving data to / from the repeater 32 and another slave station 31. The slave station 31 is installed on the seabed (close to the seabed).

[0047] Among the antennas of the master station 11, the antenna installed in seawater (in liquid) and used for communication with the slave station 21 and the repeater 32 installed in seawater is a circularly polarized antenna. Each antenna of the slave station 21 and the slave station 31 is a circularly polarized antenna or a linearly polarized antenna. The antenna of the repeater 32 is a circularly polarized antenna, and Figure 1 In the example shown, it is used when communicating with the slave station 31 and when communicating with the master station 11 .

[0048] like Figure 2 As shown in , the repeater 32 and the master station 11 can also be configured to implement wired communication. Figure 3 As shown in , the repeater 32 and the master station 11 may also be configured to implement optical communication.

[0049] The slave station 21 and the slave station 31 are grounded in the ocean or on the seabed, but the positional relationship with the master station 11 and the repeater 32 may deviate from the positional relationship suitable for communication due to the influence of waves, etc. Since the receiving antennas that receive data from the master station 11 and the repeater 32 (in other words, the slave station 21 and the slave station 31) are circularly polarized antennas, even in the case where the positional relationship deviates from the appropriate positional relationship, relatively favorable communication can still be maintained.

[0050] As a path for a signal from the slave station 21 installed in the ocean to be propagated to the master station 11, there are direct waves and lateral waves, wherein the direct wave travels linearly between the antenna of the slave station 21 and the antenna of the master station 11, and the lateral wave travels vertically upward from the antenna of the slave station 21 to the sea surface directly above the antenna of the slave station 21, passes through the sea surface and travels along the sea surface, and travels from the sea surface directly above the antenna of the master station 11 to the antenna of the master station 11.

[0051] When the attenuation received by the side wave is less than the attenuation received by the direct wave, the side wave becomes dominant and is received by the master station 11. The side wave propagates farther than the direct wave, so the side wave becomes dominant as the distance between the slave station 21 and the master station 11 increases. Such a phenomenon occurs when the distance between the antenna and the sea surface is not far.

[0052] As a path for a signal from a slave station 31 installed on the seabed to be propagated to a repeater 32, there are a direct wave that travels linearly between the antenna of the slave station 31 and the antenna of the repeater 32, and a signal that travels vertically downward from the antenna of the slave station 31 to the sea surface directly below the antenna of the slave station 31, travels along the seabed, and travels from the seabed close to the antenna of the repeater 32 to the antenna of the repeater 32.

[0053] The signal propagating from the slave station 31 into the seawater has a large attenuation, while the signal propagating from the slave station 31 along the seabed has a small attenuation. Therefore, the repeater 32 receives the signal propagating along the seabed. By using the signal propagating along the seabed, the network can be expanded to a wider range. In addition, the power consumption of the slave station 31 can be reduced. In the case where the slave station 31 is included in the configuration of the mesh network, the number of terminals required for the mesh network can be reduced.

[0054] <Configuration example of the master station>

[0055] Figure 4 is a diagram showing a configuration example of the master station 11 . Figure 4 The master station 11 shown in FIG. 1 includes a signal processing unit 101, a high frequency processing unit 102, and an antenna 103. The antenna 103 of the master station 11 is installed in seawater (liquid), and is used for communication with a slave station 21 installed in seawater, a repeater 32, and another master station 11. The antenna 103 is a circularly polarized antenna.

[0056] The signal from the slave station 21 is received by the antenna 103 of the master station 11 and provided to the high frequency processing unit 102. The high frequency processing unit 102 is configured to process the received signal or the signal to be transmitted. The operating frequency fw of the high frequency processing unit 102 is set to 1 MHz or lower, for example.

[0057] The signal processed by the high frequency processing unit 102 is supplied to the signal processing unit 101. For example, the signal processing unit 101 performs processing in a case where the signal processed by the high frequency processing unit 102 is temporarily stored or a received signal is processed and transmitted.

[0058] Figure 4 The configuration of the master station 11 shown in FIG. 1 can also be applied as the configuration of the repeater 32. Figure 4 In the case where the configuration shown in is that of a repeater 32, the antenna 103 has a function of receiving a signal from a slave station 31 and a function of transmitting a signal to a master station 11 or another repeater 32. The high frequency processing unit 102 and the signal processing unit 101 have a function of amplifying and transmitting the received signal.

