JP2003115782A - Antenna duplexer and communication device - Google Patents

Abstract

(57) [Problem] To provide a miniaturized antenna duplexer having excellent electrical characteristics, high reliability and high stability as an antenna duplexer, and a communication device using the same. SOLUTION: A reception filter 1 which is a filter having a surface acoustic wave element, transmission filters 7, 10, 4 which are filters having a dielectric laminated structure, the reception filter 1 and the transmission filter 7, The antenna duplexer includes a matching circuit 3 for matching each of the antennas 10, 4 with an antenna, and the transmission filters 7, 10, 4 and the reception filter 1 and the matching circuit 3 are integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna duplexer and a communication device used in a high frequency wireless device such as a mobile communication device.

[0002]

2. Description of the Related Art An antenna duplexer is a high-frequency device used in high-frequency radio equipment such as a mobile phone to separate a transmitted wave from a received wave. In addition, further miniaturization and higher performance are required.

The antenna duplexer is usually composed of a receiving filter, a transmitting filter and a matching circuit. Then, the transmission wave is matched from the transmission circuit unit via the transmission filter by the matching circuit and guided to the antenna. Also,
The received wave is matched by the matching circuit from the antenna and guided to the receiving circuit unit through the receiving filter.

FIG. 15 is a perspective view of a conventional first antenna duplexer. In the first antenna duplexer, a SAW filter is used as the transmission filter 50. In addition,
What is a SAW filter? Surface Acoustic
It is an abbreviation for Wave Filter and means a surface acoustic wave filter. A dielectric coaxial filter using a coaxial resonator is used as the reception filter 52. The transmission filter 50 and the reception filter 52 are mounted on the board 53.

By using a small SAW filter as the transmitting filter 50 and a dielectric coaxial filter having a high Q value of the coaxial resonator and a small insertion loss as the receiving filter 52, the first antenna duplexer Insertion loss is sufficiently small for received waves, demultiplexing characteristics are improved, and the size of the duplexer is reduced.

FIG. 16 shows a perspective view of a conventional second antenna duplexer. The second antenna duplexer uses a dielectric coaxial filter that uses a coaxial resonator as the transmission filter 54. Also, as the reception filter 55, SA
A W filter is used. The transmission filter 54 and the reception filter 55 are mounted on the board 56. The matching circuit is realized by a transmission line formed on the substrate 56.

The receiving filter 55 has a small and lightweight SAW.
By using the filter, the entire second antenna duplexer is downsized.

[0008]

However, the first antenna duplexer has a transmitting filter 50 and a receiving filter 52.
Are separately mounted on the substrate 53, and the dielectric coaxial filter used for the receiving filter 52 is generally large. Thus, the first antenna duplexer
The structure in which the transmission filter 50 and the reception filter 52 are separately mounted on the substrate 53 and the large reception filter 52 prevent further miniaturization.

In the second antenna duplexer, the transmitting filter 54 and the receiving filter 55 are separately mounted on the substrate 53, and the transmitting filter 54 is a dielectric coaxial filter. The dielectric coaxial filter is generally large. As described above, the second antenna duplexer has a structure in which the transmission filter 54, the reception filter 55, and the like are separately mounted on the substrate 53, and the transmission filter 54 is large, and is used in a matching circuit. Since the existing transmission line is routed on the substrate, miniaturization is hindered.

As described above, since the conventional antenna duplexer has a structure in which the transmission filter and the reception filter are separately mounted on the substrate, it is difficult to realize further miniaturization. is there.

Further, in the conventional antenna duplexer, when the dielectric coaxial filter is used, the dielectric coaxial filter itself is large in size, so that it is difficult to realize further miniaturization.

Further, since the conventional antenna duplexer has a structure in which the transmission filter and the reception filter are separately mounted on the substrate, the cost is increased due to the increase in the number of parts, and the reliability and stability are further improved. Is difficult to improve.

In view of the above problems, it is an object of the present invention to provide an antenna duplexer and a communication device which have excellent electrical characteristics as an antenna duplexer and are miniaturized.

In consideration of the above problems, the present invention has excellent electric characteristics as an antenna duplexer, and
It is an object of the present invention to provide an antenna duplexer and a communication device with improved reliability and stability.

[0015]

In order to solve the above-mentioned problems, a first aspect of the present invention relates to a receiving filter which is a filter having a surface acoustic wave element and a transmitting filter which is a filter having a dielectric resonator. An antenna duplexer comprising a filter and a matching circuit for matching the receiving filter and the transmitting filter with an antenna, respectively, and integrating the transmitting filter, the receiving filter and the matching circuit.

Further, in the second invention, the matching circuit is
It is the antenna duplexer of the 1st this invention which is a dielectric laminated structure.

A third aspect of the present invention is the antenna duplexer according to the first aspect of the present invention, in which the transmission filter and the matching circuit are integrated dielectric layers.

The fourth aspect of the present invention is the antenna duplexer according to the second or third aspect of the present invention, in which the permittivity of the dielectric forming the transmitting filter is different from the permittivity of the dielectric forming the matching circuit. Is.

The fifth aspect of the present invention is the antenna duplexer according to the fourth aspect of the present invention, wherein the permittivity of the dielectric forming the transmitting filter is higher than the permittivity of the dielectric forming the matching circuit. .

The sixth aspect of the present invention is the antenna duplexer according to the fifth aspect of the present invention, wherein the relative dielectric constant of the dielectric material forming the transmission filter is 10 or more.

