JP2012199424A - Electric circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric circuit which includes an inductive element and a capacitative element and prevents the occurence of eddy current, and which includes proper shield effect and realizes efficient layout.SOLUTION: An electric circuit includes: an inductive element having wiring at least partially enclosing a certain region; a first capacitative element having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring in one of an inner region and an outer region of the wiring; at least one of a second capacitative element having a comb-shaped electrode extending in the direction substantially perpendicular to the wiring in the other region of the inner region and the outer region of the wiring and a shield having a shield wire extending in the direction substantially perpendicular to the wiring.

Description

  The present disclosure generally relates to an electric circuit, and particularly relates to an electric circuit including an inductive element and a capacitive element.

  In a high-frequency circuit used in an LSI for wireless communication or the like, a desired frequency characteristic having good reflection characteristics or transmission characteristics in a predetermined frequency band may be required. Therefore, impedance matching is performed to set the impedance of the high-frequency circuit to a desired value (for example, 50Ω) in a predetermined frequency band. Passive elements such as inductors and capacitive elements are used for impedance matching, but the inductor occupies a large area in the circuit. Therefore, there is a demand for a technique for substantially reducing the area occupied by the inductor by reducing the size of the inductor or by arranging the other elements. For example, the occupied area can be reduced by arranging the inductor and the capacitor in an overlapping manner.

  An example of a passive element in which an inductor and a capacitor are overlapped is disclosed in Patent Document 1. In the high frequency circuit disclosed in Patent Document 1, a radial slit is provided in the upper electrode of the capacitor, and a spiral inductor is disposed around the capacitor or overlapping the capacitor. Since the path of the eddy current induced by the magnetic field of the spiral inductor is blocked by the slit formed in the upper electrode of the capacitor, no eddy current loss occurs. Further, since no eddy current is generated, it is possible to prevent a decrease in inductance due to a mirror image effect. Furthermore, by arranging the capacitor in the empty area at the center of the spiral inductor or in the area overlapping with the spiral inductor, the area occupied by the circuit can be reduced.

  Patent Document 2 discloses a circuit in which a capacitor disposed inside an inductor is disposed to prevent eddy currents. In this circuit, a capacitive element can be connected in a direction in which eddy current is not excited to prevent eddy current.

  In the circuit of Patent Document 1, the parasitic capacitance increases unless the distance between the inductor and the capacitor electrode is increased. However, in the current CMOS process, the inductor is disposed on the top layer or a thick film below it, and the capacitor can only be formed below or near the top layer, so it is difficult to increase the distance between the inductor and the capacitor electrode. It is. In addition, a slit is formed in the upper part of the electrode, but there is no slit in the lower part. Therefore, when a low resistance electrode cannot be realized in the lower electrode, an eddy current is generated, resulting in a decrease in inductance.

  In addition, in both the circuit of Patent Document 1 and the circuit of Patent Document 2, if a surrounding wiring exists outside the inductor region, an eddy current is induced and the inductance decreases. In order to avoid this, it is necessary to create a shield area that prevents eddy current loss from the outermost part of the wiring. Further, in order to reduce the influence of the parasitic capacitance under the inductor wiring and realize a high Q value, it is necessary to install a shield for preventing eddy current outside the inductor, which increases the mounting area.

JP 2000-260939 A JP 2008-263074 A

  In view of the above, an electric circuit that includes an inductive element and a capacitive element, prevents generation of eddy currents, has an appropriate shielding effect, and realizes an efficient arrangement is desired.

  The electric circuit includes a first element having an inductive element having a wiring that at least partially surrounds a certain region and a comb-shaped electrode extending in a direction substantially perpendicular to the wiring in one of an inner region and an outer region of the wiring. And at least one of a capacitive element and a second capacitive element having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring in a region other than the one region and a shield having a shield line extending in a direction substantially perpendicular to the wiring. It is characterized by including.

