JP4987893B2 - High frequency coupler and contactless transmission communication system using the same - Google Patents

Description

  The present invention relates to a high-frequency coupler used in a non-contact transmission communication system that performs non-contact data transmission by short-range wireless communication using an induced electric field, and a non-contact transmission communication system using the same.

Recently, short-distance wireless communication using an electrostatic field or induction field that does not require a cable or a memory card to be exchanged when exchanging data such as large-capacity images and music in small information equipment terminals. Communication has been invented and devised.
If an electrostatic field or an induction field generated only between couplers capable of communicating with weak radio waves is used, it is easy to realize a contactless transmission communication system using weak radio that does not require a radio station license.

JP2008-154198A

  A high frequency coupler is used between the transmitter and the receiver of the non-contact transmission communication system using the electrostatic field or the induction field. As a high-frequency coupler, a capacitive coupling method using a capacitor charge is known. Patent Document 1.

FIG. 9 is a perspective view showing a capacitively coupled high-frequency coupler in a contactless transmission communication system that performs wireless communication using an electrostatic field or an induced electric field.
The capacitively coupled high-frequency coupler 60 has a solid ground 12 formed on the lower surface, and a coupling electrode 20 disposed on the substrate 10 on the upper surface of which a stub 11 having a conductor pattern for impedance matching and resonance is formed. Yes.
A central portion of the coupling electrode 20 is connected to a substantially central portion of the stub 11 through a metal wire 21.
One end of the stub 11 is connected to a transmission / reception circuit module (not shown), and the other end is connected to a solid ground 12 on the lower surface through a through hole 13 penetrating the substrate 10.
The length L1 of the stub 11 is about a half wavelength of the high frequency signal.

  The high-frequency coupler using the capacitive coupling method using the electrostatic field or the induction electric field has the length L1 of the stub 11, the length of the metal wire 21, and the size of the coupling electrode 20 depending on the wavelength of the high-frequency signal used. Determined. Although there is a method of bending the stub 11 and arranging it on the substrate 10 to reduce the size of the high-frequency coupler, further downsizing is required.

An object of the present invention is to further reduce the size of a contactless transmission communication system by reducing the size and height of a high-frequency coupler.

The high frequency coupler of the present invention transmits data in a non-contact manner by an induction electric field method,
A plurality of linear conductor patterns are formed on the upper and lower surfaces of the first dielectric,
A toroidal printed coil in which the upper and lower conductor patterns are electrically connected by a through hole in which the end portion of each conductor pattern penetrates the first dielectric is used as a coupling element .
Below the first dielectric, a second dielectric having a conductor layer formed on the lower surface is stacked, and a conductor for adjusting the center frequency is formed on the outer periphery of the printed coil on the upper surface of the first dielectric. Is provided .

  According to the high frequency coupler of the present invention, a stub is not required, manufacturing variations and center frequency variations due to mounting conditions can be reduced, and a small and low-profile high frequency coupler can be obtained. In addition, if the high-frequency coupler of the present invention is used, a contactless transmission communication system that uses an induced electric field by a high-frequency signal can be reduced in size.

1 shows an induction electric field type high frequency coupler according to an embodiment of the present invention. It is a perspective view which shows the mounting state of the high frequency coupler of FIG. It is a block diagram of the non-contact transmission communication system using the high frequency coupler of the present invention. It is a frequency characteristic of the high frequency coupler of the present invention. It is a directivity characteristic of the high frequency coupler of the present invention. It is a change of the frequency by the distance between the dielectric of the high frequency coupler of the present invention and the substrate. It is an equivalent circuit diagram in a state where the high frequency coupler of the present invention is coupled. It is a perspective view which shows the other Example of the high frequency coupler of this invention. This is a high-frequency coupler using a conventional capacitive coupling method.

