JP4671225B2 - High frequency power amplifier - Google Patents

Description

  The present invention relates to a high-frequency power amplifier (high-frequency power amplifier), and more particularly to a high-frequency power amplifier that can suppress oscillation.

  A high-frequency power amplifying device (high-frequency power amplifier: HPA) is incorporated in the transmission-side output stage of a radio communication device (mobile communication device) such as an automobile phone or a mobile phone.

  A high-frequency power amplifier (HPA) having a wavelength band from 800 MHz to 2 GHz used in a cellular phone has a multistage configuration in which a plurality of amplifiers composed of transistors are connected in cascade to increase the amplification factor. In addition, each stage transistor (amplifier) is driven by a single power source.

  Since the gain of the transistor increases as the band becomes lower, the possibility of oscillation due to slight feedback increases. In order to prevent this oscillation, conventionally, a decoupling capacitor is incorporated in an amplifier circuit, and oscillation is suppressed by paying attention to the routing of a power supply line (for example, Non-Patent Document 1).

Published by Hitachi, "HITACHI RF Power Module Data Book", March 2001, p12-13.

  In a multi-stage high frequency power amplifying apparatus in which a plurality of amplifiers are connected in cascade, each amplifier is driven by the same power source. For this reason, the power supply line constitutes a feedback circuit, and a fluctuation voltage due to the internal impedance of the power supply is generated, causing oscillation. In order to suppress this voltage fluctuation, a decoupling capacitor is usually inserted between the power supply and the ground. However, as the feedback frequency becomes higher, the capacitor operates as an inductance. Therefore, in order to suppress oscillation, it is necessary to incorporate a large number of decoupling capacitors having different capacities, which hinders miniaturization of the high-frequency power amplifier. In addition, the use of a large number of decoupling capacitors causes an increase in the manufacturing cost of the high-frequency power amplifier.

An object of the present invention is to provide a high frequency power amplifying apparatus in which oscillation does not easily occur.
Another object of the present invention is to provide a high-frequency power amplifying apparatus that can achieve miniaturization.
The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

The following is a brief description of an outline of typical inventions disclosed in the present application.
(1) The high frequency power amplifier is
An input terminal;
An output terminal;
A control terminal;
A first power terminal;
A second power terminal,
A high-frequency power amplifier that amplifies a transmission signal including a high-frequency component with a plurality of amplifiers cascaded in multiple stages,
Each amplifier includes a transistor having a first electrode, a second electrode, and a control electrode,
The input terminal is connected to the control electrode of the first stage amplifier connected in cascade,
The output terminal is connected to the first electrode of the final stage amplifier connected in cascade,
The control terminal is connected to the control electrode of each amplifier;
The first power supply terminal is connected to the first electrode of each amplifier;
The second power supply terminal is connected to the second electrode of each amplifier;
In the cascaded previous stage and next stage amplifiers, the first electrode of the previous stage amplifier is connected to the control electrode of the next stage amplifier,
A band elimination filter connected to the ground is connected between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier.
In addition, the band elimination filter has a removal characteristic in which the frequency at which the attenuation amount becomes maximum coincides with or approximates the oscillation frequency at which the oscillation of the high frequency power amplifier device occurs.

The band elimination filter is:
A first microstrip line having one end connected to the first electrode of the final-stage amplifier and the other end connected to the first electrode of the other amplifier other than the final-stage amplifier;
A capacitive element connecting one electrode in the middle of the first microstrip line;
A resistive element connecting one electrode to the other electrode of the capacitive element;
One end is connected to the other electrode of the resistance element, and the other end is composed of a second microstrip line connected to the second power supply terminal.
When the frequency band of the high frequency power amplifier is 940 to 956 MHz, the oscillation frequency is around 102 MHz,
The band elimination filter is:
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 2.21 nH,
The resonant frequency is 94.0 MHz;
The bandwidth is 21.2MHz,
The removal frequency when the attenuation is maximized is 102 MHz.

(2) In the configuration of the means (1), a band elimination connected between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier is connected to the ground. Multiple filters are connected in parallel.

Each of the band elimination filters has a characteristic that the attenuation amount is the lowest at a frequency that matches or approximates one of the different oscillation frequencies among the plurality of oscillation frequencies at which the oscillation of the high-frequency power amplifier device occurs. And
The plurality of band elimination filters correspond to the ones sequentially decreasing from the maximum of the oscillation outputs of the plurality of oscillation frequencies.

