A high permeability material based anti-phase wideband power combiner

Abstract

The application relates to the technical field of radio frequency power synthesis, and provides an anti-phase broadband power synthesizer based on high magnetic permeability material, which comprises four power synthesis input ports, namely a port P2, a port P3, a port P4 and a port P5; one output port, namely a port P1; and five transmission line transformers, namely a transmission line transformer TL1, a transmission line transformer TL2, a transmission line transformer TL3, a transmission line transformer TL4 and a transmission line transformer TL5, which are all coaxial lines, a 1:1 transmission line transformer is formed by the core and the shell of each coaxial line, and the transmission line transformers are all wound on the magnetic core of the high magnetic permeability material. The synthesizer introduces the high magnetic permeability material, utilizes the natural anti-phase characteristics of the high-power transmission line transformer, constructs an anti-phase power synthesis network, and solves the problems of great difficulty in 9kHz-100MHz broadband power synthesis and insufficient power capacity in traditional broadband power synthesis.

Description

Technical Field

[0001] This invention relates to the field of radio frequency power combining technology, and more specifically, to an antiphase broadband power combiner based on a high permeability material. Background Technology

[0002] With the rapid development of fields such as communications, radar, and electronic warfare, the demand for radio frequency signal processing is increasing. These applications often require the synthesis of high-power signals from multiple signals to meet system requirements for transmit power, signal strength, and other aspects. Transmission line transformers (TLTs), as key devices enabling efficient power combining, have been widely researched and applied.

[0003] For power combining across multiple octave bands, TLT synthesizers can be used. Research on TLT synthesizers began earlier abroad, with mature technologies. The US, Japan, and Germany are the core technology developers, with research institutions and companies leading the technological breakthroughs. Through the development and application of magnetic materials and low-loss transmission line materials, hysteresis loss and signal attenuation have been effectively reduced. In terms of manufacturing processes, miniaturization and integration have been achieved through photolithography, multilayer printed circuit boards, and microelectromechanical systems (MEMS) technology. Some synthesizer models have a synthesis efficiency exceeding 90%, can withstand kilowatt-level power for high-power signals, and the integrated products are 30% smaller than traditional structures.

[0004] Driven by demand in the communications and radar sectors, domestic research institutions, universities, and enterprises have collaborated on research and development, achieving significant breakthroughs in TLT synthesizers. Theoretically, a new method for analyzing the characteristics of multi-port synthesis has been proposed; technically, innovative multi-port structures and the development of novel high-performance magnetic materials have led to the long-term stable development and improvement of related products.

[0005] With the development of broadband radio frequency technology in China, there is a greater demand for the output power of broadband power amplifiers, especially in the low-frequency band of 9kHz~100MHz, where the power demand has reached the 10kW level. The power capacity of existing broadband high-power TLT synthesizers cannot meet the needs of future application scenarios. Summary of the Invention

[0006] The present invention aims to provide an anti-phase broadband power combiner based on high permeability materials to solve the problems of high difficulty in broadband power combining and insufficient power capacity in the 9kHz~100MHz frequency band.

[0007] This invention provides an anti-phase broadband power combiner based on a high-permeability material, comprising: Four power combining input ports, namely port P2, port P3, port P4 and port P5; One output port, namely port P1; Five transmission line transformers, namely transmission line transformer TL1, transmission line transformer TL2, transmission line transformer TL3, transmission line transformer TL4 and transmission line transformer TL5; the five transmission line transformers are coaxial, and each coaxial core and shell constitute a 1:1 transmission line transformer, and each transmission line transformer is wound on a magnetic core of high permeability material; wherein, the core of each transmission line transformer has 1 port and 2 ports at both ends, and the shell has 3 ports and 4 ports at both ends; Port P2 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL2, and ports 3 and 4 of transmission line transformer TL3. Port P3 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL3, and ports 3 and 4 of transmission line transformer TL2. Port P4 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL4, and ports 3 and 4 of transmission line transformer TL5. Port P5 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL5, and ports 3 and 4 of transmission line transformer TL4. Port P1 is connected to port 1 of transmission line transformer TL1, and port 3 of transmission line transformer TL1 is grounded.

[0008] In a preferred embodiment, transmission line transformers TL2, TL3, TL4, and TL5 use coaxial cables of the same length.

[0009] In a preferred embodiment, the cores and shells of transmission line transformers TL2 and TL3 are respectively connected to the two ends of isolation resistor R1 via the core and shell of coaxial line L1.

