Signal transmission device, filter, and inter-substrate communication device

A signal transmission device includes substrates and resonance sections resonating at the predetermined resonance frequency. At least one of the substrates is formed with two or more resonators in the second direction, and the remaining one or two or more of the substrates are each formed with one or more resonators in the second direction, and at least one of the resonance sections is configured by a plurality of resonators opposing one another in the first direction between the substrates, the opposing resonators form a coupled resonator resonating as a whole at the predetermined resonance frequency through electromagnetic coupling in a hybrid resonance mode, and in a state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis.

BACKGROUND

The present disclosure relates to a signal transmission device, a filter, and an inter-substrate communication device that perform transmission of signals (electromagnetic waves) using a plurality of substrates each formed with a resonator.

A previously known transmission device performs transmission of signals (electromagnetic waves) through electromagnetic coupling of a plurality of resonators. As an example, “Wireless Power Transfer via Strongly Coupled Magnetic Resonances”, (Science vol. 317, pp. 83-86, 2007-6) describes a method of implementing a wireless power transmission system through electromagnetic coupling of coils utilizing a phenomenon of resonance. The coils for electromagnetic coupling include one at the power transmission end and another at the power reception end, which are both in the form of spiral and are positioned in the air. In such a power transmission system, the power-transmission coil and the power-reception coil are each provided with a loop conductor for excitation use. The loop conductor at the power transmission end is connected with a high-frequency power supply circuit for supply of power, and the loop conductor at the power reception end is connected with a device that becomes a load.

SUMMARY

In the wireless power transmission system described above, the coils, i.e., the power-transmission coil and the power-reception coil, and their loop conductors for excitation use share the same resonance frequency f0for resonance. Basically, these power-transmission and reception coils operate as a two-stage BPF (Band-Pass Filter) whose passband is the resonance frequency f0. In such a power transmission system, as for the power-transmission and power-reception coils, their individual band of resonance frequency when there is no electromagnetic coupling therebetween is included in the band of the resonance frequency f0when the coils are in electromagnetic coupling. Therefore, even if the power-transmission and power-reception coils are not in electromagnetic coupling, power radiation comes from the power-transmission coil. When transmission of signals is to be performed with the principles similar to those of the power transmission system as above, there arises a disadvantage of leakage of signals (electromagnetic waves).

It is desirable to provide a signal transmission device, a filter, and an inter-substrate communication device that are capable of preventing any leakage of signals (electromagnetic waves).

A signal transmission device according to a first embodiment of the present disclosure includes a plurality of substrates, and a plurality of resonance sections. The resonance sections are in a parallel arrangement along a second direction different from a first direction along which the substrates are opposing one another. Any of the resonance sections adjacent to each other perform signal transmission in a predetermined passband including a predetermined resonance frequency through electromagnetic coupling therebetween by each resonating at the predetermined resonance frequency. At least one of the substrates is formed with two or more resonators in the second direction, and the remaining one or two or more of the substrates are each formed with one or more resonators in the second direction.

At least one of the resonance sections is configured by a plurality of resonators opposing one another in the first direction between the substrates, the opposing resonators form a coupled resonator resonating as a whole at the predetermined resonance frequency through electromagnetic coupling in a hybrid resonance mode, and in a state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis.

A filter according to an embodiment of the present disclosure is in the configuration similar to that of the above-described signal transmission device in the first embodiment of the present disclosure, and is operated as a filter.

An inter-substrate communication device according to an embodiment of the present disclosure is, in the configuration of the above-described signal transmission device according to the first embodiment of the present disclosure, further provided with first and second input/output terminals. The first input/output terminal is connected directly physically at least to a first resonator in at least one of the substrates, or is electromagnetically coupled to the first resonator with a spacing therefrom. The second input/output terminal is connected directly physically to another resonator in at least any one of the substrates other than the substrate formed with the first resonator, or is electromagnetically coupled to the other resonator with a spacing therefrom. In the state that the substrates are opposing one another in the first direction, signal transmission is performed between the substrates.

In the signal transmission device, the filter, or the inter-substrate communication device according to the first embodiment of the present disclosure, in the state that a plurality of substrates are opposing one another in the first direction, a plurality of resonance sections are disposed in parallel to one another in a direction different from the first direction, i.e., second direction. Any of the resonance sections adjacent to each other perform signal transmission therebetween in a predetermined passband including a predetermined resonance frequency through electromagnetic coupling therebetween by each resonating at the predetermined resonance frequency. In at least one of the resonance sections, a plurality of resonators form a piece of coupled resonator through electromagnetic coupling thereamong in a hybrid resonance mode. The resulting coupled resonator resonates as a whole at the predetermined resonance frequency. In the state that a plurality of substrates are separated away from each other to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis.

That is, the frequency response in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong is different from the frequency response in the state that the substrates are electromagnetically coupled to one another. Accordingly, in the state that a plurality of substrates are electromagnetically coupled to one another, signal transmission is performed in a predetermined passband including a predetermined resonance frequency. On the other hand, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, signal transmission is not performed in the predetermined passband.

In the signal transmission device or the filter according to the first embodiment of the present disclosure, alternatively, first and second input/output terminals may be further provided, and in the state that a plurality of substrates are opposing one another in the first direction, signal transmission may be performed between the substrates or in each of the substrates. Herein, the first input/output terminal is connected directly physically at least to a first resonator configuring a first resonance section among a plurality of resonance sections, or is electromagnetically coupled to the first resonator with a spacing therefrom. The second input/output terminal is connected directly physically at least to another resonator configuring any of the resonance sections other than the first resonance section, or is electromagnetically coupled to the other resonator with a spacing therefrom.

Further, in the signal transmission device, the filter, or the inter-substrate communication device according to the first embodiment of the present disclosure, still alternatively, the first input/output terminal may be connected with a filter member that allows passage of signals of a predetermined passband, and interrupts passage of signals of any other resonance frequency out of a range of the predetermined passband.

Still further, in the signal transmission device, the filter, or the inter-substrate communication device according to the first embodiment of the present disclosure, still alternatively, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming a coupled resonator may all resonate at the other resonance frequency on the substrate basis.

Still alternatively, in any of the substrates formed with two or more resonators in the second direction, the resonators adjacent to each other may resonate at each different resonance frequency when no electromagnetic coupling is established.

Still further, in the signal transmission device, the filter, or the inter-substrate communication device according to the first embodiment of the present disclosure, still alternatively, among the resonance sections, the first and second resonance sections may form a coupled resonator, and the resonators configuring the first resonance section and the other resonators configuring the second resonance section may be formed in the two or more substrates in a same combination.

Still alternatively, among the resonance sections, the first and second resonance sections may form a coupled resonator, and the first and second resonance sections may be adjacent to each other in the second direction. The resonators configuring the first resonance section and the other resonators configuring the second resonance section may be formed in the substrates in a partially different combination.