FIG. 1 is a perspective view of a high-frequency coupler using an inductive coupling system according to an embodiment of the present invention.
The high frequency coupler 50 includes a first dielectric 40, a second dielectric 30, and a spiral printed coil 41 provided on the first dielectric 40.
A plurality of linear conductor patterns are formed on the upper and lower surfaces of the first dielectric 40, and the end portions of the respective conductor patterns are electrically connected to the upper and lower conductor patterns by through holes 43 penetrating the first dielectric 40. Toroidal printed coil 41 having a circular winding axis. Non-contact transmission communication by an induced electric field is performed in a magnetic current loop generated in the printed coil 41.
The first dielectric 40 is stacked on the second dielectric 30, and both ends of the printed coil 41 are led to the lower surface of the second dielectric 30 through the through holes 51 and 52.
On the lower surface of the second dielectric 30, a conductor layer 31 is formed on the outer edge excluding the through holes 51 and 52.

FIG. 2 is a perspective view in which the high frequency coupler 50 of FIG. 1 is mounted on the substrate 10 on which the transmission / reception circuit module 5 is mounted.
The high frequency coupler 50 is disposed on the upper surface of the substrate 10, one through hole 51 of the high frequency coupler is connected to the transmission / reception circuit module 5, and the other through hole 52 is formed by the through hole 14 provided in the substrate 10. It is connected to a solid ground 12 on the bottom surface of the substrate 10.

The high-frequency coupler 50 has a side length of 5.5 mm and a thickness of 1.5 mm, and is manufactured using a two-layer FR4 substrate.
In the figure, the surface of the substrate 10 is the XY plane, the terminal direction of the terminal of the printed coil 41 of the high frequency coupler 50 is the X axis direction, the direction orthogonal to the X axis is the Y axis direction, and the thickness direction of the substrate 10 is the Z axis. And

  FIG. 3 is a block diagram of a contactless transmission communication system using the high frequency coupler of the present invention. The non-contact transmission communication system shown in the figure includes a transmitter 1 that performs data transmission and a receiver 2 that performs data reception. The transmitter 1 includes a transmission unit 3 and a high frequency coupler 50 using an inductive coupling method, and the receiver 2 includes a high frequency coupler 50 using an inductive coupling method and a receiving unit 4. As shown in the figure, by arranging the high-frequency couplers 50 of the transmitter and the receiver to face each other at a short distance, the two high-frequency couplers are inductively coupled to enable non-contact transmission communication. Become.

FIG. 4 shows frequency characteristics when the distance L2 between the high-frequency couplers 50 and 50 shown in FIG. 2 is 15 mm. In the figure, the horizontal axis represents frequency and the vertical axis represents propagation loss.
FIG. 5 is a graph showing radiation directivity characteristics on the XZ plane when the frequency of the high-frequency coupler shown in FIG. 2 is 4.5 GHz. In the figure, V indicates vertical polarization, and H indicates horizontal polarization.
From the figure, it can be seen that longitudinal waves are generated in the upper surface and lower surface directions of the high-frequency coupler 50.

The center frequency of the high-frequency coupler changes due to the floating from the substrate in the mounted state of the substrate.
FIG. 6 is a graph showing changes in the center frequency due to the floating of the high frequency coupler 50 and the substrate 10 in the high frequency coupler shown in FIG. In the figure, the horizontal axis represents the gap Gp between the high-frequency coupler 50 and the substrate 10, the vertical axis represents the frequency, X represents the case where the conductor layer 31 is present, and Y represents the case where the conductor layer 31 is absent.
From the figure, it can be seen that when the conductor layer 31 is provided on the lower surface of the high frequency coupler 50, the change in frequency due to the floating of the high frequency coupler 50 and the substrate 10 is reduced.

As described above, the inductive coupling type high frequency coupler used in the contactless transmission communication system of the present invention does not require a stub.
Further, since the printed coil of the conductor pattern is formed by the printed circuit board method, a high-frequency coupler having a low profile, high dimensional accuracy, and little manufacturing variation can be obtained. Furthermore, by providing a conductor layer on the bottom surface of the high-frequency coupler, the change in the center frequency can be reduced even if the floating level during mounting varies.