  According to at least one embodiment of the present disclosure, in an electric circuit including at least an inductive element and a capacitive element, the capacitive element of the comb-shaped electrode is disposed in an appropriate position and direction, thereby functioning as a capacitor and preventing eddy currents. A capacitive element can be used so as to exhibit a function as a shield. That is, normally, an area that only needs to provide an eddy current prevention shield and a capacitive element separately is required. By using the capacitive element also as an eddy current prevention shield, the shield function and the capacitive function can be combined. It is possible to provide an efficient arrangement by providing a minute area.

It is a figure for demonstrating the shield for eddy current prevention. FIG. 2 is a cross-sectional view of a circuit taken along line A-A ′ of FIG. 1. It is a figure for demonstrating an eddy current. It is a figure for demonstrating the shield which prevents an eddy current. It is a figure which shows the structure of the 1st Example of the high frequency circuit containing an induction | guidance | derivation element and a capacitive element. FIG. 6 is a cross-sectional view taken along line B-B ′ of the high frequency circuit of FIG. 5. It is a figure which shows the structure of the 2nd Example of the high frequency circuit containing an induction | guidance | derivation element and a capacitive element. It is a figure which shows the structure of the 3rd Example of the high frequency circuit containing an induction | guidance | derivation element and a capacitive element. It is a figure which shows the structure of the 4th Example of the high frequency circuit containing an induction element and a capacitive element. It is sectional drawing taken along line C-C 'of the high frequency circuit of FIG. It is a figure which shows the structure of the 5th Example of the high frequency circuit containing an induction | guidance | derivation element and a capacitive element. It is a figure which shows the practical example of the high frequency circuit containing an induction element and a capacitive element. It is a figure which shows the equivalent circuit of the high frequency circuit of FIG. 13 is another configuration example of a high-frequency circuit having characteristics equivalent to those of the circuit of FIG. It is a figure which shows another practical example of the high frequency circuit containing an induction element and a capacitive element. It is a figure which shows the equivalent circuit of the high frequency circuit of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each drawing, the same or corresponding components are referred to by the same or corresponding reference numbers.

  FIG. 1 is a diagram for explaining an eddy current prevention shield. In FIG. 1, an eddy current prevention shield 10 is provided below an inductive element (inductor) having a metal wiring 17 that wraps around a certain region. The shield 10 for preventing eddy currents circulates except for the polyshield wires 11 and 13 extending in the vertical direction of the drawing, the polyshield wires 12 and 14 extending in the horizontal direction of the drawing, and the portions other than the notch 16 outside the polyshield wire. A ground wiring 15 connected to the policy line is included. The policy lines 11 to 14 are made of polysilicon and are arranged in the vicinity of the metal wiring 17 so as to extend in a direction substantially perpendicular to the metal wiring 17 that circulates. The ground wiring 15 may be a conductor such as polysilicon, and is provided to connect the polyshield lines 11 to 14 to a common ground potential. By notching the notch 16 to the ground wiring 15 and forming a peripheral circuit, eddy currents are prevented from being generated along the ground wiring 15 due to a change in magnetic flux generated by the inductor.

  FIG. 2 is a cross-sectional view of the circuit taken along line A-A 'of FIG. A polyshield wire 13 is formed on a silicon substrate 18, and an inductor metal wiring 17 is disposed above the polyshield wire 13. When the magnetic flux generated by the inductor changes, an eddy current tends to flow through the polyshield wire 13. However, the polyshield wire 13 is not a single continuous conductor plate, but a plurality of conductor wires arranged in parallel, and extends in a direction orthogonal to the extending direction of the metal wiring 17. Therefore, almost no eddy current flows through the polyshield wire 13. Further, since the silicon substrate 18 is shielded by the polyshield wire 13, no eddy current is generated in the silicon substrate 18.

  FIG. 3 is a diagram for explaining the eddy current. As shown in FIG. 3, a magnetic field 20 is generated when a current flows through the metal wiring 17 of the inductor. When the current flowing through the metal wiring 17 changes, the magnetic field changes, and an eddy current 21 is generated on the surface of the silicon substrate 18. When such an eddy current 21 is generated, an eddy current loss occurs. Further, the generation of eddy current causes a decrease in inductance due to a mirror image effect.