A signal transmission device according to a second embodiment of the present disclosure includes a plurality of substrates, a resonator formed to each of the substrates, a coupled resonator, and a filter member. The coupled resonator is formed, in the state that the substrates are opposing one another in a first direction, by electromagnetic coupling among the opposing resonators in a hybrid resonance mode, and the coupled resonator resonates as a whole at a predetermined resonance frequency. The filter member is provided to the resonator formed to at least one of the substrates, and the filter member allows passage of signals of a predetermined passband including the predetermined resonance frequency between the coupled resonator. In the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis, and the filter member interrupts passage of signals of the other resonance frequency out of a range of the predetermined passband.

In the signal transmission device according to the second embodiment of the present disclosure as such, in the state that a plurality of substrates are opposing one another in the first direction, a plurality of resonators form a coupled resonator resonating as a whole at a predetermined resonance frequency by electromagnetic coupling thereamong in a hybrid resonance mode. In the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis. That is, the frequency response in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong is different from the frequency response in the state that the substrates are electromagnetically coupled to one another. Accordingly, in the state that a plurality of substrates are electromagnetically coupled to one another, signal transmission is performed in a predetermined passband including a predetermined resonance frequency. On the other hand, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, signal transmission is not performed in the predetermined passband.

Moreover, irrespective of whether a plurality of substrates are opposing one another or not, in at least one of the substrates, the filter member interrupts passage of signals of any other resonance frequency out of a range of a predetermined passband. Accordingly, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, no signal transmission is performed not only in the predetermined passband but also with the other resonance frequency out of a range of the predetermined passband.

Note that, in the signal transmission device, the filter, or the inter-substrate communication device according to the first or second embodiment of the present disclosure, the expression of “signal transmission” includes not only signal transmission such as transmission/reception of analog and digital signals but also power transmission such as transmission/reception of power.

In the signal transmission device, the filter, or the inter-substrate communication device according to the first or second embodiment of the present disclosure, a piece of coupled resonator resonating as a whole at a predetermined resonance frequency is formed by electromagnetic coupling among a plurality of resonators in a hybrid resonance mode. In the state that a plurality of substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis. Accordingly, the frequency response in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong becomes different from the frequency response in the state that the substrates are electromagnetically coupled to one another. As such, in the state that a plurality of substrates are electromagnetically coupled to one another, signal transmission is performed in a predetermined passband including a predetermined resonance frequency. On the other hand, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, signal transmission is not performed in the predetermined passband. Therefore, in the state that the substrates are separated away from each other, any leakage of signals (electromagnetic waves) from the resonators formed to the substrates is to be prevented.

Especially, in the signal transmission device according to the second embodiment of the present disclosure, in at least one of the substrates, the filter member is so configured as to interrupt passage of signals of any other resonance frequency out of a range of a predetermined passband. Accordingly, in the state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, no signal transmission is performed not only in the predetermined passband but also with the other resonance frequency out of a range of the predetermined passband. This favorably prevents any leakage of signals (electromagnetic waves) with more effect.

DETAILED DESCRIPTION

In the below, embodiments of the present disclosure are described in detail by referring to the accompanying drawings.

First Embodiment

Exemplary Entire Configuration of Signal Transmission Device

FIG. 1is a diagram showing an exemplary entire configuration of a signal transmission device (an inter-substrate communication device or a filter) in a first embodiment of the present disclosure. The signal transmission device in this embodiment is configured to include a first substrate10and a second substrate20, which are disposed to oppose each other in a first direction, i.e., Z direction in the drawing. This signal transmission device is also provided with a first input/output terminal51and a second input/output terminal52. The first and second substrates10and20are each a dielectric substrate, and are disposed to oppose each other with a layer sandwiched therebetween with a spacing, i.e., inter-substrate distance Da. This layer is made of a material different from the material of the substrates (layer different in permittivity therefrom, e.g., air layer).

The first substrate10is formed with first and second resonators11and12in parallel to each other in a second direction, i.e., Y direction in the drawing. The second substrate20is formed with first and second resonators21and22in parallel to each other also in the second direction. The first and second resonators11and12in the first substrate10are of various types as shown inFIGS. 7 to 16that will be described later. For example, the resonators may be of a line resonator with a line electrode pattern, e.g., λ/4 resonator (¼ wavelength resonator), λ/2 resonator (½ wavelength resonator), 3λ/4 resonator (¾ wavelength resonator), or λ resonator (1 wavelength resonator). This is applicable also to the first and second resonators21and22in the second substrate20. Note thatFIG. 1shows an exemplary case in which the resonators11,12,21, and22are formed inside of the respective substrates. Alternatively, the resonators11,12,21, and22may be formed like strip lines on the surface (or on the underside) of the respective substrates10and20.

In this signal transmission device, in the state that the first and second substrates10and20are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the first resonator11in the first substrate10and the first resonator21in the second substrate20, thereby forming a first resonance section1. Also in the state that the first and second substrates10and20are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the second resonator12in the first substrate10and the second resonator22in the second substrate20, thereby forming a second resonance section2. As such, in the state that the first and second substrates10and20are opposing each other in the first direction, the first and second resonance sections1and2are disposed in parallel to each other in the second direction.

The first and second resonance sections1and2are each so configured as to be in electromagnetic coupling by each resonating at a predetermined resonance frequency, i.e., first or second resonance frequency f1or f2in a hybrid resonance mode that will be described later. Between the first and second resonance sections1and2, signal transmission is to be performed in a predetermined passband including the predetermined resonance frequency. On the other hand, in the state that the first and second substrates10and20are separated away from each other so as not to or fail to establish electromagnetic coupling therebetween, the resonators11,12,22, and21respectively forming the first and second resonance sections1and2are supposed to resonate not at the predetermined resonance frequency but at any other resonance frequency, i.e., resonance frequency f0.

Between the first resonator11in the first substrate10and the first resonator21in the second substrate20, electromagnetic coupling (magnetic-field coupling) is preferably established mainly by magnetic-field components via an air layer, for example. Similarly, between the second resonator12in the first substrate10and the second resonator22in the second substrate20, electromagnetic coupling (magnetic-field coupling) is preferably established mainly by magnetic-field components. The electromagnetic coupling established mainly by the electromagnetic components as such almost prevents any electric-field distribution in the air layer or others between the first and second substrates10and20. Accordingly, even if there is any change of the inter-substrate distance Da such as air layer or others between the first and second substrates10and20, the first and second resonance sections1and2are prevented from varying in resonance frequency. As a result, this prevents any variation of passing frequency and the passband to be caused by the change of the inter-substrate distance Da.

The first input/output terminal51is connected directly physically to the first resonator11in the first substrate10, i.e., electrical continuity is directly established therebetween. With this configuration, signal transmission is expected to be performed between the first input/output terminal51and the first resonance section1. The second input/output terminal52is connected directly physically to the second resonator22in the second substrate20, i.e., electrical continuity is directly established therebetween. With this configuration, signal transmission is expected to be performed between the second input/output terminal52and the second resonance section2. Because the first and second resonance sections1and2are electromagnetically coupled to each other, signal transmission is expected to be performed between the first and second input/output terminals51and52. As such, in the state that the first and second substrates10and20are opposing each other in the first direction, signal transmission is expected to be performed between the two substrates, i.e., the first and second substrates10and20.

