Doherty amplifier arrangement

Abstract

The present invention relates to a Doherty amplifier device. The amplifier device includes a substrate, a composite package amplifier having a bottom plate and an output plate, a first amplifier and a second amplifier provided on the bottom plate, a combining node that combines an output of the first amplifier and an output of the second amplifier, an output matching circuit provided on the bottom plate, having a first transmission line provided between the first amplifier and the combining node and a second transmission line provided between the combining node and the second amplifier, a third transmission line having one transmission line on which the output plate is mounted and another transmission line that connects the one transmission line to an external port, and a lead wire connected to one terminal of the output plate and the combining node. The length of the output plate and the other transmission line is equal to or less than π / 4 radian of a signal.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application Serial No. 62 / 926,720, filed October 28, 2019, based on 35 U.S.SC §119, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This application relates to Doherty amplifier devices. Background Technology

[0004] Using a standard Doherty amplifier with an active device of the same size as an example, specifically such as Figure 4 The output λ / 4 transformer is shown in Table 1. Table 1 shows a list of associated impedance matching requirements for different transformer profiles.

[0005] [Table 1]

[0006] TX1(Ω) TX2(Ω) Main terminal Peak Terminal Classic Method #1 35.35 35.35 50 50 Classic Method #2 35.35 50 100 50 Alternative method #1 50 50 50 100 Alternative method #2 40 50 78 64 Alternative method #3 50 40 32 100

[0007] Based on design constraints, it is possible to refer to Table 1 to determine the most suitable substrate and impedance required for designing a composite packaged Doherty amplifier.

[0008] The demands of compact amplifier design and delivery solutions have made higher quality and more complete solutions essential.

[0009] exist Figure 5 In conventional amplifier designs, packaged transistors form active devices with associated input and output matching networks that form passive components. However, in addition to the need for smaller design coverage, the increasing demand for delivered power necessitates eliminating the isolation between these components and combining them into a single entity. Summary of the Invention

[0010] This embodiment provides a Doherty amplifier device for amplifying input radio frequency (RF) signals. The Doherty amplifier device, having a back-off level in its output where the saturation power is less than a preset amount, includes: a substrate; a composite packaged amplifier having a base plate and an output plate on the substrate; a carrier amplifier for amplifying the input RF signal, the carrier amplifier saturating its output power at the back-off level and disposed on the base plate; a peak amplifier configured to exhibit significant leakage when the Doherty amplifier's output is less than the back-off level, the peak amplifier turning on at the back-off level and saturating its output at the saturation power level, and disposed on the base plate; a combination node combining the output of the carrier amplifier and the output of the peak amplifier; an output matching circuit having a first transmission line and a second transmission line; and a third transmission line disposed on the substrate, the third transmission line having one transmission line and another transmission line. The first transmission line is disposed between the carrier amplifier and the combination node. The second transmission line is disposed between the combination node and the peak amplifier, and the output plate has a terminal and an end terminal connected to an external port via the other transmission line, and is mounted on the other transmission line. For signals passing through this Doherty amplifier device, the output board and the third transmission line have an electrical length of less than π / 4 radians. Attached Figure Description

[0011] The foregoing and other uses, aspects and advantages of the present invention will be better understood through the following detailed description of preferred embodiments with reference to the accompanying drawings, in which:

[0012] Figure 1A The configuration of the composite packaged amplifier device of the present invention is shown;

[0013] Figure 1B The substrate of the composite packaged amplifier device of the present invention is shown;

[0014] Figure 2A The configuration of one embodiment of the composite packaged amplifier device is shown;

[0015] Figure 2B The configuration of another embodiment of the composite packaged amplifier device is shown;

[0016] Figure 3 A cross-sectional configuration of one embodiment of a composite packaged amplifier device is shown;

[0017] Figure 4 A block diagram of the Doherty amplifier is shown;

[0018] Figure 5 The configuration of a conventional amplifier device in a composite package is shown. Detailed Implementation

[0019] The following sections will describe in detail some embodiments of the Doherty amplifier device according to this application. In the description of the drawings, identical or similar numbers or symbols will refer to identical or similar elements without being interpreted repeatedly.

[0020] One practical implementation of the Doherty amplifier device Figure 1A The composite packaged amplifier shown is 30mm × 25mm in size.