And when the two band elimination filters are provided and the frequency band of the high frequency power amplifier is 940 to 956 MHz,
In the one band elimination filter,
The oscillation frequency is around 102 MHz;
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 2.21 nH,
The resonant frequency is 94.0 MHz;
The bandwidth is 21.2MHz,
The removal frequency when the attenuation amount is maximum is 102 MHz, and the oscillation frequency is 102 MHz in the band.
In the other band elimination filter,
The oscillation frequency is 102 MHz;
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 3.5 nH,
The resonant frequency is 79 MHz;
The bandwidth is 16.9MHz,
An oscillation frequency of 87 MHz is included in the band.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the means (1), the band elimination filter connected to the ground is connected between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier. . Since the band elimination filter has a removal characteristic in which the frequency at which the attenuation amount is the largest matches or approximates the oscillation frequency at which the oscillation of the high frequency power amplifier device occurs, the oscillation can be suppressed. For example, when the maximum oscillation frequency of the high-frequency power amplifying device is near 102 MHz, the removal frequency at which the attenuation amount of the band elimination filter is maximum is 102 MHz, and therefore oscillation is suppressed even if resonance occurs. As a result, a wireless communication device incorporating this high-frequency power amplifier can perform good communication without oscillation.

  According to the means (2), a plurality of band elimination filters connected to the ground are connected in parallel between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier. Has been. Each of the band elimination filters is a band elimination filter having the characteristic that the attenuation amount is the lowest at a frequency that matches or approximates one of the different oscillation frequencies among the plurality of oscillation frequencies at which the oscillation of the high-frequency power amplifier device occurs. ing. Further, the plurality of band elimination filters correspond to the ones that decrease sequentially from the maximum of the oscillation outputs of the plurality of oscillation frequencies.

  For example, when two band elimination filters are provided and the frequency band of the high-frequency power amplifier is 940 to 956 MHz, the frequency (oscillation frequency) causing the maximum oscillation of the high-frequency power amplifier is around 102 MHz, and the next largest oscillation The frequency (harmonic) that causes the error is 204 MHz. Since one of the band elimination filters incorporated to suppress this oscillation has a maximum frequency of 102 MHz, the other frequency band elimination filter has a maximum attenuation of 204 MHz. In the high frequency power amplifier, oscillation at 102 MHz and 204 MHz (harmonics) is suppressed. As a result, a wireless communication device incorporating this high-frequency power amplifier can perform good communication without oscillation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.

  In the first embodiment, an example in which the present invention is applied to a multi-stage high-frequency power amplifier (high-frequency power amplifier) in which amplifiers are cascade-connected in two stages will be described. 1 to 10 are diagrams relating to a high-frequency power amplifying apparatus which is Embodiment 1 of the present invention. FIG. 1 is an equivalent circuit diagram of the high-frequency power amplifying device, and FIG. 2 is a schematic plan view of the high-frequency power amplifying device of Example 1 shown with a part of the cap removed.

  As shown in FIG. 2, the high-frequency power amplifying apparatus (high-frequency power amplifier: HPA) 1 of the first embodiment has a plate-like square metal case 2 and a back surface ground layer soldered to the upper surface of the metal case 2. The wiring board 3 is formed with a metal cap 4 attached to the metal case 2 so as to cover the upper surface of the wiring board 3, and has a flat rectangular structure in appearance. Further, although not shown, external electrode terminals are exposed on the back surface of the wiring board 3 that protrudes away from the metal case 2. These external electrode terminals are connected with metal leads 5 by a conductive bonding material. Each lead 5 extends in parallel, and its outer end protrudes outside the wiring board 3. The lead (terminal) 5 is, for example, an input lead (RFin), a control lead (Vgg), a second power supply lead (GND), a first power supply lead (Vdd), and an output lead (RFout) from left to right. The terminals shown in the equivalent circuit diagram of FIG. 1 are configured.

  In the high-frequency power amplifying apparatus 1, a metal case 2 is fixed to a mounting substrate such as a mother board of a mobile phone (wireless communication device), for example. As a result, the heat generated in the high frequency power amplifier 1 is efficiently dissipated to the mounting substrate. The tip of each lead 5 is connected to a predetermined wiring on the mounting board by a conductive bonding material such as solder.