With such a signal transmission device, in the first resonance section1, the first resonator11in the first substrate10and the first resonator21in the second substrate20both configure a piece of coupled resonator through electromagnetic coupling therebetween in the hybrid resonance mode that will be described later. The resulting coupled resonator resonates, as a whole, at the predetermined first resonance frequency f1(or the second resonance frequency f2). In the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, the first resonator11in the first substrate10and the first resonator21in the second substrate20both do not resonate at the predetermined first resonance frequency f1(or the second resonance frequency f2) but at any other resonance frequency, i.e., resonance frequency f0.

Similarly, in the second resonance section2, the second resonator12in the first substrate10and the second resonator22in the second substrate20both configure a piece of coupled resonator through electromagnetic coupling therebetween in the hybrid resonance mode that will be described later. The resulting coupled resonator resonates, as a whole, at the predetermined first resonance frequency f1(or the second resonance frequency f2). In the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, the second resonator21in the first substrate10and the second resonator21in the second substrate20both do not resonate at the predetermined first resonance frequency f1(or the second resonance frequency f2) but at any other resonance frequency, i.e., resonance frequency f0.

As such, the frequency response in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween is different from the frequency response in the state that the first and second substrates10and20are electromagnetically coupled to each other. Accordingly, in the state that the first and second substrates10and20are electromagnetically coupled to each other, for example, signal transmission is performed in a predetermined passband including the first resonance frequency f1(or the second resonance frequency f2). On the other hand, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, signal transmission is not performed in the predetermined passband including the first resonance frequency f1(or the second resonance frequency f2) because the substrates10and20each resonate at the resonance frequency f0. As such, in the state that the first and second substrates10and20are separated away enough from each other, even if signals of a band same as that of the first resonance frequency f1(or of the second resonance frequency f2) are input, the signals are to be reflected, thereby being able to prevent any leakage of signals (electromagnetic waves) from the resonators11,12,21, and22.

(Principles of Signal Transmission in Hybrid Resonance Mode)

Described now are principles of signal transmission in the hybrid resonance mode described above. For the sake of brevity, as a resonator configuration in a comparative example, exemplified herein is a configuration in which a first substrate110is formed therein with a piece of resonator111as shown inFIG. 2. With the resonator configuration as such in the comparative example, as shown inFIG. 4A, the resonator is operated in a resonance mode of resonating at one resonance frequency f0. For a comparison, as shown inFIG. 3, exemplified is a case in which a second substrate120is disposed to oppose the first substrate110with the inter-substrate distance Da therebetween, and the first and second substrates110and120are electromagnetically coupled to each other. Herein, the second substrate120is configured similarly to the resonator configuration ofFIG. 2in the comparative example. The second substrate120is formed therein with a piece of resonator121. The resonator121in the second substrate120is configured similarly to the resonator111in the first substrate110. Therefore, when the second substrate120is not in electromagnetic coupling with the first substrate110, as shown inFIG. 4A, the resonator121is in a resonance mode of resonating only at a specific one resonance frequency f0. However, in the state ofFIG. 3, i.e., the two resonators111and121are electromagnetically coupled to each other, due to the hopping effect of radio waves, the resonators do not resonate at one resonance frequency f0like when no electromagnetic coupling is established but resonate in the hybrid resonance mode as shown inFIG. 4B. The hybrid resonance mode is a mixture of a first resonance mode of resonating at the first resonance frequency f1lower than the resonance frequency f0, and a second resonance mode of resonating at the second resonance frequency f2higher than the resonance frequency f0.

Assuming that the two resonators111and121to be in electromagnetic coupling in the hybrid resonance mode ofFIG. 3are a single piece of coupled resonator101, a parallel arrangement of the similar resonator configuration may configure a filter whose passband includes a band of the first resonance frequency f1(or of the second resonance frequency f2). Any input of signals of a frequency around the first resonance frequency f1(or the second resonance frequency f2) enables signal transmission. The signal transmission device in the embodiment ofFIG. 1has such a configuration.

Based on the principles as above, the resonance mode in the signal transmission device in the embodiment is described in more detail. The first and second resonance sections1and2ofFIG. 1are both in the configuration similar to that of the coupled resonator101ofFIG. 3. Therefore, when no electromagnetic coupling is established, these resonance sections1and2thus resonate at the first and second resonance frequencies f1and f2as shown inFIG. 4B. However, because the first and second resonance sections1and2are disposed in parallel to each other and are electromagnetically coupled to each other, the first and second resonance frequencies f1and f2each have two peaks as shown inFIG. 5. That is, on the frequency side lower than the resonance frequency f0, the peak of the resonance frequency is at a resonance frequency f11lower than the first resonance frequency f1, and at a resonance frequency f12higher than the first resonance frequency f1. On the frequency side higher than the resonance frequency f0, the peak of the resonance frequency is at a resonance frequency f21lower than the second resonance frequency f2, and at a resonance frequency f22higher than the second resonance frequency f2. In this case, on the frequency side lower than the resonance frequency f0, a predetermined passband of a specific bandwidth is formed in a range around the first resonance frequency f1, i.e., in a range from the resonance frequency f11to the resonance frequency f12. On the frequency side higher than the resonance frequency f0, a predetermined passband of a specific bandwidth is formed in a range around the second resonance frequency f2, i.e., in a range from the resonance frequency f21to the resonance frequency f22. The passband herein denotes the range showing the passing characteristics lower by 3 dB than the maximum value thereof. Such a definition of the passing characteristics is applicable also to any other exemplary configurations to be described later by referring toFIG. 17and others. In the signal transmission device in this embodiment and those in other exemplary configurations, the passband for signals defined as above does not include the resonance frequency f0.

As described above, the signal transmission device ofFIG. 1shows two different frequency responses depending on the states, i.e., in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, and in the state that the first and second substrates10and20are in electromagnetic coupling with each other via an air layer or others. As such, in the state that the first and second substrates10and20are in electromagnetic coupling with each other, for example, signal transmission is performed at the frequency of a predetermined passband including the first resonance frequency f1(or the second resonance frequency f2) as shown inFIGS. 5 and 6. On the other hand, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, signal transmission is not performed at the first resonance frequency f1(or the second resonance frequency f2) because resonance occurs not at the frequency for signal transmission but at the frequency of a different passband including the resonance frequency f0. As such, in the state that the first and second substrates10and20are separated away enough from each other, even if signals of a band same as that of the first resonance frequency f1(or of the second resonance frequency f2) are input, the signals are to be reflected, thereby being able to prevent any leakage of signals (electromagnetic waves) from the resonators11,12,21, and22.

