JP2002141707A - Filter, antenna multicoupler and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and inexpensive filter where unnecessary electromagnetic coupling between coils is suppressed and to provide an antenna multicoupler and a communication device. SOLUTION: In the antenna multicoupler 1, a transmission side circuit (band stop filter circuit) 57 is connected between a transmission terminal Tx and an antenna terminal ANT and a reception side circuit (band-pass filter circuit) 58 is connected between a reception terminal Rx and the antenna terminal ANT. Aircore coils L1, L4 of the reception side circuit 58 are mounted on a printed circuit board 40 in a way that directions of coil axes of the coils differ from each other by 90 degrees. Coil axis directions of aircore coils L5, L11 of the transmission side circuit 57 are in parallel with each other but winding directions of the coils differ from each other. The coil axis directions of the aircore coils L5, L11 and laminated coils L9, L10 respectively differ from each other by 90 degrees. Furthermore, the coils axis directions of the aircore coils L4, L5 differ from each other by 90 degrees and the winding directions differ from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter, an antenna duplexer, and a communication device used in, for example, a microwave band.

[0002]

2. Description of the Related Art In recent years, with the downsizing of communication devices such as mobile phones, the size of filters and antenna duplexers has been reduced, and the distance between components mounted on a printed circuit board in the communication device has been reduced. Is also getting smaller.

[0003] In general, in order to form the inductance, a wound coil (an air-core coil, a bobbin coil, or the like) wound with a conductive wire or a chip coil (a laminated coil, a thin-film coil, a spiral coil, or the like) is used. Can be Then, a plurality of these coils are used in one filter. For example, Japanese Utility Model Application No. 5-4603
In the publication, a plurality of air-core coils are integrated in order to reduce the number of components, and air-core coils are fitted into a coil housing portion in order to reduce fluctuation of filter characteristics, or an adjacent air-core coil is used. Are described in which the axis of the spiral portion is displaced.

[0004]

However, when a plurality of coils are used in one filter, if the distance between the components becomes small, unnecessary electromagnetic field coupling occurs between the coils. This unnecessary electromagnetic field coupling causes deterioration of filter characteristics (particularly, deterioration of attenuation characteristics). Also,
Even in the case of an antenna duplexer in which the two filters, the transmitting filter and the receiving filter, share an antenna terminal, when the distance between the components is reduced, the electromagnetic field that makes the coil of the transmitting filter and the coil of the receiving filter unnecessary. There is a problem that the coupling is performed and the isolation characteristics between the transmission band and the reception band are deteriorated.

[0005] When a plurality of air-core coils are integrated to reduce the number of parts, as in the filter described in Japanese Utility Model Application Laid-Open No. 5-4603, the air-core coil itself becomes large, and an automatic mounting machine is required. It becomes difficult to use and mount on a substrate. Further, if a coil housing portion (hole or concave portion) for fitting the air-core coil is formed in the substrate in order to make the filter characteristics less likely to change, a problem of an increase in the cost of the substrate occurs. In addition, if the axis of the spiral portion of the adjacent air-core coil is displaced so as to make the filter characteristics less likely to fluctuate, a plurality of air-core coils are arranged in zigzag. Therefore, useless space is generated on the circuit board, which hinders downsizing of the filter.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small, inexpensive filter, antenna duplexer, and communication device that suppress unnecessary electromagnetic field coupling between coils.

[0007]

In order to achieve the above object, a filter according to the present invention comprises at least one resonator and at least two wire-wound coils. The winding direction of at least one of the wound coils is different from the winding direction of the other wound coils. Alternatively, the winding type coil is mounted such that the coil axis direction of at least one of the winding type coils differs from the coil axis direction of the other winding type coils by 45 degrees or more. .

Further, the filter according to the present invention comprises at least one resonator and at least two inductance elements, one of the adjacent inductance elements is a wound coil, and the other is a chip. It is a type coil.

Further, the filter according to the present invention is a band-pass filter having at least one resonator, and the input-side and output-side reactance elements for matching with an external circuit are each an inductance element. . The two inductance elements are wound coils, and the winding directions are different from each other. Alternatively, one of the two inductance elements is a wound coil, and the other is a chip type.

Here, an air-core coil, a bobbin coil, or the like is used as the wound coil. As the chip type coil, a laminated coil, a thin film coil, a spiral coil and the like are used. Further, a dielectric resonator or the like is used as the resonator.