[0059] <Phase Shifter Configuration>

[0060] Figure 5 1 is a diagram showing a configuration example of the antenna 103 and the phase shifter 111 included in the high-frequency processing unit 102. In the following description, the case where the antenna 103 and the phase shifter 111 are included in the master station 11 will be described as an example, but any of the slave station 21, the slave station 31, and the repeater 32 is applicable.

[0061] Antenna 103 is a circularly polarized antenna and is Figure 5 The example shown includes antenna elements 103-1 to 103-4. A pair of antenna element 103-1 and antenna element 103-2 are arranged in a straight line to form a dipole antenna. A pair of antenna element 103-3 and antenna element 103-4 are arranged in a straight line to form a dipole antenna.

[0062] A dipole antenna including antenna element 103-1 and antenna element 103-2 and a dipole antenna including antenna element 103-3 and antenna element 103-4 are arranged to intersect at an angle of 90 degrees. Antenna 103 is a cross dipole antenna including antenna elements 103-1 to 103-4, and is a circularly polarized antenna.

[0063] Figure 5 The antenna 103 shown in FIG. 1 is an antenna that can transmit and receive circularly polarized signals by using two sets of linearly polarized balanced antennas and arranging antenna elements (radiating elements) constituting orthogonal polarized antennas to be orthogonal to each other.

[0064] Antenna element 103-1 and antenna element 103-2 are connected to phase shifter 111-2. Antenna element 103-3 and antenna element 103-4 are connected to phase shifter 111-1.

[0065] The master station 11 including the phase shifter 111 has a configuration to be installed in a medium having high conductivity such as seawater. In a medium having high conductivity, attenuation of electromagnetic waves is large, and in the case of implementing communication over a distance of several meters or more, communication using a frequency of the MHz band or lower is generally implemented. In such a case, the length of one wavelength is on the order of several meters, and the size of a half-wave antenna, for example, may be considered large with respect to communication equipment.

[0066] In addition, since the antenna hardly resonates in a conductive medium, it is difficult to design a resonant antenna. For this reason, when the length of one wavelength is on the order of several meters and a resonant type antenna such as a half-wave dipole antenna is used as antenna 103, the size of antenna 103 may be large.

[0067] Therefore, for example, in the case of using a circularly polarized antenna based on an electrically small-sized non-resonant antenna, a high-frequency component must be used.

[0068] Therefore, a circularly polarized antenna including a power supply unit (here, the phase shifter 111 ) having a low-cost simple configuration based on a non-resonance antenna will be described.

[0069] Figure 6 is Figure 5 In addition to the phase shifter 111 and antenna 103 shown in FIG, an illustration of the impedance in the phase shifter 111 is added. Assume Figure 6 The impedance of the electrically small-sized antenna (antenna 103) shown in is denoted by R+jX. R in the impedance R+jX is the real part of the impedance and represents resistance. jX in R+jX is the imaginary part of the impedance, j represents an imaginary unit, and X represents reactance.

[0070] The impedance R+jX is the impedance of a pair of antenna elements 103 (for example, antenna element 103-1 and antenna element 103-2) when viewed from the phase shifter 111 side. Figure 6 As shown in , when the impedance of the phase shifter 111-1 when viewed from the power supply side is Ra+jXa, the impedance of the antenna 103 when viewed from the phase shifter 111-1 is R+jX. Similarly, when the impedance to the phase shifter 111-2 is Rb+jXb, the impedance when viewed from the phase shifter 111-1 is R+jX.

[0071] In order to obtain a circularly polarized wave by orthogonally arranging a dipole antenna including antenna elements 103-1 and 103-2 and a dipole antenna including antenna elements 103-3 and 103-4, it is only necessary to connect a phase shifter 111 to each antenna 103 so that the phase difference between the impedances of the orthogonally arranged antennas is 90 degrees. The condition that the phase difference is 90 degrees is expressed by the following equation (1).

[0072] Ra×Rb+Xa×Xb=0 ... (1)

[0073] In order to obtain a simple circuit that does not include a pure resistor, it is desirable that Ra=Rb=R, and there is no change in the real part. When Ra=Rb=R is replaced in equation (1) and rearranged, the following equation (2) is obtained.

[0074] Xa×Xb=-R 2 ... (2)

[0075] In a circularly polarized antenna having an ideal axial ratio of 1, it is only necessary that the absolute values ​​of the respective reflection coefficients are equal to each other. Assume that the phase shifter 111 is located between the antenna 103 and a high frequency power source (not shown). Assuming that the reflection coefficient of the phase shifter 111-1 when viewed from the power source side is denoted by Γa, and the reflection coefficient of the phase shifter 111-2 when viewed from the power source side is denoted by Γb, the reflection coefficients Γa and Γb are expressed by the following equations (3) and (4).