(Specific Exemplary Configuration of Resonators)

Described next is a specific exemplary configuration of each of the resonators11,12,21, and22. These resonators11,12,21, and22may be configured like line resonators as shown inFIGS. 7 to 12.FIG. 7shows an exemplary configuration of a line-shaped λ/2 resonator201,FIG. 8shows an exemplary configuration of a line-shaped λ/4 resonator202,FIG. 9shows an exemplary configuration of a ring-shaped λ/2 resonator203, andFIG. 10shows an exemplary configuration of a ring-shaped λ/4 resonator204.FIG. 11shows an exemplary configuration of a spiral-shaped resonator205, andFIG. 12shows an exemplary configuration of a meander-shaped resonator206. Alternatively, the resonators11,12,21, and22may be each a combination of a discrete component(s) and a line resonator as shown inFIGS. 13 and 14.FIG. 13shows an exemplary LC resonator configured by the spiral-shaped resonator205connected at both end portions with a tip capacitor210.FIG. 14shows an exemplary LC resonator configured by the meander-shaped resonator206connected at both end portions with the tip capacitor210.

Still alternatively, the resonators11,12,21, and22may be lumped-constant resonators as shown inFIGS. 15 and 16.FIG. 15shows an exemplary configuration of lumped-constant resonators in electromagnetic coupling. In the exemplary configuration ofFIG. 15, the first resonator11in the first substrate10is a first LC resonator configured by a first capacitor211and a first coil212, and the first resonator21in the second substrate20is a second LC resonator configured by a second capacitor213and a second coil214. In this exemplary configuration, in the state that the first and second substrates10and20are opposing each other, the first and second coils212and214are in electromagnetic coupling so that the first resonators11and21are electromagnetically coupled to each other.

FIG. 16shows an exemplary configuration of lumped-constant resonators in electric-field coupling. In the exemplary configuration ofFIG. 16, the first resonator11in the first substrate10is a first LC resonator configured to include the first coil212, and first and second capacitor electrodes221and231. The first capacitor electrode221is connected at a first end portion of the first coil212, and the second capacitor electrode231is connected at a second end portion of the first coil212. The first resonator21in the second substrate20is a second LC resonator configured to include the second coil214, and third and fourth capacitor electrodes222and232. The third capacitor electrode222is connected at a first end portion of the second coil214, and the fourth capacitor electrode232is connected at a second end portion of the second coil214. In this exemplary configuration, in the state that the first and second substrates10and20are opposing each other, the opposing first and third capacitor electrodes221and222are in electric-field coupling so that the first capacitor is formed. Similarly, the opposing second and fourth capacitor electrodes231and232are in electric-field coupling so that the second capacitor is formed. As such, in the state that the first and second substrates10and20are opposing each other, the first resonators11and21are in electric-field coupling to each other. Herein, in the state that the first and second substrates10and20are separated away enough from each other, the first and second capacitor electrodes221and231in the first substrate10each form a capacity exemplarily between ground electrodes, e.g., a capacity between ground electrodes formed inside or outside of the substrate or an earth capacity, thereby configuring the first LC resonator resonating at the resonance frequency f0together with the first coil212. Similarly, the third and fourth capacitor electrodes222and232in the second substrate20each form a capacity exemplarily between ground electrodes, thereby configuring the second LC resonator resonating at the resonance frequency f0together with the second coil214.

In the exemplary configuration ofFIG. 1, in the state that the first and second substrates10and20are opposing each other in the first direction, the two resonators, i.e., the first and second resonance sections1and2, are disposed in parallel to each other. Alternatively, three or more resonance sections may be disposed in parallel to one another.FIG. 17shows an exemplary configuration in which a third resonance section3is additionally disposed in parallel to the first and second resonance sections1and2in the state that the first and second substrates10and20are opposing each other in the first direction.

In the modification ofFIG. 17, the first substrate10is formed additionally with a third resonator13in parallel to the first and second resonators11and12in the second direction (Y-direction in the drawing). Similarly, the second substrate20is formed additionally with a third resonator33in parallel to the first and second resonators21and22in the second direction. Similarly to the first resonator11or others, the third resonators13and33may be each a line resonator with a line electrode pattern, e.g., a λ/4 wavelength resonator, a λ/2 wavelength resonator, a 3λ/4 wavelength resonator, or a λ wavelength resonator. The line resonators as such are each of a one-side short-circuited type, a both-end short-circuited type, or a both-end open type, for example.

The third resonance section3is formed by, in the state that the first and second substrates10and20are opposing each other in the first direction, electromagnetically coupling the third resonator13in the first substrate10and the third resonator23in the second substrate20opposing each other in the first direction. The third resonance section3is so configured as to be electromagnetically coupled to the adjacent second resonance section2through resonance at the predetermined resonance frequency, i.e., the first or second resonance frequency f1or f2in the hybrid resonance mode. Between the second and third resonance sections2and3, signal transmission is to be performed with a predetermined passband including the predetermined resonance frequency. On the other hand, in the state that the first and second substrates10and20are separated away from each other so as not to establish electromagnetic coupling therebetween, the resonators13and23forming the third resonance section3are to resonate at a resonance frequency different from the predetermined resonance frequency, i.e., resonance frequency f0.

In this modification, the second input/output terminal52is connected directly physically to the third resonator23in the second substrate20, i.e., electrical continuity is directly established therebetween. With this configuration, signal transmission is expected to be performed between the second input/output terminal52and the third resonance section3. Because the first resonance section1is electromagnetically coupled to the second resonance section2, and the second resonance section2is electromagnetically coupled to the third resonance section3, signal transmission is expected to be performed between the first and second input/output terminals51and52. As such, in the state that the first and second substrates10and20are opposing each other in the first direction, signal transmission is expected to be performed between the two substrates, i.e., the first and second substrates10and20.

Second Embodiment

Described next is a signal transmission device in a second embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first embodiment described above is provided with the same reference numeral, and is not described again if appropriate.

FIG. 18shows a first exemplary configuration of the signal transmission device in the second embodiment. Although the signal transmission device in this first exemplary configuration is configured basically the same as the signal transmission device ofFIG. 17, there is a difference therefrom that the first input/output terminal51is connected with an LPF (Low-Pass Filter)61. In such a signal transmission device, the first, second, and third resonance sections1,2, and3are in electromagnetic coupling at a predetermined resonance frequency, i.e., a lower frequency in the hybrid resonance mode (first resonance frequency f1), and the passband for signals is a range including the first resonance frequency f1. The LPF61is a filter member that allows passage of signals of a predetermined passband including the predetermined resonance frequency, i.e., first resonance frequency f1, but interrupts the passage of signals of any other resonance frequency not in or out of the range of the predetermined passband, i.e., resonance frequency f0for each of the resonators not in electromagnetic coupling. In this signal transmission device, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, because the resonators11,12,13,21,22, and23each resonate at the resonance frequency f0, no signal is to be transmitted at the first resonance frequency f1being the passband for signals. Moreover, in this state, even if signals of the resonance frequency f0are input to the first input/output terminal51side, for example, the signals of the resonance frequency f0are to be reflected by the LPF61. Moreover, the LPF61interrupts also the output of signals of the resonance frequency f0from the first resonator11in the first substrate10to the first input/output terminal51side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is favorably prevented with more effect.