The 7th aspect of the present invention is the antenna duplexer according to the 5th aspect of the present invention, wherein the dielectric constant of the dielectric forming the matching circuit is less than 10.

The eighth aspect of the present invention further includes a laminated portion formed of the same material as the dielectric material forming the matching circuit, and the transmission filter is sandwiched between the matching circuit and the laminated portion. It is the antenna duplexer of the 2nd or 3rd invention of a laminated integrated structure.

According to a ninth aspect of the present invention, the reception filter is formed above or below the matching circuit and is sealed with resin, and the reception filter is electrically connected to the matching circuit. It is the antenna duplexer of the 8th this invention connected.

In the tenth aspect of the present invention, the matching circuit is formed above or below the transmitting filter, and the transmitting filter is electrically connected to the matching circuit. Is an antenna duplexer of the present invention.

In the eleventh aspect of the present invention, the matching circuit is formed on a side on which the reception filter is mounted, and the reception filter is electrically connected to the matching circuit. It is an antenna duplexer of the tenth invention.

Further, in a twelfth aspect of the present invention, the reception filter is formed in the matching circuit adjacent to the transmission filter and is sealed with resin, and the reception filter and the transmission filter are provided. The credit filter is the antenna duplexer of the eighth invention, each electrically connected to the matching circuit.

The 13th aspect of the present invention is the antenna duplexer according to the 8th aspect of the present invention, wherein said receiving filter is formed inside said matching circuit and sealed with resin.

The 14th aspect of the present invention is the antenna duplexer according to the 1st aspect of the present invention, wherein the transmitting filter and the matching circuit are connected by an end face electrode and / or a via electrode.

In the fifteenth aspect of the present invention, the matching circuit has a strip line, the reception filter is connected to the strip line via a via, and the strip line is pulled out from the antenna. It is the antenna duplexer of the 1st this invention connected by the electromagnetic field coupling.

In the sixteenth aspect of the present invention, the matching circuit has a strip line, the transmitting filter is connected to the strip line via a via, and the strip line is drawn from the antenna. It is the antenna duplexer of the 1st this invention connected by the electromagnetic field coupling.

The seventeenth aspect of the present invention is a receiving filter having a composite structure of a filter having a surface acoustic wave element and a filter having a dielectric resonator, and a transmitting filter having a filter having a dielectric resonator. And a matching circuit for matching the receiving filter and the transmitting filter with an antenna, respectively, and an antenna duplexer in which the receiving filter, the transmitting filter, and the matching circuit are integrated.

An eighteenth aspect of the present invention is the antenna duplexer of the first aspect of the present invention, a transmission circuit section for outputting a transmission wave to the transmission filter, and a reception signal for receiving a reception signal from the reception filter. A communication device including a circuit unit.

A nineteenth aspect of the present invention is an antenna duplexer of the seventeenth aspect of the present invention, a transmission circuit section for outputting a transmission wave to the transmission filter, and a reception signal for receiving a reception signal from the reception filter. A communication device including a circuit unit.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the first embodiment will be described.

FIG. 1 shows an antenna duplexer 2 of this embodiment.
4 shows a block diagram of a wireless unit of a communication device using No. 4. The communication device of this embodiment is, for example, a mobile phone.

The communication device according to the present embodiment performs communication by a simultaneous transmission / reception communication system such as CDMA system that simultaneously performs transmission and reception. The antenna duplexer 24 according to this embodiment uses the CDMA system or the like. It is used for a communication device that performs communication by the simultaneous transmission / reception communication method.

The communication device includes a baseband unit 20, a frequency conversion unit 21, a filter 22, a power amplifier 23, an antenna duplexer 24, an antenna 25, an oscillation unit 26, a low noise amplifier 27, a filter 28, a frequency conversion unit 29, and a filter. Three
It consists of zero.

The power amplifier 23, the filter 22, and the frequency conversion section 21 constitute a transmission circuit section 51, and the low noise amplifier 27, the filter 28, the frequency conversion section 29, and the filter 3 are included.
0 constitutes the receiving circuit section 52.

The baseband unit 20 is means for modulating the modulated wave signal with the baseband signal at the time of transmission and outputting the modulated wave signal, and demodulating the modulated wave to the baseband signal at the time of reception.

The frequency converter 21 is a means for frequency-converting the modulated signal and converting it into a signal of the transmission frequency.

The filter 22 is means for reducing an unnecessary frequency component signal of the transmission frequency signal output from the frequency conversion section 21.

The power amplifier 23 is means for amplifying a signal in which a signal of an unnecessary frequency component is reduced.

The antenna duplexer 24 is means for separating the transmitted wave and the received wave.

The antenna 25 is means for transmitting a transmission signal as a transmission wave and receiving a reception wave as a reception signal.

The oscillating section 26 is means for oscillating a high frequency signal used for converting the modulated signal into a signal having a transmission frequency in the frequency converting section 21 during transmission. In addition, at the time of reception, the received signal of the reception frequency is received by the baseband unit 20.
It is a means for oscillating a high frequency signal used for converting into a signal of a frequency to be output to

The low noise amplifier 27 is means for amplifying a received signal with low noise.

The filter 28 is means for reducing an unnecessary frequency component signal from the signal output from the low noise amplifier 27.

The frequency conversion section 29 is means for converting the signal output from the filter 28 into a signal of the frequency used when outputting to the baseband section 20.

