2-18GHz 20W power amplifier
By using the combination of input power distribution network, Class AB amplifier and impedance converter in 2~18GHz power amplifier, the problem of low output power in the prior art is solved, and power output and high in the 2~18GHz frequency band are achieved Efficiency reduces circuit area and cost.
Patent Information
- Application Number
- CN202411362681.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2024-12-24
AI Technical Summary
The existing 2~18GHz power amplifier chips have low output power at 28V voltage, and higher output power can only be achieved through higher voltage or secondary integration, resulting in the circuit area requirements of the on-chip synthetic network and cannot be effectively met. High power demand.
A 2~18GHz 20W power amplifier was designed, using an input power distribution network to divide the signal into two signals with the same amplitude and phase. A Class AB amplifier performs power amplification, impedance converter converts impedance back to the original impedance, and the output power synthesis network will The two signals are combined into one output signal, and the non-frequency conversion approach is used to solve the problems of broadband matching and power matching.
It realizes power output of more than 20W and efficiency of more than 20% in the 2~18GHz frequency band range, reduces circuit area and cost, and improves the high efficiency and high linear performance of the power amplifier.
Smart Images
Figure CN119182370A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of ultra-wideband power amplification, and in particular to a 2-18 GHz 20 W power amplifier. Background Art
[0002] 2~18GHz power amplifier chips are generally implemented using non-uniform die stacking and artificial transmission line structures. The GaN process generally uses a 100um thick or 75u thick SiC substrate. The transmission line impedance range that this substrate can currently achieve is generally 20 ohms to 150 ohms. Lower or higher impedance is not achievable. Based on this process system, the output power of the GaN power amplifier chip is 10W in the 2~18GHz frequency range and 28V voltage. Higher output power can only be obtained through higher voltage or secondary integration in the chip, but on-chip synthesis has extremely stringent requirements on the circuit area of the synthesis network, and there is a problem of low output power in the 2~18GHz frequency range and 28V voltage. Summary of the invention
[0003] The purpose of the present invention is to design a 2~18GHz 20W power amplifier in order to solve the above problems.
[0004] The present invention achieves the above-mentioned purpose through the following technical solutions: 2~18GHz 20W power amplifier, including: An input power distribution network, wherein the input power distribution network is used to divide the input signal into two signals with the same amplitude and phase; A class AB amplifier connected to the input power distribution network, the class AB amplifier is used to amplify the power of the signal and then output an amplified signal; An impedance converter connected to the class AB amplifier, the impedance converter being used to convert the impedance of the amplified signal back to the original impedance; An output power synthesis network is connected to the impedance converter, and is used to synthesize the two amplified signals into one output signal for output.
[0005] The beneficial effects of the present invention are: The 2~18GHz 20W power amplifier divides the input signal into two signals with the same amplitude and phase through an input power distribution network, the class AB amplifier amplifies the signal and outputs the amplified signal, the impedance converter transforms the impedance of the amplified signal back to the original impedance, and the output power synthesis network synthesizes the two amplified signals into one output signal and then outputs it. The present invention adopts a non-frequency conversion idea to solve the problems of broadband matching and power matching and synthesis, and realizes providing a power of more than 20W and an efficiency of more than 20% within the 2~18GHz frequency band. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 This is the overall block diagram of the 2~18GHz 20W power amplifier of the present invention; Figure 2 The circuit diagram of the class AB amplifier of the 2-18 GHz 20 W power amplifier of the present invention; Figure 3 It is a module schematic diagram of the output power synthesis network of the 2~18GHz 20W power amplifier of the present invention; Figure 4 A circuit diagram of an equalization circuit for a 2-18 GHz 20 W power amplifier of the present invention; Figure 5 This is a schematic diagram of the structure of a 2~18GHz 20W power amplifier of the present invention; Figure 6 This is the small signal gain diagram of the 2~18GHz 20W power amplifier of the present invention; Figure 7 This is a saturated output power diagram of a 2-18 GHz 20 W power amplifier of the present invention; Figure 8 This is the additional efficiency diagram of the 2~18GHz 20W power amplifier of the present invention; In the figure: 1-input power distribution network, 2-balancing circuit, 3-class AB amplifier, 4-impedance converter, 5-output power synthesis network, 51-power synthesis network, 52-matching capacitor, 53-non-uniform impedance conversion network, R-first resistor, C-first capacitor. DETAILED DESCRIPTION
[0007] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0008] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0009] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0010] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0011] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.
[0012] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0013] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.