FIG. 19shows a second exemplary configuration of the signal transmission device in this embodiment. Although the signal transmission device in this second exemplary configuration is configured basically the same as the signal transmission device ofFIG. 17, there is a difference therefrom that the first input/output terminal51is connected with an HPF (High-Pass Filter)62. In such a signal transmission device, the first, second, and third resonance sections1,2, and3are in electromagnetic coupling at a predetermined resonance frequency, i.e., a higher frequency in the hybrid resonance mode (second resonance frequency f2), and the passband for signals is a range including the second resonance frequency f2. The HPF62is a filter member that allows passage of signals of a predetermined passband including the predetermined resonance frequency, i.e., second resonance frequency f2, but interrupts the passage of signals of any other resonance frequency not in the range of the predetermined passband, i.e., resonance frequency f0for each of the resonators not in electromagnetic coupling. In this signal transmission device, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, because the resonators11,12,13,21,22, and23each resonate at the resonance frequency f0, no signal is to be transmitted at the second resonance frequency f2being the passband for signals. Moreover, in this state, even if signals of the resonance frequency f0are input to the first input/output terminal51side, for example, the signals of the resonance frequency f0are to be reflected by the HPF62. Moreover, the HPF62interrupts also the output of signals of the resonance frequency f0from the first resonator11in the first substrate10to the first input/output terminal51side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is favorably prevented with more effect.

FIG. 20shows a third exemplary configuration of the signal transmission device in this embodiment. Although the signal transmission device in this third exemplary configuration is configured basically the same as the signal transmission device ofFIG. 17, there is a difference therefrom that the first input/output terminal51is connected with a BPF (Band-Pass Filter)63. In such a signal transmission device, the first, second, and third resonance sections1,2, and3are in electromagnetic coupling at the predetermined resonance frequency, i.e., the first or second resonance frequency f1or f2in the hybrid resonance mode, and the passband for signals is a range including the first or second resonance frequency f1or f2. The BPF63is a filter member that allows passage of signals of a predetermined passband including the predetermined resonance frequency, i.e., the first or second resonance frequency f1or f2, but interrupts the passage of signals of any other resonance frequency not in the range of the predetermined passband, i.e., the resonance frequency f0for each of the resonators not in electromagnetic coupling. In this signal transmission device, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, because the resonators11,12,13,21,22, and23each resonate at the resonance frequency f0, no signal is to be transmitted at the first or second resonance frequency f1or f2being the passband for signals. Moreover, in this state, even if signals of the resonance frequency f0are input to the first input/output terminal51side, for example, the signals of the resonance frequency f0are to be reflected by the BPF63. Moreover, the BPF63interrupts also the output of signals of the resonance frequency f0from the first resonator11in the first substrate10to the first input/output terminal51side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is favorably prevented with more effect.

FIG. 21shows a fourth exemplary configuration of the signal transmission device in this embodiment. Although the signal transmission device in this fourth exemplary configuration is configured basically the same as the signal transmission device ofFIG. 17, there is a difference therefrom that the first input/output terminal51is connected with a resonator64. The resonator64is not connected directly physically to the first resonator11in the first substrate10but is disposed with a spacing from the first resonator11.

In the signal transmission device ofFIG. 21, the first, second, and third resonance sections1,2, and3are in electromagnetic coupling at the predetermined resonance frequency, i.e., the first or second resonance frequency f1or f2in the hybrid resonance mode, and the passband for signals is a range including the first or second resonance frequency f1or f2. The resonator64is a filter member that allows passage of signals of a predetermined passband including the predetermined resonance frequency, i.e., the first or second resonance frequency f1or12, but interrupts the passage of signals of any other resonance frequency not in the range of the predetermined passband, i.e., the resonance frequency10for each of the resonators not in electromagnetic coupling. The resonance frequency of the resonator64is assumed to be in the passband for signals, i.e., the first or second resonance frequency f1or f2. Accordingly, in the state that the first resonator11in the first substrate10and the first resonator21in the second substrate20are in electromagnetic coupling at the first or second resonance frequency11or f2, the resonator64is electromagnetically coupled to the first resonator11(first resonance section1). In this state, when signals of the first or second resonance frequency f1or f2are provided by the first input/output terminal51, the signals are transmitted to the first resonance section1via the resonator64.

In this signal transmission device ofFIG. 21, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, because the resonators11,12,13,21,22, and23each resonate at the resonance frequency f0, no signal is to be transmitted at the first or second resonance frequency f1or f2being the passband for signals. Moreover, in this state, the resonator64is not electromagnetically coupled to the first resonator11because the state is different from the resonance frequency of the resonator64connected to the first input/output terminal51. As such, in this state, even if signals of the resonance frequency f0are input to the first input/output terminal51side, for example, the signals of the resonance frequency f0are to be reflected by the resonator64. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is favorably prevented with more effect.

Note thatFIGS. 18 to 21show the examples of connecting the LPF61, the resonator64, and others to the first input/output terminal51side. Alternatively, the LPF61, the resonator64, and others may be connected to the second input/output terminal52side. Still alternatively, the LPF61, the resonator64, and others may be connected to both the sides of the first and second input/output terminals51and52.

Further,FIGS. 18 to 21show the examples in which the filter member is the LPF (Low-Pass Filter), the HPF (High-Pass Filter), the BPF (Band-Pass Filter), or the resonator. Alternatively, the filter member may be a BEF (Band-Elimination Filter) for interrupting signals of the resonance frequency f0for each of the resonators not in electromagnetic coupling. The filter member serves the purpose as long as it allows passage of signals of a predetermined passband including a predetermined resonance frequency, and interrupts the passage of signals of any other resonance frequency not in the range of a predetermine passband, i.e., the resonance frequency f0for each of the resonators not in electromagnetic coupling.

Still further,FIGS. 18 to 21show the examples in which the filter member is connected outside of the substrate. Alternatively, the filter member may be formed inside of the substrate.

Third Embodiment

Described next is a signal transmission device in a third embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first or second embodiment described above is provided with the same reference numeral, and is not described again if appropriate.

FIG. 22shows an exemplary configuration of the signal transmission device in the third embodiment. Although the signal transmission device in this exemplary configuration is configured basically the same as the signal transmission device ofFIG. 17, there is a difference therefrom that the resonance frequency varies among the resonators11,12,13,21,22, and23when no electromagnetic coupling is established. That is, in the signal transmission device ofFIG. 17, the resonators11,12,13,21,22, and23respectively configuring the first, second, and third resonance sections1,2, and3share the same resonance frequency when no electromagnetic coupling is established, i.e., resonance frequency f0, but in the signal transmission device ofFIG. 22, the resonance frequency varies.