With the above configuration, unnecessary electromagnetic field coupling between the coils is suppressed, and excellent filter characteristics can be obtained. Also, since the coil is small, an automatic mounting machine can be used. In addition, the coils can be densely mounted on the circuit board, so that useless space is hardly generated on the circuit board.

Further, the antenna duplexer according to the present invention has a structure in which the first filter and the second filter each having at least one resonator and at least two wound coils share one common terminal. have. The winding direction of the wire-wound coil arranged on the shared terminal side of the first filter is different from the winding direction of the wire-wound coil arranged on the shared terminal side of the second filter. Alternatively, the axial direction of the wound coil disposed on the shared terminal side of the first filter is different from the coil axial direction of the wound coil disposed on the shared terminal side of the second filter by at least 45 degrees. A winding type coil is mounted.

With the above configuration, unnecessary electromagnetic field coupling between the wound coils of the first and second filters disposed on the common terminal side is suppressed, and excellent isolation characteristics can be obtained.

Further, the antenna duplexer and the communication device according to the present invention are provided with the filter having the above-described characteristics, whereby unnecessary electromagnetic field coupling between the coils can be suppressed, and excellent high-frequency characteristics can be obtained.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a filter, an antenna duplexer and a communication device according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment, FIGS. 1 to 9] FIG. 1 is a plan view of an antenna duplexer 1 in which components are mounted on a circuit board 40. FIG. In the antenna duplexer 1, the transmitting circuit 57 is electrically connected between the transmitting terminal Tx and the antenna terminal ANT, and the receiving circuit 58 is electrically connected between the receiving terminal Rx and the antenna terminal ANT. are doing. The antenna duplexer 1 outputs a transmission signal input from the transmission system circuit to the transmission terminal Tx to the antenna terminal ANT via the transmission circuit 57, and outputs a reception signal input from the antenna terminal ANT to the reception circuit. The signal is output from the receiving terminal Rx to the receiving system circuit via the terminal 58.

FIG. 2 is an electric circuit diagram of the antenna sharing device 1. The transmission circuit 57 is a variable frequency band rejection filter circuit. The band rejection filter circuit 57 includes the resonance circuit 2
A resonator 2 electrically connected to the transmitting terminal Tx via the resonance capacitor C1 and electrically connected to the antenna terminal ANT via the resonance capacitor C2 and the matching coil L4. And the resonator 3 which is provided. The matching coil L4 functions as a reactance element for synthesizing the phases of the transmitting circuit 57 and the receiving circuit 58. The resonance capacitors C1 and C2 are capacitors that determine the magnitude of the stopband attenuation. Resonator 2
The series resonance circuit of the resonance capacitor C1 is connected to the series resonance circuit of the resonator 3 and the resonance capacitor C2 by the coupling coil L.
1 electrically. Further, capacitors C5 and C6 are electrically connected in parallel to these two series resonance circuits, respectively.

As shown in FIG. 1, the coupling coil L1 and the matching coil L4 are air-core coils wound with a copper wire or the like. And, in the horizontal direction, the coil axis direction of the coil L1 is 9 degrees with respect to the coil axis direction of the coil L4.
The coils L1 and L4 are mounted on the circuit board 40 so as to differ by 0 degrees. Thereby, the adjacent coils L1, L
Unnecessary electromagnetic field coupling between the four can be suppressed, and deterioration of the attenuation characteristic of the band rejection filter circuit 57 can be prevented.

As shown in FIG. 2, a PIN diode D1, which is a reactance element, is connected to an intermediate connection point between the resonator 2 and the resonance capacitor C1 with a cathode grounded via a frequency variable capacitor C3. 2 are electrically connected in parallel. On the other hand, a PIN diode D2 is electrically connected in parallel to the resonator 3 with the cathode grounded at the intermediate connection point between the resonator 3 and the resonance capacitor C2 via a frequency variable capacitor C4. I have. The frequency variable capacitors C3 and C4 are capacitors for respectively changing two attenuation pole frequencies of the attenuation characteristic of the frequency variable band rejection filter circuit 57. Further, a choke coil L15 is connected between the anode of the PIN diode D2 and the ground.

The voltage control terminal CONT1 is electrically connected to an intermediate connection point between the anode of the PIN diode D1 and the frequency variable capacitor C3 via the control voltage supply resistor R1, the bypass capacitor C22 and the choke coil L2, and controls the voltage. It is electrically connected to the intermediate connection point between the anode of the PIN diode D2 and the frequency variable capacitor C4 via the voltage supply resistor R1, the bypass capacitor C22 and the choke coil L3.