FIG. 7 shows an equivalent circuit in a state where the transmitter and the receiver of the contactless transmission communication system using the high frequency coupler of the present invention are coupled.
In the figure, the transmitter 1 shows an equivalent circuit of the high-frequency coupler 50 based on the inductive coupling method and the impedance R1A of the transmitter 3. The receiver 2 shows an equivalent circuit of the high-frequency coupler 50 using the inductive coupling method and the impedance R1B of the receiver 2. The equivalent circuit of the high frequency coupler 50 is represented by inductances L5A and L5B and capacitors C4A and C4B connected in parallel to the transmitter 1 or the receiver 2, and the equivalent circuit between the high frequency couplers is connected in parallel. It is represented by the inductance Lo and the capacitance Co.

FIG. 8 is a perspective view showing another embodiment of the inductive coupling type high frequency coupler used in the present invention.
In the above-described embodiment, the high-frequency coupler 50 </ b> B has a conductor pattern forming the printed coil 41 on the upper surface of the first dielectric 40 and a conductor portion 48 extending from the outside to the end of the conductor pattern. The conductor 48 is connected to the conductor pattern of the printed coil 41 at a predetermined position 43.

  By making the high-frequency coupler have such a structure, the capacitance C4A and the capacitance Co in the equivalent circuit of FIG. 7 can be adjusted by changing the area of the conductor portion 48. The center frequency can be changed without changing the pattern of the printed coil 41. The conductor 48 is trimmed to change the area.

  When the connection position 43 between the conductor 48 and the printed coil 41 is close to the through hole 51, the adjustment ratio of the capacitor C4A in FIG. 7 increases, and when the connection position 43 is close to the through hole 52, the adjustment ratio of the capacity Co increases. Become.

  The first dielectric 40 and the second dielectric 30 are not limited to dielectrics, and magnetic materials may be used. When a magnetic material is used for the second dielectric 30, the printed coil 41 can be reduced in size, and the high-frequency coupler can be further reduced in size.

DESCRIPTION OF SYMBOLS 1 Transmitter 2 Receiver 3 Transmitter 4 Receiver 5 Transmitting / receiving circuit module 10 Substrate 11 Stub 12 Solid ground 13, 14, 43, 51, 52 Through hole 16 Stub length 20 Bonding electrode 21 Metal wires 30, 40 Dielectric 31 Conductor Layer 48 Conductor 41 Printed Coil 50, 50B, 60 High Frequency Coupler

Claims (3)

In a high-frequency coupler using an induction electric field system that transmits data without contact,
A plurality of linear conductor patterns are formed on the upper and lower surfaces of the first dielectric,
A toroidal printed coil in which the upper and lower conductor patterns are electrically connected by a through hole in which the end portion of each conductor pattern penetrates the first dielectric is used as a coupling element .
Below the first dielectric, a second dielectric having a conductor layer formed on the lower surface is stacked,
A high-frequency coupler comprising a conductor portion for adjusting a center frequency provided on an outer periphery of a printed coil on an upper surface of the first dielectric . 2. The high frequency coupler according to claim 1, wherein the conductor layer formed on the lower surface of the second dielectric is attached to the substrate so as to contact the substrate of the transmitter or the substrate of the receiver. A transmission circuit for generating a high-frequency signal for transmitting data;
A transmitter including a high-frequency coupler for transmitting the high-frequency signal as an induction electric field;
A high frequency coupler on the receiving side facing the high frequency coupler on the transmitting side; and
It consists of a receiver with a circuit that receives and processes high-frequency signals received by a high-frequency coupler,
The high frequency coupler on the transmission side and the high frequency coupler on the reception side are:
A plurality of linear conductor patterns are formed on the upper and lower surfaces of the first dielectric,
A toroidal printed coil in which the end portions of the respective conductor patterns are electrically connected to the upper and lower conductor patterns by through holes penetrating the first dielectric to form a magnetic current loop is used as a coupling element,
Below the first dielectric, a second dielectric having a conductor layer formed on the lower surface is stacked,
A conductor for adjusting the center frequency is provided on the outer periphery of the printed coil on the upper surface of the first dielectric,
A non-contact transmission communication system, wherein data is transmitted in a non-contact manner by inductive coupling between opposing high-frequency couplers of the transmitter and the receiver.

Images