To be specific, the first resonator11in the first substrate10is supposed to resonate at the resonance frequency f0, the second resonator12therein is at the resonance frequency fb, and the third resonator13therein is at the resonance frequency fb′ when no electromagnetic coupling is established. Moreover, the first resonator21in the second substrate20is supposed to resonate at the resonance frequency f0, the second resonator22therein is at the resonance frequency fa, and the third resonator13therein is at the resonance frequency fa′ when no electromagnetic coupling is established. That is, in the same substrate, any resonators adjacent to each other are supposed to resonate at each different resonance frequency, i.e., f0fb≠fb′, f0≠fa≠fa′. Moreover, in each of the second and third resonance sections2and3, the opposing resonators are assumed as resonating at each different resonance frequency when no electromagnetic coupling is established, i.e., fb≠fa, fb′≠fa′.

Herein, in each of the second and third resonance sections2and3, the opposing resonators are assumed as resonating at each different resonance frequency when no electromagnetic coupling is established, but when electromagnetic coupling is established in the hybrid resonance mode with the first and second substrates10and20opposing each other, the resonance frequency remains, as a whole, the same as the predetermined resonance frequency f1(or the second resonance frequency f2). That is, also in this embodiment, through electromagnetic coupling in the mixed resonance frequency between the second resonator12in the first substrate10and the second resonator22in the second substrate20, the resonators resonate, as a whole, at the predetermined first resonance frequency (or the second resonance frequency). Similarly, through electromagnetic coupling in the hybrid resonance mode between the third resonator13in the first substrate10and the third resonator23in the second substrate20, the resonators resonate, as a whole, at the predetermined first resonance frequency (or the second resonance frequency).

According to this embodiment, as for the resonators11,12, and13in the first substrate10, the adjacent resonators resonate at different resonance frequencies. Accordingly, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, in the first substrate, the first and second resonators11and12are not in electromagnetic coupling, and the second and third resonators12and13are also not in electromagnetic coupling. Moreover, the degree of electromagnetic coupling between the first and third resonators11and13is very small or negligible. Similarly, as for the resonators21,22, and23in the second substrate20, the adjacent resonators resonate at different resonance frequencies. Accordingly, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, in the second substrate20, the first and second resonators21and22are not in electromagnetic coupling, and the second and third resonators22and23are also not in electromagnetic coupling. Moreover, the degree of electromagnetic coupling between the first and third resonators21and23is very small or negligible. The resonators21,22, and23are not in electromagnetic coupling. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is to be prevented with more effect.

Note that, when the resonators in the same substrate are supposed to resonate at each different resonance frequency, i.e., f0≠fb≠fb′ and f0≠fb′, and f0≠fa≠fa′ and f0≠fa′, in the state that the first and second substrates10and20are separated away enough from each other so as not to establish electromagnetic coupling therebetween, electromagnetic coupling is not established among the resonators11,12, and13in the first substrate10, and similarly, electromagnetic coupling is not established among the resonators21,22, and23in the second substrate20. This is preferable because any leakage of signals (electromagnetic waves) from the resonators11,12,13,21,22, and23is to be prevented thereby with more effect.

Fourth Embodiment

Described next is a signal transmission device in a fourth embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to third embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the first to third embodiments described above, exemplified is the configuration of the signal transmission device in which the two substrates10and20are disposed to oppose each other. Alternatively, three or more substrates may be disposed to oppose one another to configure a signal transmission device.FIG. 23shows an example of such a configuration, i.e., a third substrate30is additionally provided to the signal transmission device ofFIG. 22.

The third substrate30is formed with first, second, and third resonators31,32, and33in parallel to each other in the second direction, i.e., Y direction in the drawing. The first input/output terminal51is connected directly physically to the first resonator31in the third substrate30, i.e., electrical continuity is directly established therebetween. In the third substrate30as such, the first resonator31is supposed to resonate at the resonance frequency f0, the second resonator32is at the resonance frequency fc, and the third resonator33is at the resonance frequency fc′ when no electromagnetic coupling is established, i.e., f0≠fc≠fc′.

In this signal transmission device, in the state that the first, second, and third substrates10,20, and30are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the first resonator11in the first substrate10and the first resonator21in the second substrate20, and the first resonator11in the first substrate10and the first resonator31in the third substrate30, thereby forming the first resonance section1. Also in the state that the first, second, and third substrates10,20, and30are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the second resonator12in the first substrate10and the second resonator22in the second substrate20, and the second resonator12in the first substrate10and the second resonator32in the third substrate30, thereby forming the second resonance section2. Also in the state that the first, second, and third substrates10,20, and30are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the third resonator13in the first substrate10and the third resonator23in the second substrate20, and the third resonator13in the first substrate10and the third resonator33in the third substrate30, thereby forming the third resonance section3. As such, in the state that the first, second, and third substrates10,20, and30are opposing each other in the first direction, the first, second, and third resonance sections1,2, and3are disposed in parallel to each other in the second direction.

Fifth Embodiment

Described next is a signal transmission device in a fifth embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to fourth embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the embodiments described above, exemplified is the configuration in which the substrate and the resonator has a one-to-one relationship in the first direction, i.e., Z direction. Alternatively, a plurality of resonators may be formed in layers in the first direction in one substrate.FIG. 24shows an example of such a configuration, i.e., resonators in the second resonator20are configured differently in the signal transmission device ofFIG. 22.

In the configuration example ofFIG. 24, the second resonator22in the second substrate20ofFIG. 22is configured by two second resonators22-1and22-2, which are disposed one on the other in the first direction. The second resonator23is configured by three third resonators23-1,23-2, and23-3, which are disposed one on the other in the first direction. In the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, the two second resonators22-1and22-2both resonate at a resonance frequency fa similarly to the second resonator22ofFIG. 22. The three third resonators23-1,23-2, and23-3all resonate at the resonance frequency fa′ similarly to the third resonator23ofFIG. 22. The signal transmission device ofFIG. 24operates, for signal transmission, substantially similarly to the signal transmission device ofFIG. 22.

Sixth Embodiment

Described next is a signal transmission device in a sixth embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to fifth embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the embodiments described above, exemplified is the configuration in which the resonators configuring the resonance sections are formed to a plurality of substrates in the same combination. Alternatively, the resonators configuring the resonance sections may be formed to the substrates in the partially different combination.FIG. 25shows an example of such a configuration, i.e., a fourth substrate40is additionally provided to the signal transmission device ofFIG. 23, and a combination of substrates configuring a resonance section varies on the resonance section basis.

In the exemplary configuration ofFIG. 25, the first substrate10is formed therein with the first and second resonators11and12. The second substrate20is formed therein with the first and second resonators21and22. The third substrate30is formed therein only with the first resonator31. The fourth substrate40is formed therein only with a first resonator41. The second input/output terminal52is connected directly physically to the first resonator41in the fourth substrate40, i.e., electrical continuity is directly established therebetween.

In the exemplary configuration ofFIG. 25, in the state that the substrates are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the first resonator11in the first substrate10and the first resonator31in the third substrate30, thereby forming the first resonance section1. Also in the state that the substrates are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the second resonator12in the first substrate10and the first resonator21in the second substrate20, thereby forming the second resonance section2. Also in the state that the substrates are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing in the first direction, i.e., the second resonator22in the second substrate20and the first resonator41in the fourth substrate40, thereby forming the third resonance section3. As such, in the state that the substrates are opposing each other in the first direction, the first, second, and third resonance sections1,2, and3are arranged in the second direction, and in parallel to each other in the diagonal direction.