  The wiring board 3 has a multilayer wiring board structure in which dielectrics and conductor layers are sequentially stacked, and an active part (active element) such as a transistor and a passive part (passive element) such as a capacitor (C) and a resistor (R) on the upper surface thereof. ) Has been implemented. The high-frequency power amplifying apparatus 1 constitutes an equivalent circuit as shown in FIG. 1 by the wiring of the wiring board 3 and the mounted electronic components.

  As shown in the equivalent circuit, the high-frequency power amplifying apparatus 1 is configured to amplify a transmission signal including a high-frequency component between an input terminal (RFin) and an output terminal (RFout) by a plurality of amplifiers cascaded in multiple stages. Yes. The high-frequency power amplifying apparatus 1 has a two-stage configuration in which transistors Q1 and Q2 are connected in cascade. Each of the transistors Q1 and Q2 is a field effect transistor, and has a drain electrode as the first electrode, a source electrode as the second electrode, and a gate electrode as the control electrode.

  In the preceding stage (first stage) and the next stage (final stage) amplifiers (transistors Q1, Q2) connected in cascade, the first electrode (drain electrode) of the preceding stage amplifier (transistor Q1) is the same as that of the next stage amplifier (transistor Q2). It is connected to the control electrode (gate electrode). The drain electrodes of the transistors Q1 and Q2 are connected to the first power supply terminal (Vdd) and serve as electrodes that output the output signals of the transistors Q1 and Q2. The source electrodes of the transistors Q1 and Q2 are connected to the second power supply terminal (GND).

  The input terminal (RFin) is connected to the control electrode (gate electrode) of the first-stage amplifier (transistor Q1). The output terminal (RFout) is connected to the first electrode (drain electrode) of the final stage amplifier (transistor Q2). The control terminal (Vgg) is connected to the control electrode (gate electrode) of each amplifier (transistors Q1, Q2).

  In the first embodiment, as shown in FIG. 2, the semiconductor device 10 in which the transistor Q1 is formed and the semiconductor device 11 in which the transistor Q2 is formed are mounted on the upper surface of the wiring board 3 by solder connection. Further, as passive elements, capacitive elements (capacitors) indicated by C1 to C14 shown in the equivalent circuit diagram of FIG. 1 and resistance elements indicated by R1 to R5 are mounted. The capacitive element (capacitor) and the resistance element are both chip components (chip resistance, chip capacitor) having electrodes at both ends. In FIG. 2, these capacitive elements and resistive elements are not labeled. In FIG. 2, the thick wiring portion is a microstrip line. In the equivalent circuit of FIG. 1, the elongated rectangular portion is a microstrip line.

  As shown in FIG. 1, a matching circuit such as an input matching circuit, an interstage matching circuit, an output matching circuit, and a gate bias circuit is constituted by a capacitive element and a resistance element.

  In addition, this is one of the features of the present invention, which is a power supply line connected to the first power supply terminal (Vdd), which is connected to the ground between the drain electrode of the transistor Q2 and the drain electrode of the transistor Q1. A band elimination filter (band rejection filter: BEF) is connected. In the first embodiment, as shown in the equivalent circuit diagram of FIG. 1, the band elimination filter (BEF) is shown as a band elimination filter (BEF1). FIG. 1 is a circuit diagram in which a power source (power source) 12 is added to the first power source terminal (Vdd).

  The band elimination filter (BEF1) is shown in FIGS. 3 and 4 as being cut from the wiring board 3 for easy understanding. As shown in FIG. 3, a ground layer 15 is provided on the back surface of the wiring board 3. A wiring 16 is formed on the upper surface of the wiring board 3. The wiring 16 forms a microstrip line at a necessary location.

  As shown in FIG. 3 and FIG. 4, the band elimination filter (BEF1) includes a first microstrip line (MSLbef1), a capacitor element (Cbef1), a resistance element (Rbef1), and a second microstrip line (MSLbef2). It is configured.