[0021] Alternative method #2 is used in conjunction with a 0.508 mm thick printed circuit board (PCB) substrate (shown in Table 1). Then, for example, the PCB substrate 30 is made of a material such as a composite epoxy resin, and its dielectric constant is 3.0 or greater.

[0022] The composite packaged amplifier device has a PCB substrate 30, a composite packaged amplifier 20, an input RF power shunt 1, a main path input matching network 2, and a peak path input matching network 3.

[0023] The composite package amplifier 20, the input RF power shunt 1, the main path input matching network 2, and the peak path input matching network are disposed on the PCB substrate 30.

[0024] The PCB substrate 30 has an input main path 5, an input peak path 6, an output main and peak path 7, a final transformer 8, an output RF path 9, an input RF path 19 and a ground pattern 60 disposed on the main surface of the PCB substrate 30, and a ground metal 65 disposed on the back side of the PCB substrate 30.

[0025] The final transformer 8 is, for example, a microstrip line. The microstrip line disposed on the PCB substrate 30 has a ground metal located on the back side of the PCB substrate 30.

[0026] An input RF power shunt 1, such as a 3dB hybrid coupler assembly, is connected to the input RF path 19. A main path input matching network 2 is deployed between the input RF power shunt 1 and the composite package amplifier 20. The main path input matching network 2 is connected to the input RF power shunt 1 via a first capacitor C1, to the composite package amplifier 20 via pattern 31b, and in parallel to the input main path 5 via a first resistor R1. The first capacitor C1 has a capacitance of approximately 6pF, and the first resistor R1 has a resistance of approximately 10 ohms.

[0027] Peak path input matching network component 3 is deployed between the input RF power shunt 1 and the composite package amplifier 20. Peak path input matching network component 3 is connected to the input RF power shunt 1 via a second capacitor C2, to the composite package amplifier 20 via pattern 32b, and in parallel to the input peak path 6 via a second resistor R2. Therefore, for example, the capacitance of the second capacitor C2 is approximately 12 pF, and the resistance of the second resistor R2 is approximately 50 ohms.

[0028] Finally, transformer 8 is connected between output RF path 9 and composite package amplifier 20 via third capacitor C3, and is connected in parallel to output main and peak paths 7. The capacitance of third capacitor C3 is, for example, approximately 6 pF.

[0029] The composite packaged amplifier 20 has a package for a base plate 25, containing semiconductor molds 40a and 40b, internal input matching components 10a and 10b, internal output matching circuit 4, input metal plates 11a and 11b, and output metal plate 12. The semiconductor molds 40a and 40b, internal input matching components 10a and 10b, and internal output matching circuit 4 are disposed on the base plate 25. Then, for example, the input metal plates 11a and 11b, the output metal plate 12, and the base plate are made of a material such as copper.

[0030] The semiconductor housings 40a and 40b are each connected to the internal input matching components 10a and 10b via wires 51a and 51b, respectively. The semiconductor housings 40a and 40b are each connected to the internal output matching circuit 4 via wires 52a and 52b, respectively. The output metal plate 12 is connected to the internal output matching circuit 4 via wire 55. The base plate 25 and metal plates 11a, 11b, and 12 of the composite package amplifier 20 are molded from resin. This resin is then made of, for example, epoxy resin, polyimide resin, or other materials.

[0031] The final transformer 8 has a third transmission line 8a and a fourth transmission line 8b. The output metal plate 12 is connected to the third transmission line 8a of the final transformer 8. The input metal plates 11a and 11b are respectively connected to the first and second transformers 31b and 32b.

[0032] Figure 1B It shows Figure 1A The PCB substrate 30 was not installed. Figure 1A The composite package amplifier. Patterns 31 and 32 have patterns 31a, 32a and patterns 31b, 32b disposed on PCB substrate 30. Then, patterns 31a and 32a of patterns 31 and 32 are respectively connected to the input metal plates 11b and 11a of the composite package amplifier 20.

[0033] Finally, the third transmission line 8a of transformer 8 will be connected to the output metal plate 12 of composite package amplifier 20.

[0034] The ground pattern 60 has patterns 31a, 32a and patterns 31b, 32b disposed on the PCB substrate 30. The ground pattern 60 will then be connected to the base plate 25 of the composite package amplifier 20.