[0014] like Figure 1-8 As shown, 2~18GHz 20W power amplifier, including: An input power distribution network 1, wherein the input power distribution network 1 is used to divide the input signal into two signals with the same amplitude and phase; A class AB amplifier 3 connected to the input power distribution network 1, the class AB amplifier 3 is used to amplify the power of the signal and then output an amplified signal; An impedance converter 4, connected to the class AB amplifier 3, and configured to convert the impedance of the amplified signal back to the original impedance; The output power synthesis network 55 is connected to the impedance converter 4, and is used for synthesizing the two amplified signals into one output signal for output.
[0015] In this embodiment, the input power distribution network 1 is implemented using a power distribution network that is independent of the operating frequency, and distributes the input signal's equal-amplitude and in-phase power into two signals; compared to the traditional system that uses a characteristic impedance of 50 ohms, the input uses a characteristic impedance of 50 ohms, and the output uses a characteristic impedance of 100 ohms. The two output characteristic impedances of 100 ohms are connected in parallel, and the input at the input end is still a characteristic impedance of 50 ohms, thereby realizing a power distribution network that is independent of the operating frequency, and further realizing ultra-wideband operation.
[0016] In practical applications, the class AB amplifier 3 adopts a distributed circuit structure. For a distributed amplifier, the unit power density and output impedance per millimeter of the device are constant values. At the same time, the impedance range that can be achieved by the passive transmission line on the chip is also determined by the process parameters. Therefore, in this embodiment, the output characteristic impedance of the class AB amplifier 3 is selected as 25 ohms, and the input characteristic impedance is selected as 100 ohms. The 100 ohm input impedance realizes broadband matching of the input power distribution network 1, and the 25 ohm output impedance increases the output power level of the distributed power amplifier, thereby ensuring the high power and high efficiency output of the 2~18GHz 20W power amplifier. Specifically, the first-stage amplifier circuit in the class AB amplifier 3 uses 7 tube buds, that is, the 100 ohm characteristic impedance is matched to the input impedance of the 7 tube buds; the second-stage amplifier circuit uses 10 tube buds to synthesize the output, that is, the output uses an output impedance of 25 ohms, so as to improve the power tolerance of the process platform and facilitate secondary synthesis.
[0017] In this embodiment, the impedance converter 4 can be implemented by any impedance converter 4 that can convert the impedance of the amplified signal back to the original impedance; in order to solve the problem of insufficient bandwidth of broadband matching, a specific impedance value is selected to achieve complete numerical impedance matching in the frequency range of 2~18GHz, that is, the output characteristic impedance of the class AB amplifier 3 is 25 ohms, and the characteristic impedance needs to be raised to 50 ohms. Therefore, in this embodiment, the impedance converter 4 uses a non-uniform transmission line transformer to match the output characteristic impedance to the 50 ohms required by the synthesis end; the non-uniform transmission line transformer is a planar transmission line structure with non-uniform characteristics. In order to make the input port have a characteristic impedance of 25 ohms and the output port have a characteristic impedance of 50 ohms, it is necessary to increase the main line bandwidth and reduce the secondary line width to increase the power tolerance of the main line. At the same time, the line width becomes larger to reduce the high-frequency conductor loss.
[0018] In the present invention, the 2~18GHz 20W power amplifier divides the input signal into two signals with the same amplitude and phase through an input power distribution network 1, the class AB amplifier 3 amplifies the signal and outputs the amplified signal, the impedance converter 4 converts the impedance of the amplified signal back to the original impedance, and the output power synthesis network 55 synthesizes the two amplified signals into one output signal and outputs it. The present invention adopts the idea of non-frequency impedance transformation to solve the problems of broadband matching and power matching and synthesis, and realizes providing a power greater than 20W and an efficiency greater than 20% within the 2~18GHz frequency band.
[0019] In one embodiment, the output power synthesis network 55 includes: A power synthesis network 51, connected to the class AB amplifier 3, the power synthesis network 51 is used to synthesize the two amplified signals into one output signal; The non-uniform impedance conversion network 53 is connected to the power synthesis network 51 , and is used to convert the impedance of the output signal into the original impedance.
[0020] In this embodiment, the output power synthesis network 55 adopts a non-uniform impedance conversion network 53 which is independent of the operating frequency to realize broadband power synthesis. The power synthesis network 51 synthesizes the two amplified signals into one output signal and then outputs it, that is, two 50 ohm characteristic impedances are synthesized into one 25 ohm characteristic impedance output, and then the non-uniform impedance conversion network 53 changes the 25 ohm characteristic impedance into a 50 ohm characteristic impedance and then outputs it, thereby realizing broadband high power synthesis.
[0021] In one embodiment, the output power synthesis network 55 further includes a matching capacitor 52 , and the matching capacitor 52 is connected to the non-uniform impedance transformation network.
[0022] In practical applications, the output power of a 2-18 GHz 20 W power amplifier is relatively large. Therefore, in this embodiment, two capacitors are connected in series to form a matching capacitor 52 to reduce the power borne by each capacitor during operation.