[0076] [Mathematical expression 1]

[0077]

[0078] [Mathematical expression 2]

[0079]

[0080] In equations (3) and (4), Zref represents the reference impedance. When the reference impedance is set to a real number, the condition that the absolute value of the reflection coefficient Γa = the absolute value of the reflection coefficient Γb is obtained as follows: Xa = R

[0081] Circuits that can achieve this include those that satisfy the following conditions:

[0082] Xa=R,Xb=-R,and R>|X|

[0083] Therefore, if Figure 7 As shown in , the phase shifter 111-1 only needs to have a capacitance C represented by the following equation (5), and the phase shifter 111-2 only needs to have an inductance L represented by the following equation (6). In equations (5) and (6), f represents the center frequency (desired frequency) of the transmission or reception frequency.

[0084] [Mathematical expression 3]

[0085]

[0086] [Mathematical expression 4]

[0087]

[0088] The phase shifter 111-1 is provided with a capacitor 121-1 and a capacitor 121-2 each having a capacitance C calculated by equation (5). The phase shifter 111-2 is provided with an inductor 122-1 and an inductor 122-2 each having an inductance L calculated by equation (6).

[0089] The capacitor 121-1 in the phase shifter 111-1 is provided between a high-frequency power source (not shown) and the antenna element 103-4, and the capacitor 121-2 is provided between the high-frequency power source and the antenna element 103-3. The inductor 122-1 in the phase shifter 111-2 is provided between the high-frequency power source and the antenna element 103-2, and the inductor 122-2 is provided between the high-frequency power source and the antenna element 103-1.

[0090] like Figure 8 The redescription shown in Figure 7 The configuration of the phase shifter 111 and the antenna 103 is shown in FIG. Figure 8 middle, Figure 7 The phase shifter 111 - 1 and the phase shifter 111 - 2 in FIG. 1 are collectively referred to as a phase shifter 111 .

[0091] The phase shifter 111 includes an inductor 122-1 and an inductor 122-2 connected to the antenna element 103-1 and the antenna element 103-2, respectively. The phase shifter 111 also includes a capacitor 121-1 and a capacitor 121-2 connected to the antenna element 103-3 and the antenna element 103-4, respectively.

[0092] The capacitor 121-1 in the phase shifter 111 is provided between a high frequency power source (not shown) and the antenna element 103-4, and the inductor 122-2 is provided between the high frequency power source and the antenna element 103-1. The capacitor 121-1 and the inductor 122-2 are short-circuited on the power source side.

[0093] The capacitor 121-2 in the phase shifter 111 is provided between the high frequency power supply and the antenna element 103-3, and the inductor 122-1 is provided between the high frequency power supply and the antenna element 103-2. The capacitor 121-2 and the inductor 122-1 are short-circuited on the power supply side.

[0094] For example, such a configuration of the phase shifter 111 can form an ideal circularly polarized antenna having an axial ratio of 1 at a frequency f. The phase shifter 111 capable of obtaining such an effect can be realized by four lumped constants. Therefore, the master station 11, the slave stations 21 and 31, and the repeater 32 including the phase shifter 111 and the antenna 103 can be reduced in size and manufactured at a low cost.

[0095] <Another configuration of phase shifters>

[0096] Fig. 9is a diagram showing another configuration example of the phase shifter 111 . Fig. 9 The phase shifter 111 shown in FIG. Figure 8 The phase shifter 111 shown in FIG. 1 is different in that a balun 141 is added, and the other points are the same. By inserting the balun, noise can be reduced and characteristics can be stabilized.

[0097] Fig. 9 The balun 141 shown in FIG. 1 is a floating balun, and includes a transformer 142-1 and a transformer 142-2. The two transformers are provided with, for example, a ferrite core having a bifilar winding so that the polarities thereof are identical to each other.

[0098] Fig.10 Shown as Fig. 9 A configuration example of the phase shifter 111 of the balun is added. Fig.10 The case where the added balun 151 is a balun called a forced balun is shown.

[0099] The balun 151 includes transformers 151-1 to 151-3. The wiring forming the balun 151 is formed by, for example, three-strand winding with three wires around a toroidal core, thereby having an impedance conversion ratio of 1:1 and forcibly converting balance and unbalance.

