JP2012205207A - High frequency circuit, high frequency component, and communication apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency circuit of low power consumption, with low NF (noise figure), improved reception sensitivity, and with a high attenuation amount outside a pass band.SOLUTION: In the high frequency circuit, one of a first band pass filter connected to an input stage of an amplifier and a second band pass filter connected to an output stage of the amplifier is a capacitive band pass filter having a resonance point on a low frequency side in a pass band, and the other is an inductive band pass filter having a resonance point on a high frequency side in the pass band.

Description

  The present invention relates to a high-frequency circuit, a high-frequency component, and a high-frequency component using them, which are used in a communication system of a mobile phone, a receiving circuit unit such as GPS, Bluetooth, and wireless LAN.

  2. Description of the Related Art Conventionally, a high-frequency circuit unit for receiving radio waves such as microwave bands and quasi-microwave bands from communication satellites and ground base stations amplifies a received signal with an amplifier LNA as shown in FIG. It was configured to remove interference waves (signals other than the received signal) outside the passband through the BPF. The received signal is weak compared to the transmitted signal. For example, the radio wave from the communication satellite is only −100 dBm or less. For this reason, the amplifier is saturated in the strong electric field region of the interference wave, and the received signal may not be amplified correctly. Even if the amplifier does not saturate, it may be difficult to achieve stable reception with a large suppression level of the received signal.

Therefore, a band-pass filter is connected to the previous stage of the amplifier to attenuate the interference wave input to the amplifier so that stable reception of the interference wave is possible even in a strong electric field region.
If a band-pass filter is connected in front of the amplifier, it is possible to secure an attenuation amount of the interference wave, but in general, a band-pass filter having a large attenuation amount outside the band tends to increase the insertion loss. There was a problem that the insertion loss increased and the reception sensitivity deteriorated.

  In order to solve such a problem, the present inventor disclosed in Patent Document 1 as a first bandpass filter connected to the front stage of the amplifier, the insertion loss in the passband is a second band connected to the rear stage of the amplifier. Using a filter that is smaller than the pass filter, the second band-pass filter uses a filter that has an attenuation amount at a frequency outside the pass band that is greater than the attenuation amount of the first band-pass filter, thereby improving reception sensitivity. And a high attenuation outside the passband.

JP 2010-147589 A

  However, in the case of the high-frequency circuit disclosed in Patent Document 1, the bandpass filter with a small insertion loss can input the interference wave to the amplifier without being sufficiently attenuated and can stably receive the interference wave in a strong electric field region. I was worried about not. In addition, since a band-pass filter having a relatively large insertion loss is connected to the rear stage side of the amplifier, an amplifier having a high gain is required to obtain a predetermined output power, and there is a problem that power consumption increases. there were.

Therefore, the present invention provides a bandpass filter having a small insertion loss as a bandpass filter connected to the subsequent stage of the amplifier while improving the reception sensitivity and obtaining a high attenuation outside the passband while having a small NF (noise figure). A first object is to obtain a high-frequency circuit that can be used and has low power consumption.
It is a second object of the present invention to reduce the size of the high-frequency components that constitute the high-frequency circuit that connects the band-pass filter before and after the amplifier and to suppress the deterioration of the electrical characteristics caused by the configuration.
It is a third object of the present invention to provide a small communication device that uses the high-frequency circuit or the high-frequency component and has excellent electrical characteristics and can reduce power consumption.

A first invention includes an amplifier, a first bandpass filter connected to an input stage of the amplifier, and a second bandpass filter connected to an output stage of the amplifier, and the first band One of the pass filter and the second band pass filter is a capacitive band pass filter having a resonance point on the low frequency side of the pass band, and the other is an induction having a resonance point on the high frequency side of the pass band. It is a high frequency circuit characterized by being a characteristic band pass filter.
It is preferable to use a low noise amplifier as the amplifier because the noise figure of the high frequency circuit can be suppressed.

The capacitive band pass filter can increase the attenuation on the low frequency side outside the pass band in the vicinity of the pass band than on the high frequency side. For this reason, the insertion loss characteristic of the bandpass filter in the passband tends to have a higher loss on the low frequency side than on the high frequency side, but attenuation poles are provided on each of the low frequency side and the high frequency side of the passband, Therefore, the loss can be reduced as compared with the band-pass filter having a large out-of-band attenuation.
The inductive bandpass filter can increase the amount of attenuation in the vicinity of the passband on the high frequency side outside the passband than on the low frequency side. For this reason, the insertion loss characteristics of the band-pass filter in the pass band tend to be larger on the high frequency side than on the low frequency side. However, like the capacitive band-pass filter, the band-pass filter has a large out-of-band attenuation. Compared with, it is possible to reduce the loss.

  A high-frequency circuit configured using such a band-pass filter has excellent reception sensitivity, small NF, and low power consumption, along with a large out-of-band attenuation. When there is a high-field interference wave near the passband, use a capacitive bandpass filter as the first bandpass filter and an inductive bandpass filter as the second bandpass filter. It ’s fine. Also, when there is a high electric field interference wave on the high frequency side near the pass band, an inductive band pass filter is used as the first band pass filter, and a capacitive band pass is used as the second band pass filter. Use a filter.