The filter 30 is a means for reducing an unnecessary frequency component signal from the signal frequency-converted by the frequency converter 29.

Next, the operation of the wireless communication device of this embodiment will be described.

The baseband unit 20 modulates the modulated wave signal with a baseband signal which is an audio signal input from a microphone or the like and outputs a modulated signal, and the frequency conversion unit 21 converts the modulated signal into an oscillating unit. This modulated signal is converted into a signal of the transmission frequency by mixing with the carrier wave signal input from 26. Then, the filter 22 reduces unnecessary frequency components of the signal of the transmission frequency, and the power amplifier 23
The output signal from the filter 22 is amplified and output as a transmission signal. Next, the antenna duplexer 24 guides the transmission signal to the antenna 25, and the transmission signal is output from the antenna 25 as a transmission wave in the air.

The antenna 25 receives the received wave,
The antenna duplexer 24 guides the reception signal received by the antenna 25 to the low noise amplifier 27 on the receiving side. The low noise amplifier 27 amplifies the received signal, and the filter 28 reduces unnecessary frequency component signals from the output signal from the low noise amplifier 27. The frequency conversion unit 29 mixes the frequency conversion carrier supplied from the oscillation unit 26 and the output signal from the filter 28, and converts the mixed signal into the signal of the frequency of the baseband unit 20. The filter 30 reduces unnecessary frequency components of the frequency-converted signal. The baseband unit 20 demodulates the signal output from the filter 30. The demodulated signal is output from the speaker as voice. The operation of the wireless communication device has been described above.

Next, the antenna duplexer 24 used in such a wireless communication device will be described.

FIG. 2 shows an antenna duplexer 24 of this embodiment.
The circuit configuration of is shown.

The antenna duplexer 24 includes a receiving SAW filter 31, a matching circuit 32, and a transmitting dielectric multilayer filter 3.
It consists of 3.

The receiving SAW filter 31 includes the antenna 2
The low-noise amplifier 27 of the receiving circuit unit receives the received wave
Is a SAW filter (surface acoustic wave filter).
The SAW filter is an SAW filter that applies an RF signal to a comb-shaped electrode formed on a piezoelectric substrate to convert an electric signal into strain energy and propagates it as a surface acoustic wave SAW. Is converted into an electric signal to select an RF signal of a specific frequency.

The transmitting dielectric multilayer filter 33 is a multilayer dielectric filter 33 that guides the transmission signal output from the power amplifier 23 of the transmitting circuit section to the antenna 25.

The matching circuit 32 includes an antenna 25 and a receiving S.
This is a circuit that matches the AW filter 31 and also matches the antenna 25 and the transmission dielectric multilayer filter 33.

FIG. 3 shows a sectional view of the antenna duplexer 24.

As shown in FIG. 3, the antenna duplexer 24 has a structure in which the dielectric laminated portion and the SAW filter portion are integrated.

The first LTCC (Low Temp) shown in FIG.
The matching circuit 32 is formed in the erasure co-fired ceramic (low temperature firing ceramic) 3 by a combination of a lumped constant inductor and a capacitor. In addition, a receiving SAW is provided on the upper surface of the first LTCC 3.
The filter 31 is sealed with the sealing resin 2 as the SAW filter 1. In addition, on the lower surface of the first LTCC3,
The third LTCC 7 is formed, and the transmission dielectric laminated filter 33 is formed in a laminated structure. The stripline resonator 4, which is a main component of the transmission dielectric multilayer filter 33, and the internal conductor 10 that forms a capacitor are formed inside the multilayer structure of the third LTCC 7. A second LTC is provided on the lower surface of the third LTCC 7.
C6 is formed, and L is below the second LTCC6.
GA (land grid array) electrodes 5 are formed. Further, the end surface electrode 11 is provided on the side surface of the third LTCC 7.
a and 11b are formed.

FIG. 4 shows an example of the laminated structure of the first LTCC 3, the second LTCC 6, and the third LTCC 7 of the antenna duplexer 24, that is, the laminated structure of the matching circuit 32 and the transmission dielectric laminated filter 33. The exploded perspective view for demonstrating is shown.

As shown in FIG. 4, the third LTCC7 is
This is a structure in which a third LTC substrate 7a, 7b, 7c is sequentially stacked. The first LTCC 3 is formed on the upper side of the third LTCC 7, and the second LTCC 6 is formed on the lower side of the third LTCC 7.

Stripline resonators 4a to 4c are formed on the upper surface of the third LTC substrate 7c. Input / output coupling capacitors 10a and 10b and inter-stage coupling capacitors 10c and 10d are formed on the upper surface of the third LTC substrate 7b. Further, the shield electrode 15a is formed on the upper surface of the third LTC substrate 7a, and
The shield electrode 15b is also formed on the upper surface of the CC substrate 6. Although not shown in FIG. 4, the matching circuit 3
2 and the transmitting dielectric multilayer filter 33 are connected by, for example, the end face electrodes 12a to 12d or via electrodes.

The second LTCC substrate 6 of this embodiment is an example of the laminated portion of the present invention.

Next, the operation of the antenna duplexer 24 of this embodiment will be described.

First, the operation of the transmitting dielectric multilayer filter 33 will be described.