  FIG. 4 is a diagram for explaining a shield for preventing eddy currents. In the example shown in FIG. 4, the silicon oxide film 22 is formed on the silicon substrate 18, and the polyshield line 13 is provided thereon. Even if the magnetic field 20 changes, almost no eddy current is generated in the polyshield wire 13 as described above. Moreover, since the silicon substrate 18 is shielded by the polyshield wire 13, no eddy current is generated in the silicon substrate 18.

  FIG. 5 is a diagram showing a configuration of a first example of a high-frequency circuit including an inductive element and a capacitive element. In the following description, the high-frequency circuit means a circuit intended to target a high-frequency signal, but may be an electric circuit that is not limited to a signal having a specific frequency or higher. The high-frequency circuit shown in FIG. 5 includes an inductive element having a wiring 30 that at least partially surrounds a certain region, and a comb-shaped electrode that extends in a direction substantially perpendicular to the wiring 30 in one of the inner region and the outer region of the wiring 30. And a first capacitive element 31 having The high-frequency circuit further includes a second capacitive element 32 having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring 30 and a shield having a shield line extending in a direction substantially perpendicular to the wiring 30 in a region other than the one region. 33.

  In the example shown in FIG. 5, the wiring 30 completely surrounds the inner region by double wrapping. The shape of the wiring 30 is not limited to this. For example, a shape that surrounds the internal region partially except for the portions of the input / output ends 30a and 30b that input and output electric signals by wrapping around in a single layer. It may be. Each of the first capacitive element 31 and the second capacitive element 32 includes a comb-shaped electrode 34 and a comb-shaped electrode 35 as representatively shown in one of them. The comb-shaped electrode 34 and the comb-shaped electrode 35 are opposed to each other such that the plurality of comb-shaped portions of the comb-shaped electrode 34 and the plurality of comb-shaped portions of the comb-shaped electrode 35 are interdigitated. Thereby, a large capacitance value is realized. As described above, the comb electrode 34 and the comb electrode 35 extend in a direction substantially perpendicular to the wiring 30. Here, the comb-shaped electrode 34 and the comb-shaped electrode 35 extend in a direction substantially perpendicular to the wiring 30. The extending direction of each comb-like portion of the comb-shaped electrode 34 and the comb-shaped electrode 35 is substantially the same as the extending direction of the wiring 30 in the vicinity. Be vertical.

  In the example of FIG. 5, the first capacitor element 31 is disposed in a region outside the wiring 30, and the second capacitor element 32 is disposed in a region inside the wiring 30. A shield 33 is provided below the wiring 30 between the inner region and the outer region. The shield 33 is the same as the eddy current prevention shield 10 shown in FIG. That is, the shield 33 is connected to the polyshield wire extending around the polyshield wire extending in the vertical direction of the drawing, the polyshield wire extending in the horizontal direction of the drawing, and the polyshield wire so as to circulate outside the notch portion outside the polyshield wire. Wiring may be included. The shield 33 may be grounded. The policy line is made of polysilicon and may be arranged in the vicinity of the wiring 30 so as to extend in a direction substantially perpendicular to the wiring 30 that circulates.

  Since the first capacitor element 31, the second capacitor element 32, and the shield 33 have constituent elements (comb-shaped electrodes and polyshield wires) extending in a direction substantially perpendicular to the wiring 30, eddy currents are generated. Little or no eddy current loss occurs. In addition, the first capacitive element 31, the second capacitive element 32, and the shield 33 can prevent an eddy current from being generated in the substrate existing therebelow. In addition, the first capacitor element 31 disposed in the region outside the wiring 30 performs both a function of providing an appropriate shield for the external region and a function of providing a capacitance. Further, since the wiring 30 and the shield 33 are separated from each other as shown in FIG. 6 described below, the influence of parasitic capacitance on the inductive element can be minimized.