In the present invention, a capacitive bandpass filter having a first port and a second port is disposed between the first resonator on the first port side, the third resonator on the second port side, and the stages thereof. It is preferable that the second resonator is a three-stage resonator having an interdigitally coupled resonator electrode.
Also, an inductive bandpass filter having a first port and a second port is provided with a first resonator on the first port side, a third resonator on the second port side, and a second disposed between those stages. A three-stage resonator including a resonator, the resonator electrodes of the first resonator and the second resonator are interdigitally coupled, and the resonator electrodes of the second resonator and the third resonator are combs. It is preferable to adopt a configuration in which lines are connected.

  The second invention is a high-frequency component characterized in that the high-frequency circuit of the first invention is configured on a substrate.

In the present invention, the substrate is preferably a multilayer ceramic substrate.
A multilayer ceramic substrate includes a plurality of ground electrodes formed in different layers and a resonator constituting the first band-pass filter and the second band-pass filter in a region sandwiched between the ground electrodes. An electrode pattern for the electrode and the capacitor electrode is provided so that the first electrode pattern constituting the first bandpass filter and the second electrode pattern constituting the second bandpass filter do not overlap in the stacking direction. It is preferably formed in different planar regions via a plurality of via hole groups that are arranged and connect different ground electrodes.

  A third invention is a communication apparatus using the high frequency circuit of the first invention.

  A fourth invention is a communication apparatus using the high-frequency component of the second invention.

According to the present invention, a band-pass filter having a small insertion loss as a band-pass filter connected to the subsequent stage of the amplifier while improving NF (noise figure), improving reception sensitivity, and obtaining a high attenuation outside the pass band. Therefore, a high-frequency circuit with low power consumption can be obtained.
In addition, it is possible to reduce the size of the high-frequency components that constitute the high-frequency circuit that connects the band pass filter before and after the amplifier, and to suppress the deterioration of the electrical characteristics due to the configuration.
Furthermore, by using the high-frequency circuit and the high-frequency component, it is possible to provide a small communication device that is excellent in electrical characteristics and can reduce power consumption.

It is a circuit block diagram which shows the structural example of the high frequency circuit which concerns on one embodiment of this invention. It is an attenuation characteristic of a band pass filter used for a high frequency circuit concerning one embodiment of the present invention. It is an equivalent circuit of the band pass filter used for the high frequency circuit concerning one embodiment of the present invention. It is the attenuation | damping characteristic of the other band pass filter used for the high frequency circuit which concerns on one embodiment of this invention. It is an equivalent circuit of the other band pass filter used for the high frequency circuit concerning one embodiment of the present invention. It is an equivalent circuit diagram which shows the structural example of the high frequency circuit which concerns on one embodiment of this invention. It is an external appearance perspective view which shows the structural example of the high frequency component which concerns on one embodiment of this invention. It is a circuit block diagram which shows the structural example of the high frequency circuit part of the radio | wireless communication apparatus comprised using the high frequency circuit which concerns on one embodiment of this invention. It is a circuit block diagram which shows the other structural example of the high frequency circuit part of the radio | wireless communication apparatus comprised using the high frequency circuit which concerns on one embodiment of this invention. It is the external appearance perspective view and bottom view which show the other structural example of the high frequency circuit part of the radio | wireless communication apparatus comprised using the high frequency circuit which concerns on one embodiment of this invention. It is a circuit block diagram which shows the other structural example of the high frequency circuit part of the radio | wireless communication apparatus comprised using the high frequency circuit which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the internal structure of the multilayer ceramic substrate used for the high frequency circuit component which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the internal structure of the multilayer ceramic substrate used for the high frequency circuit component which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the internal structure of the multilayer ceramic substrate used for the high frequency circuit component which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the internal structure of the multilayer ceramic substrate used for the high frequency circuit component which concerns on one embodiment of this invention. It is a frequency characteristic figure of the amount of attenuation of a band pass filter used for high frequency circuit parts concerning one embodiment of the present invention. It is a frequency characteristic figure of the amount of attenuation of other band pass filters used for high frequency circuit parts concerning one embodiment of the present invention. It is a frequency characteristic figure of the amount of attenuation of high frequency circuit parts concerning one embodiment of the present invention. It is a frequency characteristic figure of NF of the high frequency circuit component concerning one embodiment of the present invention. It is a circuit block diagram which shows an example of the conventional high frequency circuit part.

Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a circuit configuration of a high-frequency circuit according to an embodiment of the present invention. In this high-frequency circuit, a capacitive bandpass filter having a resonance point on the low frequency side of the passband is connected to the front stage of the amplifier, and an inductive bandpass filter having a resonance point on the high frequency side of the passband is connected to the subsequent stage. Connected. As already described, what kind of band pass filter is connected to the front stage and the rear stage of the amplifier can be set depending on whether the interference wave is on the low frequency side or the high frequency side near the pass band.

