Non-reversible device, radio frequency module, and communication apparatus

Abstract

Embodiments of the present application provide a non-reversible device, a radio frequency module, and a communication apparatus. The non-reversible device at least comprises a first port and a second port, the impedance of the first port and the impedance of the second port are equal, and the impedance of the first port and the impedance of the second port are both less than a standard impedance. The non-reversible device has a small volume and low insertion loss. When the non-reversible device is used in a radio frequency module, and the impedance of a port of a radio frequency component connected to the non-reversible device is less than a standard impedance, the complexity of an impedance matching circuit between the non-reversible device and the radio frequency component can be reduced, thereby reducing the volume increase and insertion loss caused by the impedance matching circuit.

Description

Non-reversible devices, radio frequency modules, and communication devices

[0001] This application claims priority to Chinese patent application No. 202410793846.9, filed on June 18, 2024, with the China National Intellectual Property Administration and entitled “Irreversible Device, Radio Frequency Module and Communication Apparatus”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic power, and in particular to a non-reversible device, a radio frequency module, and a communication device. Background Technology

[0003] Circulators, isolators, and other non-reversible devices offer advantages such as non-reciprocity and low insertion loss, making them widely used in RF modules / circuits. In RF modules / circuits, the industry standardizes the port impedance of each RF component as a standard impedance (e.g., 50Ω). Currently, a common design approach for non-reversible devices is to define the impedance of each port as 50Ω. Since the output impedance of the power amplifier circuit connected to the non-reversible device is typically low, generally less than 50Ω, impedance matching is required on the connection link between the power amplifier circuit and the non-reversible device, leading to complex impedance matching and higher insertion loss. Summary of the Invention

[0004] In view of this, embodiments of this application provide an irreversible device, a radio frequency module, and a communication device to reduce signal insertion loss caused by the irreversible device.

[0005] The first aspect of this application provides a non-reversible device, which includes a first port and a second port, wherein the impedance of the first port and the impedance of the second port are equal, and both the impedance of the first port and the impedance of the second port are less than the standard impedance.

[0006] In this embodiment, the impedances of the first and second ports of the non-reversible device are equal, and both impedances are less than the standard impedance. This symmetrical impedance between the first and second ports reduces insertion loss when signals pass through them, thus lowering the insertion loss caused by the non-reversible device. Furthermore, since the impedance of the internal ferrite junction of the non-reversible device is typically less than the standard impedance, there is no need to add impedance matching circuits between the first port and its corresponding internal ferrite junction, or between the second port and its corresponding internal ferrite junction. This reduces the size of the non-reversible device and lowers insertion loss. When the non-reversible device is used in an RF module, the port impedance of the non-reversible device connected to RF components is less than the standard impedance, reducing the complexity of the impedance matching circuit between the non-reversible device and the RF components, thereby lowering insertion loss caused by the impedance matching circuit.

[0007] In some embodiments of this application, the non-reversible device further includes a third port; the impedance of the third port is less than the standard impedance, or the impedance of the third port is the standard impedance. Based on the impedance symmetry between the first and second ports of the non-reversible device, the insertion loss generated when the signal passes through the first and second ports of the non-reversible device can be reduced, thereby reducing the insertion loss of the non-reversible device.

[0008] Optionally, the impedance of the third port is equal to the impedance of the first port. In a non-reversible device, the impedance of the third port is equal to the impedance of the first port; specifically, a non-reversible device with three ports can be a three-port impedance-symmetrical circulator.

[0009] Optionally, the third port is connected to a load. In the case where the third port of a non-reversible device is connected to a load, the non-reversible device may specifically be an isolator.

[0010] Optionally, when the standard impedance is 50 ohms, the less than standard impedance includes: greater than 1 ohm and less than 50 ohms.

[0011] A second aspect of this application provides a radio frequency module, including a power amplifier and an irreversible device; the irreversible device includes a first port and a second port, the output port of the power amplifier is connected to the first port of the irreversible device, the impedance of the first port of the irreversible device and the impedance of the second port of the irreversible device are equal, and both the impedance of the first port of the irreversible device and the impedance of the second port of the irreversible device are less than the standard impedance.

[0012] In the RF module provided in this application embodiment, the first and second ports of the included non-reversible device have symmetrical impedances, which can reduce the insertion loss generated when the transmitted signal passes through the first and second ports of the non-reversible device, thereby reducing the insertion loss of the non-reversible device. When the transmit power of the RF module is high (e.g., up to tens or hundreds of W), the output port impedance of the power amplifier is usually small (e.g., around a few Ω). Because the impedance of the first port of the non-reversible device is less than the standard impedance, the difference between the output port impedance of the power amplifier and the impedance of the first port of the non-reversible device is small, making the impedance matching method between the output port of the power amplifier and the first port of the non-reversible device simpler, with a smaller area and lower insertion loss, supporting the power amplifier to output a transmit signal with a larger bandwidth.

[0013] Optionally, the impedance of the output port of the power amplifier is less than the standard impedance.

[0014] In this embodiment, the impedance of the output port of the power amplifier is less than the standard impedance, and the impedance of the first port of the non-reversible device is less than the standard impedance. Therefore, the difference between the impedance of the output port of the power amplifier and the impedance of the first port of the non-reversible device is small, making the impedance matching method between the output port of the power amplifier and the first port of the non-reversible device simpler, with smaller area and lower insertion loss, and supporting the power amplifier to output a transmission signal with a larger bandwidth.

[0015] Optionally, the impedance of the output port of the power amplifier is equal to the impedance of the first port of the non-reversible device, and the output port of the power amplifier is directly connected to the first port of the non-reversible device. In this case, there is no need to design an impedance matching circuit between the output port of the power amplifier and the first port of the non-reversible device, thus reducing insertion loss.

[0016] Optionally, the impedance of the output port of the power amplifier is not equal to the impedance of the first port of the non-reversible device, and the output port of the power amplifier is connected to the first port of the non-reversible device through a first impedance matching circuit.

[0017] Because the output port impedance of the power amplifier is less than the standard impedance, the impedance of the first port of the non-reversible device is also less than the standard impedance. The impedance transformation ratio of the first impedance matching circuit is smaller, the matching circuit is simpler, occupies less area, and has lower insertion loss.

[0018] Optionally, the RF module further includes a low-noise amplifier and a filter; the second port of the non-reversible device is connected to the first port of the filter; the third port of the non-reversible device is connected to the input port of the low-noise amplifier; wherein the impedance of the third port of the non-reversible device is less than or equal to the standard impedance.

[0019] The RF module provided in this application includes a non-reversible device with symmetrical impedances at its first and second ports. This reduces insertion loss when the transmitted signal passes through the first and second ports of the non-reversible device, thereby reducing the insertion loss of the non-reversible device. When the RF module's transmit power is high (e.g., tens or hundreds of W), the output port impedance of the power amplifier is typically low (e.g., around a few Ω). Because the impedance of the first port of the non-reversible device is less than the standard impedance, the difference between the output port impedance of the power amplifier and the first port impedance of the non-reversible device is small. This makes the impedance matching method between the power amplifier's output port and the first port of the non-reversible device simpler, results in a smaller area and lower insertion loss, and supports a wider bandwidth transmit signal output by the power amplifier. This RF module can be applied to Time Division Duplex (TDD) systems.

[0020] Optionally, the impedance of the first port of the filter is equal to or less than the standard impedance; the impedance of the input port of the low-noise amplifier is equal to or less than the standard impedance.

[0021] Thus, the aforementioned RF module can be applied to various application scenarios. In particular, this RF module can be used in Time Division Duplex (TDD) systems. Furthermore, the impedance of each port of the RF components in the RF module can be defined as less than the standard impedance. Compared to defining it as the standard impedance, this significantly reduces the difficulty of the impedance matching circuit connecting the various RF components in the RF module, reduces insertion loss in the impedance matching circuit, and enables miniaturization of the RF module.

[0022] In some embodiments of this application, the impedance of the second port of the non-reversible device is equal to the impedance of the first port of the filter; the second port of the non-reversible device is directly connected to the first port of the filter. In this case, there is no need to design an impedance matching circuit between the second port of the non-reversible device and the first port of the filter, thereby reducing the complexity of impedance matching and reducing insertion loss.

[0023] In other embodiments of this application, the impedance of the second port of the non-reversible device is not equal to the impedance of the first port of the filter; the second port of the non-reversible device is connected to the first port of the filter through a second impedance matching circuit. In this case, the impedance of the first port of the filter can be equal to or less than the standard impedance. When the impedance of the first port of the filter is less than the standard impedance, compared to when the impedance of the first port of the filter is the standard impedance, the impedance transformation ratio of the second impedance matching circuit is smaller, the matching circuit is simpler, occupies less area, and has less insertion loss.

[0024] In some embodiments of this application, the impedance of the third port of the non-reversible device is equal to the impedance of the input port of the low-noise amplifier; the third port of the non-reversible device is directly connected to the input port of the low-noise amplifier. In this case, there is no need to design an impedance matching circuit between the third port of the non-reversible device and the input port of the low-noise amplifier, thereby reducing the complexity of impedance matching and reducing insertion loss.