A capacitor C15 is electrically connected between the ground and the antenna terminal ANT.
The capacitor C15 forms a T-shaped phase circuit together with the matching coil L4 of the transmitting circuit 57 and the matching coil L5 of the receiving circuit 58.

On the other hand, the receiving circuit 58 is a variable frequency band-pass filter circuit. Bandpass filter circuit 58
Is a three-stage coupled resonance circuit, and the resonance coil L
9 and a resonator 4 electrically connected to the antenna terminal ANT via the matching coil L5.
A resonator 6 electrically connected to the receiving terminal Rx via the reference numeral 10 and the matching coil L11 and a resonator 5 electrically connected between the resonators 4 and 6 via coupling capacitors C11 and C12. Have.

The matching coils L5 and L11 function as input-side and output-side reactance elements for matching the variable frequency band-pass filter circuit 58 with an external circuit. Matching coils L5, L11
Is an air-core coil wound with a copper wire or the like as shown in FIGS. Then, the matching coils L5, L
No. 11 has mutually parallel coil axis directions and mutually different winding directions. 5 and 6, arrows K1 and K2 indicate the directions in which the high-frequency current flows through the coils L5 and L11, respectively. Therefore, the directions of the magnetic fields generated by the matching coils L5 and L11 are reversed, and cancel each other. As a result, the matching coils L5 and L11 are not electromagnetically coupled to each other, so that the attenuation characteristics of the band-pass filter circuit 58 can be prevented from deteriorating.

Further, the resonance coils L9 and L10 are laminated coils as shown in FIGS. 7 and 8 show the resonance coil L9 as a representative example. As shown in FIG. 8, the resonance coils L9 and L10 are formed by forming coil conductor patterns 43a to 43d on each of the ceramic green sheets 42 by a method such as a printing method, and then forming the coil conductor patterns 43a to 43d. Is a via hole 47 provided in the ceramic green sheet 42.
The ceramic green sheets 42 are stacked and integrally fired so as to form a spiral coil 43 by electrically connecting them in series via a sintering unit to form a sintered laminate. As shown in FIG. 7, external terminals 48 and 49 are formed at the left and right ends of the sintered laminate, respectively. One end of the coil conductor pattern 43a is connected to the external terminal 48, and one end of the coil conductor pattern 43d is connected to the external terminal 49. A mark 50 for recognizing the winding direction of the spiral coil 43 is printed on the upper surfaces of the resonance coils L9 and L10.

When the resonance coils L9 and L10 are mounted on the circuit board 40, the coil axis direction of the spiral coil 43 is perpendicular to the circuit board 40. Therefore,
The matching coils L5, L11 and the resonance coils L9, L10 whose coil axis directions are parallel to the circuit board 40 are mounted with the coil axis directions different from each other by 90 degrees. Thus, unnecessary electromagnetic field coupling between the adjacent coils L5 and L9 or between L11 and L10 can be suppressed, and deterioration of the attenuation characteristic of the band-pass filter circuit 58 can be further prevented.

The matching coils L4 and L5 are
The coil axis directions are different from each other by 90 degrees, and the winding directions are also different from each other. The matching coil L4 constitutes a part of the transmission side circuit 57, and the matching coil L5
Constitutes a part of the receiving circuit 58, unnecessary electromagnetic field coupling between the transmitting circuit 57 and the receiving circuit 58 can be suppressed, and the isolation between the transmitting band and the receiving band can be suppressed. Deterioration of characteristics can be prevented.

At the intermediate connection point between the resonator 4 and the resonance coil L9, a series circuit of a frequency variable capacitor C7 and a PIN diode D4 is electrically connected to the resonator 4 with the cathode of the PIN diode D4 grounded. Are connected in parallel. At an intermediate connection point between the resonator 5 and the coupling capacitors C11 and C12, a series circuit of a frequency variable capacitor C8 and a PIN diode D5 is electrically parallel to the resonator 5 with the cathode of the PIN diode D5 grounded. Connected to At an intermediate connection point between the resonator 6 and the resonance coil L10, a series circuit of a frequency variable capacitor C9 and a PIN diode D6 is electrically connected in parallel to the resonator 6 with the cathode of the PIN diode D6 grounded. Connected.

The voltage control terminal CONT2 is electrically connected to the intermediate connection point between the anode of the PIN diode D4 and the frequency variable capacitor C7 via the bypass capacitor C23 and the choke coil L6.
3 and the PIN diode D5 via the choke coil L7.
Is electrically connected to an intermediate connection point between the anode of the capacitor C8 and the variable capacitor C8.
And an intermediate connection point between the anode of the PIN diode D6 and the frequency variable capacitor C9 via the choke coil L8.