  FIG. 6 is a cross-sectional view taken along line B-B ′ of the high frequency circuit of FIG. 5. The high-frequency circuit shown in FIG. 6 includes a silicon substrate 40, an insulating film 41 formed thereon, and a plurality of interlayer insulating films 42 to 45 stacked thereon. The insulating films 41 to 45 are made of, for example, silicon oxide. Each polyshield line of the shield 33 is provided on the insulating film 41, and these polyshield lines are covered with an interlayer insulating film 42. If the silicon substrate 40 and the insulating film 41 are regarded as one substrate, the shield 33 is a polyshield provided on the substrate. The shield 33 can prevent eddy currents from being generated in the silicon substrate 40 as described above. Further, since the wiring 30 and the shield 33 are separated from each other, the influence of parasitic capacitance on the inductive element can be minimized.

  Comb electrodes 47 a to 47 c are provided on the interlayer insulating film 42, and the comb electrodes 47 a to 47 c are covered with the interlayer insulating film 43. Comb electrodes 48 a to 48 c are provided on the interlayer insulating film 43, and the comb electrodes 48 a to 48 c are covered with the interlayer insulating film 44. Inductive element wirings 30 are provided on the interlayer insulating film 44, and these wirings 30 are covered with an interlayer insulating film 43.

  The comb-shaped electrodes 47a to 47c may include a plus-side comb-shaped electrode and a minus-side comb-shaped electrode of the second capacitive elements 32a to 32c shown in FIG. Similarly, the comb-shaped electrodes 48a to 48c may include a plus-side comb-shaped electrode and a minus-side comb-shaped electrode of the second capacitive elements 32a to 32c shown in FIG. For example, the plus-side comb electrode of the comb-shaped electrode 47a and the plus-side comb-shaped electrode of the comb-shaped electrode 48a are connected in parallel, and the minus-side comb-shaped electrode of the comb-shaped electrode 47a and the minus-side comb-shaped electrode of the comb-shaped electrode 48a are paralleled. To the second capacitor element 32a. The comb electrodes 47 a to 47 c and the comb electrodes 48 a to 48 c also have a function of preventing eddy currents from being generated in the silicon substrate 40.

  FIG. 7 is a diagram showing a configuration of a second embodiment of a high-frequency circuit including an inductive element and a capacitive element. 7, the same or corresponding components as those in FIG. 5 are referred to by the same numerals, and a description thereof will be omitted as appropriate. The high-frequency circuit shown in FIG. 7 includes an inductive element having a wiring 30 that at least partially surrounds a certain region, and a comb-shaped electrode that extends in a direction substantially perpendicular to the wiring 30 in one of the inner region and the outer region of the wiring 30. And a first capacitive element 31 having The high-frequency circuit further includes a shield 50 having a shield line extending in a direction substantially perpendicular to the wiring 30 in a region other than the one region.

  In the example of FIG. 7, the first capacitive element 31 is disposed in a region outside the wiring 30, and the shield 50 is disposed in a region inside the wiring 30. The shield 50 is also provided below the wiring 30 between the inner region and the outer region. The shield 50 is the same as the eddy current prevention shield 10 shown in FIG. That is, the shield 50 is connected to the polyshield wire extending around the polyshield wire extending in the vertical direction of the drawing, the polyshield wire extending in the horizontal direction of the drawing, and the polyshield wire so as to go around other than the notch portion outside the polyshield wire. Wiring may be included. The shield 50 may be grounded. The policy line is made of polysilicon and may be arranged in the vicinity of the wiring 30 so as to extend in a direction substantially perpendicular to the wiring 30 that circulates.