FIG. 5 shows an example of the circuit of the transmitting dielectric multilayer filter 33. In FIG. 5A, the transmission dielectric multilayer filter 33 is a band elimination filter (BEF: Band).
FIG. 5B is an example of a circuit in the case of an Elimination Filter). In FIG. 5B, the transmission dielectric multilayer filter 33 is a band pass filter (BPF: BandP).
2 is an example of a circuit in the case of (ass Filter). Further, the exploded perspective view of FIG. 4 shows the case where the transmitting dielectric multilayer filter 33 is a bandpass filter, that is, FIG.
This corresponds to the circuit (b).

In FIG. 5A, the transmission line 40 has a capacitance of 3
The strip line resonators 38a, 38b, and 38c are connected to one of the strip line resonators 38a, 38b, and 38c via 7a, 37b, and 37c, and the other of the strip line resonators 38a, 38b, and 38c is grounded. As described above, the transmission dielectric multilayer filter 33 can function as a band elimination filter including, for example, three resonators. That is, the stripline resonator 4 formed in the third LTCC 7 is a quarter-wave stripline resonator 3
8a, 38b, 38c, and the inner conductor 10
Operate as capacitors 37a, 37b, 37c.

As shown in FIG. 5B, the transmitting dielectric multilayer filter 33 can be configured as a bandpass filter. In FIG. 5B, one of the stripline resonators 35a, 35b and 35c is grounded, and the other is capacitively coupled via the input / output coupling capacitors 36a and 36d and the interstage coupling capacitors 36b and 36c. ing. The strip line resonators 35a, 35b and 35c are the strip line resonators 4a and 4 shown in FIG. 4, respectively.
It corresponds to b and 4c. In addition, the input / output coupling capacitance 36
a and 36d correspond to 10a and 10b shown in FIG. 4, respectively. The interstage coupling capacitors 36b and 36c correspond to the interstage coupling capacitors 10c and 10d shown in FIG. 5, respectively.

The third LTCC 7 constituting the transmitting dielectric multilayer filter 33 is formed by using a high dielectric constant low temperature fired ceramic having a relative dielectric constant of 10 or more, preferably about 40 to 60. To do.

FIG. 6 (a) shows an example of such a high dielectric constant low temperature fired ceramic. That is, the third LTCC
7, Bi ₂ —O ₃ —Nb ₂ O ₅ and BaO—TiO ₂ —
It is formed by using a high dielectric constant low temperature fired ceramic such as Nd ₂ O ₃ -glass. As shown in FIG. 6A, BiO
₂ -CaO-Nb ₂ O ₅ is a relative dielectric constant of 58, Ba
O-TiO ₂ —Nd ₂ O ₃ -glass has a relative dielectric constant of 70. By using such a high dielectric constant low temperature fired ceramic, it is possible to form a smaller 1/4 wavelength stripline resonator 4. Further, as the transmission dielectric multilayer filter 33, if the third LTCC 7 is configured with a band elimination filter that is more advantageous in reducing the loss than the bandpass filter, it is advantageous in reducing the loss in the transmission dielectric multilayer filter 33. become. In this way, it is possible to provide the transmitting dielectric multilayer filter 33 in which the transmitting signal has a low loss in the pass band. Further, since the high dielectric constant low temperature fired ceramic is used for the third LTCC 7, the transmission dielectric multilayer filter 33 can be downsized.

The second LTCC 6 is a low dielectric constant type L
It is formed by using TCC.

FIG. 6B shows an example of low dielectric constant low temperature fired ceramics. That is, as the second LTCC 6,
MgO-SiO ₂ - glass (dielectric constant 7.2), Al ₂ O
_{3 -Gd 2 O 3 -MgO-SiO} 2 - glass (dielectric constant 7.
5), a low dielectric constant low temperature fired ceramic such as Al ₂ O ₃ -glass (relative dielectric constant 7 to 8). In general,
The low dielectric constant low temperature fired ceramic has a larger bending strength than the high dielectric constant low temperature fired ceramic. For example, in FIG.
The bending strengths of the low dielectric constant low temperature fired ceramics shown in (b) are all higher than the bending strength of the high dielectric constant low temperature fired ceramics of FIG. 6 (a). As described above, the second L having a large bending strength is provided below the transmitting dielectric multilayer filter 33.
By arranging the TCC 6, it is possible to provide a device having a strong terminal electrode strength even when the LGA electrode 5 is used. Further, the first LTCC 3 in which the matching circuit 32 is formed is also formed by using a low dielectric constant LTCC having a large bending strength similarly to the second LTCC 6. Therefore, the upper and lower sides of the third LTCC 7 constituting the transmitting dielectric multilayer filter 33 are formed of the same material as the first LTCC 7.
When sandwiched between No. 3 and the second LTCC 6, it is possible to prevent warpage of the laminate due to the difference in expansion coefficient during firing. Furthermore, it is possible to provide a stable and reliable dielectric laminated filter 33 for transmission that is resistant to impact such as dropping.

That is, it is desirable to use a high-dielectric-constant low-temperature fired ceramic having a relative dielectric constant of 10 or more for LTCC7, and a relative dielectric constant of 10 for LTCC3 and LTCC6.
It is desirable to use low dielectric constant low temperature fired ceramics of less than.

Next, the operation of the receiving SAW filter 31 will be described.

The receiving SAW filter 31 can realize high attenuation in the vicinity of the pass band. Further, the size can be significantly reduced as compared with the dielectric laminated filter or the dielectric coaxial filter.