Here, for example, the resonators 2 to 6 shown in FIG.
And as shown in FIG. 4, a λ / 4 coaxial dielectric resonator is used. 3 and 4 show the resonator 2 as a representative example. The dielectric resonators 2 to 6 include a cylindrical dielectric 17 formed of a high dielectric constant material such as a TiO ₂ -based ceramic, an outer conductor 18 provided on the outer peripheral surface of the cylindrical dielectric 17, and a cylindrical dielectric 17. And an inner conductor 19 provided on the inner peripheral surface of the dielectric 17. The outer conductor 18 is connected to one open end face 1 of the dielectric 17.
7a (hereinafter referred to as open end face 17a), the inner conductor 1
9 is electrically opened (separated) from the other open end face 17.
b (hereinafter referred to as short-circuit side end face 17b), the inner conductor 19
Is electrically short-circuited (conductive). Dielectric resonator 2
Is electrically connected to the resonance capacitor C1 via the conductor 20 and the like at the open end face 17a. These dielectric resonators 2 to 6 are soldered together by an outer conductor 18 and are integrated.

Next, the operation and effect of the antenna duplexer 1 having the above configuration will be described. The trap frequency of the frequency variable band rejection filter circuit 57 which is a transmission side circuit is:
The resonance frequency of the resonance system composed of the frequency variable capacitor C3, the resonance capacitor C1, and the resonator 2, and the resonance frequency of the resonance system composed of the frequency variable capacitor C4, the resonance capacitor C2, and the resonator 3 Decided. When a positive voltage is applied as a control voltage to the voltage control terminal CONT1, the PIN diodes D1 and D2 are turned on. Therefore, the frequency variable capacitors C3 and C4
Are grounded via PIN diodes D1 and D2, and the two attenuation pole frequencies are both lowered.
7 has a lower pass band.

Conversely, when a negative voltage is applied as a control voltage, the PIN diodes D1 and D2 are turned off.
Instead of applying a negative voltage, the voltage control terminal CON
100k control circuit to supply control voltage to T1
Ohm or higher impedance and voltage control terminal CO
By preventing the voltage from being applied to NT1, the control voltage may be set to 0V and the PIN diodes D1 and D2 may be turned off. As a result, the frequency variable capacitors C3 and C4 are opened, the two attenuation pole frequencies are both increased, and the pass band of the transmission side circuit 57 is increased. As described above, the transmission-side circuit 57 can have two different passband characteristics by grounding or opening the band variable capacitors C3 and C4 by voltage control.

On the other hand, the passing frequency of the variable frequency band-pass filter circuit 58, which is the receiving side circuit, is determined by the frequency variable capacitor C7, the resonance coil L9 and the resonator 4, and the frequency variable capacitor C8. And a resonance system composed of the resonator 5 and a resonance system composed of the frequency variable capacitor C9, the resonance coil L10, and the resonator 6. Then, when a positive voltage is applied as a control voltage to the voltage control terminal CONT2, the PIN diodes D4, D5, D6 are turned on. Accordingly, the frequency variable capacitors C7, C8, C9
Are grounded via PIN diodes D4, D5, and D6, respectively, and the passing frequency is lowered. Conversely, when a negative voltage is applied as the control voltage, the PIN diodes D4, D5,
D6 is turned off. As a result, the frequency variable capacitors C7, C8, and C9 are opened, and the passing frequency is increased. Thus, the receiving side circuit 58 can have two different passband characteristics by grounding or opening the frequency variable capacitors C7 to C9 by voltage control.

This frequency variable bandpass filter circuit 58
In accordance with the switching between the high and low pass bands of the transmitting side circuit 57, when the low frequency pass band is selected as the transmission band, the band pass frequency is lowered, and the high frequency pass band is selected as the transmission band. At this time, the voltage is controlled to increase the band pass frequency.

Unnecessary electromagnetic field coupling between adjacent coils L1 and L4, between L5 and L11, between L5 and L9, between L11 and L10, and between L4 and L5 can be suppressed. As a result, it is possible to obtain the antenna duplexer 1 having the transmission-side circuit 57 and the reception-side circuit 58 having excellent filter characteristics, and having excellent isolation characteristics between the transmission terminal Tx and the reception terminal Rx. . FIG. 9 shows the isolation characteristics of the duplexer 1 (S2
1) (see solid line 59). For comparison, the coil L1
And the coil axis directions of L4 and L4 are made parallel, and the winding directions of coils L5 and L11 are made the same, and the isolation characteristics of the antenna duplexer that does not suppress unnecessary electromagnetic field coupling between the coils are also described. (See dotted line 60).