[0100] In addition, if Fig.11 As shown in , a matching circuit 161 may be added to the balun 151. The matching circuit 161 includes a transformer including a primary side coil and a secondary side coil, and transmits power using mutual inductance between the primary side coil and the secondary side coil, and implements impedance matching through impedance-voltage conversion according to a winding ratio of the two coils.

[0101] Although in Fig.11 FIG. 1 shows a configuration in which the matching circuit 161 is added to the balun 151. The matching circuit 161 may also be added to the balun 141 ( Fig. 9 ).

[0102] Fig.12 is a diagram showing the configuration of another phase shifter 111 . Fig.12 The phase shifter 111 shown in FIG. Figure 8 The configuration is the same as that of the phase shifter 111 shown in FIG. 1 , except that the capacitors 121 - 1 and 121 - 2 include capacitors 121 - 1 ′ and 121 - 2 ′ having variable capacitances, and the other points are the same.

[0103] The capacitors 121 - 1 ′ and 121 - 2 ′ may be, for example, capacitors whose capacitances are variable by external control such as varactor diodes.

[0104] The phase shifter 111 is included in the master station 11, for example, and it is assumed that the master station 11 is affected by the surrounding environment. When the master station 11 is affected by the surrounding environment, there is a risk of causing the impedance of the antenna 103 to change. The capacitance of the capacitor 121 is made variable to allow following such impedance changes of the antenna 103 and returning (adjusting) to an appropriate impedance.

[0105] Here, the case where the capacitor 121 is variable is described as an example, but the inductor 122 may be variable. In addition, both the capacitor 121 and the inductor 122 may be variable. At least one of the capacitor 121 or the inductor 122 may be variable.

[0106] The phase shifter 111 may be provided with an adjustment unit that adjusts the variable capacitor 121 and / or the inductor 122 to follow the change in impedance.

[0107] You can also use the Balun 141 ( Fig. 9 ) or Balun 151( Fig.10 )Connect to Fig.12 In addition, a balun 151 (141) and a matching circuit 161 may be connected to the phase shifter 111 shown in FIG. Fig.12 The phase shifter 111 shown in FIG.

[0108] Fig.13 is a diagram showing the configuration of another phase shifter 111 . Fig.13 The phase shifter 111 shown in FIG. Figure 8 The phase shifter 111 shown in FIG. 1 is different in that a resistor 201 is added, and other points are the same.

[0109] Actual circuit elements may not have the ideal capacitance C or inductance L calculated by equation (5) or (6). For example, the inductor 122 generally has an equivalent series resistance (ESR), and due to the equivalent series resistance, the ideal capacitance C or inductance L calculated by equation (5) or (6) may not be obtained.

[0110] A compensation circuit may be provided to achieve the ideal capacitance C or inductance L calculated by equation (5) or (6).

[0111] exist Fig.13 In the illustrated phase shifter 111, a resistor 201 having a resistance value comparable to an equivalent series resistance is provided on the capacitor 121 side so that impedance is not unbalanced due to the equivalent series resistance of the inductor 122. The resistor 201-1 is connected in series to the capacitor 121-1 of the phase shifter 111, and the resistor 201-2 is connected in series to the capacitor 121-2.

[0112] As Fig.14The phase shifter 111 shown in FIG. 1 shows a configuration example in which an inductor 122 is provided in parallel as a compensation circuit. Fig.14 In the phase shifter 111 shown, the inductor 122-1-1 and the inductor 122-1-2 are connected in parallel, one end of which is connected to the antenna element 103-2, and the other end of which is connected to a power source (not shown). Fig.14 In the illustrated phase shifter 111, an inductor 122-2-1 and an inductor 122-2-2 are connected in parallel, one end thereof is connected to the antenna element 103-1, and the other end thereof is connected to a power source (not shown).

[0113] By adopting a parallel arrangement for the inductor 122, the influence of the equivalent series resistance of the inductor 122 can be reduced. In addition, in the case where it is impossible to obtain the inductance L represented by equation (6) by using one inductor 122, for example, in the case where there is no element corresponding to the inductance L calculated by equation (6) in the E12 series or the E24 series, a plurality of inductors 122 can be used to obtain the inductance L calculated by equation (6).

[0114] Instead of parallel connection, for example Fig.15 The inductor 122 shown in FIG. 1 can be connected in series. Fig.15 The phase shifter 111 shown in FIG. 1 shows a configuration example in which a parallel arrangement is provided for the inductor 122 as a compensation circuit and an adjustment unit 221 is added.