[0025] In other embodiments of this application, the impedance of the third port of the non-reversible device is not equal to the impedance of the input port of the low-noise amplifier; the third port of the non-reversible device is connected to the input port of the low-noise amplifier through a third impedance matching circuit. In this case, the impedance of the input port of the low-noise amplifier can be equal to or less than the standard impedance. Compared with the case where the impedance of the input port of the low-noise amplifier is the standard impedance, the impedance transformation of the third impedance matching circuit is smaller when the impedance of the input port of the low-noise amplifier is less than the standard impedance.

[0026] In some embodiments, the radio frequency module further includes an antenna unit; the second port of the filter is connected to the antenna unit.

[0027] In the embodiments of this application, the first impedance matching circuit, the second impedance matching circuit, and the third impedance matching circuit independently include any one or a combination of discrete circuits, microstrip matching circuits, and integrated passive devices.

[0028] In this embodiment, the radio frequency module is applied to a time-division duplex (TDD) system. The radio frequency module applied to the TDD system includes the aforementioned filter.

[0029] Optionally, the RF module further includes a low-noise amplifier and a duplexer; the second port of the non-reversible device is connected to the first port 701 of the duplexer, and the second port of the duplexer is connected to the input port of the low-noise amplifier.

[0030] In this embodiment, the impedances of the first and second ports of the non-reversible device are symmetrical, which reduces the insertion loss generated when the transmitted signal passes through the first and second ports of the non-reversible device, thereby reducing the insertion loss of the non-reversible device. When the transmit power of the RF module is high (e.g., up to tens or hundreds of W), the output port impedance of the power amplifier is low (e.g., around a few Ω). The small difference between the output port impedance of the power amplifier and the first port impedance of the non-reversible device makes the impedance matching method between the output port of the power amplifier and the first port of the non-reversible device simpler, with a smaller area and lower insertion loss, supporting the power amplifier to output a transmit signal with a larger bandwidth. This RF module can be applied to the FDD standard.

[0031] Optionally, the impedance of the first port 701 of the duplexer is equal to or less than the standard impedance; the impedance of the second port of the duplexer is equal to or less than the standard impedance; and the impedance of the input port of the low-noise amplifier is equal to or less than the standard impedance.

[0032] This allows the RF module to be suitable for various application scenarios. It can be used with the FDD standard. Specifically, the impedance of each port of the RF components in the RF module is defined as less than the standard impedance. Compared to defining it as the standard impedance, this reduces the difficulty of the impedance matching circuit connecting the various RF components in the RF module, reduces the insertion loss of the matching circuit, and enables the miniaturization of the RF module.

[0033] In some embodiments of this application, the impedance of the second port of the non-reversible device is equal to the impedance of the first port 701 of the duplexer; the second port of the non-reversible device is directly connected to the first port 701 of the duplexer. This eliminates the need for an impedance matching circuit between the second port of the non-reversible device and the first port 701 of the duplexer, thereby reducing insertion loss.

[0034] In some other embodiments of this application, the impedance of the second port of the non-reversible device is not equal to the impedance of the first port 701 of the duplexer; the second port of the non-reversible device is connected to the first port 701 of the duplexer through a fourth impedance matching circuit.

[0035] In this case, the impedance of the first port 701 of the duplexer can be equal to or less than the standard impedance. Because the impedance of the second port of the non-reversible device is less than the standard impedance but not the standard impedance, its impedance matching method with the first port 701 of the duplexer is simpler and has lower insertion loss. Compared to when the impedance of the first port 701 of the duplexer is the standard impedance, when the impedance of the first port 701 of the duplexer is less than the standard impedance, the impedance transformation ratio of the fifth impedance matching circuit is smaller, the matching circuit is simpler, occupies less area, and has lower insertion loss.

[0036] Optionally, the non-reversible device further includes a third port; this third port is connected to a load. When the third port of the non-reversible device is connected to a load, the non-reversible device can be an isolator.

[0037] In some embodiments of this application, the impedance of the third port of the non-reversible device is equal to the impedance of the load; the third port of the non-reversible device is directly connected to the load. In this case, there is no need to design a matching circuit between the third port of the non-reversible device and the load, thereby reducing the complexity of matching and reducing insertion loss.

[0038] In some other embodiments of this application, the impedance of the third port of the non-reversible device is not equal to the impedance of the load; the third port of the non-reversible device is connected to the load through a fifth impedance matching circuit.

[0039] In some embodiments, the radio frequency module further includes an antenna unit; the second port of the duplexer is connected to the antenna unit.

[0040] In the embodiments of this application, the fourth impedance matching circuit and the fifth impedance matching circuit independently include any one or a combination of discrete circuits, microstrip matching circuits, and integrated passive devices.

[0041] In this embodiment of the application, the radio frequency module is applied to the frequency division duplex (FDD) standard. The radio frequency module applied to the FDD standard includes the aforementioned duplexer.

[0042] A third aspect of this application provides a communication device, including the radio frequency module described in the second aspect of this application.

[0043] Optionally, the impedance of the external port of the RF module is less than the standard impedance.

[0044] Optionally, the communication device may include a base station or a terminal device. Attached Figure Description

[0045] Figure 1a is a schematic diagram of the specific structure of a non-reversible device provided in an embodiment of this application.

[0046] Figure 1b is a schematic diagram of the specific structure of another non-reversible device provided in the embodiments of this application.

[0047] Figure 2 is a schematic diagram of a structure of an existing non-reversible device using ferrite materials.

[0048] Figure 3 is a schematic diagram of another structure of an irreversible device using ferrite material.

[0049] Figure 4 is a schematic diagram of the structure of an irreversible device using ferrite material provided in an embodiment of this application.

[0050] Figure 5 is a schematic diagram of another non-reversible device using ferrite material provided in an embodiment of this application.

[0051] Figure 6 is a schematic diagram comparing the port impedance of a conventional circulator and an improved circulator provided in an embodiment of this application.

[0052] Figure 7 is a schematic diagram of the structure of a radio frequency module provided in an embodiment of this application.

[0053] Figure 8 is a schematic diagram of another radio frequency module provided in an embodiment of this application.

[0054] Figure 9 is a schematic diagram of the structure of a radio frequency module supporting TDD provided in an embodiment of this application.

[0055] Figure 10 is a schematic diagram of another radio frequency module supporting TDD provided in an embodiment of this application.

[0056] Figure 11 is a schematic diagram of another radio frequency module supporting TDD provided in an embodiment of this application.

[0057] Figure 12 is a schematic diagram of another radio frequency module supporting TDD provided in an embodiment of this application.

[0058] Figure 13 is a schematic diagram of the structure of an FDD-supporting radio frequency module provided in an embodiment of this application.

[0059] Figure 14 is a schematic diagram of another FDD-supporting radio frequency module provided in an embodiment of this application.

[0060] Figure 15 is a schematic diagram of another FDD-supporting radio frequency module provided in an embodiment of this application.

[0061] Figure 16 is a schematic diagram of another FDD-supporting radio frequency module provided in an embodiment of this application.

[0062] Figure 17 is a schematic diagram of another FDD-supporting radio frequency module provided in an embodiment of this application.

[0063] Figure 18 is a schematic diagram comparing the impedance matching methods of a conventional 50Ω matched RF module and a low-impedance matched RF module provided in the embodiments of this application.

[0064] Figure 19 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0065] The embodiments of this application will now be described in conjunction with the accompanying drawings.

[0066] To facilitate understanding of the irreversible devices, radio frequency modules, and communication devices provided in the embodiments of this application, their application scenarios are described below. The communication devices provided in the embodiments of this application can be applied to various communication systems, such as Internet of Things (IoT) systems, narrowband Internet of Things (NB-IoT) systems, long term evolution (LTE) systems, 5th generation (5G) communication systems, and new communication systems emerging in future communication development (such as 6G).

[0067] In this application embodiment, the communication device may include a base station or a terminal device.

[0068] A base station is a device with wireless transceiver capabilities. Specifically, a base station can be a base transceiver station (BTS) in a Global System for Mobile Communications (GSM) or Code Division Multiple Access (CDMA) system, a Node B (NB) in a Wideband Code Division Multiple Access (WCDMA) system, an Evolutionary Node B (eNB or eNodeB) in a Long Term Evolution (LTE) system, or a radio controller in a cloud radio access network (CRAN) scenario. For example, the base station can also be a relay station, access point, vehicle-mounted equipment, wearable devices, a g node (gNodeB or gNB) in a new radio (NR) system, or a base station in a future public land mobile network (PLMN).

[0069] In some deployments, base stations can consist of centralized units (CUs) and distributed units (DUs). This means the base station's functions are split, with some functions deployed in a CU and the remaining functions in a DU. Multiple DUs sharing a single CU can save costs and facilitate network expansion. In other base station deployments, the CU can be divided into a CU-control plane (CP) and a CU-user plane (UP). In still other deployments, the base station can be a radio unit (RU). And in yet another deployment, the base station can be an open radio access network (ORAN) architecture, etc. This application does not limit the specific type of base station. For example, a base station can be a radio remote unit (RRU), a massive multiple-input multiple-output (MASIVE MIMO) unit, an outdoor unit (ODU), or other wireless base stations with wireless communication capabilities.

[0070] Terminal equipment, also known as user equipment (UE) or terminal, is a device with wireless transceiver capabilities. It can be deployed on land (indoors or outdoors, handheld, wearable, or vehicle-mounted), on water (e.g., on ships), or in the air (e.g., on airplanes, balloons, or satellites). Terminal equipment can include mobile phones, laptops, tablets, computers with wireless transceiver capabilities, wearable devices, routers, customer premises equipment (CPE), virtual reality (VR) terminal equipment, augmented reality (AR) terminal equipment, wireless terminals in industrial control, self-driving, remote medical care, smart grids, transportation safety, smart cities, smart homes, and more. It is understandable that the terminal device could also be a terminal device in a future 6G network or a terminal device in a future evolved PLMN, etc.