  In order to simplify the following description, the pass frequency band fb is 2.3 GHz to 2.7 GHz (including wireless communication specification WiBro; 2.3 GHz to 2.4 GHz, WiMAX; 2.495 GHz to 2.690 GHz. As a communication system for mobile phones such as GSM1800 (1.71 GHz to 1.88 GHz) and GSM1900 (1.85 GHz to 1.99 GHz), the interference wave is low in the vicinity of the passband. Although the case where it exists in the frequency side is demonstrated, it is not limited to it. WiBro, WiMAX, and GSM are trademarks or registered trademarks.

  FIG. 2 is an attenuation frequency characteristic diagram of a first bandpass filter configured as a capacitive bandpass filter. In the vicinity of 2.05 GHz on the low frequency side of the pass frequency band, an attenuation pole A due to resonance is obtained, attenuation of −25 dB or less is obtained at a frequency including the frequency band of the interference wave, and the signal due to the interference wave is input to the amplifier. To suppress.

FIG. 3 is an equivalent circuit diagram illustrating a configuration example of the first bandpass filter. The first band pass filter includes a terminal (first port) Pa1, a terminal (second port) Pa2, first to third resonators, and a capacitor Ca4.
Each resonator includes an inductor and a capacitor. The first resonator connected to the first port Pa1 includes an inductor La1 and a capacitor Ca1, and the second resonator includes an inductor La2 and a capacitor Ca2. The third resonator connected to the second port Pa2 includes an inductor La3 and a capacitor Ca3. The second resonator is disposed between the stages of the first resonator and the third resonator, and the inductors are disposed close to each other and are inductively coupled. In the figure, inductive binding is represented by a curve M.

  In the resonator electrode constituting the inductor of each resonator, the short-circuit side of adjacent resonator electrodes is arranged in different directions. With such an arrangement, the resonator electrodes are interdigitally coupled, and the coupling between the resonator electrodes is stronger than the comb line structure in which the short-circuit side is arranged in the same direction. The coupling includes an inductive coupling and an electrostatic coupling, and the electrostatic coupling generated on the open side is stronger than the inductive coupling generated on the short-circuit side of the resonator electrode at a frequency in the vicinity of the pass frequency band, and the first band pass. The coupling in the pass frequency band of the filter is dominated by capacitance, and an attenuation pole based on the coupling is formed on the low frequency side of the pass frequency band. The resonance frequency of the attenuation pole A is determined by the inductive coupling M, the electrostatic coupling, and the capacitor Ca4.

  FIG. 4 is an attenuation frequency characteristic diagram of a second bandpass filter configured as an inductive bandpass filter. It has an attenuation pole B due to resonance in the vicinity of 3.02 GHz on the high frequency side of the pass frequency band, and attenuates −25 dB or less at a frequency including the frequency band of 3.3 GHz to 3.8 GHz which is another frequency band of WiMAX. As a result, unnecessary signals are prevented from being input to the amplifier.

FIG. 5 is an equivalent circuit diagram illustrating a configuration example of the second bandpass filter. The second band pass filter includes a terminal (first port) Pb1, a terminal (second port) Pb2, first to third resonators, and a capacitor Cb4.
Each resonator includes an inductor and a capacitor. The first resonator connected to the first port Pb1 includes an inductor Lb1 and a capacitor Cb1, and the second resonator includes an inductor Lb2 and a capacitor Cb2. The third resonator connected to the 2-port Pb2 has an inductor Lb3 and a capacitor Cb3.
The second resonator is disposed between the stages of the first resonator and the third resonator, and the inductors are disposed close to each other and are inductively coupled. In the figure, as in the case of the first band pass filter, inductive coupling is represented by a curve M.

In the resonator electrode constituting the inductor of each resonator, the resonator electrode of the first resonator and the resonator electrode of the second resonator are arranged so that the short-circuit sides of the resonator electrodes are in different directions. . Further, the resonator electrode of the second resonator and the resonator electrode of the third resonator are arranged so that the short-circuit side of the resonator electrode is in the same direction. With such an arrangement, the resonator electrodes of the first resonator and the second resonator are interdigitally coupled, and the resonator electrodes of the second resonator and the third resonator are comb-line coupled.
With such a configuration, the inductive coupling generated on the short-circuit side of the resonator electrode is made stronger than the electrostatic coupling generated on the open side at a frequency near the pass frequency band, so that the pass frequency band of the second band-pass filter is obtained. Inductive coupling is dominant, and an attenuation pole based on coupling is formed on the high frequency side of the pass frequency band. The resonance frequency of the attenuation pole B is determined by the inductive coupling M, the electrostatic coupling, and the capacitor Cb4. Although the circuit configuration of other resonators sandwiching the second resonator is asymmetrical, the electrical characteristics are the same even if the input / output ports are switched, and the connection direction with other circuits is not limited.

A configuration example of a high-frequency circuit using such a first band-pass filter and a second band-pass filter is shown in the block diagram of FIG. A first band pass filter 50 a is connected between the input port Pr 1 and the amplifier 10, and a second band pass filter 50 b is connected between the output port Pr 2 and the amplifier 10. The configuration of the first band-pass filter 50a is the same as the capacitive band-pass filter shown in FIG. 3, and the second band-pass filter 50b is the same as the inductive band-pass filter shown in FIG. Yes, the description is omitted.
In the figure, an inductor 215 connected between the amplifier and the band-pass filters 50a and 50b constitutes a matching circuit. Of course, a capacitor may be used depending on the configuration of the matching circuit. Further, the power supply path to the amplifier, the choke coil arranged in the power supply path, etc. are not shown and are omitted.