[0035] The main objective of this invention is to provide a low-cost but mass-producible compact amplifier solution in a surface-mount package.

[0036] The reason for prioritizing surface mount packaging over conventional drop-in ceramic packaging is the accuracy of pick and place positioning during mass production.

[0037] However, in a specific surface mount package, in this particular example, the electrical terminals have been designed to provide a width of 1.525 mm. Equations 1a and 1b show empirical formulas for determining the characteristic impedance of the microstrip based on known dielectric material information.

[0038] [Equation 1a]

[0039] when hour,

[0040] Characteristic impedance,

[0041] [Equation 1b]

[0042] when hour,

[0043] Characteristic impedance,

[0044] Where W represents the width of the dielectric substrate and H represents the thickness of the dielectric substrate, and ε eff The effective dielectric of the substrate is represented by the aforementioned equation, which can be used to approximate the characteristic impedance of the microstrip.

[0045] Using a fixed width value of 1.525 mm, Table 2 shows examples of RF electrical impedance associated with a standard dielectric substrate with varying thickness.

[0046] [Table 2]

[0047] Substrate Name Dielectric Dielectric thickness RF electrical impedance Substrate A 2.2 0.508mm 50Ω Substrate B 2.2 0.254mm 30.3Ω Substrate C 3.66 0.508mm 40Ω Substrate D 3.66 0.254mm 24.1Ω Substrate E 6.15 0.508mm 31.6Ω Substrate F 6.15 0.254mm 18.9Ω

[0048] The length of a λ / 4 transformer varies with frequency (the length increases as the frequency decreases). Using Doherty as an example, the same principle applies. Figure 2A and 2BThis illustrates how the package can be further used for different frequencies.

[0049] exist Figure 2A In one embodiment shown, the location where the interconnecting wires between the dielectric (item #4) and the final transformer (item #8) are joined is circled. This location has been chosen so as to provide RF signal excitation as close as possible to the edge of the transformer.

[0050] exist Figure 2B In another embodiment shown, the (circled) interconnecting wires are joined at the top edge of the package leadframe / microstrip transformer TX1. Again, this is to ensure that the RF excitation is as close as possible to the edge of TX1.

[0051] Figure 2A The internal output matching circuit 4 is shown to have transmission lines 27 and 28 (first and second transmission lines), which are each connected to the encapsulated semiconductor molds 40a and 40b via wires 52a and 52b, respectively. A first region connected between transmission lines 27 and 28 of the internal output matching circuit 4 is connected to the output metal plate 12 via wire 55. This first region is positioned on the side of transmission line 28. Wire 55 is concentrated and joined on the first region of transmission lines 27 and 28. For the signal passing through the amplifier, the output metal plate 12 and the fourth transmission line 8b have an electrical length of less than π / 4 radians. For example, the length of the output metal plate 12 corresponding to a frequency of 20 GHz is 5 mm. Then, the length of the output metal plate 12 and the fourth transmission line 8b is 20 mm. The final transformer 8 is shorted by using the output metal plate 12 as a microstrip line, and has a third transmission line 8a and a fourth transmission line 8b. The composite packaged amplifier device 100 is composed of a small device. Each transmission line and each pattern example is made of copper, and each wire is made of gold, etc.

[0052] Figure 2B An internal output matching circuit 4 is shown, having transmission lines 27 and 28 each connected to encapsulated semiconductor molds 40a and 40b via wires 52a and 52b, respectively. A second region connected between transmission lines 27 and 28 of the internal output matching circuit 4 is connected to the output metal plate 13 instead of the output metal plate 12 via wire 56. This second region is positioned on the side of transmission line 27. Wire 56 is concentrated and joined on the second region of transmission lines 27 and 28. For signals passing through this amplifier, the output metal plate 13 and the fourth transmission line 8b have electrical lengths less than π / 4 radians. For example, the length of the output metal plate 13 corresponding to a frequency of 10 GHz is 20 mm, which is more than... Figure 2AThe output metal plate 12 is longer. Then, the output metal plate 13 and the fourth transmission line 8b are 40mm long. Finally, the transformer 8 is shorted by using the output metal plate 13 as a microstrip line, having a third transmission line 8a and a fourth transmission line 8b. The composite packaged amplifier device 100 is composed of small devices. Each transmission line and each pattern example is made of copper, and each conductor is made of gold, etc.