Also, as the receiving SAW filter 31, S
By using the AW filter, it is possible to balance the front end portion.

Next, the operation of the matching circuit 32 will be described.

The matching circuit 32 is formed in the first LTCC 3 by a combination of a lumped constant type inductor and a capacitor. First LTCC3 in which matching circuit 32 is formed
Is formed by using a low dielectric constant type LTCC having a large bending strength as in the second LTCC 6 as described above. In order for the antenna duplexer 32 to function, it is necessary to form a stripline having a characteristic impedance of 50 ohms in the matching circuit 32 located between the receiving SAW filter 31 and the transmitting dielectric multilayer filter 33.

In general, when a low dielectric constant material is used, an inductor can be formed more easily than when a high dielectric constant material is used. For example, when a low dielectric constant material is used, in order to form a strip line having a characteristic impedance of 50 ohms, the width of the strip line needs to be about 100 μm. Such a strip line can be easily formed in terms of process. On the other hand, when a high dielectric constant material is used, in order to form a strip line having a characteristic impedance of 50 ohms, the width of the strip line needs to be about several μm. However, it is very difficult to form a stripline having a width as small as several μm in a process manner.

Therefore, in order to form a stripline having a characteristic impedance of 50 ohms, as is apparent from the above, the matching circuit 32 has a relative permittivity of 10.
Less than is desirable.

By thus constructing the first LTCC 3 with a low dielectric constant material, it becomes possible to easily form a stripline having a characteristic impedance of 50 ohms or more. Further, since electromagnetic coupling between adjacent strip lines is relatively small, it is possible to suppress interference between elements. Further, since a stripline having a characteristic impedance of 50 ohms or more can be easily formed, matching with the receiving SAW filter 31 can be easily achieved.

When mounting the transmission dielectric multilayer filter 33, it is desirable that the bending strength of the first LTCC 3 is large. As described above, the first LTCC3 uses a low dielectric constant material having a large bending strength. That is, as shown in FIG. 6, the first LTCC 3 has a bending strength equal to or more than twice that of the case where a high dielectric constant material is used. Therefore, the receiving SAW filter 3
The reliability at the time of mounting 1 is also high.

Further, by using the heterogeneous lamination technique,
Even if a high dielectric constant type LTCC is used for the transmission dielectric multilayer filter 33 for downsizing, and a low dielectric constant type LTCC can be used for the matching circuit 32, an inductor can be formed. It will be easier. Also, the matching circuit 3
2 is integrated with the transmission dielectric laminated filter 33 as a laminated structure, which is advantageous for downsizing.

In the present embodiment, the matching circuit is composed of the inductor and the capacitor using the low dielectric constant low temperature fired ceramic, but the same effect can be obtained even if the matching circuit is composed of the transmission line.

Next, a method of manufacturing the antenna duplexer 24 will be described.

FIG. 7 shows a flowchart of a method of manufacturing the antenna duplexer 24. In addition, the antenna duplexer 2 is shown in FIG.
The essential points of the manufacturing method of No. 4 are shown below.

First, as shown in FIG. 8A, the second L
TCC6, third LTCC7, and first LTCC
Each dielectric sheet of each layer constituting the dielectric laminated structure composed of 3 is pressed and laminated (S1), and the internal electrodes are printed on the laminated dielectric sheet (S2). Figure 8
(B) shows the structure thus pressed and laminated.

Next, the structure shown in FIG. 8B is integrally fired (S3), and the bumps 9 are formed on the integrally fired dielectric laminated structure as shown in FIG. 8C (S4). ). Further, as shown in FIG. 8D, the SAW filter 1 is mounted (S5), and finally the SAW filter 1 is sealed with the resin 2 (S5).
By performing 6), the antenna duplexer 24 can be manufactured as shown in FIG.

As described above, the matching circuit 32 and the transmission dielectric laminated filter 33 are integrally fired to produce an integrated dielectric laminated structure.

(Second Embodiment) Next, a second embodiment will be described.

FIG. 9 shows a sectional view of the antenna duplexer 24a according to the second embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Unlike the first embodiment, the matching circuit 32 is formed inside the first LTCC 3a and the second LTCC 6a, and the first LTCC 3a and the second LTC 3a are formed.
Both CC6a are formed of a low dielectric constant material.

Further, the transmitting dielectric multilayer filter 33 has
Like the first embodiment, it is formed in the third LTC7.

That is, on the upper surface of the second LTCC 6a, the third LTCC 7 is formed as the transmitting dielectric multilayer filter 33.
Is formed, and as the receiving SAW filter 31, S
The AW filter 1 is sealed with a sealing resin 2. That is, the transmission dielectric multilayer filter 33 and the reception SAW filter are formed adjacent to each other on the second LTCC 6a.

Further, the first LTCC 3a and the second LTC
The CC 6a is formed of a low dielectric constant material similarly to the first LTCC 3 and the second LTCC 6 of the first embodiment.

As described above, the receiving SAW filter 31 is arranged adjacent to the transmitting SAW filter 31, and the matching circuit 32 is formed in the first LTCC 3a and the second LTCC 6a, whereby the antenna duplexer 24a is integrated. It is formed as a chemical structure.

Therefore, the antenna duplexer 24a is made smaller and has a lower profile as in the first embodiment, has excellent electrical characteristics, and has reliability and stability even when dropped. .