  In the high-frequency circuit having such a configuration, it is possible to attenuate signals outside the pass frequency band while suppressing an increase in insertion loss in the pass frequency band. For this reason, reception sensitivity is improved, NF is small, and power consumption is reduced.

The high-frequency circuit of the present invention is preferably a high-frequency component composed of a laminate including an insulator layer and a conductor pattern, and an amplifier semiconductor element and a chip component mounted on the surface.
As the insulator layer, dielectric ceramics, resin, or a composite material of resin and ceramic can be used. Laminating is performed using a known method. For example, when dielectric ceramics are used, LTCC (low temperature co-fired ceramic) technology or HTCC (high temperature co-fired ceramic) technology is used.

In the case of LTCC technology, the laminated body is made of a ceramic dielectric that can be sintered at a low temperature of 1000 ° C. or lower, for example, as an insulator layer, and a predetermined conductive pattern is formed by printing a conductive paste such as Ag or Cu. A plurality of ceramic green sheets having a thickness of 10 to 200 μm are used, laminated and integrally sintered to form a multilayer ceramic substrate.
Examples of ceramic dielectrics that can be sintered at low temperatures include ceramics having Al, Si, and Sr as main components and Ti, Bi, Cu, Mn, Na, K, etc. as auxiliary components, Al, Mg, Si, and Gd. And ceramics containing Al, Si, Zr and Mg.

  FIG. 7 is an external perspective view showing a configuration example of the high-frequency component. The stacked body 100 has an upper surface on which the amplifier semiconductor element 10 and the chip component 210 are mounted, and a lower surface on which terminal electrodes and the like (not shown) are formed. The inner layer on the upper surface side of the multilayer body 100 includes a plurality of ground electrodes formed in different layers and the first band-pass filter and the second band-pass filter in a region sandwiched between the ground electrodes. An electrode pattern for the resonator electrode and the capacitor electrode is preferably configured. A plurality of first electrode patterns constituting the first band-pass filter and second electrode patterns constituting the second band-pass filter are arranged so as not to overlap in the stacking direction and connect different ground electrodes. Preferably, they are formed in different planar regions via the via hole groups.

Such a high-frequency circuit and a high-frequency component are used in a high-frequency circuit unit of a wireless communication device. 8 and 9 are circuit blocks showing a configuration example of the high-frequency circuit unit.
In the high frequency circuit block of FIG. 8, a high frequency switch circuit 40 is connected to the input port Pr <b> 1 of the high frequency circuit 1. In the figure, an SPDT (Single Pole Double Throw) switch is shown as the high-frequency switch circuit 40, but is not limited to this. A multi-pole multi-throw switch such as an SPnT (n is a natural number of 3 or more) switch or a DP3T (Double Pole Throw) switch may be used.

In the high frequency circuit section, an antenna is connected to the port Po1 on the port Pu1 side of the high frequency switch circuit 40. The high frequency circuit 1 is connected to the high frequency switch circuit 40 port Pu2. A transmission circuit and other reception circuits are connected to the port Pu3 of the high-frequency switch circuit 40.
When the high-frequency circuit unit performs a reception operation, a signal including an interference wave incident on the antenna appears at the input port Pr1 of the high-frequency circuit 1 and is input to the high-frequency circuit 1 through the high-frequency switch circuit 40. A signal that passes through the high-frequency circuit 1 and appears at the output port Pr2 is a signal that is outside the pass frequency band is attenuated and the signal within the pass frequency band is correctly amplified. An RFIC (Radio-Frequency Integrated Circuit) that converts a signal from the baseband unit into a transmission signal and converts the received signal into a frequency that can be processed by the baseband unit is connected to the output port Pr2. Since the signal input to the RFIC is a signal outside the pass frequency band that is sufficiently attenuated, it is possible to prevent the RFIC from malfunctioning. In addition, since the insertion loss of the high-frequency circuit 1 is small, power consumption necessary for amplification can be suppressed. In particular, when operating power of the wireless communication apparatus is supplied by a battery, battery consumption can be suppressed.
Instead of the high-frequency switch circuit 40, a demultiplexing circuit can be used.

  FIG. 9 shows a high-frequency circuit unit in which a filter circuit 90 is connected in parallel with the high-frequency circuit 1. The filter circuit 90 is a filter having a different pass band from the first band pass filter 50a of the high frequency circuit 1, and is preferably any one of a band pass filter, a high pass filter, and a low pass filter. According to such a configuration, the signal can be demultiplexed without using the high-frequency switch circuit 40.

  FIG. 10 is a perspective view of a high-frequency component according to an embodiment of the present invention. This high-frequency component is used in a high-frequency circuit section of a wireless communication device for WiMAX, and includes a plurality of filters and a balun, and a high-frequency amplifier, a low-noise amplifier, and a high-frequency switch are mounted and integrated on a multilayer ceramic substrate. Is.