[0115] exist Fig.15 In the phase shifter 111 shown, the inductor 122-1-1 and the inductor 122-1-2 are connected in series, one end of which is connected to the antenna element 103-2, and the other end of which is connected to a power source (not shown). Fig.15 In the illustrated phase shifter 111, an inductor 122-2-1 and an inductor 122-2-2 are connected in series, one end of which is connected to the antenna element 103-1, and the other end of which is connected to a power source (not shown).

[0116] Adjustment unit 221 is provided between inductors 122-1-1 and 122-1-2 connected in series and between inductors 122-2-1 and 122-2-2 connected in series. Adjustment unit 221 adjusts the inductance L of inductor 122-1 including inductor 122-1-1 and inductor 122-1-2 and the inductance L of inductor 122-2 including inductor 122-2-1 and inductor 122-2-2.

[0117] You can also use the Balun 141 ( Fig. 9 ) or Balun 151( Fig.10 )Connect to Figures 12 to 15In addition, a balun 151 (141) and a matching circuit 161 may be connected to the phase shifter 111 shown in FIG. Figures 12 to 15 The phase shifter 111 shown in FIG.

[0118] As described above, a circuit configuration for compensating for manufacturing errors and parasitic impedance generated in operation may be employed.

[0119] For example, since the repeater 32 and other devices are installed in seawater, circuits such as the phase shifter 111 are protected by resins such as silicon for waterproofing. In such a configuration, parasitic impedance may be generated for materials such as silicon. In consideration of the occurrence of such parasitic impedance occurring in operation, a compensation circuit may be adopted.

[0120] <Antenna shape>

[0121] Fig.16 30 is a diagram showing a configuration example in a case where the antenna includes a propeller antenna 301 .

[0122] Fig.16 The antenna shown in FIG. 1 includes antenna elements 301-1 to 301-4 and is configured as a propeller type. The propeller type antenna element 301 is configured to rotate by wave force or tidal force. For example, each antenna element 301 is processed to have a shape that is easily applied with wave force, and the antenna 301 is processed to have a shape that is easily rotated by wave force.

[0123] The antenna element 301 is configured similarly to the antenna element 103 ( Figure 8 ) is the same cross dipole antenna. Antenna element 301 is connected to phase shifter 111. Phase shifter 111 has a reference Figures 8 to 15 Any of the configurations of the phase shifter 111 described. The output from the phase shifter 111 is provided to the movable contact portion 311 using a slip ring or other unit.

[0124] A terminal connected to the movable contact portion 311 of the antenna element 301 is provided on the antenna element 301 side, and the terminal rotates according to the rotation of the antenna element 301. A terminal provided to contact the rotating terminal is a fixed terminal, and is connected to the transmission / reception circuit 312.

[0125] The transmission / reception circuit 312 processes a signal received through the antenna element 301 and supplied through the movable contact portion 311. Furthermore, the transmission / reception circuit 312 generates a signal desired to be transmitted through the antenna element 301 and supplies the signal to the antenna element 301 through the movable contact portion 311.

[0126] The movable contact portion 311 is also connected to a power generation unit 313. The power generation unit 313 generates power by using the rotation of the antenna 301. The power generated by the power generation unit 313 can be stored in a storage battery (not shown).

[0127] The master station 11 , the slave stations 21 and 31 , and the repeater 32 , each of which has the antenna 301 and the power generation unit 313 , can operate using the power generated by the power generation unit 313 .

[0128] Fig.17 is a diagram showing another shape of the antenna. Fig.17 The antenna shown in includes spherical antenna elements 351-1 to 351-4. Fig.18 There is shown a configuration of each pair included in the antenna 301. A pair included in the antenna 301 (for example, the antenna element 351-1 and the antenna element 351-2) includes an electrode pair 351 and a sheath portion 355.

[0129] The sheath portion 355 includes a pair of wires 353 that electrically connect the electrode 351 to the power supply terminal corresponding to the electrode 351. The sheath portion 355 has, for example, a columnar shape, along which the connection between the electrode pair 351 is made. As the columnar shape, a cylindrical or prism shape is assumed.

[0130] The sheath portion 355 may include a low-loss dielectric therein. As the low-loss dielectric, for example, air, pure water, resin, glass, ceramic material, and other materials are assumed. It should be noted that the low-loss dielectric inside the sheath portion 355 may include a variety of materials.