[0071] Communication devices generally operate under two systems: time division duplex (TDD) and frequency division duplex (FDD). These will be described in detail below.

[0072] Communication devices may include radio frequency (RF) modules / circuits. Non-reversible devices such as circulators and isolators have advantages such as non-reciprocity and low insertion loss, and are widely used in RF modules / circuits. In RF modules / circuits, the industry defines the ports of RF components as standard impedances (e.g., 50Ω). Currently, a common design approach for non-reversible devices is to define the impedance of each port of the non-reversible device as a standard impedance of 50Ω. Since the output impedance of power amplifier circuits is relatively small (generally less than 50Ω), impedance matching is required on the connection links between the power amplifier circuit and the non-reversible device. For example, the output impedance of the power amplifier circuit must be matched to the standard impedance before connecting to the non-reversible device, and / or, the impedance of each port of the non-reversible device must be matched to the standard impedance before connecting to the power amplifier circuit. However, the above impedance matching circuitry is complex and results in significant signal insertion loss.

[0073] This application provides an irreversible device, a radio frequency module, and a communication device, which can reduce the insertion loss of the irreversible device and the radio frequency module containing the irreversible device. The following details the process.

[0074] Please refer to Figures 1a and 1b together. Figures 1a and 1b are schematic diagrams of two specific structures of the non-reversible device provided in the embodiments of this application. As shown in Figures 1a and 1b, the non-reversible device 10 includes a first port (port 1 as shown in Figure 1a or Figure 1b) and a second port (port 2 as shown in Figure 1a or Figure 1b); the impedance of port 1 and the impedance of port 2 are equal, and the impedance of both port 1 and port 2 is less than the standard impedance.

[0075] In this embodiment, the impedances of port 1 and port 2 of the non-reversible device 10 are equal, and both are less than the standard impedance. This symmetrical impedance between port 1 and port 2 of the non-reversible device 10 reduces insertion loss when signals pass through ports 1 and 2, thereby reducing the insertion loss caused by the non-reversible device 10. Furthermore, since the impedance of the internal ferrite junction of the non-reversible device 10 is typically less than the standard impedance, it is unnecessary to add an impedance matching circuit between port 1 and the corresponding internal ferrite junction, or between port 2 and the corresponding internal ferrite junction, thus reducing the size of the non-reversible device 10 and the insertion loss caused by it.

[0076] The non-reversible device in this application embodiment, since the impedance of the first port and the second port of the non-reversible device are both less than the standard impedance and the impedances are equal, can be called a two-port symmetrical low-resistance non-reversible device.

[0077] The standard impedance is an industry-defined impedance standard for the ports of RF components in an RF module. For example, the standard impedance can be 50 ohms (Ω), 100 ohms, etc. When the standard impedance is 50 ohms, impedances less than the standard impedance include those greater than 1 ohm and less than 50 ohms.

[0078] In this embodiment, the non-reversible device may include at least two ports, and the signal transmission direction between any two ports of the non-reversible device is irreversible. For example, a signal can be input from the first port of the non-reversible device and output from the second port; however, once the signal is input from the second port, it cannot be output from the first port; or the signal is not allowed to be input from the second port. Therefore, a non-reversible device can also be called a non-reciprocal device. A non-reversible device may include a circulator or an isolator.

[0079] Specifically, when the non-reversible device includes only two ports, it can be an isolator. When the non-reversible device includes more than two ports (e.g., three ports), it can be a circulator, for example. Furthermore, it should be noted that when the non-reversible device is a multi-port device with more than two ports, the first port and the second port satisfying the above conditions can be any two of the multiple ports, and are not limited to ports 1 and 2 marked in Figure 1b. It can be understood that the first port and the second port are two ports located in the signal transmission direction flowing through the non-reversible device.

[0080] The non-reversible device 10 shown in Figure 1a is specifically an isolator. The isolator can be a radio frequency isolator, allowing signals to enter from port 1 and exit from port 2, but not allowing signals to enter from port 2 and exit from port 1. The isolator can isolate a device connected to its first port from another device connected to its second port.

[0081] A circulator is a multi-port device that directs incident waves entering any of its ports to the next port in a sequential direction determined by a static deflecting magnetic field. In other words, a circulator is a non-reversible device with multiple ports. For example, if a signal is input from port 1 in Figure 1b, the signal can only be output from port 2; similarly, a signal input from port 2 can only be output from port 3, and so on. Hence, it is called a circulator.

[0082] Irreversible devices such as isolators or circulators are typically made of ferrite materials. Ferrite materials exhibit gyromagnetic properties (also known as tensor permeability properties) under the combined influence of an applied high-frequency wave field and a constant DC magnetic field. These gyromagnetic properties cause electromagnetic waves propagating in ferrite to undergo polarization rotation (Faraday effect) and strong absorption of electromagnetic wave energy (ferromagnetic resonance). Circulators / isolators are widely used due to their small size, wide bandwidth, and low insertion loss; for example, they can be used in radio frequency modules.

[0083] In some embodiments of this application, as shown in FIG1b, the non-reversible device 10 further includes a third port (port 3 as shown in FIG1b).

[0084] In one possible embodiment, the impedance of port 3 is a standard impedance. In this case, the impedances of ports 1 and 2 of the non-reversible device 10 are still symmetrical, which can still reduce the insertion loss generated when the signal passes through ports 1 and 2 of the non-reversible device 10, thereby reducing the insertion loss of the non-reversible device.

[0085] In another possible embodiment, the impedance of port 3 is equal to the impedance of port 1. In this case, the impedances of port 1, port 2, and port 3 of the non-reversible device 10 are all equal and all less than the standard impedance. This symmetrical impedance across the three ports of the non-reversible device better reduces insertion loss when a signal passes through any two ports, thus better reducing the insertion loss caused by the non-reversible device. Furthermore, since the impedances of the first, second, and third ports of the non-reversible device in this embodiment are all less than the standard impedance and the impedances of the three ports are equal in this case, the non-reversible device can be called a three-port symmetrical low-impedance non-reversible device.

[0086] In another possible embodiment, the impedance of port 3 is less than the standard impedance, and the impedance of port 3 is not equal to the impedance of port 1. In this case, a simple impedance matching circuit (see the description of Figure 4 below) can be added between port 3 of the non-reversible device 10 and the corresponding internal ferrite junction. This impedance matching circuit is simple, occupies a small area, and has low insertion loss, thereby reducing the size of the non-reversible device 10 and reducing the insertion loss caused by the non-reversible device 10.

[0087] In yet another possible embodiment, port 3 of the non-reversible device 10 is connected to a load. When port 3 of the non-reversible device 10 is connected to a load, the non-reversible device 10 is a special type of circulator, also known as an isolator.

[0088] Furthermore, when port 3 of the non-reversible device 10 in Figure 1b is not connected to a load, but to an RF component (such as a low-noise amplifier), the non-reversible device can specifically be a circulator.

[0089] Designing the impedance of each port of an irreversible device to a standard impedance standard, while regulating RF industry standards to some extent, can lead to redundant design in certain scenarios, resulting in performance degradation of the RF module. The impedance of the ferrite junction in an irreversible device (e.g., around 20Ω) is generally less than the standard impedance. If the impedance of each port of an irreversible device is designed to be a standard impedance, then the impedance of each port needs to be matched to the standard impedance. Please refer to Figure 2, which is a schematic diagram of a conventional irreversible device using ferrite materials. As shown in Figure 2, this irreversible device uses a three-port device as an example. This device includes a ferrite core, matching 1, matching 2, matching 3, port 1, port 2, and port 3. The ferrite core includes three ferrite junctions: junction 1, junction 2, and junction 3. Since the impedance of the ferrite junction is less than the standard impedance, in order to match the impedance of each port of the irreversible device to the standard impedance, an impedance matching circuit (as shown in Figure 2, matching 1, matching 2, and matching 3) needs to be added between each port of the irreversible device and the corresponding ferrite junction. As shown in Figure 2, ferrite junction 1 is connected to port 1 through matching 1, ferrite junction 2 is connected to port 2 through matching 2, and ferrite junction 3 is connected to port 3 through matching 3. The impedance transformation of the non-reversible device in Figure 2 is relatively large, the impedance matching is complex, and the insertion loss is significant. Overall, this deteriorates key performance indicators of the RF module's transmit link, such as transmit power and power amplifier power consumption, and also worsens key performance indicators of the RF module's receive link, such as front-end insertion loss and sensitivity. Furthermore, because the non-reversible device in this case has multiple impedance matching circuits, its size is also large, which is not conducive to its application in miniaturized RF modules.