With such a configuration that a plurality of resonance sections are disposed in the second direction, and in parallel to each other in the diagonal direction, the number of the resonators for placement to each substrate is possibly reduced. Further, when the substrates are adjusted in size to correspond to the number of the resonators, the resulting signal transmission device is favorably reduced in size. Still further, because any resonator for electromagnetic coupling with the first resonator31in the third substrate30connected directly physically to the first input/output terminal51(electrical continuity is directly established therebetween) is not disposed in parallel to the third substrate30, in the state that the third substrate30is disposed away enough from other substrates so as not to establish electromagnetic coupling thereto, any leakage of signals (electromagnetic waves) from the resonator31is favorably prevented with effect. Similarly, because any resonator for electromagnetic coupling with the first resonator41in the fourth substrate40connected directly physically to the second input/output terminal52(electrical continuity is directly established therebetween) is not disposed in parallel to the fourth substrate40, in the state that the fourth substrate40is disposed away enough from other substrates so as not to establish electromagnetic coupling thereto, any leakage of signals (electromagnetic waves) from the resonator41is favorably prevented with more effect.

Seventh Embodiment

Described next is a signal transmission device in a seventh embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to sixth embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the embodiments described above, exemplified is the configuration in which, in the state that two or more substrates are opposing each other, two or more resonance sections are each configured by a coupled resonator including two or more resonators coupled in the hybrid resonance mode. Alternatively, only one resonance section may configure a coupled resonator in the hybrid resonance mode.FIG. 26shows an example of such a configuration, i.e., only the second resonance section2is configured by a coupled resonator in the hybrid resonance mode in the signal transmission device ofFIG. 17.

In the exemplary configuration ofFIG. 26, the first substrate10is formed therein with the first and second resonators11and12. The second substrate20is formed therein with the first and second resonators21and22. The second input/output terminal52is connected directly physically to the second resonator22in the second substrate20, i.e., electrical continuity is directly established therebetween.

In the exemplary configuration ofFIG. 26, in the state that the first and second substrates10and20are opposing each other in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the second resonator12in the first substrate10and the first resonator21in the second substrate20, thereby forming the second resonance section2. The first resonance section1is configured only by the first resonator11inside of the first substrate10. The third resonance section3is configured only by the second resonator22inside of the second substrate20. In the state that the first and second substrates10and20are opposing each other in the first direction, the first resonator11in the first substrate10resonates at the predetermined first resonance frequency f1(or the second resonance frequency f2). Also in the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, the first resonator11also resonates at the predetermined first resonance frequency f1(or the second resonance frequency f2). Similarly, in the state that the first and second substrates10and20are opposing each other in the first direction, the second resonator22in the second substrate20resonates at the predetermined first resonance frequency f1(or the second resonance frequency f2). Also in the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, the second resonator22also resonates at the predetermined first resonance frequency f1(or the second resonance frequency f2).

As such, even if only one resonance section configures a coupled resonator in the hybrid resonance mode, due to the effects of the resonance section, signal transmission is performed in a predetermined passband including a predetermined resonance frequency when a plurality of substrates are electromagnetically coupled to one another. On the other hand, when the substrates are disposed away enough from one another so as not to establish electromagnetic coupling thereamong, signal transmission is not performed in the predetermined passband, thereby being able to prevent any leakage of signals (electromagnetic waves) from the resonators formed to the substrates when the substrates are separated away enough from each other.

Eighth Embodiment

Described next is a signal transmission device in an eighth embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to seventh embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the embodiments described above, exemplified is the configuration of including the two input/output terminals51and52. Alternatively, three or more input/output terminals may be provided.FIG. 27shows an example of such a configuration of including three first input/output terminals51-1,51-2, and51-3, and three second input/output terminals52-1,52-2, and52-3.

In the exemplary configuration ofFIG. 27, similarly to the exemplary configuration ofFIG. 25, four substrates10,20,30, and40are provided. The first substrate10is formed therein with the first, second, and third resonator11,12, and13. The second substrate20is formed therein with the first, second, and third resonators21,22, and23. The third substrate30is formed therein with the first and second resonators31and32in layer in the first direction. The fourth substrate40is formed therein with only the first resonator41.

In the exemplary configuration ofFIG. 27, in the state that the substrates are opposing one another in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the first resonator11in the first substrate10and the second resonator32in the third substrate30, and electromagnetic coupling is established between the resonators opposing each other also in the first direction, i.e., the first resonator11in the first substrate10and the first resonator21in the second substrate20, thereby forming the first resonance section1. Also in the state that the substrates are opposing one another in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the second resonator12in the first substrate10and the second resonator22in the second substrate20, thereby forming the second resonance section2. Also in the state that the substrates are opposing one another in the first direction, electromagnetic coupling is established between the resonators opposing each other in the first direction, i.e., the third resonator13in the first substrate10and the third resonator23in the second substrate20, and electromagnetic coupling is established between the resonators opposing each other also in the first direction, i.e., the third resonator23in the second substrate20and the first resonator41in the fourth substrate40, thereby forming the third resonance section3. As such, in the state that the substrates are opposing one another in the first direction, the first, second, and third resonance sections1,2, and3are disposed in parallel to each other in the second direction.

One of the three first input/output terminals, i.e., the first input/output terminal51-1, is connected directly to the first resonator31in the third substrate30, i.e., electrical continuity is directly established therebetween. One of the remaining two first input/output terminals, i.e., first input/output terminal51-2, is connected directly to the second resonator32in the third substrate30. The remaining first input/output terminal51-3is connected directly to the first resonator21in the second substrate20.

One of the three second input/output terminals, i.e., the second input/output terminal52-1, is connected directly to the third resonator13in the first substrate10. One of the remaining two second input/output terminals, i.e., second input/output terminal52-2, is directly connected to the first resonator41in the fourth substrate40.

In this exemplary configuration, in the state that the substrates are opposing one another in the first direction, electromagnetic coupling is established among the resonance sections at the predetermined first resonance frequency (or the second resonance frequency f2). Therefore, no matter from which input/output terminal signals are provided, i.e., the three first input/output terminals51-1,51-2, and51-3, and the three second input/output terminals52-1,52-2, and52-3, the signals are to be transmitted to any other arbitrary terminal(s). Especially when signals are input/output using the first input/output terminal51-3, and the second input/output terminal52-3, signal transmission is to be possibly performed in the same substrate, i.e., in the second substrate20in this case.

Ninth Embodiment

Described next is a signal transmission device in a ninth embodiment of the present disclosure. Herein, any component part substantially the same as that of the signal transmission device in the first to eighth embodiments described above is provided with the same reference numeral, and is not described again if appropriate.

In the embodiments described above, exemplified is the configuration in which two or more resonance sections (coupled resonators) are disposed in parallel to each other in the state that a plurality of substrates are opposing one another. Alternatively, only one resonance section (coupled resonator) may be connected with filter member such as LPF (Low-Pass Filter). If this is the configuration, the filter member is preferably provided at least on the output end of signals.