  3 and 4, a portion extending linearly from the left end toward the right end is the first microstrip line (MSLbef1). One end (right end in the figure) of the first microstrip line (MSLbef1) is connected to the first electrode (drain electrode: D) of the final stage transistor Q2, and the other end (left end in the figure) is the first stage transistor Q1. Connected to the first electrode (drain electrode: D). One electrode 20a of a capacitive element (Cbef1) made of a chip capacitor is connected to the first microstrip line (MSLbef1). The other electrode 20b of the capacitive element (Cbef1) is connected to a wiring 16d provided on the upper surface of the wiring board 3. One electrode 21a of a resistance element (Rbef1) made of a chip resistor is connected to the wiring 16d in contact with or close to the other electrode 20b. The other electrode 21b of the resistance element (Rbef1) is connected to one end of a second microstrip line (MSLbef2) provided on the upper surface of the wiring board 3. The other end of the second microstrip line (MSLbef2) is connected to the through hole 22 and is connected to the conductor 23 connected to the ground layer 15.

In Example 1, the length a of the first microstrip line (MSLbef1) is 30 mm, the width b is 2.96 mm, the length e of the second microstripline (MSLbef2) is 0.934 mm, and the width d is It is 0.275 mm. A chip capacitor having a capacitance (capacitor) of 1000 pF is mounted as the capacitor element (Cbef1), and a chip resistor having a resistance of 0.55 to 2.2Ω is mounted as the resistor element (Rbef1). As a result, in the band elimination filter (BEF1), the microstrip line including MSLbef1, MSLbef2 and chip resistance (Rbef1) is 2.21 nH as a whole, and the capacitor is 1000 pF.
The band elimination filter (BEF1) having the above configuration has a removal frequency of 102 MHz at which the attenuation is the largest.

  When the high-frequency power amplifying apparatus 1 is used in a frequency band of 940 to 956 MHz, the primary oscillation frequency at which the largest oscillation occurs is near 102 MHz as shown in FIG. Therefore, by using the band elimination filter (BEF1), the elimination frequency (102 MHz) at which the attenuation amount of the band elimination filter (BEF1) is maximized is located in the vicinity of the primary oscillation frequency, and thus oscillation is suppressed. That is, the oscillation frequency is 94 MHz, but when no resistor is attached, the frequency of 102 MHz is included in the band, and the oscillation frequency can be suppressed.

  Here, the difference in the relationship between the gain and the frequency when the resistance value of the chip resistor (Rbef1) is changed, and the difference in the gain and the output (Pout) with respect to the frequency when the resistance value is changed are shown in FIGS. Show.

FIG. 6 is a graph showing a variation in gain due to a difference in the number of chip resistors (Rbef1) included in the band elimination filter (BEF1). A thick solid line described as one 2.2Ω represents a gain curve when one chip resistor having a resistance value of 2.2Ω is connected. As indicated by this gain curve, the minimum value of the gain is -20.5 dB. The dotted line described as two 2.2Ω indicates a gain curve when two chip resistors having a resistance value of 2.2Ω are connected in parallel. As shown by this gain curve, the minimum value of the gain is −25.1 dB. The one-dot chain line indicated as 2.2Ω3 indicates a gain curve when three chip resistors having a resistance value of 2.2Ω are connected in parallel. As indicated by this gain curve, the minimum value of the gain is -27.5 dB. The thin solid line written as 2.2Ω4 indicates a gain curve when four chip resistors having a resistance value of 2.2Ω are connected in parallel. As indicated by this gain curve, the minimum value of the gain is -29.1 dB.
From this graph, it can be seen that the gain gradually decreases as the chip resistance connected in parallel increases.

  6 to 10 are graphs showing the correlation between the oscillation frequency and the removal characteristic of the band elimination filter when the number of mounted chip resistors is changed. 7 is a graph when one chip resistor is mounted, FIG. 8 is a graph when two chip resistors are mounted in parallel, FIG. 9 is a graph when three chip resistors are mounted in parallel, and FIG. 10 is a chip. It is a graph at the time of mounting four resistors in parallel. From these graphs, it can be seen that there is almost no deviation of the resonance frequency due to the inductance of the resistor. It was also confirmed that the oscillation of the high-frequency power amplifying apparatus 1 was completely suppressed when the attenuation amount of the band elimination filter (BEF1) became −29.1 dB or less.