[0090] If the impedance of the port connected to the power amplifier in the irreversible device is designed to be less than the standard impedance, while the other ports are designed to have the standard impedance, the impedance matching between the irreversible device and the power amplifier can be simplified. However, due to the impedance asymmetry between the ports of the irreversible device in the signal transmission direction, the insertion loss of the irreversible device is relatively large. Please refer to Figure 3, which is a schematic diagram of another structure of an irreversible device using ferrite material. As shown in Figure 3, this irreversible device is an example of a three-port device. This irreversible device includes a ferrite core, a matching element 2, a matching element 3, a port 1, a port 2, and a port 3. The ferrite core includes three ferrite junctions: junction 1, junction 2, and junction 3. Junction 1 of the ferrite core is connected to port 1, junction 2 of the ferrite core is connected to port 2 through matching element 2, and junction 3 of the ferrite core is connected to port 3 through matching element 3. Figure 3 shows that the impedance of port 1, where the irreversible device connects to the output port of the power amplifier circuit, is designed to be the same as the impedance of junction 1. The impedances of ports 2 and 3 of the irreversible device are both designed to be standard impedances. Compared to Figure 2, this saves one impedance matching circuit (as shown in Figure 2, matching 1 is omitted), thereby reducing the size of the irreversible device and the signal insertion loss it causes. However, the impedances of ports 1 and 2 of the irreversible device are not equal in the signal transmission direction. That is, the impedance between port 1 (the signal input terminal of the irreversible device) connected to the output port of the power amplifier circuit and port 2 (the signal output terminal of the irreversible device) from which the signal flows out is asymmetrical. When the signal emitted by the power amplifier passes through the irreversible device, the irreversible device will still cause significant insertion loss to the signal.

[0091] In this embodiment, the impedance of port 1 of the non-reversible device 10 and the impedance of port 2 of the non-reversible device are both designed to be less than the standard impedance. This eliminates the need to add more impedance matching circuits inside the non-reversible device, thereby reducing the size of the non-reversible device and reducing the insertion loss of the non-reversible device.

[0092] Please refer to Figure 4, which is a schematic diagram of an irreversible device using ferrite material according to an embodiment of this application. As shown in Figure 4, taking a three-port device as an example, the irreversible device includes a ferrite, a mating element 3, port 1, port 2, and port 3. The ferrite includes three ferrite junctions: junction 1, junction 2, and junction 3. Junction 1 of the ferrite is connected to port 1, junction 2 of the ferrite is connected to port 2, and junction 3 of the ferrite is connected to port 3 through mating element 3. Figure 4 shows that the impedance of port 1 of the irreversible device can be designed to be the same as the impedance of junction 1, the impedance of port 2 of the irreversible device can be designed to be the same as the impedance of junction 2, and the impedance of port 3 of the irreversible device can be designed to be a standard impedance. This means that the irreversible device in Figure 4 only requires an impedance matching circuit (matching 3 as shown in Figure 4) between junction 3 and port 3. Compared with Figure 2, this saves two impedance matching circuits (such as matching 1 and matching 2 shown in Figure 2), and compared with Figure 3, it saves one matching circuit (such as matching 2 shown in Figure 3). This reduces the size of the irreversible device 10 and the signal insertion loss caused by the irreversible device 10. Furthermore, the equal impedances of ports 1 and 2 of the irreversible device, i.e., the symmetrical impedances of ports 1 and 2, reduce the insertion loss generated when the signal passes through ports 1 and 2 of the irreversible device, thereby reducing the insertion loss of the irreversible device.

[0093] Please refer to Figure 5, which is a schematic diagram of another irreversible device using ferrite material provided in an embodiment of this application. As shown in Figure 5, this irreversible device is exemplified by a three-port device, which includes a ferrite, port 1, port 2, and port 3. The ferrite includes three ferrite junctions: junction 1, junction 2, and junction 3. Junction 1 of the ferrite is connected to port 1, junction 2 of the ferrite is connected to port 2, and junction 3 of the ferrite is connected to port 3. Figure 5 shows how the impedance of port 1 of the irreversible device can be designed to be the same as that of junction 1, the impedance of port 2 to be the same as that of junction 2, and the impedance of port 3 to be the same as that of junction 3. This eliminates the need for additional matching circuits in the irreversible device shown in Figure 5. Compared to Figure 2, this saves three matching circuits (such as matching circuits 1, 2, and 3 shown in Figure 2), and compared to Figure 3, it saves two matching circuits (such as matching circuits 2 and 3 shown in Figure 3). This significantly reduces the size of the irreversible device and lowers the signal insertion loss caused by the irreversible device 10. Furthermore, the equal impedances of ports 1, 2, and 3 of the irreversible device 10, meaning the impedances of the three ports are symmetrical, effectively reduces the insertion loss when the signal passes through any two ports, thus reducing the overall insertion loss of the irreversible device.

[0094] Figure 6 illustrates the effect of the non-reversible device provided in the embodiments of this application by taking a three-port circulator with a standard impedance of 50Ω as an example.

[0095] Please refer to Figure 6, which is a schematic diagram comparing the port impedances of a conventional circulator and an improved circulator provided in this application embodiment. As shown in Figure 6, the left side represents the conventional circulator, where the impedances of all three ports are standard impedances (50Ω). The right side represents the improved circulator of this application, where the impedances of all three ports are less than the standard impedances (1-50Ω). "1-50Ω" refers to impedances greater than 1Ω and less than 50Ω. The improved circulator of this application can also be called a low-impedance circulator. This low-impedance circulator is a three-port symmetrical circulator, meaning that the impedances of all three ports are less than 50Ω and are equal. This low-impedance circulator can achieve low insertion loss, small area, and large bandwidth in the matching circuit.

[0096] The low-impedance circulator in Figure 6 is a circulator with all three ports being low-impedance. In other embodiments of this application, the low-impedance circulator can also be a circulator with two low-impedance ports and the other port having a standard impedance. This low-impedance circulator can be applied to the transmit and receive links of an RF module to achieve unidirectional low-loss and efficient transmission of transmit or receive signals, reduce transmit link power consumption, and improve receive link sensitivity.

[0097] This application also provides an RF module employing the aforementioned non-reversible device.

[0098] Please refer to Figure 7, which is a schematic diagram of the structure of a radio frequency (RF) module provided in an embodiment of this application. The RF module may include a power amplifier 20 and an irreversible device 10. The irreversible device 10 includes port 1 and port 2. The output port U of the power amplifier 20 is connected to port 1 of the irreversible device 10. The impedance of port 1 of the irreversible device 10 is equal to the impedance of port 2 of the irreversible device 10, and both the impedance of port 1 and port 2 of the irreversible device 10 are less than the standard impedance.

[0099] The RF module in Figure 7 enables signal transmission. The transmit (TX) signal is amplified by the power amplifier 20, enters port 1 of the non-reversible device 10, and is then transmitted from port 2 of the non-reversible device 10.

[0100] The irreversible device 10 included in the RF module provided in this application has symmetrical impedances at ports 1 and 2 in the signal transmission direction. This reduces the insertion loss generated when the transmitted signal passes through the first port 1 to the second port 2 of the irreversible device, thereby reducing the insertion loss of the irreversible device 10. When the transmit power of the RF module is high (e.g., up to tens or hundreds of W), the impedance of the output port U of the power amplifier 20 is usually small (e.g., around a few Ω). Because the impedance of port 1 of the irreversible device 10 is less than the standard impedance, the difference between the output port impedance of the power amplifier and the impedance of port 1 of the irreversible device 10 is small. This makes the impedance matching method between the output port U of the power amplifier 20 and the port 1 of the irreversible device simpler, with a smaller area and lower insertion loss, supporting the power amplifier to stably output a transmit signal with a larger bandwidth.

[0101] In some embodiments of this application, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is directly connected to the port 1 of the non-reversible device 10. "Direct connection" refers to a connection without impedance matching circuitry, but directly via a wire (e.g., a microstrip line with a specific impedance).

[0102] In this embodiment, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10 (in this case, the output port U of the power amplifier 20 is less than the standard impedance), the output port U of the power amplifier 20 is directly connected to the port 1 of the non-reversible device 10. This eliminates the need for an impedance matching circuit between the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10, thereby better reducing insertion loss caused by the impedance matching circuit. For example, if the impedance of the output port U of the power amplifier 20 is 25Ω and the impedance of the port 1 of the non-reversible device 10 is also 25Ω, then the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0103] In some other embodiments of this application, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61 (see FIG8).

[0104] Please refer to Figure 8, which is a schematic diagram of another radio frequency module provided in an embodiment of this application. Figure 8 adds a first impedance matching circuit 61 to Figure 7, and the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61.

[0105] In this embodiment, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61. Since the impedance of the output port U of the power amplifier 20 is less than the standard impedance, the impedance of the port 1 of the non-reversible device 10 is also less than the standard impedance. The impedance transformation of the first impedance matching circuit 61 is relatively small; this impedance matching circuit is simple, occupies a small area, and has low insertion loss.

[0106] For example, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is 25Ω, then the first impedance matching circuit 61 is a 5Ω to 25Ω matching circuit; the output port U of the power amplifier 20 is connected to port 1 of the non-reversible device 10 through the 5Ω to 25Ω matching circuit, and the impedance transformation ratio of the 5Ω to 25Ω matching circuit is 5. However, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is a standard impedance (e.g., 50Ω), a 5Ω to 50Ω matching circuit needs to be set between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10, and the impedance transformation ratio of the 5Ω to 50Ω matching circuit is 10. As can be seen, compared with the standard impedance of port 1 of the non-reversible device 10, in the RF module of this application embodiment where the impedance of port 1 of the non-reversible device 10 is less than the standard impedance, the impedance transformation ratio of the first impedance matching circuit 61 is smaller, the impedance matching circuit is simpler, the area occupied by the impedance matching circuit is smaller, and the insertion loss of the impedance matching circuit is smaller.