In the present embodiment, the matching circuit 32 is described as being formed inside the first LTCC 3a and the second LTCC 6a, but the present invention is not limited to this.
It may be formed on either one of C3a and the second LTCC 6a.

(Third Embodiment) Next, a third embodiment will be described.

FIG. 10 shows a sectional view of the antenna duplexer 24b according to the third embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the antenna duplexer 24b of FIG. 10, the matching circuit 32 is formed in the first LTCC 3b having a cavity structure, and the SAW filter 1 is sealed with the sealing resin 2 in the cavity structure of the first LTCC 3b. It is a thing.

Further, the first LTCC 3b is formed by using a material having a low dielectric constant similarly to the first LTCC 3 of the first embodiment.

In this way, the antenna duplexer 24b has the first
The matching circuit 32 is formed in the LTCC 3b, and the SAW filter 1 is formed in the cavity structure portion thereof. Since the antenna duplexer 24b has such an integrated structure, it is downsized as in the first embodiment, has excellent electrical characteristics, and has reliability and stability even when dropped. .

In the third embodiment, the antenna duplexer 24b of FIG. 10 has been described as having the first LTCC 3b having the cavity structure formed on the upper portion of the third LTCC 7, but the present invention is not limited to this. Alternatively, the first LTCC 3b having the cavity structure may be formed below the third LTCC 7.

In FIG. 11, the first LTCC 3b is the third LT.
The antenna duplexer 24d formed under the CC is shown. In the antenna duplexer 24d of FIG. 11, the LGA electrode 5
A cavity is formed on the side of, the matching circuit 32 is formed in the first LTCC 3b having the cavity structure, and the SAW filter 1 is sealed with the sealing resin 2 in the cavity structure of the first LTCC 3b. is there. Therefore,
A cavity is formed on the substrate 60 side. Thus, unlike the present embodiment, even if the cavity structure is formed on the LGA electrode 5 side, that is, the substrate 60 side, the same effect as that of the present embodiment can be obtained.

The receiving filter of the present invention is the first to the first.
The receiving SAW filter in each of the third embodiments is not limited to a filter having a surface acoustic wave element, and may be a filter having a surface acoustic wave element and a filter having a dielectric resonator. .

FIG. 12 is a diagram of the first embodiment showing an antenna duplexer 24e which is a composite filter in which the receiving filter is composed of a filter having a surface acoustic wave element and a filter having a dielectric resonator. Unlike the antenna duplexer described with reference to FIG. 3, SA is used as a reception filter.
Not only the W filter 1 but also the coaxial resonator 9 is used.

The first LTCC (Low Temp) of FIG.
performance Co-fired Cerami
c: low temperature fired ceramic) 3 has a matching circuit 32 of FIG.
Are formed by a combination of a lumped constant type inductor and a capacitor. Further, instead of the receiving SAW filter 31 of FIG. 2, a composite filter including the SAW filter 1 and the coaxial resonator 9 is formed as a receiving filter on the upper surface of the first LTCC 3. Both the SAW filter 1 and the coaxial resonator 9 are sealed with the sealing resin 2. Further, a third LTCC 7 is formed on the lower surface of the first LTCC 3, and the transmitting dielectric multilayer filter 33 of FIG. 2 is formed in a laminated structure. The stripline resonator 4, which is a main component of the transmission dielectric multilayer filter 33, and the internal conductor 10 that forms a capacitor are formed inside the multilayer structure of the third LTCC 7. A second LTC is provided on the lower surface of the third LTCC 7.
C6 is formed, and L is below the second LTCC6.
GA (land grid array) electrodes 5 are formed. Further, the end surface electrode 11 is provided on the side surface of the third LTCC 7.
a and 11b are formed.

As shown in FIG. 12, by designing a filter having a composite structure composed of the SAW filter 1 and the coaxial resonator 9 as the receiving filter, the design of the receiving filter of this embodiment is performed. The degree of freedom of can be increased.

That is, the SAW filter can easily form the attenuation pole in the vicinity of the pass band, but it is difficult to form the attenuation pole in a portion slightly away from the pass band. Therefore, for example, if the attenuation pole is formed at the resonance frequency of the coaxial resonator, the insufficient design of the attenuation pole of the SAW filter can be compensated.

Further, a filter having a dielectric resonator such as the coaxial resonator 9 can easily make the impedance of the other side open, but a filter having a surface acoustic wave element can easily make the impedance of the other side. Difficult to open to. Therefore, by using not only the filter having the surface acoustic wave element as the receiving filter but also the filter having the dielectric resonator such as the coaxial resonator 9, the phase design of the filter having the surface acoustic wave element is performed. Can be made up for the insufficient part of.

Furthermore, the antenna duplexer of this embodiment is not limited to the above-mentioned respective embodiments, and electromagnetic coupling can be used for the antenna duplexer as shown in FIG. That is, FIG. 13 is an exploded perspective view showing a modified example of the antenna duplexer of the present embodiment. The same parts as those in each of the above-described embodiments are designated by the same reference numerals and detailed description thereof will be omitted.

The antenna duplexer 24f shown in FIG. 13 is the same as that shown in FIG.
The antenna duplexer 24e is different in the following points. That is, the strip lines 42a, 42
b, the receiving filter as a composite filter composed of the SAW filter 1 and the coaxial resonator 9 is a strip line 42a, and the transmitting filter formed in the third LTCC 7 is a strip line 42b and a via. Connected through. The transmission filter and the reception filter are respectively connected to the phase line 4 drawn from the antenna as indicated by the electromagnetic field coupling 43 and the electromagnetic field coupling 44.
5, and the strip line drawn from the reception filter and the strip line drawn from the transmission filter are electromagnetically coupled to each other. These points are different from the antenna duplexer 24e of FIG.