The first embodiment has the following effects.
(1) Between the first electrode (drain electrode) of the final-stage amplifier (transistor Q2) and the first electrode (drain electrode) of the first-stage amplifier (transistor Q1) that is an amplifier other than the final-stage amplifier. A band elimination filter (BEF1) connected to the ground is connected. The band elimination filter (BEF1) has a removal characteristic in which the frequency (rejection frequency) at which the attenuation amount is the largest approximates the oscillation frequency at which the oscillation of the high frequency power amplifying apparatus 1 occurs. Oscillation can be suppressed. For example, when the maximum oscillation frequency of the high-frequency power amplifying apparatus 1 is around 102 MHz, the removal frequency at which the attenuation amount of the band elimination filter (BEF1) is maximum is 102 MHz. Is done. As a result, a wireless communication device incorporating the high-frequency power amplifier 1 can perform good communication without oscillation.

(2) In the first embodiment, in order to suppress oscillation, a band elimination filter (BEF1) that combines a microstrip line, a capacitive element, and a resistive element is incorporated, and thus a structure in which a plurality of decoupling capacitors are mounted as in the prior art. Compared to the above, the high-frequency power amplifying apparatus 1 can be downsized.

  FIG. 11 is a schematic plan view showing the high frequency power amplifier according to the second embodiment of the present invention with the cap removed. The high frequency power amplifying apparatus 1 according to the second embodiment is the same as the high frequency power amplifying apparatus 1 according to the first embodiment. The resistance element (Rbef1) constituting the band elimination filter (BEF1) is dispersed in the wiring 16f with a metal oxide or the like that increases the resistance. This is an example of a resistor. The resistance element (Rbef1) of this example is formed by connecting one end to the first microstrip line (MSLbef1), and the other end is connected to the wiring 16g. An electrode at one end of a chip capacitor as a capacitive element (Cbef1) is connected to the wiring 16g, and the other end of the chip capacitor is connected to a second microstrip line (MSLbef1).

  Also in the high frequency power amplifying apparatus 1 of the second embodiment, the oscillation of the high frequency power amplifying apparatus 1 can be suppressed as in the first embodiment. In addition, since the resistor is formed by diffusion as the resistance element (Rbef1), there is an effect of downsizing without an external resistor.

  FIG. 12 is an equivalent circuit diagram of the high-frequency power amplifying device according to the third embodiment of the present invention, and FIG. 13 is a graph showing a state in which oscillation can be suppressed by the band elimination filter in the high-frequency power amplifying device according to the third embodiment.

  The high-frequency power amplifying apparatus 1 of the third embodiment is an example in which a plurality of band elimination filters are connected in parallel between the first electrode of the final stage amplifier and the first electrodes of amplifiers other than the final stage amplifier. Each band elimination filter is a band elimination filter having the characteristic that the attenuation amount is the lowest at a frequency that matches or approximates one of the oscillation frequencies different from each other among a plurality of oscillation frequencies at which oscillation of the high-frequency power amplification device occurs. The plurality of band elimination filters correspond to the ones sequentially decreasing from the maximum of the oscillation outputs of the plurality of oscillation frequencies. This suppresses oscillation at each oscillation frequency.

  The high-frequency power amplifying apparatus 1 according to the third embodiment is an example in which two band elimination filters are connected in parallel between the drain electrode of the transistor Q2 and the drain electrode of the transistor Q1, as shown in the equivalent circuit diagram of FIG. .

  One band elimination filter is a band elimination filter (BEF1) as in the first embodiment, and the other one is a band elimination filter (BEF2). The band elimination filter (BEF2) is provided to suppress oscillation at the secondary oscillation frequency.

  The other band elimination filter (BEF2) has the same configuration as the band elimination filter (BEF1), and includes a first microstrip line (MSLbef3), a capacitor element (Cbef2), a resistance element (Rbef2), and a second element. It is constituted by a microstrip line (MSLbef4). This band elimination filter (BEF2) suppresses oscillation at an oscillation frequency of 87 MHz, has a capacitance of 1000 pF, and has an inductance of 3.5 nH due to the capacitive element, the resistive element, and the first and second microstrip lines. The resonance frequency is 79 MHz, the bandwidth is 16.9 MHz, and the oscillation frequency is 87 MHz in the band.