[0107] Please refer to Figure 9, which is a schematic diagram of a TDD-supporting radio frequency module provided in an embodiment of this application. As shown in Figure 9, the radio frequency module may include a power amplifier 20, a low-noise amplifier 30, an irreversible device 10, and a filter 40; the output port U of the power amplifier 20 is connected to port 1 of the irreversible device 10, and port 2 of the irreversible device 10 is connected to the first port 401 of the filter 40; port 3 of the irreversible device 10 is connected to the input port I of the low-noise amplifier 30; wherein, the impedance of port 1 of the irreversible device 10 is equal to the impedance of port 2 of the irreversible device 10, and both the impedance of port 1 of the irreversible device 10 and the impedance of port 2 of the irreversible device 10 are less than the standard impedance; the impedance of port 3 of the irreversible device 10 is less than the standard impedance, or the impedance of port 3 of the irreversible device 10 is the standard impedance. In some embodiments, the radio frequency module may further include an antenna unit 50, and the second port 402 of the filter 40 is connected to the antenna unit 50. The antenna unit 50 may include at least one antenna.

[0108] In this embodiment, the power amplifier 20 (PA), the non-reversible device 10, the filter 40, and the antenna unit 50 can form the transmit (TX) link of the radio frequency module. The TX signal can be emitted from the TX interface of an radio frequency transceiver (not shown in Figure 9), and the TX signal can be transmitted through the TX link. Specifically, after the TX signal is amplified by the power amplifier 20, it is unidirectionally transmitted to the filter 40 via the non-reversible device 10, and after being transmitted to the antenna unit 50, it is converted into an electromagnetic wave of a certain frequency and transmitted into space.

[0109] The low-noise amplifier (LNA) 30, the non-reversible device 10, the filter 40, and the antenna unit 50 can form the receive (RX) link of the radio frequency system. RX signals can be received through the RX link. Specifically, the antenna unit 50 converts spatial electromagnetic waves into current and voltage signals, which are then transmitted to the non-reversible device 10 via the filter 40, and finally amplified by the low-noise amplifier 30, converting them into RX signals. These RX signals undergo a series of processing steps before being sent to the RX interface of the transceiver (not shown in Figure 9).

[0110] The input impedance of filter 40 is relatively discrete. If filter 40 is directly used as the load of power amplifier 20, it will affect the output characteristics of power amplifier 20. Usually, a non-reversible device 10 is added between power amplifier 20 and filter 40 (port 1 of non-reversible device 10 is connected to the output port U of power amplifier 20, and port 2 of non-reversible device 10 is connected to the first port 401 of filter 40). This device acts as a reverse isolation between filter 40 and power amplifier 20, which not only ensures the stability of the output load of power amplifier 20, but also greatly suppresses the influence of reflected signals on power amplifier 20, enabling power amplifier 20 to work with high performance and stability.

[0111] In this embodiment, the impedances of ports 1 and 2 of the non-reversible device 10 are symmetrical, which can reduce the insertion loss of the TX signal when passing through ports 1 and 2 of the non-reversible device 10, thereby reducing the insertion loss of the non-reversible device 10. When the transmit power of the RF module is high (e.g., up to tens or hundreds of W), the impedance of the output port U of the power amplifier 20 is small (e.g., around a few Ω). The difference between the impedance of the output port U of the power amplifier 20 and the impedance of port 1 of the non-reversible device 10 is small, making the impedance matching method between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10 simpler, smaller in area, and even eliminating the need for an impedance matching circuit. This further reduces the insertion loss of the signal when passing through the non-reversible device 10 from the power amplifier 20, supporting the power amplifier 20 to output a TX signal with a larger bandwidth.

[0112] Furthermore, when the impedance of the ferrite junction inside the irreversible device 10 is less than the standard impedance of 50Ω, and the impedances of port 1 and port 2 of the irreversible device 10 are less than the standard impedance, and the impedance of the ferrite junction inside the irreversible device 10 is equal to the impedances of port 1 and port 2 of the irreversible device 10, it is not necessary to add an impedance matching circuit between port 1 and the corresponding internal ferrite junction of the irreversible device 10, nor is it necessary to add an impedance matching circuit between port 2 and the corresponding internal ferrite junction of the irreversible device 10 (see Figure 4 or Figure 5). This can effectively reduce the size of the irreversible device 10 and reduce the insertion loss caused by the irreversible device 10.

[0113] When the impedance of the ferrite junction inside the irreversible device 10 is less than the standard impedance of 50Ω, and the impedances of ports 1 and 2 of the irreversible device 10 are less than the standard impedance, and the impedance of the ferrite junction inside the irreversible device 10 is not equal to the impedances of ports 1 and 2 of the irreversible device 10, a simple impedance matching circuit can be added between port 1 and the corresponding internal ferrite junction, and a simple impedance matching circuit can be added between port 2 and the corresponding internal ferrite junction. Compared with matching circuits 1 and 2 shown in Figure 3, this simple impedance matching circuit can reduce the area and insertion loss of the impedance matching circuit. For example, when the impedance of the ferrite junction is 20Ω and the impedance of port 1 of the non-reversible device 10 is 25Ω, only a 20Ω to 25Ω matching circuit needs to be added between port 1 of the non-reversible device 10 and the corresponding internal ferrite junction, resulting in a relatively small impedance transformation. When the impedance of the ferrite junction is 20Ω and the impedance of port 1 of the non-reversible device 10 is the standard impedance of 50Ω, a 20Ω to 50Ω matching circuit needs to be added between port 1 of the non-reversible device 10 and the corresponding internal ferrite junction, resulting in a slightly larger impedance transformation. Therefore, compared to the standard 50Ω port of the traditional non-reversible device 10, the area and insertion loss of the impedance matching circuit can also be reduced.

[0114] In this application, the phrase "the impedance of port 3 of the non-reversible device 10 is less than the standard impedance" can include the following two cases: the impedance of port 3 of the non-reversible device 10 is less than the standard impedance, and the impedance of port 3 of the non-reversible device 10 is equal to the impedance of port 1; or, the impedance of port 3 of the non-reversible device 10 is less than the standard impedance, and the impedance of port 3 of the non-reversible device 10 is not equal to the impedance of port 1. In particular, when the impedance of port 3 of the non-reversible device 10 is equal to the impedance of port 1 of the non-reversible device 10, ports 1, 2, and 3 of the non-reversible device 10 are all low-impedance and impedance-symmetrical, which can better reduce the insertion loss generated when the signal passes through any two ports of the non-reversible device.

[0115] Furthermore, since the impedance of the internal ferrite junction of the irreversible device 10 is typically lower than the standard impedance, when the impedance of port 3 of the irreversible device 10 is lower than the standard impedance, and the impedance of the internal ferrite junction of the irreversible device 10 is equal to the impedance of port 3, it is not necessary to add an impedance matching circuit between port 3 and the corresponding internal ferrite junction (see Figure 5), thereby reducing the size of the irreversible device 10 and reducing the insertion loss caused by the irreversible device 10. When the impedance of port 3 of the irreversible device 10 is lower than the standard impedance, and the impedance of the internal ferrite junction of the irreversible device 10 is not equal to the impedance of port 3, a simple impedance matching circuit can be added between port 3 and the corresponding internal ferrite junction.

[0116] In this application, when the standard impedance is 50 ohms, the impedance less than the standard impedance can include: greater than 1 ohm and less than 50 ohms.

[0117] In some embodiments of this application, the impedance of each port of the RF components (such as the power amplifier 20, low-noise amplifier 30, non-reversible device 10, and filter 40 as shown in Figure 9) in the RF module can be defined as less than the standard impedance, or it can be defined as the standard impedance (except for the power amplifier 20 in this case), so that the RF module can be applied to different application scenarios. In some embodiments, the impedance of the output port U of the power amplifier 20, the impedance of the first port 401 of the filter 40, and the impedance of the input port I of the low-noise amplifier 30 are all less than the standard impedance. Defining the impedance of each port of the RF components in the RF module as less than the standard impedance, compared with defining it as a standard impedance connection, can better reduce the difficulty of the impedance matching circuit connecting the various RF components in the RF module, reduce the insertion loss of the impedance matching circuit, and realize the miniaturization of the RF module.

[0118] In some embodiments of this application, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is directly connected to the port 1 of the non-reversible device 10. "Direct connection" refers to a connection without impedance matching circuitry, but directly via a wire (e.g., a microstrip line with a specific impedance).

[0119] In this embodiment, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10 (in this case, the output port U of the power amplifier 20 is less than the standard impedance), the output port U of the power amplifier 20 is directly connected to the port 1 of the non-reversible device 10. This eliminates the need for an impedance matching circuit between the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10, thereby reducing the complexity of impedance matching and insertion loss. For example, if the impedance of the output port U of the power amplifier 20 is 25Ω and the impedance of the port 1 of the non-reversible device 10 is also 25Ω, then the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0120] In some other embodiments of this application, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61 (see FIG10).

[0121] Please refer to Figure 10, which is a schematic diagram of another TDD-supporting radio frequency module provided in this application embodiment. Figure 10 adds a first impedance matching circuit 61 to Figure 9, and the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61.