The structure of the matching circuit is roughly classified into the following two structures. The first configuration is a configuration in which a strip line having a narrow line width is routed over a relatively long distance of about 5 to 20 millimeters. The second configuration is a combination of the inductor L and the capacitor C. In particular, the inductor L has a structure in which a strip line having a narrow line width is drawn in a spiral shape several times to about ten times. Therefore, the propagation loss in the strip line was very large. Therefore, the antenna duplexer 24f of FIG.
As shown in FIG.
By constructing 4f, the antenna duplexer 24f can be significantly reduced in loss.

By using the electromagnetic field couplings 43 and 44 in this manner, not only the same effect as that of the present embodiment can be obtained, but also a significant reduction in loss can be realized.

A metal foil can be used for the stripline resonator of the antenna duplexer of each of the above embodiments. That is, FIG. 14 shows such an antenna duplexer 24.
The sectional view of c is shown. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Unlike the first embodiment, the stripline resonator 14 is made of metal foil. In addition, HTC (High Temperature Ce
ramic: high temperature fired ceramics) 13a, 13b
For example, a material with a firing temperature of 1300 degrees Celsius or higher,
Although it cannot be co-fired with silver and copper, it is a high-temperature fired ceramic with less material loss than LTCC. That is, the stripline resonator 14 that is a metal foil is sandwiched between the HTCs 13a and 13b, and the voids in the layer in which the stripline resonator 14 is formed are filled with the resin 12.

Materials forming the HTCs 13a and 13b are shown in FIG. 6 (c). That is, HTCs 13a and 13b have ZrO ₂ —TiO ₂ —MgO—Nb ₂ O ₅ (relative permittivity 43), BaO—TiO ₂ —Nd ₂ O ₃ (relative permittivity 9
0), BaO—TiO ₂ —Sm ₂ O ₃ (relative permittivity 70 to 8)
0) etc.

By using a metal foil for the stripline resonator 14 and using such a high temperature fired ceramic for the HTCs 14a and 14b sandwiching the metal foil, the dielectric multilayer filter for transmission 33 can be further reduced in loss and height. Can be attenuated. As described above, the metal foil can be used for the stripline resonator.

Incidentally, the HTCs 13a and 1 of this embodiment are
3b instead of the LTCC described in the first embodiment.
May be used.

Further, the transmitting filter of the present invention is not limited to the transmitting dielectric multilayer filter 33 of the present embodiment, and a dielectric coaxial filter may be used. In short, the transmitting filter of the present invention only needs to be a dielectric filter that can be integrated with the receiving filter together with the matching circuit.

The receiving surface acoustic wave filter 31 of the present embodiment is an example of the receiving filter of the present invention, and the transmitting dielectric laminated filter 33 of the present embodiment is an example of the transmitting filter of the present invention. Is.

The laminated layer of the present invention is not limited to the structure of vertically laminated layers. When the antenna duplexer is mounted, it includes the case where each layer of the laminated structure is laminated left and right, front and back, or inclined according to the mounting position. When manufacturing a laminated structure,
Depending on the manufacturing method, it includes the case where each layer is laminated right and left, front and back, or inclined.

[0127]

As is apparent from the above description, the present invention can provide an antenna duplexer and a communication device which have excellent electrical characteristics as an antenna duplexer and are miniaturized.

Further, the present invention can provide an antenna duplexer and a communication device which have excellent electrical characteristics as an antenna duplexer and have improved reliability and stability.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a communication device according to first to third embodiments of the present invention.

FIG. 2 is a block diagram showing a configuration of an antenna duplexer according to the first to third embodiments of the present invention.

FIG. 3 is a sectional view showing the structure of the antenna duplexer according to the first embodiment of the present invention.

FIG. 4 is an exploded perspective view showing an example of a laminated structure of a transmission dielectric laminated filter and a matching circuit portion of the antenna duplexer according to the first embodiment of the present invention.

FIG. 5 (a) is a diagram showing an equivalent circuit when the transmission dielectric multilayer filter in the first to third embodiments of the present invention is realized by a band elimination filter. (B) The first to third embodiments of the present invention. The figure which shows the equivalent circuit at the time of implement | achieving the transmission dielectric laminated filter in embodiment by a bandpass filter.

FIG. 6A is a diagram showing an example of a high dielectric constant type low temperature fired ceramic according to the first to third embodiments of the present invention. FIG. 6B is a low dielectric constant system according to the first to third embodiments of the present invention. The figure which shows the example of low temperature firing ceramics (c) The figure which shows the example of high dielectric constant type high temperature firing ceramics in the 1st-3rd embodiment of this invention.

FIG. 7 is a flowchart showing a method of manufacturing the antenna duplexer according to the first embodiment of the present invention.