  FIG. 11 is a block diagram showing the circuit configuration of the high-frequency component. The DP3T high-frequency switch circuit 40 connects / disconnects the first reception path and the first antenna, connects / disconnects the second reception path and the second antenna, and transmits the transmission signal path, The connection / disconnection between the second antenna and the second antenna is switched to enable transmission diversity.

  In the first path of the reception signal connected to the port Pu2a of the high frequency switch circuit 40, the high frequency circuit 1 including the first band pass filter 50a, the low noise amplifier 10, and the second band pass filter 50b, A balun 60 is provided. The second path of the received signal connected to the port Pu2b includes a high-frequency circuit 1 including a first bandpass filter 55a, a low noise amplifier 15, and a second bandpass filter 55b, and a balun 65. A low-pass filter 80, a high-frequency amplifier 20, and a balun 70 are provided in the transmission signal path connected to the port Pu3. The port Pu1a is connected to the first antenna via the port ANT1, and the port Pu1b is connected to the second antenna via the port ANT2.

  Chip components such as respective semiconductor elements constituting the high-frequency switch circuit 40, the high-frequency amplifier 20, and the low-noise amplifiers 10 and 15, and some circuit elements such as a DC cut capacitor and a matching circuit are mounted on the multilayer ceramic substrate 100. After being appropriately connected by a connecting means such as a bonding wire BW, it is sealed with a resin 200.

A plurality of terminal electrodes are formed on the bottom surface of the high-frequency component. A ground electrode GND connected to the inner-layer ground electrode through a via hole is provided in the center of the lower surface to provide a stable ground potential and improve the connection strength with the circuit board.
Each terminal electrode is formed on each side surface around the ground electrode GND, and on the first side surface side, the ground terminal G, the first antenna terminal ANT1, the second antenna terminal ANT2, the power supply terminal V, A non-connection terminal NC is formed. A power supply terminal V and a non-connecting terminal NC are formed on the second side surface on the lower side of the drawing adjacent to the first side surface, and a power supply terminal V is formed on the third side surface of the upper side of the drawing facing the second side surface. ing. On the fourth side facing the first side through the ground electrode GND, output balanced terminals RX1-, RX1 + of the balun 60, output balanced terminals RX2-, RX2 + of the balun 65, input balanced terminals TX1-, TX1 +, a ground terminal G, and a power supply terminal V are formed. Part of the reference numerals given to the terminal electrodes corresponds to the ports in the circuit block diagram shown in FIG.
Reference numerals not shown in FIG. 11 include a non-connection terminal NC and a power supply terminal V. The non-connecting terminal NC is a floating terminal that has no connection with a circuit in the multilayer ceramic substrate. A voltage is applied to the power supply terminal V in order to operate the high-frequency switch circuit, the high-frequency amplifier, and the low-noise amplifier, but these are not distinguished in the figure.

  12 to 15 are exploded perspective views showing the internal structure of a part of the multilayer ceramic substrate. Hereinafter, a structural example of the high-frequency component will be described in detail with reference to these drawings. What is shown is a portion corresponding to the first path of the received signal. The circuit configuration of the first bandpass filter 50a is the same as that shown in FIG. 3, and the circuit configuration of the second bandpass filter 50b is as follows. This is the same as that shown in FIG. Moreover, since the characteristic of those electrical characteristics is also the same, the description is omitted.

12 to 15, S <b> 1 to S <b> 11 indicate the top surfaces of the first to the plurality of dielectric layers from the top surface on which the chip components and the like are mounted.
In the figure, via holes for use in electrical connection between circuit element electrode patterns formed in each layer and heat dissipation are shown in black. Reference numerals assigned to the electrode patterns constituting the first and second bandpass filters correspond to equivalent circuits. Via holes formed and connected across a plurality of layers are denoted by the same reference numerals. In addition, the thickness of each layer is not reflected in the drawing, and some layers that are not necessary for the description are omitted.

On the upper surface of the layer S1, mounting electrodes on which chip components such as semiconductor elements and reactance elements are mounted and electrodes for wi-bonding are formed. A semiconductor element for the low noise amplifier 10 is mounted on the terminal Pd1, a semiconductor element for the high frequency switch circuit 40 is mounted on the terminal Pd2, and a semiconductor element for the high frequency amplifier 20 is mounted on the terminal Pd3.
A port Pu2a (not shown) of the semiconductor element for the low noise amplifier 10 is connected to one end side of the electrode pattern lp1 by a bonding wire, Sh1 formed on the other end side, and a via hole formed on the lower layer side thereof. The capacitor electrode pattern Cin formed in the layer S9 is connected via Sh1. The electrode pattern Cin corresponds to the capacitor electrode pattern Ca1 formed in the layer S8 and the capacitor electrode pattern Ca1 formed in the layer S10, and forms a coupling capacitor connected in series to the signal path. This coupling capacitor is used to block DC current from the high frequency switch circuit.

  The electrode pattern Ca1 and the electrode pattern Ca1 are connected via the via hole Sh2, and form a capacitor Ca1 facing the ground electrode GND formed in the layers S7 and S11. Each ground electrode GND is formed on substantially the entire surface including the omitted portion.