[0131] The shape of the electrode 351 can be as follows Fig.18 The spherical shape shown in A of FIG. 1 and may be any shape close to a sphere. For example, Fig.18 As shown in B, the shape may be a shape of an ellipsoid.

[0132] For ease of manufacture, the surface may not be smooth, and the shape may be as follows Fig.18 The polyhedron shape shown in C. In this case, a regular icosahedron or a higher polyhedron can be used. The shape may be a shape other than a regular polyhedron.

[0133] Regardless of the shape, each electrode 351 has a diameter greater than the width of the connection line 353, even if the diameter is the minimum diameter. As the material of the electrode 351, for example, a metal with high corrosion resistance, such as copper (Cu), aluminum (Al), gold (Au), platinum (Pt) or silver (Ag) and alloys thereof, or other materials are assumed. A dielectric may be provided inside the electrode 351. In this case, the dielectric inside the electrode 351 may include a variety of materials.

[0134] Since the antenna has Fig.18 The configuration shown in , therefore, can improve the transmission characteristics in an antenna for wireless communication via a lossy medium.

[0135] <Application for unbalanced antenna>

[0136] In the above-described embodiments, a balanced antenna is used as an example. The present technology is not limited to the application to a balanced antenna, but can also be applied to an unbalanced antenna. The present technology applied to an unbalanced antenna will be described below.

[0137] Fig.19 The antenna 401 shown in FIG. 4 is an antenna that realizes circularly polarized waves by supplying power to an orthogonal linear polarization radiation element 411 - 1 and an orthogonal linear polarization radiation element 411 - 2 with a phase difference of 90 degrees. Fig.19 The radiating element 411-1 and the radiating element 411-2 shown in the figure are each a linearly polarized microstrip antenna (sometimes referred to as a patch antenna). The microstrip antenna is a planar antenna including a dielectric substrate, a radiating element (antenna element) formed using printed wiring, and a ground plane, and the radiating element and the ground plane are formed on both surfaces of the dielectric substrate.

[0138] The antenna 401 is connected to the phase shifter 421. The phase shifter 421 includes an inductor 423 and a capacitor 425. The inductor 423 is connected to the radiation element 411-1, and the capacitor 425 is connected to the radiation element 411-2. The inductor 423 and the capacitor 425 are short-circuited on the opposite side of the antenna 401 side. The rear surface (the surface opposite to the surface where the radiation element 411 is provided) of the dielectric substrate constituting the antenna 401 is completely grounded.

[0139] In the unbalanced antenna, the equation for obtaining capacitance C corresponding to the previously described equation (5) is the following equation (7), and the equation for obtaining inductance L corresponding to the previously described equation (6) is the following equation (8).

[0140] [Mathematical expression 5]

[0141]

[0142] [Mathematical expression 6]

[0143]

[0144] The capacitor 425 constituting the phase shifter 421 is the capacitance C calculated by equation (7), and the inductor 423 is the inductance L calculated by equation (8).

[0145] Fig. 20 is a diagram showing another shape of the antenna. Fig. 20 The antenna 401 shown in FIG. 4 is a circularly polarized microstrip antenna. The radiating element of the microstrip antenna can be circularly polarized by slotting or other methods, so that the antenna can be used as the circularly polarized antenna 401 described above.

[0146] The signal supplied to the radiation element 413 via the inductor 423 of the phase shifter 421 is a signal whose phase is shifted by 90 degrees from the signal supplied to the radiation element 413 via the capacitor 425 .

[0147] Fig.21 is a diagram showing another shape of the antenna. Fig.21 The antenna 401 shown in FIG. 4 is an antenna to which a monopole antenna is applied. The antenna 401 includes an L-shaped metal sheet 431. The metal sheet 431 has two orthogonal surfaces. A hole 433-1 is formed on one surface (metal sheet 431-1), and a hole 433-2 is formed on the other surface (metal sheet 431-2).

[0148] The wire passes through hole 433-1, one side of the wire is connected to inductor 423 of phase shifter 421, and the other side is connected to antenna element 435-1. Antenna element 435-1 and metal sheet 431-1 form a monopole antenna. The wire passes through hole 433-2, one side of the wire is connected to capacitor 425 of phase shifter 421, and the other side is connected to antenna element 435-2. Antenna element 435-2 and metal sheet 431-2 form a monopole antenna.