[0122] In this embodiment, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61. Since the impedance of the output port U of the power amplifier 20 is less than the standard impedance, the impedance of the port 1 of the non-reversible device 10 is also less than the standard impedance. The impedance transformation of the first impedance matching circuit 61 is relatively small; this impedance matching circuit is simple, occupies a small area, and has low insertion loss.

[0123] For example, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is 25Ω, then the first impedance matching circuit 61 is a 5Ω to 25Ω matching circuit; the output port U of the power amplifier 20 is connected to port 1 of the non-reversible device 10 through the 5Ω to 25Ω matching circuit, and the impedance transformation ratio of the 5Ω to 25Ω matching circuit is 5. However, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is a standard impedance (e.g., 50Ω), a 5Ω to 50Ω matching circuit needs to be set between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10, and the impedance transformation ratio of the 5Ω to 50Ω matching circuit is 10. As can be seen, compared with the standard impedance of port 1 of the non-reversible device 10, in the RF module of this application embodiment where the impedance of port 1 of the non-reversible device 10 is less than the standard impedance, the impedance transformation ratio of the first impedance matching circuit 61 is smaller, the impedance matching circuit is simpler, the area occupied by the impedance matching circuit is smaller, and the insertion loss of the impedance matching circuit is smaller.

[0124] In one possible implementation, when the impedance of port 2 of the non-reversible device 10 is equal to the impedance of the first port 401 of the filter 40, port 2 of the non-reversible device 10 is directly connected to the first port 401 of the filter 40. In this case, there is no need to design an impedance matching circuit between port 2 of the non-reversible device 10 and the first port 401 of the filter 40, thereby reducing the complexity of impedance matching and reducing the insertion loss of the signal flowing from port 2 of the non-reversible device 10 to the filter 40. Furthermore, as mentioned earlier in this application, since the impedance of the internal ferrite junction of the non-reversible device 10 is typically less than the standard impedance of 50Ω, and the impedance of port 2 of the non-reversible device 10 is less than the standard impedance, and the impedance of the internal ferrite junction of the non-reversible device 10 is equal to the impedance of port 2 of the non-reversible device 10, it is not necessary to add an impedance matching circuit between port 2 of the non-reversible device 10 and the corresponding internal ferrite junction (see Figure 4 or Figure 5), thereby effectively reducing the size of the non-reversible device 10 and reducing the insertion loss caused by the non-reversible device 10.

[0125] For example, if the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 401 of the filter 40 is also 25Ω, then port 2 of the non-reversible device 10 and the first port 401 of the filter 40 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0126] In another possible implementation, when the impedance of port 2 of the non-reversible device 10 is not equal to the impedance of the first port 401 of the filter 40, port 2 of the non-reversible device 10 is connected to the first port 401 of the filter 40 through the second impedance matching circuit 62 (see Figure 11).

[0127] Please refer to Figure 11, which is a schematic diagram of another TDD-supporting RF module provided in an embodiment of this application. Figure 11 is based on Figure 9 with the addition of a second impedance matching circuit 62. The port 2 of the non-reversible device 10 is connected to the first port 401 of the filter 40 through the second impedance matching circuit 62.

[0128] In this embodiment, when the impedance of port 2 of the non-reversible device 10 and the impedance of the first port 401 of the filter 40 are not equal, port 2 of the non-reversible device 10 is connected to the first port 401 of the filter 40 through the second impedance matching circuit 62. In this case, the impedance of the first port of the filter can be equal to or less than the standard impedance. Specifically, when the impedance of port 2 of the non-reversible device 10 is less than the standard impedance, and the impedance of the first port 401 of the filter 40 is also less than the standard impedance, the impedance transformation ratio of the second impedance matching circuit 62 is smaller, the matching circuit is simpler, occupies less area, and has lower insertion loss. When the impedance of port 2 of the non-reversible device 10 is less than the standard impedance, and the impedance of the first port 401 of the filter 40 is the standard impedance, the impedance transformation ratio of the second impedance matching circuit 62 is slightly larger.

[0129] For example, if the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 401 of the filter 40 is 30Ω, then the second impedance matching circuit 62 is a 25Ω to 30Ω matching circuit; port 2 of the non-reversible device 10 is connected to the first port 401 of the filter 40 through the 25Ω to 30Ω matching circuit, and the impedance transformation ratio of the 25Ω to 30Ω matching circuit is 1.2. If the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 401 of the filter 40 is a standard impedance (e.g., 50Ω), a 25Ω to 50Ω matching circuit needs to be set between port 2 of the non-reversible device 10 and the first port 401 of the filter 40, and the impedance transformation ratio of the 25Ω to 50Ω matching circuit is 2. As can be seen, when the impedance of the first port 401 of the filter 40 is less than the standard impedance, the impedance transformation ratio of the second impedance matching circuit 62 is smaller, the matching circuit is simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller.

[0130] In some embodiments of this application, the impedance of port 3 of the reversible device 10 is equal to the impedance of input port I of the low-noise amplifier 30, and port 3 of the reversible device 10 is directly connected to input port I of the low-noise amplifier 30. In this case, it is not necessary to design an impedance matching circuit between port 3 of the reversible device 10 and input port I of the low-noise amplifier 30, thereby reducing the complexity of impedance matching and reducing insertion loss. In addition, since the impedance of the ferrite junction inside the reversible device 10 is usually less than the standard impedance, when the impedance of port 3 of the reversible device 10 is less than the standard impedance, and the impedance of the ferrite junction inside the reversible device 10 is equal to the impedance of port 3 of the reversible device 10, it is also not necessary to add an impedance matching circuit between port 3 of the reversible device 10 and the corresponding internal ferrite junction (see Figure 5), thereby reducing the size of the reversible device 10 and reducing the insertion loss caused by the reversible device 10.

[0131] Among them, the impedance of port 3 of the non-reversible device 10 is equal to the impedance of input port I of the low-noise amplifier 30, which can include the following two cases: (1) The impedance of port 3 of the non-reversible device 10 is less than the standard impedance, the impedance of input port I of the low-noise amplifier 30 is less than the standard impedance, and the impedance of port 3 of the non-reversible device 10 is equal to the impedance of input port I of the low-noise amplifier 30. (2) The impedance of port 3 of the non-reversible device 10 is equal to the standard impedance, and the impedance of input port I of the low-noise amplifier 30 is equal to the standard impedance.

[0132] In the above situation (1), the impedances of port 1 of the reversible device 10 and port 3 of the reversible device 10 can be equal or unequal. For example, if the impedance of port 3 of the reversible device 10 is 25Ω (at this time, the impedances of port 1 of the reversible device 10 and port 3 of the reversible device 10 are equal), and the impedance of input port I of the low-noise amplifier 30 is also 25Ω, then port 3 of the reversible device 10 and input port I of the low-noise amplifier 30 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width). If the impedance of port 3 of the reversible device 10 is 30Ω (at this time, the impedances of port 1 of the reversible device 10 and port 3 of the reversible device 10 are unequal), and the impedance of input port I of the low-noise amplifier 30 is also 30Ω, then port 3 of the reversible device 10 and input port I of the low-noise amplifier 30 can be connected by a 30Ω wire (e.g., a 30Ω microstrip line of equal width).

[0133] In the above situation (2), the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are not equal. For example, if the impedance of port 3 of the non-reversible device 10 is 50Ω and the impedance of input port I of the low-noise amplifier 30 is also 50Ω, then port 3 of the non-reversible device 10 and input port I of the low-noise amplifier 30 can be connected by a 50Ω wire (e.g., a 50Ω microstrip line of equal width).

[0134] In some other embodiments of this application, the impedance of port 3 of the non-reversible device 10 is not equal to the impedance of input port I of the low noise amplifier 30, and port 3 of the non-reversible device 10 is connected to input port I of the low noise amplifier 30 through a third impedance matching circuit 63 (see Figure 12).

[0135] Please refer to Figure 12, which is a schematic diagram of another TDD-supporting RF module provided in this embodiment of the application. Figure 12 is based on Figure 11 with the addition of a third impedance matching circuit 63. The port 3 of the non-reversible device 10 is connected to the input port I of the low-noise amplifier 30 through the third impedance matching circuit 63.

[0136] In this embodiment, when the impedance of port 3 of the irreversible device 10 and the impedance of input port I of the low-noise amplifier 30 are not equal, port 3 of the irreversible device 10 is connected to input port I of the low-noise amplifier 30 through a third impedance matching circuit 63. When the impedance of port 3 of the irreversible device 10 is less than the standard impedance, and the impedance of input port I of the low-noise amplifier 30 is also less than the standard impedance, the impedance transformation ratio of the third impedance matching circuit 63 is smaller, the matching circuit is simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller. When the impedance of port 3 of the irreversible device 10 is less than the standard impedance, and the impedance of input port I of the low-noise amplifier 30 is the standard impedance, the impedance transformation ratio of the third impedance matching circuit 63 is slightly larger.

[0137] Among them, the impedance of port 3 of the non-reversible device 10 and the impedance of input port I of the low-noise amplifier 30 are not equal, which can include the following three cases: (1) The impedance of port 3 of the non-reversible device 10 is less than the standard impedance, and the impedance of input port I of the low-noise amplifier 30 is equal to the standard impedance. (2) The impedance of port 3 of the non-reversible device 10 is equal to the standard impedance, and the impedance of input port I of the low-noise amplifier 30 is less than the standard impedance. (3) The impedance of port 3 of the non-reversible device 10 is less than the standard impedance, the impedance of input port I of the low-noise amplifier 30 is less than the standard impedance, and the impedance of port 3 of the non-reversible device 10 and the impedance of input port I of the low-noise amplifier 30 are not equal.