  Since these first capacitive element 31 and shield 50 have constituent elements (comb-shaped electrodes and polyshielded wires) extending in a direction substantially perpendicular to the wiring 30, eddy currents are hardly generated and eddy currents are hardly generated. There is almost no loss. Further, the first capacitive element 31 and the shield 50 can prevent an eddy current from being generated in the substrate existing therebelow. In addition, the first capacitor element 31 disposed in the region outside the wiring 30 performs both a function of providing an appropriate shield for the external region and a function of providing a capacitance. Further, since the wiring 30 and the shield 50 are separated from each other, the influence of parasitic capacitance on the inductive element can be minimized.

  FIG. 8 is a diagram showing a configuration of a third example of the high-frequency circuit including the inductive element and the capacitive element. The high-frequency circuit shown in FIG. 8 includes an inductive element having a wiring 30 that at least partially surrounds a certain region, and a comb-shaped electrode that extends in a direction substantially perpendicular to the wiring 30 in one of the inner region and the outer region of the wiring 30. The first capacitive element 32 having The high-frequency circuit further includes a shield 51 having a shield line extending in a direction substantially perpendicular to the wiring 30 in a region other than the one region.

  In the example of FIG. 8, the first capacitive element 32 is disposed in a region inside the wiring 30, and the shield 51 is disposed in a region outside the wiring 30. The shield 51 is also provided below the wiring 30 between the inner region and the outer region. The shield 51 is the same as the eddy current prevention shield 10 shown in FIG. In other words, the shield 51 is connected to the polyshield wire extending around the polyshield wire extending in the vertical direction of the drawing, the polyshield wire extending in the horizontal direction of the drawing, and the polyshield wire so as to go around other than the notch portion outside the polyshield wire. Wiring may be included. The shield 51 may be grounded. The policy line is made of polysilicon and may be arranged in the vicinity of the wiring 30 so as to extend in a direction substantially perpendicular to the wiring 30 that circulates.

  Since these first capacitive element 32 and shield 51 have their constituent elements (comb-shaped electrodes and polyshielded wires) extending in a direction substantially perpendicular to the wiring 30, almost no eddy currents are generated, and eddy currents are generated. There is almost no loss. Further, the first capacitive element 32 and the shield 51 can prevent an eddy current from being generated in the substrate existing therebelow. Further, the shield 51 disposed in the region outside the wiring 30 provides an appropriate shield for the external region. Further, since the wiring 30 and the shield 51 are separated from each other, the influence of parasitic capacitance on the inductive element can be minimized.

  FIG. 9 is a diagram showing the configuration of a fourth example of the high-frequency circuit including the inductive element and the capacitive element. The high-frequency circuit shown in FIG. 9 includes an inductive element having a wiring 30 that at least partially surrounds a certain region, and a comb-shaped electrode that extends in a direction substantially perpendicular to the wiring 30 in one of the inner region and the outer region of the wiring 30. The first capacitive element 32 having The high-frequency circuit further includes a second capacitor element 61 having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring 30 in a region other than the one region.

  In the example of FIG. 9, the first capacitor element 32 is disposed in a region inside the wiring 30, and the second capacitor element 61 is disposed in a region outside the wiring 30. The second capacitor element 61 is further provided below the wiring 30 between the inner region and the outer region.

  Since the first capacitor element 32 and the second capacitor element 61 have constituent elements (comb-shaped electrodes) extending in a direction substantially perpendicular to the wiring 30, eddy currents are hardly generated and eddy currents are hardly generated. There is almost no loss. Further, the first capacitive element 32 and the second capacitive element 61 can prevent an eddy current from being generated in the substrate existing therebelow. In addition, the second capacitor element 61 disposed in the region outside the wiring 30 performs both a function of providing an appropriate shield for the external region and a function of providing a capacitor. The wiring 30 and the second capacitive element 61 are relatively close to each other as shown in FIG. 10 described below, and there is a slight influence of parasitic capacitance on the inductive element. However, as compared with the case where the capacitive element is provided only outside the wiring 30, the size of the electrode of the second capacitive element 61 is increased by extending the second capacitive element 61 below the wiring 30. Larger capacity values can be realized.