[0149] Antenna 401 is configured so that two sets of monopole antennas are arranged in an orthogonal positional relationship. The two sets of monopole antennas are arranged to be orthogonal to each other, and when a signal whose phase is shifted by 90 degrees is provided, antenna 401 functions as a circularly polarized antenna.

[0150] exist Figures 19 to 21 The phase shifter 421 shown in FIG. Fig.12 The inductor 423 and the capacitor 425 are configured in the same manner as described, so that one or both of the inductor 423 and the capacitor 425 are variable and adjustment according to environmental changes can be achieved.

[0151] You can also use the Balun 141 ( Fig. 9 ) or Balun 151( Fig.10 )Connect to Figures 19 to 21 In addition, the balun 151 (141) and the matching circuit 161 may be connected to Figures 19 to 21 The phase shifter 421 shown in FIG.

[0152] As reference Figures 13 to 15 As described, Figures 19 to 21The phase shifter 421 shown in FIG. 2 may also be provided with a resistor 201 equivalent to an equivalent series resistor, a plurality of inductors 423 connected in parallel or in series, or an adjustment unit 221 .

[0153] The circularly polarized antenna may have a configuration other than that illustrated here.

[0154] In this specification, a system refers to an entire device including a plurality of devices.

[0155] It should be noted that the effects described in this specification are merely examples and not limitations, and other effects may be provided.

[0156] It should be noted that the embodiments of the present technology are not limited to the embodiments described above, and various changes can be made without departing from the gist of the present technology.

[0157] It should be noted that the present technology may also have the following configurations.

[0158] (1) A communication device comprising:

[0159] A circularly polarized antenna comprising a first antenna element, and a second antenna element arranged orthogonally to the first antenna element; and

[0160] a phase shifter including a capacitor connected to the first antenna element, and an inductor connected to the second antenna element,

[0161] Wherein, where resistance is denoted by R, imaginary unit is denoted by j, reactance is denoted by X, the center frequency of the antenna is denoted by f, capacitance is denoted by C, and inductance is denoted by L,

[0162] The impedance of the antenna is represented by R+jX,

[0163] The capacitance of the capacitor is a value calculated by C = 1 / {πf(R+X)}, and

[0164] The inductance of the inductor is a value calculated by L=(RX) / (4πf).

[0165] (2) The communication device according to (1),

[0166] Wherein, the antenna is a balanced antenna.

[0167] (3) The communication device according to (1) or (2),

[0168] Therein, the capacitor and the inductor are short-circuited.

[0169] (4) The communication device according to any one of (1) to (3),

[0170] wherein the first antenna element and the second antenna element are each a dipole antenna,

[0171] The two radiating elements included in the first antenna element are each connected to a capacitor, and

[0172] Two radiating elements included in the second antenna element are each connected to an inductor.

[0173] (5) The communication device according to any one of (1) to (4), further comprising

[0174] Connect to the balun of the phase shifter.

[0175] (6) The communication device according to (5), further comprising

[0176] Connect to the matching circuit of the balun.

[0177] (7) The communication device according to any one of (1) to (6),

[0178] Wherein, at least one of the capacitor or the inductor is variable.

[0179] (8) The communication device according to any one of (1) to (7),

[0180] Here, a resistor having a resistance value equivalent to the equivalent series resistance of the inductor is connected to the capacitor.

[0181] (9) The communication device according to any one of (1) to (8),

[0182] The inductor includes a plurality of inductors connected in parallel or in series.

[0183] (10) The communication device according to any one of (1) to (9), further comprising

[0184] Power generation unit,

[0185] wherein the antenna is a propeller antenna, and

[0186] The power generation unit generates electricity through the rotation of the propeller antenna.

[0187] (11) A communication device comprising:

[0188] a circularly polarized antenna comprising a first antenna element and a second antenna element of orthogonal linear polarizations; and

[0189] a phase shifter including a capacitor connected to the first antenna element, and an inductor connected to the second antenna element,

[0190] Wherein, where resistance is denoted by R, imaginary unit is denoted by j, reactance is denoted by X, the center frequency of the antenna is denoted by f, capacitance is denoted by C, and inductance is denoted by L,

[0191] The impedance of the antenna is represented by R+jX,

[0192] The capacitance of the capacitor is a value calculated by C = 1 / {2πf(R+X)}, and

[0193] The inductance of the inductor is a value calculated by L=(R x ) / (2πf).

[0194] (12) The communication device according to (11),

[0195] Wherein, the antenna is an unbalanced antenna.