[0138] In the above situation (1), the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 can be equal or unequal. If the impedance of port 3 of the non-reversible device 10 is 25Ω (at this time, the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are equal), and the impedance of input port I of the low-noise amplifier 30 is a standard impedance (for example, 50Ω), a third impedance matching circuit 63 of 25Ω to 50Ω needs to be set between port 3 of the non-reversible device 10 and input port I of the low-noise amplifier 30. The impedance transformation ratio of this matching circuit is 2. If the impedance of port 3 of the non-reversible device 10 is 30Ω (at this time, the impedances of port 1 and port 3 of the non-reversible device 10 are not equal), and the impedance of input port I of the low-noise amplifier 30 is a standard impedance (for example, 50Ω), a third impedance matching circuit 63 of 30Ω to 50Ω needs to be set between port 3 of the non-reversible device 10 and input port I of the low-noise amplifier 30. The impedance transformation ratio of this matching circuit is 1.67.

[0139] In the above situation (2), the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are not equal. If the impedance of port 3 of the non-reversible device 10 is a standard impedance (for example, 50Ω), and the impedance of input port I of the low-noise amplifier 30 is 25Ω, a third impedance matching circuit 63 of 50Ω to 25Ω needs to be set between port 3 of the non-reversible device 10 and input port I of the low-noise amplifier 30. The impedance transformation ratio of this matching circuit is 2.

[0140] In the above situation (3), the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 can be equal or unequal. For example, if the impedance of port 3 of the non-reversible device 10 is 25Ω (at this time, the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are equal), and the impedance of input port I of the low-noise amplifier 30 is 30Ω, then the third impedance matching circuit 63 is a 25Ω to 30Ω third impedance matching circuit 63, and its impedance transformation ratio is 1.2. If the impedance of port 3 of the non-reversible device 10 is 25Ω (at this time, the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are equal), and the impedance of input port I of the low-noise amplifier 30 is 20Ω, then the third impedance matching circuit 63 is a 25Ω to 20Ω third impedance matching circuit 63, and its impedance transformation ratio is 1.25. If the impedance of port 3 of the non-reversible device 10 is 35Ω (at this time, the impedances of port 1 of the non-reversible device 10 and port 3 of the non-reversible device 10 are not equal), and the impedance of input port I of the low-noise amplifier 30 is 30Ω, then the third impedance matching circuit 63 is a 35Ω to 30Ω third impedance matching circuit with an impedance transformation ratio of 1.17.

[0141] As can be seen, when the impedance of the input port I of the low-noise amplifier 30 is less than the standard impedance, the impedance transformation ratio of the third impedance matching circuit 63 is smaller, the matching circuit is simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller.

[0142] Specifically, the non-reversible device 10 in the RF module shown in Figures 9 to 12 can be a circulator.

[0143] Among them, the radio frequency modules shown in Figures 9 to 12 can be used for time division duplex (TDD) systems.

[0144] Please refer to Figure 13, which is a schematic diagram of the structure of an FDD-supporting radio frequency module provided in an embodiment of this application. As shown in Figure 13, the radio frequency module may include a power amplifier 20, a low-noise amplifier 30, an irreversible device 10, and a duplexer 70; the output port U of the power amplifier 20 is connected to port 1 of the irreversible device 10, port 2 of the irreversible device 10 is connected to the first port 701 of the duplexer 70, and the second port 702 of the duplexer 70 is connected to the input port I of the low-noise amplifier 30; wherein, the impedance of port 1 of the irreversible device 10 and the impedance of port 2 of the irreversible device 10 are equal and both are less than the standard impedance. In some embodiments, the radio frequency module may also include an antenna unit 50. The third port 703 of the duplexer 70 is connected to the antenna unit 50.

[0145] In this embodiment, the power amplifier 20, the non-reversible device 10, the duplexer 70, and the antenna unit 50 can form the transmit (TX) link of the radio frequency module. The TX signal can be transmitted through the TX link. Specifically, after the TX signal is amplified by the power amplifier 20, it is transmitted unidirectionally to the duplexer 70 via the non-reversible device 10, and then to the antenna unit 50, where it is converted into an electromagnetic wave of a certain frequency and transmitted into space.

[0146] The low-noise amplifier 30, duplexer 70, and antenna unit 50 can form the receive (RX) link of the radio frequency module. The RX signal can be received through the RX link. Specifically, after the antenna unit 50 converts the spatial electromagnetic wave into a current and voltage signal, it is transmitted to the low-noise amplifier 30 through the duplexer 70, and then amplified by the low-noise amplifier 30 and converted into an RX signal.

[0147] In this embodiment, the impedances of ports 1 and 2 of the non-reversible device 10 are symmetrical, which can reduce the insertion loss of the TX signal when passing through ports 1 and 2 of the non-reversible device 10, thereby reducing the insertion loss of the non-reversible device 10. When the impedance of the output port U of the power amplifier 20 is small, the difference between the impedance of the output port U of the power amplifier 20 and the impedance of port 1 of the non-reversible device 10 is small, making the impedance matching circuit between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10 simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller. It may even eliminate the need to set an impedance matching circuit between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10, thereby supporting the power amplifier 20 to output a TX signal with a larger bandwidth more efficiently.

[0148] Furthermore, when the impedance of the ferrite junction inside the irreversible device 10 is less than the standard impedance of 50Ω, and the impedances of port 1 and port 2 of the irreversible device 10 are less than the standard impedance, and the impedance of the ferrite junction inside the irreversible device 10 is equal to the impedances of port 1 and port 2 of the irreversible device 10, it is not necessary to add an impedance matching circuit between port 1 and the corresponding internal ferrite junction of the irreversible device 10, nor is it necessary to add an impedance matching circuit between port 2 and the corresponding internal ferrite junction of the irreversible device 10 (see Figure 4 or Figure 5). This can effectively reduce the size of the irreversible device 10 and reduce the insertion loss caused by the irreversible device 10.

[0149] In cases where the impedance of the ferrite junction inside the irreversible device 10 is less than the standard impedance of 50Ω, and the impedances of ports 1 and 2 of the irreversible device 10 are also less than the standard impedance, and the impedance of the ferrite junction inside the irreversible device 10 is not equal to the impedances of ports 1 and 2 of the irreversible device 10, a simple impedance matching circuit can be added between port 1 and the corresponding internal ferrite junction, and a simple impedance matching circuit can be added between port 2 and the corresponding internal ferrite junction. Compared with matching circuits 1 and 2 shown in Figure 3, this simple impedance matching circuit can reduce the area and insertion loss of the impedance matching circuit. For example, when the impedance of the ferrite junction is 20Ω and the impedance of port 1 of the non-reversible device 10 is 25Ω, only a 20Ω to 25Ω matching circuit needs to be added between port 1 of the non-reversible device 10 and the corresponding internal ferrite junction, resulting in a relatively small impedance transformation. However, when the impedance of the ferrite junction is 20Ω and the impedance of port 1 of the non-reversible device 10 is the standard impedance of 50Ω, a 20Ω to 50Ω matching circuit needs to be added between port 1 of the non-reversible device 10 and the corresponding internal ferrite junction, resulting in a larger impedance transformation. Therefore, compared to the standard impedance of 50Ω port of the traditional non-reversible device 10, the area and insertion loss can still be reduced.

[0150] Optionally, the impedance of the output port U of the power amplifier 20 is less than the standard impedance; the impedance of the first port 701 of the duplexer 70 is equal to or less than the standard impedance; the impedance of the second port 702 of the duplexer 70 is equal to or less than the standard impedance; and the impedance of the input port I of the low-noise amplifier 30 is equal to or less than the standard impedance. Where the standard impedance is 50 ohms, "less than the standard impedance" includes: greater than 1 ohm and less than 50 ohms.

[0151] In this embodiment, the impedance of each port of the RF components in the RF module (such as the power amplifier 20, low-noise amplifier 30, non-reversible device 10, duplexer 70, etc., as shown in Figure 13) can be defined as less than the standard impedance, or it can be defined as the standard impedance (except for the power amplifier 20), which can be applied to different application scenarios. In some embodiments, the impedance of the output port U of the power amplifier 20, the impedance of the first port 401 of the filter 40, and the impedance of the input port I of the low-noise amplifier 30 are all less than the standard impedance. Defining the impedance of each port of the RF components in the RF module as less than the standard impedance, compared with defining it as a standard impedance connection, can better reduce the difficulty of the impedance matching circuit connecting the various RF components in the RF module, reduce the insertion loss of the impedance matching circuit, and realize the miniaturization and low power consumption of the RF module.

[0152] Where the standard impedance is 50Ω, the impedance less than the standard impedance can be greater than 1Ω and less than 50Ω. The ports of each RF component can be internal ports of the RF module or all external ports.

[0153] In some embodiments of this application, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is directly connected to the port 1 of the non-reversible device 10. Here, "direct connection" means that the connection is made directly through a wire without using an impedance matching circuit.