[0053] Figure 3 by Figure 2A The cross-section of the composite package amplifier shown illustrates an actual implementation of the Doherty amplifier. The composite package amplifier 20 is disposed on a PCB substrate 30. A ground pattern 60 of the PCB substrate 30 is electrically and thermally connected to a ground metal 65 of the substrate 30 via through-holes 90. An output metal plate 12 is connected via conductors 55 to a first transmission line 28 of the internal output matching assembly 4. The output metal plate 12 is soldered to a third transmission line 8a of the final transformer 8. A base plate 25 is soldered to the ground pattern 60 of the PCB substrate 30. Examples of each transmission line and each pattern are made of copper, each solder is made of a gold and tin compound, and each conductor is made of gold, etc. The base plate 25, input metal plate 11a, and output metal plate 12 of the composite package amplifier 20 are molded from resin.

[0054] However, the semiconductor device according to the invention is not limited thereto, and may include various semiconductor devices. For example, another embodiment is a conventional amplifier device, rather than the Doherty amplifier device of the above embodiments.

[0055] While specific embodiments of the invention have been described herein for illustrative purposes, many modifications and variations will be apparent to those skilled in the art. Therefore, the appended claims are intended to encompass all such modifications and variations that fall within the true spirit and scope of the invention.

Claims

1. A Doherty amplifier apparatus that amplifies an input radio frequency (RF) signal, the Doherty amplifier apparatus having a back-off level from a saturation power that is less than a preset amount in an output of the Doherty amplifier, the Doherty amplifier apparatus comprising: a substrate; a compound package amplifier having a bottom plate and an output plate on the substrate; a carrier amplifier for amplifying the input radio frequency (RF) signal, the carrier amplifier saturating an output power of the carrier amplifier at the back-off level, and disposed on the bottom plate; a peak amplifier configured to exhibit a substantial amount of leakage when the Doherty amplifier is less than the back-off level in the output of the Doherty amplifier, the peak amplifier turning on at the back-off level, and saturating an output of the peak amplifier at the saturation power, and disposed on the bottom plate; a combining node that combines the output of the carrier amplifier with the output of the peak amplifier; an output matching circuit having a first transmission line and a second transmission line; a third transmission line disposed on the substrate, the third transmission line including one transmission line and another transmission line; and wherein the first transmission line is disposed between the carrier amplifier and the combining node; wherein the second transmission line is disposed between the combining node and the peak amplifier, wherein the output plate has one terminal and an end terminal connected to an external port via the other transmission line, and is mounted on the one transmission line, and wherein the output plate and the third transmission line have an electrical length that is equal to or less than π / 4 radians for a signal that passes through the Doherty amplifier apparatus.

2. The Doherty amplifier apparatus of claim 1, wherein one terminal of the output plate is connected to the combining node by a plurality of conductive lines.

3. The Doherty amplifier apparatus of claim 2, wherein the one terminal of the output plate is opposite a point connected to the other transmission line.

4. The Doherty amplifier apparatus of claim 1, wherein the carrier amplifier and the peak amplifier are each independently connected to an input matching circuit.

5. The Doherty amplifier apparatus of claim 1, further comprising: a terminal disposed on the substrate, the terminal disposed on the substrate being connected to the other transmission line via a capacitance.

6. An amplifier apparatus that amplifies an input radio frequency (RF) signal, the amplifier apparatus comprising: a substrate; a compound package amplifier having a bottom plate and an output plate on the substrate; first and second amplifiers disposed on the bottom plate, the first and second amplifiers for amplifying the input radio frequency (RF) signal; a combining node that combines an output of the first amplifier with an output of the second amplifier; an output matching circuit provided on the backplane, the output matching circuit having a first transmission line provided between the first amplifier and the combining node, and a second transmission line provided between the combining node and the second amplifier; a third transmission line provided on the substrate, the third transmission line having one transmission line on which the output plate is mounted and another transmission line that connects the one transmission line to an external port; and a plurality of conductive lines connected to one terminal of the output plate on the side of the combining node and the combining node, wherein the output plate and the other transmission line have an electrical length equal to or less than π / 4 radians for a signal that passes through the amplifier device. ​

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