  FIG. 13 is a graph showing a state in which oscillation can be suppressed by the band elimination filter (BEF1) and the band elimination filter (BEF2) in the high frequency power amplifying apparatus 1 of the third embodiment. The horizontal axis of the graph is frequency (GHz), and the vertical axis is amplitude (dBm). The characteristics by BEF1, the characteristics by BEF2, and the characteristics by BEF1 and BEF2 are shown. The band elimination filter (BEF1) can suppress the oscillation of the primary oscillation frequency in the vicinity of 102 MHz as in the first embodiment. Further, the oscillation at the secondary oscillation frequency in the vicinity of 79 to 102 MHz can be suppressed by the characteristics of BEF1 and BEF2. Thereby, it is possible to suppress the oscillation of the primary and secondary oscillation frequencies.

  Further, this is a modification of the third embodiment. However, when the oscillation frequency varies at 102 MHz, the other band elimination filter having a resonance frequency of 79.0 MHz is added to one band elimination filter having a resonance frequency of 94.0 MHz. For example, the resonance frequency of one band elimination filter is set to 94.0 MHz and the other resonance frequency is set to 84.0 MHz, and the band removal band is expanded from 77.5 MHz to 104.5 MHz. The bandwidth of one band elimination filter with a resonance frequency of 94.0 MHz is 21.2 MHz, and the bandwidth of one band elimination filter with a resonance frequency of 84.0 MHz is 17.0 MHz. As a result, even if the oscillation frequency varies from 77.5 MHz to 104.5 MHz, the oscillation frequency is within the band of the two band elimination filters. In the third embodiment, the purpose is to block two frequencies, and in the modified example, the purpose is to widen the band blocking frequency.

  The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Nor.

1 is an equivalent circuit diagram of a high-frequency power amplifying device that is Embodiment 1 of the present invention. It is a typical top view of the high frequency electric power amplifying device of Example 1 shown by removing a part of cap. It is a typical perspective view which shows the zone | band removal filter part in the high frequency power amplifier of Example 1. FIG. FIG. 4 is a schematic plan view of a band elimination filter portion shown in FIG. 3. 6 is a graph showing a state in which oscillation can be suppressed by a band elimination filter in the high-frequency power amplification device according to the first embodiment. It is a graph which shows the fluctuation | variation of the gain by the difference in the number of incorporation of the chip resistor which comprises the said band elimination filter. It is a graph which shows the correlation with the oscillating frequency in case the chip resistance which comprises the said band elimination filter is one, and the removal characteristic of a band elimination filter. It is a graph which shows the correlation of the oscillation frequency at the time of using two chip resistors which comprise the said band elimination filter in parallel, and the removal characteristic of a band elimination filter. It is a graph which shows the correlation of the oscillation frequency at the time of using three chip resistors which comprise the said band elimination filter in parallel, and the removal characteristic of a band elimination filter. It is a graph which shows the correlation with the oscillating frequency at the time of using four chip resistors which comprise the said band elimination filter in parallel, and the removal characteristic of a band elimination filter. It is a typical top view which removes and shows the cap of the high frequency electric power amplifier which is Example 2 of this invention. It is the equivalent circuit schematic of the high frequency power amplifier which is Example 3 of this invention. It is a graph which shows the state which was able to suppress oscillation with the zone | band removal filter in the high frequency power amplifier of the present Example 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... High frequency power amplifier (High frequency power amplifier: HPA), 2 ... Metal case, 3 ... Wiring board, 4 ... Cap, 5 ... Lead, 10, 11 ... Semiconductor device, 12 ... Power supply (power source), 15 ... Ground layer 16, 16d, 16f, 16g ... wiring, 20a ... one electrode, 20b ... the other electrode, 21a ... one electrode, 21b ... the other electrode, 22 ... a through hole, 23 ... a conductor.

Claims (11)