[0010] In a preferred embodiment, the cores and shells of transmission line transformers TL4 and TL5 are respectively connected to the two ends of isolation resistor R2 via coaxial line L2.

[0011] In a preferred embodiment, the isolation resistor should be selected as a high-power resistor that can operate at radio frequency and has its own heat dissipation flange, and be mounted on a metal carrier plate.

[0012] In a preferred embodiment, transmission line transformer TL2 and transmission line transformer TL3 are wound on different magnetic cores or on the same magnetic core.

[0013] In a preferred embodiment, transmission line transformer TL4 and transmission line transformer TL5 are wound on different magnetic cores or on the same magnetic core.

[0014] In a preferred embodiment, the high permeability material core is a ferrite core.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The synthesizer of this invention introduces high permeability materials and utilizes the natural anti-phase characteristics of high-power transmission line transformers to construct an anti-phase power combining network. That is, a single circuit covers the entire 9kHz~100MHz frequency band and is matched with a 50Ω system throughout the entire frequency band to achieve the synthesis of four signals with a phase difference of 180°. This solves the problems of high difficulty in broadband power combining in the 9kHz~100MHz frequency band (such as low efficiency, limited bandwidth, poor isolation, poor phase consistency) and insufficient power capacity in traditional broadband power combining.

[0016] 2. The synthesizer of this invention uses a coaxial line to connect the load resistor and the signal port, which can reduce the impact of the parasitic capacitance of the isolation resistor on the synthesis link.

[0017] 3. The synthesizer of this invention has an input power of more than 3000W per channel and a combined power output of more than 10kW. The synthesis ports are isolated, which enables the synthesized RF amplifier to work stably and is suitable for high-power RF systems.

[0018] 4. The synthesizer of this invention uses a transmission line transformer to adapt the port impedance to 50Ω, which is well matched with the 50Ω system throughout the entire operating frequency band. Multiple circuits can be directly connected in series to form a flexible configuration of the number of synthesized channels, and synthesize a larger RF power output. Attached Figure Description

[0019] Figure 1 This is the schematic diagram of a high-power synthesizer.

[0020] Figure 2a This is a schematic diagram of a transmission line transformer.

[0021] Figure 2b This is a schematic diagram of a transmission line transformer equivalent to a transmission line.

[0022] Figure 2c This is a schematic diagram of a transmission line transformer equivalent to a transformer.

[0023] Figure 3a A schematic diagram illustrating the principle of unbalanced-to-balanced conversion for transmission line transformers.

[0024] Figure 3b A schematic diagram illustrating the principle of balanced-to-unbalanced conversion for transmission line transformers.

[0025] Figure 4a A schematic diagram of a 4:1 transmission line transformer.

[0026] Figure 4b The equivalent circuit diagram of a 4:1 transmission line transformer.

[0027] Figure 5 The equivalent circuit diagram of a 1:4 transmission line transformer.

[0028] Figure 6 This is a schematic diagram of an antiphase broadband power combiner based on a high permeability material, provided as an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] like Figure 1 As shown, the high-power combiner based on the transmission line transformer is a five-port device. Ports P2 and P3 are 0° signal combining input ports, which are connected to two in-phase RF power amplifiers respectively. Ports P4 and P5 are 180° signal combining input ports, and port P1 is the power combining output port, which can be connected to the corresponding broadband antenna or the device under test. The synthesizer internally consists of five transmission line transformers TL1~TL5 and two isolation resistors R1~R2. Transmission line transformers TL2, TL3, TL4, and TL5 are connected to ports P2, P3, P4, and P5, respectively. R1 is the isolation resistor between ports P2 and P3, and R2 is the isolation resistor between ports P4 and P5. Transmission line transformer TL1 forms an impedance transformation circuit, with one end connected to transmission line transformers TL2, TL3, TL4, and TL5, and the other end connected to port P1. The load resistances of ports P1, P2, P3, P4, and P5 are respectively the load resistances R1~R2~R3~R4~R5~R5~R1~R2~R3~R4 ... L 1. Load resistance R L 2. Load resistance R L 3. Load resistance R L 4. Load resistance R L 5.