FIG. 28shows an exemplary first configuration of a signal transmission device in this embodiment. The signal transmission device in this example of the first configuration does not include the second resonance section2(second resonators12and22) in the signal transmission device ofFIG. 1, but additionally includes an LPF161as the filter member. The LPF161is connected to the second input/output terminal52side (the first resonator21in the second substrate20). In this signal transmission device, as a predetermined resonance frequency, in the first resonance section1, the range including the lower frequency in the hybrid resonance mode, i.e., the first resonance frequency f1, is a passband for signals. The LPF161is a filter member that allows the passage of signals of a predetermined passband including the first resonance frequency f1as the predetermined resonance frequency, and interrupts the passage of signals of any other resonance frequency not in the range of the predetermined passband, i.e., the resonance frequency f0for each of the resonators11and21when no electromagnetic coupling is established. In this signal transmission device, in the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, signal transmission is not performed at the first or second resonance frequency f1being the passband for signals because the resonators11and21each resonate at the resonance frequency f0when no electromagnetic coupling is established. Moreover, also in this state, even if signals of the resonance frequency f0are provided to the second input/output terminal52side, the signals of the resonance frequency f0are to be reflected by the LPF161. Moreover, the LPF161interrupts also the output of signals of the resonance frequency f0from the first resonator21in the second substrate20to the second input/output terminal52side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11and21is favorably prevented with more effect.

FIG. 29shows an exemplary second configuration of a signal transmission device in this embodiment. The signal transmission device in this example of the second configuration does not include the second resonance section2(second resonators12and22) in the signal transmission device ofFIG. 1, but additionally includes an HPF (High-Pass Filter)162as the filter member. The HPF162is connected to the second input/output terminal52side (the first resonator21in the second substrate20). In this signal transmission device, as a predetermined resonance frequency, in the first resonance section1, the range including the higher frequency in the hybrid resonance mode, i.e., the second resonance frequency f2, is a passband for signals. The HPF162is filter member that allows the passage of signals of a predetermined passband including the second resonance frequency f2as the predetermined resonance frequency, and interrupts the passage of signals of any other resonance frequency not in the range of a predetermined passband, i.e., the resonance frequency f0for each of the resonators11and21when no electromagnetic coupling is established. In this signal transmission device, in the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, signal transmission is not performed at the second resonance frequency f2, i.e., the passband for signals, because the resonators11and21each resonate at the resonance frequency f0when no electromagnetic coupling is established. Moreover, also in this state, even if signals of the resonance frequency f0are input to the second input/output terminal52side, the signals of the resonance frequency f0are to be reflected by the HPF162. Moreover, the HPF162interrupts also the output of signals of the resonance frequency f0from the first resonator21in the second substrate20to the second input/output terminal52side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11and21is favorably prevented with more effect.

FIG. 30shows an exemplary third configuration of a signal transmission device in this embodiment. The signal transmission device in this example of the third configuration does not include the second resonance section2(second resonators12and22) in the signal transmission device ofFIG. 1, but additionally includes a BPF (Band-Pass Filter)163as the filter member. The BPF163is connected to the second input/output terminal52side (the first resonator21in the second substrate20). In this signal transmission device, as a predetermined resonance frequency, in the first resonance section1, the range including the first or second resonance frequency f1or f2in the hybrid resonance mode is a passband for signals. The BPF163is a filter member that allows the passage of signals of a predetermined passband including the first or second resonance frequency f1or f2as the predetermined resonance frequency, and interrupts the passage of signals of any other resonance frequency not in the range of the predetermined passband, i.e., the resonance frequency f0for each of the resonators11and12when no electromagnetic coupling is established. In this signal transmission device, in the state that the first and second substrates10and20are disposed away enough from each other so as not to establish electromagnetic coupling therebetween, signal transmission is not performed at the first or second resonance frequency f1or f2, i.e., the passband for signals, because the resonators11and12each resonate at the resonance frequency f0when no electromagnetic coupling is established. Moreover, also in this state, even if signals of the resonance frequency f0are input to the second input/output terminal52side, the signals of the resonance frequency f0are to be reflected by the BPF163. Moreover, the BPF163interrupts also the output of signals of the resonance frequency f0from the first resonator21in the second substrate20to the first input/output terminal51side. Accordingly, any leakage of signals (electromagnetic waves) from the resonators11and12is favorably prevented with more effect.

FIG. 31is an exemplary first configuration of the BPF163. In this exemplary first configuration, the BPF163is an LC resonator circuit of series resonance type, in which a capacitor C1and an inductor L1are connected together in series. With this LC resonator circuit, series resonance occurs at the first or second resonance frequency f1or f2.

FIG. 32shows an exemplary second configuration of the BPF163. In this exemplary second configuration, the BPF163is an LC resonator circuit of parallel resonance type, in which first and second LC resonator circuits are disposed in parallel for coupling with a magnetic field M. The first LC resonator circuit is the one configured by a first capacitor C11and a first inductor L11, and the second LC resonator circuit is the one configured by a second capacitor C12and a second inductor L12. With this LC resonator circuit, parallel resonance occurs at the first or second resonance frequency f1or f2.

Note that, inFIGS. 28 to 30, exemplified is the case of connecting the filter member such as the LPF161to the second input/output terminal52side, i.e., the first resonator21in the second substrate20. Alternatively, the filter member may be connected to the first input/output terminal51side, i.e., the first resonator11in the first substrate10. Still alternatively, the filter member may be connected to both the sides of the first and second input/output terminals51and52.

FIGS. 28 to 30show the examples in which the filter member is the LPF (Low-Pass Filter), the HPF (High-Pass Filter), the BPF (Band-Pass Filter). Alternatively, the filter member may be a BEF (Band-Elimination Filter) for interrupting signals of the resonance frequency f0for each of the resonator when no electromagnetic coupling is established. The filter member serves the purpose as long as it allows passage of signals of a predetermined passband including a predetermined resonance frequency, and interrupts the passage of signals of any other resonance frequency not in the range of a predetermine passband, i.e., the resonance frequency f0for each of the resonators when no electromagnetic coupling is established.

Still further,FIGS. 28 to 30show the examples in which the filter member is connected outside of the substrate. Alternatively, the filter member may be formed inside of the substrate.

OTHER EMBODIMENTS

While the present disclosure has been described in detail, the foregoing description is in all aspects illustrative and not restrictive, and numerous other modifications and variations are possibly devised.

As an example, the signal transmission device of each embodiment described above is not only available for signal transmission, i.e., transmission/reception of analog or/and digital signals, but also available as a power transmission device for transmission/reception of power.

The present disclosure contains subject matter related to that disclosed in Japanese Patent Application JP 2010-194558 filed in the Japan Patent Office on Aug. 31, 2010, and that in Japanese Priority Patent Application JP 2010-267139 filed on Nov. 30, 2010, the entire content of which is hereby incorporated by reference.