  FIG. 10 is a cross-sectional view taken along line C-C ′ of the high frequency circuit of FIG. 10. The high-frequency circuit shown in FIG. 10 includes a silicon substrate 70, an insulating film 71 formed thereon, and a plurality of interlayer insulating films 72 to 75 stacked thereon. The insulating films 71 to 75 are made of, for example, silicon oxide. Between the interlayer insulating films 72 and 73 and between the interlayer insulating films 73 and 74, the first capacitor element 32a and the second capacitor elements 61a and 61b are provided. The positions of the first capacitor element 32a and the second capacitor elements 61a and 61b on the plane are shown in FIG. Generation of eddy current in the silicon substrate 70 can be prevented by the comb electrodes of the second capacitive elements 61 a and 61 b immediately below the wiring 30. As described above, the capacitance value of the second capacitor element 61 can be set to be relatively large. However, since the distance between the wiring 30 and the second capacitor element 61 is short, the influence of the parasitic capacitance on the inductor becomes relatively large. .

  FIG. 11 is a diagram showing a configuration of a fifth example of the high-frequency circuit including the inductive element and the capacitive element. The high-frequency circuit shown in FIG. 11 includes an inductive element having a wiring 30 that at least partially surrounds a certain region, and a comb-shaped electrode extending in a direction substantially perpendicular to the wiring 30 in one of the inner region and the outer region of the wiring 30. And a first capacitive element 31 having The high-frequency circuit further includes a second capacitor element 62 having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring 30 in a region other than the one region.

  In the example of FIG. 11, the first capacitor element 31 is disposed in a region outside the wiring 30, and the second capacitor element 62 is disposed in a region inside the wiring 30. The second capacitor 62 is further provided below the wiring 30 between the inner region and the outer region.

  Since the first capacitor element 31 and the second capacitor element 62 have constituent elements (comb-shaped electrodes) extending in a direction substantially perpendicular to the wiring 30, eddy currents are hardly generated and eddy currents are hardly generated. There is almost no loss. Further, the first capacitive element 31 and the second capacitive element 62 can prevent an eddy current from being generated in the substrate existing therebelow. In addition, the first capacitor element 31 disposed in the region outside the wiring 30 performs both a function of providing an appropriate shield for the external region and a function of providing a capacitance. The wiring 30 and the second capacitor element 62 are relatively close to each other, and there is a slight influence of parasitic capacitance on the inductive element. However, compared with the case where the capacitive element is provided only inside the wiring 30, the size of the electrode of the second capacitive element 62 is increased by extending the second capacitive element 62 to the lower side of the wiring 30. Larger capacity values can be realized.

  FIG. 12 is a diagram illustrating a practical example of a high-frequency circuit including an inductive element and a capacitive element. In FIG. 12, the same or corresponding components as those of FIGS. 5, 7, 8, 9, and 11 are referred to by the same numerals, and a description thereof will be omitted as appropriate. In FIG. 12, the comb electrodes outside the capacitive elements 31 arranged in the region outside the wiring 30 are connected to each other by the ground wiring 82 and further connected to the ground wiring 83. Further, the comb electrodes inside these capacitive elements 31 are connected to the wiring 30. Furthermore, the comb electrodes inside the capacitive elements 32 arranged inside the wiring 30 are connected to each other by the ground wiring 80 and further connected to the ground wiring 83 via the ground wiring 81. In addition, the comb electrodes outside the capacitive elements 32 are connected to the wiring 30. The ground wiring 83 is connected to the ground potential. The ground wiring 82 is provided so as not to form a circuit.

  FIG. 13 is a diagram showing an equivalent circuit of the high-frequency circuit of FIG. As shown in FIG. 13, the input terminal IN and the output terminal OUT are connected by an inductive element array in which inductive elements are connected in series. One end of the capacitive element is connected to each point on the inductive element array, and the other end of the capacitive element is connected to the ground potential. The inductive element row in FIG. 13 corresponds to the wiring 30 in FIG. 12, and each inductive element in the inductive element row corresponds to a piecewise showing inductance of the wiring 30. 13 corresponds to the capacitive elements 31 and 32 in FIG. With the circuit shown in FIG. 13, it is possible to realize filter characteristics that combine band elimination characteristics and low-pass characteristics.