The electrode pattern Ca1 of the layer S8 is connected to the capacitor electrode Ca4 of the layer S9 through the via hole Sh3. Capacitor electrode Ca4 constitutes capacitor Ca4 so as to face capacitor electrode Ca3 formed in layers S8 and S10 described later.
Furthermore, it is connected to one end side of a strip-shaped resonator electrode La1 formed in the layers S5 and S6 and extending along one side of the multilayer ceramic substrate through an upper via hole Sh4. The other end of the resonator electrode La1 is connected to the ground electrode GND of the layer S7 via the via hole Sh5 and the via hole Sh5 on the lower layer side. Further, it is also connected to the ground electrode GND of the layer S2 via the upper layer via hole Sh5. Each resonator electrode La1 is connected in parallel to form an inductor La1, and the capacitor Ca1 forms a first resonator. By connecting the resonator electrodes in parallel, the resistance can be reduced and the performance of the resonator can be improved.

On the same layer as the resonator electrode La1 of the inductor La1, the resonator electrode La2 positioned adjacent to each other is formed. One end of the resonator electrode La2 is connected to the ground electrode GND of the layer S2 and the layer S7 via the via hole Sh6 adjacent to the via hole Sh4 and the via hole Sh6 connected to the upper and lower sides thereof.
The other end of the resonator electrode La2 is connected to the capacitor electrodes Ca2 (layer S8) and Ca2 (layer S10) through the via hole Sh7. Each capacitor electrode Ca2 faces the ground electrode GND of the layers S7, S9, and S11 to form a capacitor Ca2.
The inductor La2 formed by the resonator electrode La2 and the capacitor Ca2 constitute a second resonator.

On the same layer as the resonator electrode of the inductor La2, the resonator electrode La3 positioned adjacent to each other is formed. One end of the resonator electrode La3 is connected to the capacitor electrode Ca3 (layer S8) via the via hole Sh8 adjacent to the via hole Sh6 and the via hole Sh8 connected to the lower layer side thereof. Capacitor electrode Ca3 is connected to capacitor electrode Ca3 (layer S10) through via hole Sh9. Each capacitor electrode Ca3 is opposed to the ground electrode GND of the layers S7, S9, and S11 to form a capacitor Ca3. Further, the capacitor electrode Ca3 is connected to a terminal Pd4 formed on the upper surface of the layer S1 through the upper via hole Sh11.
The other end side of the resonator electrode La3 is connected to the ground electrode GND of the layer S2 and the layer S7 via the via hole Sh10 and the via hole Sh10 connected therebelow.
The inductor La3 formed by the resonator electrode La3 and the capacitor Ca3 constitute a third resonator.

By arranging the short-circuit side of adjacent resonator electrodes in the opposite direction, the resonance electrode La2 of the second resonator includes the resonance electrode La1 of the first resonator and the resonance electrode of the third resonator. Interdigitally coupled to La3.
The inductive coupling can be adjusted by the interval between the adjacent resonance electrodes. The electrostatic coupling can be adjusted by the distance on the open end side of the resonance electrode.
In this embodiment, the open ends of the resonance electrode La1 of the first resonator and the resonance electrode La3 of the third resonator are connected to the capacitor electrodes Ca1 and Ca3 formed on the layers S8 and S10, respectively. Capacitor electrodes Ca1 and Ca3 are arranged close to each other on the layer S8, and capacitor electrodes Ca1 and Ca3 are arranged close to each other on the layer S10 to strengthen the coupling.
With such a configuration, the first band-pass filter 50a has a stronger electrostatic coupling on the open side than the inductive coupling generated on the short-circuit side of the resonator electrode, and has a resonance point on the low frequency side of the pass band. Capacitive bandpass filter.
In this embodiment, the resonator electrodes of the resonators are arranged in a substantially parallel relationship, but may not be parallel for adjustment of coupling and impedance. For example, if the electrostatic coupling on the open end side is to be strengthened, the gap between the resonator electrodes on the open end side is narrowed, the short circuit side is widened, or the width of the resonator electrode is partially adjusted to be adjusted. It is also possible.

  An inductor constituting the input-side matching circuit is connected to the terminal Pd4 of the layer S1. And it connects with the input port of the low noise amplifier 10 mounted in terminal Pd1 via the bonding wire. The output port of the low-noise amplifier 10 is connected to the terminal Pd5 through an inductor that forms a matching wire and a matching circuit on the input side.

The via hole Sh12 formed in the terminal Pd5 is connected to the capacitor electrode pattern Cb1 formed in the layer S8 through the via hole Sh13 formed in the lower layer side. The electrode pattern Cb1 is connected to the capacitor electrode pattern Cb4 formed in the layer S9 and the capacitor electrode pattern Cb1 formed in the layer S10 through the via hole Sh14. The capacitor electrode pattern Cb4 is opposed to a capacitor electrode pattern Cb3 formed in a layer S8, which will be described later, and constitutes a capacitor Cb4. Here, the capacitance value of the capacitor Cb4 of the second band pass filter is configured to be relatively small with respect to the capacitor Ca4 of the first band pass filter.
The electrode pattern Cb1 formed on the layer S8 faces the ground electrode GND formed on the layers S7 and S9, and the electrode pattern Cb1 formed on the layer S10 faces the ground electrode GND formed on the layers S9 and S11. Thus, the capacitor Cb1 is formed.