FIG. 8 (a) is a diagram showing the main points of the method of manufacturing the antenna duplexer in the first embodiment of the present invention, showing a dielectric sheet to be laminated (b) the first embodiment of the present invention FIG. 6 is a diagram showing the main points of the method of manufacturing the antenna duplexer in the embodiment of the present invention, showing the laminated structure before being integrally fired (c). FIG. 4 is a diagram showing a dielectric laminated structure having bumps formed thereon (d) a diagram showing the main points of the method of manufacturing the antenna duplexer according to the first embodiment of the present invention, in which the SAW filter is mounted. FIG. 6E is a view showing the essential points of the method of manufacturing the antenna duplexer according to the first embodiment of the present invention, in which the SAW filter is sealed with resin. Figure showing the body

FIG. 9 is a sectional view showing the structure of an antenna duplexer according to a second embodiment of the present invention.

FIG. 10 is a sectional view showing a structure of an antenna duplexer according to a third embodiment of the present invention.

FIG. 11 is a sectional view showing a structure of a modification of the antenna duplexer according to the third embodiment of the invention.

FIG. 12 is a diagram showing a structure of an antenna duplexer in which a receiving filter according to an embodiment of the present invention includes a SAW filter and a coaxial resonator.

FIG. 13 is an exploded perspective view showing a configuration of an antenna duplexer using electromagnetic field coupling according to the embodiment of the present invention.

FIG. 14 is a sectional view showing a structure of an antenna duplexer using a metal foil for the stripline resonator according to the embodiment of the present invention.

FIG. 15 is a diagram showing an outline of a conventional antenna duplexer.

FIG. 16 is a schematic diagram showing an outline of a conventional antenna duplexer.

[Explanation of symbols]

1 SAW filter 2 Sealing resin 3 First LTCC 4 Stripline resonator 5 LGA electrode 6 Second LTCC 7 Third LTCC 8 interlayer via holes 9 bumps 10 Inner conductor 11 Edge electrode 12 resin 13a, 13b HTC 14 metal foil 24 antenna duplexer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Yamada             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Toshio Ishizaki             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5J006 HB05 HB22 JA01 JA02 KA01                       NA04 NC03 PB03                 5K011 BA03 DA27 EA01 EA06 JA01                       KA05

Claims (19)

[Claims] 1. A receiving filter, which is a filter having a surface acoustic wave element, a transmitting filter, which is a filter having a dielectric resonator, and a matching circuit for matching the receiving filter and the transmitting filter with an antenna, respectively. And an antenna duplexer in which the transmission filter, the reception filter, and the matching circuit are integrated. 2. The antenna duplexer according to claim 1, wherein the matching circuit has a dielectric laminated structure. 3. The antenna duplexer according to claim 1, wherein the transmitting filter and the matching circuit have an integrated dielectric laminated structure. 4. The antenna duplexer according to claim 2, wherein the dielectric constant of the dielectric forming the transmitting filter is different from the dielectric constant of the dielectric forming the matching circuit. 5. The antenna duplexer according to claim 4, wherein the dielectric constant of the dielectric forming the transmission filter is higher than the dielectric constant of the dielectric forming the matching circuit. 6. The antenna duplexer according to claim 5, wherein a relative dielectric constant of a dielectric material forming the transmission filter is 10 or more. 7. The antenna duplexer according to claim 5, wherein the relative dielectric constant of the dielectric forming the matching circuit is less than 10. 8. A laminated integrated structure comprising a laminated portion formed of the same material as a dielectric material forming the matching circuit, wherein the transmission filter is sandwiched between the matching circuit and the laminated portion. The antenna duplexer according to Item 2 or 3. 9. The receiving filter is formed on an upper portion or a lower portion of the matching circuit and is sealed with resin, and the receiving filter is electrically connected to the matching circuit. The described antenna duplexer. 10. The antenna duplexer according to claim 8, wherein the matching circuit is formed above or below the transmission filter, and the transmission filter is electrically connected to the matching circuit. 11. The antenna sharing system according to claim 10, wherein the matching circuit is formed on a side where the reception filter is mounted, and the reception filter is electrically connected to the matching circuit. vessel. 12. The reception filter is formed in the matching circuit adjacent to the transmission filter, and is sealed with resin, and the reception filter and the transmission filter are respectively the matching circuit. The antenna duplexer according to claim 8, which is electrically connected to the antenna duplexer. 13. The antenna duplexer according to claim 8, wherein the reception filter is formed inside the matching circuit and is sealed with resin. 14. The antenna duplexer according to claim 1, wherein the transmission filter and the matching circuit are connected by an end face electrode and / or a via electrode. 15. The matching circuit includes a strip line, the reception filter is connected to the strip line via a via, and is connected to the strip line extracted from the antenna by electromagnetic coupling. The antenna duplexer according to claim 1, wherein: 16. The matching circuit has a strip line, the transmission filter is connected to the strip line via a via, and is connected to the strip line extracted from the antenna by electromagnetic coupling. The antenna duplexer according to claim 1, wherein: 17. A receiving filter having a composite structure of a filter having a surface acoustic wave element and a filter having a dielectric resonator, a transmitting filter having a filter having a dielectric resonator, and the receiving filter and An antenna duplexer, comprising: a matching circuit that matches each of the transmitting filters with an antenna, wherein the receiving filter, the transmitting filter, and the matching circuit are integrated. 18. A communication device comprising: the antenna duplexer according to claim 1, a transmission circuit section for outputting a transmission wave to the transmission filter, and a reception circuit section for inputting a reception signal from the reception filter. . 19. A communication device comprising: the antenna duplexer according to claim 17, a transmission circuit section for outputting a transmission wave to the transmission filter, and a reception circuit section for inputting a reception signal from the reception filter. .