Since the coils L1, L4, L5, L11, etc. are small, an automatic mounting machine can be used. In addition, the coils L1, L4 and the like can be densely mounted on the circuit board 40, so that useless space is hardly generated on the circuit board 40.

[Second Embodiment, FIGS. 10 and 11]
In the embodiment, the antenna duplexer 1 of the first embodiment is further reduced in size. FIG. 10 is a plan view of an antenna duplexer 61 in which components are mounted on a circuit board 40.
FIG. 11 is an electric circuit diagram thereof. 10 and 11, R2 to R5 are resistors, and C24 is a capacitor. 10 and FIG. 11, FIG. 1 and FIG.
Are denoted by the same reference numerals, and duplicate description will be omitted.

The receiving circuit 58 is a variable frequency band-pass filter circuit in which two stages of resonance circuits are coupled. The matching coils L5 and L11 function as input-side and output-side reactance elements for matching the frequency variable band-pass filter circuit 58 with an external circuit, respectively. The matching coil L5 is an air-core coil, and its coil axis direction is parallel to the circuit board 40. On the other hand, the matching coil L11 is a laminated coil, and its coil axis direction is perpendicular to the circuit board 40.

Therefore, the matching coils L5 and L11
Is mounted such that the coil axis directions are different from each other by 90 degrees. As a result, unnecessary electromagnetic field coupling between the coils L5 and L11 can be suppressed, and the deterioration of the attenuation characteristic of the receiving circuit 58 can be further prevented. As the coil L11, as shown in FIG. 10, an air core coil having a different winding direction from the coil L5 may be used.

[Third Embodiment, FIG. 12] A third embodiment shows an embodiment of a communication device according to the present invention, and will be described using a mobile phone as an example. FIG. 12 shows a mobile phone 1
FIG. 20 is an electric circuit block diagram of an RF section 20. 12, reference numeral 122 denotes an antenna element, 123 denotes a duplexer, 131 denotes a transmission-side isolator, 132 denotes a transmission-side amplifier, 133 denotes a transmission-side interstage bandpass filter, 134
Is a transmission-side mixer, 135 is a reception-side amplifier, 136 is a reception-side interstage bandpass filter, 137 is a reception-side mixer,
138 is a voltage controlled oscillator (VCO) and 139 is a local band-pass filter.

Here, as the duplexer 123, the antenna duplexers 1 and 61 of the first and second embodiments can be used. By mounting these duplexers 1 and 61, a mobile phone having excellent isolation characteristics can be realized.

[Other Embodiments] The filter, antenna duplexer, and communication device according to the present invention are not limited to the above-described embodiment, but can be variously modified within the scope of the gist.

For example, in the above embodiment, the coil axes of the adjacent coils are set to be different from each other by 90 degrees. However, it is not always necessary to set the directions to 90 degrees, and the coil axes are set to be different by 45 degrees or more. If so, there is an effect of suppressing unnecessary electromagnetic field coupling. In the above-described embodiment, the coil axes of the coils L1 and L4 of the transmission-side circuit may be parallel to each other, and the winding directions may be different from each other. Alternatively, the coil axis directions of the coils L5 and L11 of the receiving side circuit are mutually
It may be set to be different by 5 degrees or more.

Further, in addition to the PIN diode, a field effect transistor, a variable capacitance diode, or the like may be used. As the resonator, a distributed constant line or the like may be used in addition to the dielectric resonator.

[0044]

As is apparent from the above description, according to the present invention, the filter has at least two coils, and even if the filter size is reduced and the distance between the components is reduced, the two filters are used. Unnecessary electromagnetic field coupling between the coils can be suppressed. Therefore, it is possible to obtain a small and inexpensive filter or duplexer having excellent filter characteristics.

According to the present invention, there is provided an antenna duplexer in which a first filter and a second filter each including at least one resonator and at least two coils share one common terminal. Unnecessary electromagnetic field coupling between the coil arranged on the common terminal side of the first filter and the coil arranged on the common terminal side of the second filter can be suppressed. As a result, it is possible to obtain an antenna duplexer or a communication device having excellent isolation characteristics.