[0023] In practical applications, in view of the gain characteristics of semiconductor field effect transistors, that is, as the operating frequency increases, the core gain decreases, an equalization circuit 2 must be set in the design process of an ultra-wideband 2~18GHz 20W power amplifier to compensate for this characteristic, so as to ensure that the 2~18GHz 20W power amplifier has a flat frequency response within the operating frequency range.
[0024] In one embodiment, the 2-18 GHz 20 W power amplifier further includes an equalizing circuit 2, which is connected in series between the input power distribution network 1 and the class AB amplifier 3, and is used to perform equalization compensation on the signal.
[0025] Furthermore, the equalization circuit 2 includes a first capacitor C and a first resistor R, and the first capacitor C and the first resistor R are connected in parallel.
[0026] In this embodiment, the equalization circuit 2 is composed of RC in parallel, and the resistance part and the capacitance part work together to play a broadband equalization role to improve the small signal gain characteristics of the 2~18GHz 20W power amplifier, so that the 2~18GHz 20W power amplifier has a better frequency response within the frequency band, thereby providing a small signal gain greater than 20dB in the 2~18GHz frequency range.
[0027] The 2-18 GHz 20W power amplifier of the present invention adopts a non-uniform transmission line transformer to achieve a 2-18 GHz 20W power output on a 28V GaN process platform. Two 12W power amplifiers integrated in the chip adopt non-50 ohms to improve the output power, and adopt a non-frequency conversion idea to solve the problems of broadband matching and power distribution and synthesis; the input power distribution network 1 directly connects two 100 ohm characteristic impedances in parallel to form a 50 ohm characteristic impedance, and no other matching unit is required at the input end to reduce the area of the circuit and reduce the cost; the equalization circuit 2 adopts RC parallel connection to improve the flatness characteristics within the band and the stability of the 2-18 GHz 20W power amplifier; the power amplification part adopts a class AB amplifier 3 composed of two-stage amplification circuits, and the gate width size of the front and rear stage tube cores is designed with a reasonable push-to-pull ratio, so that when the rated power is output, the tube cores of each stage are in the linear working area, and the overall circuit power consumption is maintained at the static power consumption level to ensure the entire 2-18 GHz The high efficiency and high linearity of the 20W power amplifier are required; the non-standard design of the input and output impedance of the two 12W class AB amplifiers 3 uses a non-frequency impedance transformation design, and fully adopts lumped parameters to achieve complete matching and ultra-wideband operation; the output power synthesis network realizes broadband high-power synthesis, reduces the circuit area, and reduces the cost; the 2~18GHz 20W power amplifier circuit is mirror-symmetrical between the RF input and RF output center lines, and the input stage input power distribution network 1 of the two symmetrical power amplifier circuits performs power equal power division, which can divide the input RF signal power equally, and the two symmetrical power amplifier units are output after power synthesis through the output synthesis network, achieving a power of more than 20W and an efficiency of more than 20% in the 2~18GHz frequency band.
[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A 2~18GHz 20W power amplifier, characterized in that: The 2~18GHz 20W power amplifier includes: An input power distribution network, wherein the input power distribution network is used to divide the input signal into two signals with the same amplitude and phase; A class AB amplifier connected to the input power distribution network, the class AB amplifier is used to amplify the power of the signal and then output an amplified signal; An impedance converter connected to the class AB amplifier, the impedance converter being used to convert the impedance of the amplified signal back to the original impedance; An output power synthesis network is connected to the impedance converter, and is used to synthesize the two amplified signals into one output signal for output.
2. The 2~18GHz 20W power amplifier according to claim 1, characterized in that: The impedance transformer is a non-uniform transmission line transformer.
3. The 2~18GHz 20W power amplifier according to claim 1, characterized in that: The output power synthesis network comprises: A power synthesis network connected to the class AB amplifier, the power synthesis network is used to synthesize the two amplified signals into one output signal; A non-uniform impedance conversion network is connected to the power synthesis network, and the non-uniform impedance conversion network is used to convert the impedance of the output signal into the original impedance.
4. The 2~18GHz 20W power amplifier according to claim 3, characterized in that: The output power synthesis network also includes a matching capacitor, which is connected to the non-uniform impedance transformation network.
5. The 2~18GHz 20W power amplifier according to claim 1, characterized in that: The 2-18 GHz 20 W power amplifier further includes an equalizing circuit, which is arranged in series between the input power distribution network and the class AB amplifier, and is used for performing equalizing compensation on the signal.
6. The 2-18 GHz 20 W power amplifier according to claim 5, characterized in that: The equalizing circuit includes a first capacitor and a first resistor, and the first capacitor is connected in parallel with the first resistor.