[0032] A transmission line transformer is constructed by winding a transmission line around a high-permeability (μ) (typically referring to a ferromagnetic material with a permeability greater than 100) and low-loss magnetic ring. The transmission line can be twisted, parallel, or coaxial, while the magnetic ring is generally made of nickel-zinc high-frequency ferrite or manganese-zinc material, with diameters ranging from a few millimeters to tens of millimeters, depending on the power rating. The main characteristic of a transmission line transformer is its extremely wide operating bandwidth, with an upper frequency limit reaching several gigahertz and a frequency coverage factor of up to 10,000. The operation of a transmission line transformer combines the principles of transmission lines and transformers; that is, its energy is transmitted either through a transmission line or via a transformer, depending on the frequency of the excitation signal.

[0033] Figure 2a The diagram shows the structure of a 1:1 transmission line transformer. It consists of two equal-length wires wound together and wrapped around a magnetic ring. The circuit is simple and has a large power capacity. The wire represented by the dashed line has its signal input at terminal 1 and ground at terminal 2. The other wire, represented by the solid line, has its ground input at terminal 3 and its load input at terminal 4. R... L R is the load impedance. s Source impedance, It is a signal source. Figure 2b The diagram shows a circuit configuration that operates as a transmission line, where... The voltage difference between port 1 and port 3. 2 represents the voltage difference between port 2 and port 4. Figure 2c The diagram shows a circuit operating in the manner of a standard transformer. According to transmission line theory, to extend its upper frequency limit, the terminations should be matched as closely as possible; secondly, the transmission line length should be minimized, ideally less than 1 / 8 of the minimum operating wavelength in engineering practice. In this case, the voltage and current at the transmission line output and input can be approximated as equal in magnitude and phase.

[0034] Depend on Figure 2b , Figure 2c It can be seen that since terminals 2 and 3 are grounded simultaneously, the load R L A voltage with the same amplitude but opposite phase as the input voltage was obtained, and Z... i =R LTherefore, this type of transmission line transformer is equivalent to a 1:1 impedance anti-phase transformer. In the high-frequency range, due to the large excitation impedance and negligible excitation current, the transmission line method plays a major role, and the upper frequency limit is no longer limited by leakage inductance and distributed capacitance, nor by the upper frequency limit of the magnetic core. In the lower mid-frequency band, the transformer approximates an ideal transformer, and because the transmission line is very short, the input signal is directly applied to the load, and energy transmission is not affected by the transformer. At very low frequencies, the transformer transmission method plays a major role; due to the use of a magnetic core with very high permeability μ, the transmission line transformer still has good low-frequency characteristics. Therefore, it is easy to see that the transmission line transformer has excellent broadband transmission characteristics. If its principle is improved and its inherent anti-phase characteristic is utilized, a composite circuit with both high bandwidth and high power capacity can be obtained.

[0035] Transmission line transformers can convert between balanced and unbalanced circuits. Figure 3a The signal source shown is an unbalanced input, where R L R is the load impedance. s Source impedance, As a signal source, The voltage at ports 1 and 3. This represents the current flowing from port 1 to port 2. Two equal and completely out of phase voltage outputs relative to ground can be obtained through a transmission line transformer Tr. For example... Figure 3b As shown, two signal sources form a balanced input, and an unbalanced voltage output to ground can be obtained through a transmission line transformer Tr, where R... L R is the load impedance. s Source impedance, As a signal source, The voltage at ports 1 and 3. This represents the current flowing from port 1 to port 2.

[0036] Transmission line transformers can be used to construct impedance transformers, with 4:1 and 1:4 impedance transformers being the most common. Transmission line transformers are configured according to... Figure 4a The wiring shown can achieve a 4:1 impedance transformation. Figure 4b This is its circuit diagram. R L R is the load impedance. s Source impedance, As the signal source. Let the load R be... L The voltage on is The current flowing from port 1 to port 2 is ,Depend on Figure 4b It can be seen that the voltages at the transmission line terminals (terminals 2 and 4) and the starting terminals (terminals 1 and 3) are also... Then the input voltage at terminal 1 to ground is equal to 2. If the current supplied by the signal source is Then the current flowing through the upper and lower coils of the transmission line transformer is also... ,Depend on Figure 4b It can be seen that through load R L The current is 2 Therefore, we can conclude that: R L = / 2

[0037] The output impedance presented at the signal source is: R i =2 / =4R L As can be seen, the input impedance is four times the load impedance, thus achieving a 4:1 impedance transformation. To achieve impedance matching, the characteristic impedance of the transmission line must be: Z C = / =2R L If the transmission line transformer is classified as Figure 5 Wiring, R L Rs is the load impedance, Us is the source impedance, and Us is the signal source. The voltage between ports 1 and 3 is [voltage value], and the current flowing from port 1 to port 2 is [current value]. This allows for a 1:4 impedance transformation. For example... Figure 5 It can be known that:

[0038] The input impedance presented at the signal source is:

[0039] As can be seen, the input impedance Ri is 1 / 4 of the load resistance RL, achieving a 1:4 impedance transformation. To achieve impedance matching, the characteristic impedance of the transmission line must be:

[0040] Based on the above component principles and Figure 1 The schematic diagram illustrates that this invention proposes an anti-phase broadband power combiner based on a high-permeability material, implemented using a radio frequency coaxial line and a high-permeability magnetic ring. For example... Figure 6 As shown, the inverted broadband power combiner based on high permeability material includes: Four power combining input ports, namely port P2, port P3, port P4 and port P5; One output port, namely port P1; Five transmission line transformers, namely transmission line transformer TL1, transmission line transformer TL2, transmission line transformer TL3, transmission line transformer TL4, and transmission line transformer TL5, are constructed using coaxial cables. Each coaxial cable's core and shell form a 1:1 transmission line transformer, and each transformer is wound on a high-permeability magnetic core (such as a ferrite core) to provide the required inductance. They form isolation circuits or impedance transformation circuits through different connection methods. Each transmission line transformer has one port and two ports at both ends of its core, and three ports and four ports at both ends of its shell. Port P2 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL2, and ports 3 and 4 of transmission line transformer TL3. Port P3 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL3, and ports 3 and 4 of transmission line transformer TL2. Port P4 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL4, and ports 3 and 4 of transmission line transformer TL5. Port P5 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL5, and ports 3 and 4 of transmission line transformer TL4. Port P1 is connected to port 1 of transmission line transformer TL1, and port 3 of transmission line transformer TL1 is grounded.

[0041] The following is the signal flow of the aforementioned inverted broadband power combiner based on high permeability materials: Port P2 is connected to port 2 of transmission line transformer TL2, and the current flows from port 2 of transmission line transformer TL2 to port 1. Port 1 of transmission line transformer TL2 is connected to port 3 of transmission line transformer TL3, and the current flows from port 3 of transmission line transformer TL3 to port 4. Port P3 is connected to port 2 of transmission line transformer TL3, and the current flows from port 2 of transmission line transformer TL3 to port 1. Port 1 of transmission line transformer TL3 is connected to port 3 of transmission line transformer TL2, and the current flows from port 3 of transmission line transformer TL2 to port 4.

[0042] In transmission line transformers TL2 and TL3, the current flowing from port 3 to port 4 is combined at point A, and the current becomes twice as strong, resulting in a decrease in impedance to 25Ω.

[0043] The signals input to ports P4 and P5 have the same amplitude as the signals input to ports P2 and P3, but are 180° out of phase.

[0044] Port P4 is connected to port 2 of transmission line transformer TL4, and the current flows from port 2 to port 1 of transmission line transformer TL4. Port 1 of transmission line transformer TL4 is connected to port 3 of transmission line transformer TL5, and the current flows from port 3 to port 4 of transmission line transformer TL5.

[0045] Port P5 is connected to port 2 of transmission line transformer TL5, and the current flows from port 2 to port 1 of transmission line transformer TL5. Port 1 of transmission line transformer TL5 is connected to port 3 of transmission line transformer TL4, and the current flows from port 3 to port 4 of transmission line transformer TL4.

[0046] In transmission line transformers TL4 and TL5, the current flowing from port 3 to port 4 is combined at point B, and the current becomes twice as strong, resulting in a decrease in impedance to 25Ω.

[0047] Point A is connected to port 2 of transmission line transformer TL1, and point B is connected to port 4 of transmission line transformer TL1. Transmission line transformer TL1 is an impedance transformer that boosts the reduced impedance to 50Ω before output.

[0048] Transmission line transformers TL2, TL3, TL4, and TL5 can be wound on different magnetic cores or on the same magnetic core. Figure 6 In the case of winding on the same magnetic core, such as magnetic core Fer1, magnetic core Fer2, and magnetic core Fer3, the magnetic flux of the main and auxiliary coils of the transformer can be enhanced by utilizing the magnetic flux of the same excitation in the magnetic core, thereby reducing the number of turns and the coupling capacitance, and thus extending the maximum operating frequency.