[0196] (13) The communication device according to (11) or (12),

[0197] The first antenna element and the second antenna element are respectively microstrip antennas.

[0198] (14) The communication device according to (11) or (12),

[0199] The first antenna element and the second antenna element are each a monopole antenna.

[0200] (15) The communication device according to any one of (11) to (14),

[0201] Therein, the capacitor and the inductor are short-circuited.

[0202] (16) The communication device according to any one of (11) to (15),

[0203] Wherein, at least one of the capacitor or the inductor is variable.

[0204] Reference numerals list

[0205] 1. Communication system

[0206] 11——Main Station

[0207] 12. Communication Station

[0208] 13 - Communication Station

[0209] 14 - Satellite

[0210] 21 - Slave

[0211] 31 - Slave

[0212] 32 - Repeater

[0213] 101——Signal Processing Unit

[0214] 102——High frequency processing unit

[0215] 103——Antenna

[0216] 111——Phase Shifter

[0217] 121——Capacitor

[0218] 122——Inductor

[0219] 141——Barron

[0220] 151——Barron

[0221] 161——Matching Circuit

[0222] 201——Resistors

[0223] 221——Regulation unit

[0224] 301 - Antenna

[0225] 311 - Movable contact parts

[0226] 312——Transmit / Receive Circuit

[0227] 313——Power generation unit

[0228] 351——Electrode

[0229] 353——Connect

[0230] 355——Sheath part

[0231] 401 - Antenna

[0232] 411——Radiating element

[0233] 413——Radiating element

[0234] 421——Phase Shifter

[0235] 423——Inductor

[0236] 425——Capacitor

[0237] 431 - Metal Sheet

[0238] 433 - Holes

[0239] 435——Antenna element

Claims

1. A communication device, comprising: A circularly polarized antenna, comprising a first antenna element and a second antenna element arranged orthogonally to the first antenna element; as well as a phase shifter comprising a capacitor connected to the first antenna element and an inductor connected to the second antenna element, Wherein, where resistance is denoted by R, imaginary unit is denoted by j, reactance is denoted by X, the center frequency of the antenna is denoted by f, capacitance is denoted by C, and inductance is denoted by L, The impedance of the antenna is represented by R+jX, The capacitance of the capacitor is a value calculated by C = 1 / {πf(R+X)}, and The inductance of the inductor is a value calculated by L=(RX) / (4πf). The communication device according to claim 1 , wherein the antenna is a balanced antenna. The communication device according to claim 1 , wherein the capacitor and the inductor are short-circuited.

4. The communication device according to claim 1, in, The first antenna element and the second antenna element are each a dipole antenna, The two radiating elements included in the first antenna element are each connected to a capacitor, and Two radiating elements included in the second antenna element are each connected to an inductor.

5. The communication device according to claim 1, further comprising Connect to the balun of the phase shifter.

6. The communication device according to claim 5, further comprising Connect to the matching circuit of the balun.

7. The communication device according to claim 1, in, At least one of the capacitor or the inductor is variable.

8. The communication device according to claim 1, in, A resistor having a resistance value comparable to the equivalent series resistance of the inductor is connected to the capacitor.

9. The communication device according to claim 1, in, The inductor includes a plurality of inductors connected in parallel or in series.

10. The communication device according to claim 1, further comprising a power generation unit, in, The antenna is a propeller antenna, and The power generation unit generates electricity through the rotation of the propeller antenna.

11. A communication device, comprising: A circularly polarized antenna comprising a first antenna element and a second antenna element of orthogonal linear polarization; as well as a phase shifter comprising a capacitor connected to the first antenna element and an inductor connected to the second antenna element, Wherein, where resistance is denoted by R, imaginary unit is denoted by j, reactance is denoted by X, the center frequency of the antenna is denoted by f, capacitance is denoted by C, and inductance is denoted by L, The impedance of the antenna is represented by R+jX, The capacitance of the capacitor is a value calculated by C = 1 / {2πf(R+X)}, and The inductance of the inductor is a value calculated by L=(R x ) / (2πf).

12. The communication device of claim 11, wherein the antenna is an unbalanced antenna.

13. The communication device of claim 11, wherein the first antenna element and the second antenna element are each microstrip antennas.

14. The communication device of claim 11, wherein the first antenna element and the second antenna element are each monopole antennas.

15. The communication device of claim 11, wherein the capacitor and the inductor are short-circuited.

16. The communication device of claim 11, wherein at least one of the capacitor or the inductor is variable.

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