  A via hole Sh15 is formed in an upper layer overlapping the electrode pattern Cb1 formed in the layer S8, and is connected to one end side of the band-shaped resonator electrode Lb1 formed in the layers S5 and S6 and extending along one side of the multilayer ceramic substrate. The other end side of the resonator electrode Lb1 is connected to the capacitor electrode pattern GND of the layers S7 and S9 through the via hole Sh16 and the via hole Sh16 on the lower layer side. Further, it is also connected to the ground electrode GND of the layer S2 via the upper layer via hole Sh16. The resonator electrode Lb1 is connected in parallel to form an inductor Lb1, and the capacitor Cb1 forms a first resonator.

On the same layer as the resonator electrode Lb1 of the inductor Lb1, the resonator electrode Lb2 positioned next to each other is formed. One end of the resonator electrode Lb2 is connected to the capacitor electrode pattern Cb2 of the layer S8 through a via hole Sh18 adjacent to the via hole Sh16 and a via hole Sh18 connected therebelow. The electrode pattern Cb2 is connected to the capacitor electrode pattern Cb2 of the layer S10 through the via hole Sh22. The electrode pattern Cb2 formed on the layer S8 constitutes the capacitor Cb2 so as to face the ground electrode GND on the layers S7 and S9 and the electrode pattern Cb2 formed on the layer S10 face the ground electrode GND on the layers S9 and S11.
The other end side of the resonator electrode Lb2 is connected to the ground electrodes of the capacitor layers S2 and S7 through the via hole Sh17.
The inductor Lb2 formed by the resonator electrode Lb2 and the capacitor Cb2 constitute a second resonator.

On the same layer as each resonator electrode Lb2 of the inductor Lb2, the resonator electrode Lb3 positioned adjacent to each other is formed. One end of the resonator electrode Lb3 is connected to the capacitor electrode Cb3 (layer S8) via the via hole Sh20 adjacent to the via hole Sh18 and the via hole Sh20 connected to the lower layer side thereof. The capacitor electrode Cb3 is connected to the capacitor electrode Cb3 (layer S10) through the via hole Sh23.
Each capacitor electrode Cb3 is opposed to the ground electrode GND of the layers S7, S9, and S11 to form a capacitor Cb3. The capacitor electrode Cb3 is connected to the electrode pattern Ba1 for the balun 60 formed on the upper surface of the layer S3 through the upper via hole Sh21. The electrode patterns Ba1, Bb1, and Bb2 are electrode patterns for the balun 60.
The other end side of the resonator electrode Lb3 is connected to the ground electrode GND of the layer S2 and the layer S7 through the via hole Sh19.
The inductor Lb3 formed by the resonator electrode Lb3 and the capacitor Cb3 constitute a third resonator.

The second band pass filter 50b has a configuration in which the first resonator and the second and third resonators are arranged in opposite directions in the short-circuit direction. The second and third resonators have a configuration in which the short-circuit direction is the same direction.
Each resonance electrode Lb1 of the first resonator is interdigitally coupled to each resonance electrode Lb2 of the second resonator, and each resonance electrode Lb2 of the second resonator is connected to each resonance electrode Lb3 of the third resonator. Comline joins.
The inductive coupling can be adjusted by the interval between the adjacent resonance electrodes. The electrostatic coupling can be adjusted by the distance on the open end side of the resonance electrode. In this embodiment, the resonator electrodes of the resonators are arranged in a substantially parallel relationship, but the widths of the resonator electrodes are made different, and the widths of the resonator electrodes of the first resonator and the third resonator are different. The width of the resonator electrode and the resonator electrode of the second resonator are increased in this order. Further, the interval between the resonator electrodes is defined as the interval between the resonator electrode of the second resonator and the resonator electrode of the first resonator, and the distance between the resonator electrode of the second resonator and the resonator electrode of the third resonator. It is narrower than the interval.

  In the present embodiment, the open ends of the resonance electrode Lb1 of the first resonator and the resonance electrode Lb3 of the third resonator are connected to the capacitor electrodes Cb1 and Cb3 formed in the layers S8 and S10, respectively. The capacitor electrodes Cb1 and Cb3 are arranged close to each other on the layer S8, but the capacitor electrodes Cb1 and Cb3 are arranged apart from each other on the layer S10, and are more resonators than the first band pass filter 50a. Electrostatic coupling on the open end side of the electrode is weakened. In addition, the second bandpass filter 50b has inductivity generated on the short-circuit side of the resonator electrode by using both interdigital coupling and combline coupling for coupling the resonator electrodes of the first to second resonators. The coupling is stronger than the electrostatic coupling generated on the open side, and an inductive bandpass filter having a resonance point on the high frequency side of the passband is obtained.