An input terminal;
An output terminal;
A control terminal;
A first power terminal;
A second power terminal,
A high-frequency power amplifier that amplifies a transmission signal including a high-frequency component with a plurality of amplifiers cascaded in multiple stages,
Each amplifier includes a transistor having a first electrode, a second electrode, and a control electrode,
The input terminal is connected to the control electrode of the first stage amplifier connected in cascade,
The output terminal is connected to the first electrode of the final stage amplifier connected in cascade,
The control terminal is connected to the control electrode of each amplifier;
The first power supply terminal is connected to the first electrode of each amplifier;
The second power supply terminal is connected to the second electrode of each amplifier;
In the cascaded previous stage and next stage amplifiers, the first electrode of the previous stage amplifier is connected to the control electrode of the next stage amplifier,
A band elimination filter connected to the ground is connected between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier ,
The band elimination filter is:
A first microstrip line having one end connected to the first electrode of the final stage amplifier and the other end connected to the first electrode of the other amplifier except the final stage amplifier;
A capacitive element connecting one electrode in the middle of the first microstrip line;
A resistive element connecting one electrode to the other electrode of the capacitive element;
A high frequency power amplifier comprising: a second microstrip line having one end connected to the other electrode of the resistance element and the other end connected to the second power supply terminal . 2. The high frequency power amplifying apparatus according to claim 1, wherein the band elimination filter has a removal characteristic such that a frequency at which an attenuation amount is maximum matches or approximates an oscillation frequency at which oscillation of the high frequency power amplifying apparatus occurs. The high frequency power amplifying apparatus according to claim 1 , wherein the resistance element is a chip resistor. The high frequency power amplifier according to claim 1 , wherein the resistance element is a wiring resistance formed on a wiring board. When the frequency band of the high frequency power amplifier is 940 to 956 MHz,
The oscillation frequency is 102 MHz;
The band elimination filter is:
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 2.21 nH,
The resonant frequency is 94.0 MHz;
The bandwidth is 21.2MHz,
The high frequency power amplifier according to claim 1 , wherein the removal frequency when the attenuation amount is maximum is 102 MHz. An input terminal;
An output terminal;
A control terminal;
A first power terminal;
A second power terminal,
A high-frequency power amplifier that amplifies a transmission signal including a high-frequency component with a plurality of amplifiers cascaded in multiple stages,
Each amplifier includes a transistor having a first electrode, a second electrode, and a control electrode,
The input terminal is connected to the control electrode of the first stage amplifier connected in cascade,
The output terminal is connected to the first electrode of the final stage amplifier connected in cascade,
The control terminal is connected to the control electrode of each amplifier;
The first power supply terminal is connected to the first electrode of each amplifier;
The second power supply terminal is connected to the second electrode of each amplifier;
In the cascaded previous stage and next stage amplifiers, the first electrode of the previous stage amplifier is connected to the control electrode of the next stage amplifier,
A plurality of band elimination filters connected to the ground are connected in parallel between the first electrode of the final stage amplifier and the first electrode of the amplifier other than the final stage amplifier ,
Each band elimination filter is
A first microstrip line having one end connected to the first electrode of the final stage amplifier and the other end connected to the first electrode of the other amplifier except the final stage amplifier;
A capacitive element connecting one electrode in the middle of the first microstrip line;
A resistive element connecting one electrode to the other electrode of the capacitive element;
A high frequency power amplifier comprising: a second microstrip line having one end connected to the other electrode of the resistance element and the other end connected to the second power supply terminal . Each of the band elimination filters has a characteristic that the attenuation amount is the lowest at a frequency that matches or approximates one of the different oscillation frequencies among the plurality of oscillation frequencies at which the oscillation of the high-frequency power amplifier device occurs. And
The high frequency power amplifier according to claim 6 , wherein the plurality of band elimination filters correspond to a plurality of oscillation outputs having a plurality of oscillation frequencies that are sequentially decreased from the maximum. The high-frequency power amplifier according to claim 6 , wherein the resistance element is a chip resistor. The high frequency power amplifying apparatus according to claim 6 , wherein the resistance element is a wiring resistance formed on a wiring board. Two band elimination filters are provided,
When the frequency band of the high frequency power amplifier is 940 to 956 MHz,
In the one band elimination filter,
The oscillation frequency is 102 MHz;
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 2.21 nH,
The resonant frequency is 94.0 MHz, the bandwidth is 21.2 MHz,
The removal frequency when the attenuation amount is maximum is 102 MHz, and the oscillation frequency is 102 MHz in the band.
In the other band elimination filter,
The oscillation frequency is 102 MHz;
The capacitance by the capacitive element is 1000 pF,
Inductance due to the capacitive element, the resistive element, and the first and second microstrip lines is 3.5 nH,
The resonant frequency is 79 MHz, the bandwidth is 16.9 MHz;
The high frequency power amplifier according to claim 6 , wherein an oscillation frequency of 87 MHz is included in the band. RF power amplifier of claim 1 0 in which the resonance frequency of the band elimination filter of the one is a 94.0MHz, the resonance frequency of the other band-reject filter is characterized by a 84.0MHz.

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