[Brief description of the drawings]

FIG. 1 is a plan view showing a mounting structure of an embodiment of an antenna duplexer according to the present invention.

FIG. 2 is an electric circuit diagram of the antenna duplexer shown in FIG.

FIG. 3 is a perspective view showing an example of a resonator used in the duplexer shown in FIG. 1;

FIG. 4 is a sectional view of the resonator shown in FIG. 3;

5 is a perspective view showing an example of an air-core coil used in the antenna duplexer shown in FIG.

FIG. 6 is a perspective view showing an example of another air-core coil used in the antenna duplexer shown in FIG. 1;

FIG. 7 is an exemplary perspective view showing an example of a laminated coil used in the antenna duplexer shown in FIG. 1;

8 is an exploded perspective view showing the configuration of the laminated coil shown in FIG.

FIG. 9 is a graph showing isolation characteristics of the duplexer shown in FIG. 1;

FIG. 10 is a plan view showing a mounting structure of another embodiment of the antenna duplexer according to the present invention.

FIG. 11 is an electric circuit diagram of the antenna duplexer shown in FIG.

FIG. 12 is a block diagram showing an embodiment of a communication device according to the present invention.

[Explanation of symbols]

 1, 61: antenna duplexer 2-6: coaxial dielectric resonator 57: transmitting side circuit (frequency variable band rejection filter circuit) 58: receiving side circuit (frequency variable band pass filter circuit) L1: coupling coil L4, L5 , L11 matching coil L9, L10 resonance coil Tx transmission terminal Rx reception terminal ANT antenna terminal 120 mobile phone 123 duplexer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01P 1/213 H04B 1/48 H04B 1/48 H01F 15/00 DF term (Reference) 5E070 AA05 AB01 BA01 BA12 CA06 CA15 CA16 CB03 CB13 CB17 DB02 EA01 EA07 5J006 HA03 HA15 HA21 HA34 JA01 JA02 JA11 KA02 KA12 KA13 KA24 LA03 LA23 MA07 MA12 NA05 NB07 NB08 NC01 NE12 NE13 NF01 5K011 BA04 DA02 DA27 GA06 JA01 KA05 KA13

Claims (12)

[Claims] 1. A motor comprising at least one resonator and at least two winding coils, wherein a winding direction of at least one of the winding coils is different from a winding direction of another winding coil. The featured filter. 2. A semiconductor device comprising: at least one resonator; and at least two winding coils, wherein a coil axis direction of at least one of the winding coils is equal to a coil axis direction of another winding coil. Wherein the wound coil is mounted so as to differ by at least 45 degrees. 3. The semiconductor device according to claim 1, further comprising at least one resonator and at least two inductance elements, wherein one of the adjacent inductance elements is a wound coil and the other is a chip coil. And filter. 4. A band-pass filter having at least one resonator, wherein input-side and output-side reactance elements for matching with an external circuit are inductance elements, and the two inductance elements are: What is claimed is: 1. A filter comprising: a wound coil, wherein winding directions are different from each other. 5. A band-pass filter having at least one resonator, wherein input-side and output-side reactance elements for matching with an external circuit are inductance elements, respectively. Wherein the inductance element is a wound coil and the other inductance element is a chip coil. 6. The filter according to claim 1, wherein the resonator is a dielectric resonator. 7. An antenna duplexer having a structure in which a first filter and a second filter each including at least one resonator and at least two coiled coils share one common terminal, An antenna duplexer, wherein a winding direction of a wire-wound coil arranged on the common terminal side of a filter is different from a winding direction of a wire-wound coil arranged on the common terminal side of the second filter. . 8. The filter according to claim 1, wherein at least one of the first filter and the second filter is a filter.
The antenna duplexer according to claim 7, wherein the filter is the filter according to (1). 9. An antenna duplexer having a structure in which a first filter and a second filter each including at least one resonator and at least two wire-wound coils share one common terminal, The coil axis direction of the wound coil disposed on the shared terminal side of the filter is different from the coil axis direction of the wound coil disposed on the shared terminal side of the second filter by 45 degrees or more. An antenna duplexer having a wound coil mounted thereon. 10. The antenna duplexer according to claim 9, wherein at least one of the first filter and the second filter is the filter according to claim 2. 11. An antenna duplexer comprising a first filter and a second filter, wherein at least one of the first filter and the second filter is a filter according to claim 3. An antenna duplexer, which is the filter according to any one of the above. 12. A communication device comprising at least one of the filter according to claim 1 and the duplexer according to claim 7.