  A plurality of ground electrodes GND are formed on the multilayer ceramic substrate, and the ground electrodes GND formed in different layers are connected by a plurality of via holes. A part of the via hole connecting the ground electrode GND is configured as a via hole group Sh including a via hole arranged in a column. In this embodiment, the via hole group Sh is formed in the layers S2 to S10. There are a via hole group Sh that passes through the layers S2 to S10 and a via hole group Sh that changes the position in the layer in which the ground electrode GND is formed. The via hole group Sh formed in each layer is shown by surrounding the layers S3, S8 and S10 with broken lines. The via hole group denoted by reference numeral SB is a thermal via for a high-frequency amplifier arranged in the path of the transmission signal. Since the thermal via group SB also connects the plurality of ground electrodes GND, the same function as the via hole group Sh is exhibited.

  The via hole group Sh includes a first band-pass filter provided in each layer, a second. The band pass filter and the electrode pattern constituting the balun are separated into different regions α, β, γ (illustrated in the layer S3). In at least a layer sandwiched between the pair of ground electrodes GND, the electrode patterns of the respective circuits are arranged without overlapping in the stacking direction. Such a configuration reduces electromagnetic coupling between different circuits. Since interference with other circuits is reduced, the first band-pass filter and the second band-pass filter can perform without reducing their functions.

The electrical characteristics of the obtained high-frequency components were evaluated using a network analyzer and noise sole.
FIG. 16 shows the characteristics of the band-pass filter 50a connected between the antenna port ANT1 and the low noise amplifier 10. FIG. 17 shows the characteristics of the band-pass filter 50 b connected between the low noise amplifier 10 and the balun circuit 60. The band pass filter 50a has an attenuation pole on the low band side of the pass band, and the band pass filter 50b has an attenuation pole on the high band side of the pass band.
The band-pass filter 50a has a large attenuation of about 60 dB near 1 GHz and about 40 dB near 2 GHz. Therefore, unnecessary signals such as GSM signals and WCDMA signals input from the antenna can be greatly attenuated, and a low-noise amplifier using these unnecessary signals. Can be prevented.
Since the band pass filter 50b has a large attenuation of about 25 dB at around 3.3 GHz and about 35 dB at 4.6 GHz, the signal that has passed through the low noise amplifier 10 can cause unnecessary signals in the 3.3 GHz band and 2 of the pass band. The double harmonic signal can be greatly attenuated, and malfunction of the RFIC can be prevented.

18 shows signal characteristics between the antenna port ANT1 and the reception ports RX1- and RX1 + when the band-pass filter having the signal characteristics shown in FIGS. 16 and 17 is connected in the high-frequency component having the circuit block shown in FIG. It is. A gain of 12 dB is secured in the pass band, and a large attenuation of 40 dB or more is secured in the unnecessary band.
FIG. 19 shows the noise figure of this circuit. While ensuring the gain and attenuation, the noise figure is about 3.5 dB. By using a high-frequency component constituted by this circuit, it is possible to perform high-quality communication while suppressing power consumption.

  According to the present invention, a high frequency circuit with low NF and low power consumption can be obtained while obtaining a high attenuation outside the passband. Furthermore, it is possible to reduce the size by configuring the high-frequency circuit as a multilayer high-frequency component, and to suppress deterioration of electrical characteristics due to the configuration. Furthermore, by using the high-frequency circuit and the high-frequency component, it is possible to provide a small-sized communication device that has excellent electrical characteristics and can reduce power consumption.

DESCRIPTION OF SYMBOLS 1 High frequency circuit 10 Low noise amplifier 40 High frequency switch circuit 50a 1st band pass filter 50b 2nd band pass filter 60 Balun 90 Filter circuit 100 Multilayer ceramic substrate

Claims (6)

An amplifier, a first bandpass filter connected to the input stage of the amplifier, and a second bandpass filter connected to the output stage of the amplifier;
Either the first bandpass filter or the second bandpass filter is a capacitive bandpass filter having a resonance point on the low frequency side of the passband, and the other is on the high frequency side of the passband. A high-frequency circuit, which is an inductive band-pass filter having a resonance point. The capacitive bandpass filter has a first port and a second port, and is disposed between the first resonator on the first port side, the third resonator on the second port side, and the stages thereof. The second resonator is composed of a three-stage resonator having an interdigitally coupled resonator electrode,
The inductive bandpass filter has a first port and a second port, a first resonator on the first port side, a third resonator on the second port side, and a first resonator disposed between these stages. The three resonators are constituted by three-stage resonators, the resonator electrodes of the fourth resonator and the fifth resonator are interdigitally coupled, and the resonator electrodes of the second resonator and the third resonator are coupled. The high-frequency circuit according to claim 1, wherein comb lines are coupled.   A high frequency component comprising the high frequency circuit according to claim 1 or 2 on a substrate.   The substrate is a multilayer ceramic substrate, and a plurality of ground electrodes formed in different layers inside the substrate, and the first band pass filter and the second band pass filter in a region sandwiched between the ground electrodes The electrode pattern for the resonator electrode and the capacitor electrode constituting the first band pass filter and the second electrode pattern constituting the second band pass filter are arranged in the stacking direction. The high-frequency component according to claim 3, wherein the high-frequency component is formed in different planar regions through a plurality of via hole groups that do not overlap and connect between the ground electrodes.   A communication apparatus using the high-frequency circuit according to claim 1.   A communication apparatus using the high-frequency component according to claim 3.

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