  FIG. 14 shows another configuration example of the high-frequency circuit having characteristics equivalent to those of the circuit of FIG. 14, the same or corresponding elements as those of FIGS. 5, 7, 8, 9, and 11 are referred to by the same numerals, and a description thereof will be omitted as appropriate. In FIG. 14, the comb-shaped electrode outside each capacitive element 31 disposed in the region outside the wiring 30 is connected to the ground potential. Further, the comb electrodes inside these capacitive elements 31 are connected to the wiring 30. The capacitive elements 32 arranged inside the wiring 30 are not used and are in a floating state, and are not connected to the wiring 30 or the ground potential. Even with such a configuration, a high-frequency circuit (filter) having the circuit shown in FIG. 13 as an equivalent circuit can be realized.

  FIG. 15 is a diagram illustrating another practical example of a high-frequency circuit including an inductive element and a capacitive element. In FIG. 15, the same or corresponding elements as those of FIGS. 5, 7, 8, 9, and 11 are referred to by the same numerals, and a description thereof will be omitted as appropriate. In FIG. 15, the comb electrodes on the outside of the capacitive elements 31 arranged in the region outside the wiring 30 are connected to the ground potential. Further, the comb electrodes inside these capacitive elements 31 are connected to the wiring 30. The capacitive elements 32 arranged inside the wiring 30 are not used and are in a floating state, and are not connected to the wiring 30 or the ground potential. One end of the wiring 30 is connected to the ground potential, and the other end is connected to the signal transmission wiring.

  FIG. 16 is a diagram showing an equivalent circuit of the high-frequency circuit of FIG. As shown in FIG. 16, one end of an inductive element array in which inductive elements are connected in series is connected in the middle of the signal transmission wiring between the input terminal IN and the output terminal OUT. The other end of the inductive element array is connected to the ground potential. One end of the capacitive element is connected to each point on the inductive element array, and the other end of the capacitive element is connected to the ground potential. The inductive element array in FIG. 16 corresponds to the wiring 30 in FIG. 15, and each inductive element in the inductive element array corresponds to a piecewise showing inductance of the wiring 30. Further, the capacitor in FIG. 16 corresponds to the capacitor 31 in FIG. With the circuit shown in FIG. 16, it is possible to realize a filter characteristic of a trap filter that attenuates a signal in a predetermined frequency band.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the said Example, A various deformation | transformation is possible within the range as described in a claim.

30 Wiring 31, 32 Capacitance element 33 Shield 34 Comb electrode 35 Comb electrode 40 Silicon substrate 41 Insulating films 42 to 45 Interlayer insulating film

Claims (7)

An inductive element having wiring that at least partially surrounds a region;
A first capacitive element having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring in one of the inner region and the outer region of the wiring;
The region other than the one region includes at least one of a second capacitor element having a comb-shaped electrode extending in a direction substantially perpendicular to the wiring and a shield having a shield line extending in a direction substantially perpendicular to the wiring. Characteristic electrical circuit.   2. The electric circuit according to claim 1, wherein the first capacitive element is disposed in the outer region, and the second capacitive element is disposed in the inner region.   3. The electric circuit according to claim 1, wherein the shield is provided below the wiring between the inner region and the outer region.   The electric circuit according to claim 1, wherein the shield is a polyshield provided on a substrate.   The electric circuit according to claim 1, wherein the first capacitive element is disposed in the outer region, and the shield is disposed in the inner region.   The electric circuit according to claim 1, wherein the first capacitive element is disposed in the inner region, and the shield is disposed in the outer region.   The first capacitive element is disposed in the outer region, the second capacitive element is disposed in the inner region, and one of the first capacitive element and the second capacitive element is: The electric circuit according to claim 1, wherein the electric circuit extends below the wiring between the inner region and the outer region.

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