[0049] Furthermore, the cores and shells of transmission line transformers TL2 and TL3 are respectively connected to the cores and shells of coaxial cable L1 across the isolation resistor R1 to isolate ports P2 and P3. When the input power of port P2 is the same as that of port P3, the voltages generated at both ends are the same, and no power is consumed in the isolation resistor R1. At this time, the isolation resistor R1 is essentially non-existent and does not affect the operation of the circuit. When the power of ports P2 and P3 is different, the difference in power is consumed in the isolation resistor R1, avoiding crosstalk between the two ports and achieving the isolation function.

[0050] Similarly, the cores and shells of transmission line transformers TL4 and TL5 are connected to the two ends of isolation resistor R2 via the core and shell of coaxial cable L2, respectively, to isolate ports P4 and P5. When the input power of port P4 is the same as that of port P5, the voltages generated at both ends are the same, and no power is consumed in isolation resistor R2. At this time, isolation resistor R2 is essentially non-existent and does not affect the operation of the circuit. When the power of ports P4 and P5 is different, the difference in power is consumed in isolation resistor R2, avoiding crosstalk between the two ports and achieving the function of isolation.

[0051] By adding coaxial lines L1 and L2, the impact of the parasitic capacitance of the isolation resistor on the synthesized link can be reduced.

[0052] Since each port has an input power of approximately 3000W, the power imbalance between the ports needs to be dissipated through the resistors. Therefore, the resistors must be power resistors capable of operating at RF frequencies, with built-in heat dissipation flanges, and mounted on a metal substrate. In extreme cases, such as when one port has no input and only one port has a 3000W power input, more than 1500W of power will be dissipated through the isolation resistors. Therefore, the power rating of the resistors must be sufficient.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An anti-phase broadband power combiner based on a high permeability material, characterized in that, include: Four power combining input ports, namely port P2, port P3, port P4 and port P5; One output port, namely port P1; Five transmission line transformers, namely transmission line transformer TL1, transmission line transformer TL2, transmission line transformer TL3, transmission line transformer TL4 and transmission line transformer TL5; the five transmission line transformers are coaxial, and each coaxial core and shell constitute a 1:1 transmission line transformer, and each transmission line transformer is wound on a magnetic core of high permeability material; wherein, the core of each transmission line transformer has 1 port and 2 ports at both ends, and the shell has 3 ports and 4 ports at both ends; Port P2 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL2, and ports 3 and 4 of transmission line transformer TL3. Port P3 is connected to port 2 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL3, and ports 3 and 4 of transmission line transformer TL2. Port P4 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL4, and ports 3 and 4 of transmission line transformer TL5. Port P5 is connected to port 4 of transmission line transformer TL1 via ports 2 and 1 of transmission line transformer TL5, and ports 3 and 4 of transmission line transformer TL4. Port P1 is connected to port 1 of transmission line transformer TL1, and port 3 of transmission line transformer TL1 is grounded.

2. The anti-phase broadband power combiner based on high permeability material according to claim 1, characterized in that, Transmission line transformers TL2, TL3, TL4, and TL5 use coaxial cables of the same length.

3. The anti-phase broadband power combiner based on high permeability material according to claim 1, characterized in that, The cores and shells of transmission line transformers TL2 and TL3 are respectively connected to the two ends of isolation resistor R1 via the core and shell of coaxial line L1.

4. The anti-phase broadband power combiner based on high permeability material according to claim 3, characterized in that, The isolation resistor R1 should be selected as a high-power resistor that can operate at radio frequency, and should have a built-in heat dissipation flange and be mounted on a metal carrier plate.

5. The anti-phase broadband power combiner based on high permeability material according to claim 1, characterized in that, The cores and shells of transmission line transformers TL4 and TL5 are respectively connected to the two ends of isolation resistor R2 via coaxial line L2.

6. The anti-phase broadband power combiner based on high permeability material according to claim 5, characterized in that, The isolation resistor R2 should be selected as a high-power resistor that can operate at radio frequency, and should have a built-in heat dissipation flange and be mounted on a metal carrier plate.

7. The anti-phase broadband power combiner based on high permeability material according to claim 1, characterized in that, Transmission line transformers TL2 and TL3 are wound on different magnetic cores or on the same magnetic core.

8. The anti-phase broadband power combiner based on high permeability material according to claim 1, characterized in that, Transmission line transformers TL4 and TL5 are wound on different magnetic cores or on the same magnetic core.

9. The anti-phase broadband power combiner based on high permeability materials according to any one of claims 1-8, characterized in that, The magnetic core of the high permeability material is a ferrite core.

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