[0154] In this embodiment, when the impedance of the output port U of the power amplifier 20 is equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10 are directly connected. This eliminates the need for an impedance matching circuit between the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10, thereby reducing the complexity of impedance matching and insertion loss. For example, if the impedance of the output port U of the power amplifier 20 is 25Ω and the impedance of the port 1 of the non-reversible device 10 is also 25Ω, then the output port U of the power amplifier 20 and the port 1 of the non-reversible device 10 can be connected via a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0155] In some other embodiments of this application, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61 (see FIG14).

[0156] Please refer to Figure 14, which is a schematic diagram of another FDD-supporting RF module provided in this application embodiment. Figure 14 is based on Figure 13 with the addition of a first impedance matching circuit 61. The output port U of the power amplifier 20 is connected to port 1 of the non-reversible device 10 through the first impedance matching circuit 61.

[0157] In this embodiment, when the impedance of the output port U of the power amplifier 20 is not equal to the impedance of the port 1 of the non-reversible device 10, the output port U of the power amplifier 20 is connected to the port 1 of the non-reversible device 10 through the first impedance matching circuit 61. Since the impedance of the output port U of the power amplifier 20 is less than the standard impedance, the impedance of the port 1 of the non-reversible device 10 is also less than the standard impedance. The first impedance matching circuit 61 has a smaller impedance transformation ratio, is simpler, occupies less area, and has lower insertion loss.

[0158] For example, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is 25Ω, then the first impedance matching circuit 61 is a 5Ω to 25Ω impedance matching circuit; the output port U of the power amplifier 20 is connected to port 1 of the non-reversible device 10 through the 5Ω to 25Ω impedance matching circuit, and the impedance transformation ratio of the 5Ω to 25Ω impedance matching circuit is 5. However, if the impedance of the output port U of the power amplifier 20 is 5Ω and the impedance of port 1 of the non-reversible device 10 is a standard impedance (e.g., 50Ω), a 5Ω to 50Ω impedance matching circuit needs to be set between the output port U of the power amplifier 20 and port 1 of the non-reversible device 10, and the impedance transformation ratio of the 5Ω to 50Ω impedance matching circuit is 10. As can be seen, compared with the standard impedance of port 1 of the non-reversible device 10, in the RF module of this application embodiment where the impedance of port 1 of the non-reversible device 10 is less than the standard impedance, the impedance transformation ratio of the first impedance matching circuit 61 is smaller, the impedance matching circuit is simpler, the area occupied by the impedance matching circuit is smaller, and the insertion loss of the impedance matching circuit is smaller.

[0159] In some embodiments of this application, when the impedance of port 2 of the non-reversible device 10 is equal to the impedance of the first port 701 of the duplexer 70, port 2 of the non-reversible device 10 is directly connected to the first port 701 of the duplexer 70. In this case, there is no need to design an impedance matching circuit between port 2 of the non-reversible device 10 and the first port 701 of the duplexer 70, thereby reducing the complexity of impedance matching and reducing insertion loss.

[0160] For example, if the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 701 of the duplexer 70 is also 25Ω, then port 2 of the non-reversible device 10 and the first port 701 of the duplexer 70 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0161] In some other embodiments of this application, when the impedance of port 2 of the non-reversible device 10 is not equal to the impedance of the first port 701 of the duplexer 70, port 2 of the non-reversible device 10 is connected to the first port 701 of the duplexer 70 through the fourth impedance matching circuit 64 (see FIG15).

[0162] Please refer to Figure 15, which is a schematic diagram of another FDD-supporting RF module provided in this application embodiment. Figure 15 adds a fourth impedance matching circuit 64 to Figure 13, and the port 2 of the non-reversible device 10 is connected to the first port 701 of the duplexer 70 through the fourth impedance matching circuit 64.

[0163] In this embodiment, when the impedance of port 2 of the irreversible device 10 and the impedance of the first port 701 of the duplexer 70 are not equal, port 2 of the irreversible device 10 is connected to the first port 701 of the duplexer 70 through the fourth impedance matching circuit 64. In this case, the impedance of the first port 701 of the duplexer 70 can be equal to or less than the standard impedance. When the impedance of port 2 of the irreversible device 10 is less than the standard impedance and the impedance of the first port 701 of the duplexer 70 is the standard impedance, the impedance transformation ratio of the fourth impedance matching circuit 64 is slightly larger. When the impedance of port 2 of the irreversible device 10 is less than the standard impedance and the impedance of the first port 701 of the duplexer 70 is also less than the standard impedance, the impedance transformation ratio of the fourth impedance matching circuit 64 is smaller, the matching circuit is simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller.

[0164] For example, if the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 701 of the duplexer 70 is 30Ω, then the fourth impedance matching circuit 64 is a 25Ω to 30Ω matching circuit; port 2 of the non-reversible device 10 is connected to the first port 701 of the duplexer 70 through the 25Ω to 30Ω matching circuit, and the impedance transformation ratio of the 25Ω to 30Ω matching circuit is 1.2. If the impedance of port 2 of the non-reversible device 10 is 25Ω and the impedance of the first port 701 of the duplexer 70 is a standard impedance (e.g., 50Ω), a 25Ω to 50Ω matching circuit needs to be set between port 2 of the non-reversible device 10 and the first port 701 of the duplexer 70, and the impedance transformation ratio of the 25Ω to 50Ω matching circuit is 2. It can be seen that when both the non-reversible device port 2 and the duplexer port 1 are low impedance, compared with the standard impedance of the first port 701 of the duplexer 70, the impedance of the first port 701 of the duplexer 70 is less than the standard impedance. Therefore, the impedance transformation ratio of the fourth impedance matching circuit 64 is smaller, the matching circuit is simpler, the area occupied by the matching circuit is smaller, and the insertion loss of the matching circuit is smaller.

[0165] In some embodiments of this application, when the impedance of the second port 702 of the duplexer 70 is equal to the impedance of the input port I of the low-noise amplifier 30, the second port 702 of the duplexer 70 is directly connected to the input port I of the low-noise amplifier 30. In this case, there is no need to design an impedance matching circuit between the second port 702 of the duplexer 70 and the input port I of the low-noise amplifier 30, thereby reducing the complexity of impedance matching and reducing insertion loss.

[0166] The impedance of the second port 702 of the duplexer 70 is equal to the impedance of the input port I of the low-noise amplifier 30, which can include the following two cases: (1) The impedance of the second port 702 of the duplexer 70 is less than the standard impedance, the impedance of the input port I of the low-noise amplifier 30 is less than the standard impedance, and the impedance of the second port 702 of the duplexer 70 is equal to the impedance of the input port I of the low-noise amplifier 30. (2) The impedance of the second port 702 of the duplexer 70 is equal to the standard impedance, and the impedance of the input port I of the low-noise amplifier 30 is equal to the standard impedance.

[0167] In the above case (1), for example, if the impedance of the second port 702 of the duplexer 70 is 25Ω and the impedance of the input port I of the low noise amplifier 30 is also 25Ω, then the second port 702 of the duplexer 70 and the input port I of the low noise amplifier 30 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0168] In the above situation (2), for example, if the impedance of the second port 702 of the duplexer 70 is 50Ω and the impedance of the input port I of the low noise amplifier 30 is also 50Ω, then the second port 702 of the duplexer 70 and the input port I of the low noise amplifier 30 can be connected by a 50Ω wire (e.g., a 50Ω microstrip line of equal width).

[0169] Optionally, port 3 of the non-reversible device 10 is connected to load 80 (see Figure 16). Figure 16 is a schematic diagram of another FDD-supporting RF module provided in an embodiment of this application. Figure 16 adds load 80 to Figure 15. Port 3 of the non-reversible device 10 is connected to load 80.

[0170] In this embodiment, when the load 80 is connected to port 3 of the non-reversible device 10, the non-reversible device 10 is a special type of circulator, also known as an isolator. The impedance of the load 80 can be, for example, a standard impedance.

[0171] In some embodiments of this application, when the impedance of port 3 of the non-reversible device 10 is equal to the impedance of the load 80, port 3 of the non-reversible device 10 is directly connected to the load 80. In this case, there is no need to design an impedance matching circuit between port 3 of the non-reversible device 10 and the load 80, thereby reducing the complexity of impedance matching and reducing insertion loss.

[0172] For example, if the impedance of port 3 of the non-reversible device 10 is 25Ω and the impedance of the load 80 is also 25Ω, then the third port of the reversible device and the load 80 can be connected by a 25Ω wire (e.g., a 25Ω microstrip line of equal width).

[0173] In other embodiments of this application, when the impedance of port 3 of the non-reversible device 10 is not equal to the impedance of the load 80, port 3 of the non-reversible device 10 is connected to the load 80 through a fifth impedance matching circuit 65 (see FIG. 17). FIG. 17 is a schematic diagram of another FDD-supporting RF module provided in an embodiment of this application. FIG. 17 adds a fifth impedance matching circuit 65 to FIG. 16, and port 3 of the non-reversible device 10 is connected to the load 80 through the fifth impedance matching circuit 65.

[0174] In this case, when the impedance of the load 80 is the standard impedance, the impedance of port 3 of the non-reversible device 10 is less than the standard impedance. For example, if the impedance of the load 80 is 50Ω and the impedance of port 3 of the non-reversible device 10 is 25Ω, then the fifth impedance matching circuit 65 is a 25Ω to 50Ω matching circuit. Port 3 of the non-reversible device 10 is connected to the load 80 through the 25Ω to 50Ω matching circuit, and the impedance conversion ratio of the fifth impedance matching circuit 65 is 2.

[0175] The irreversible device 10 in the RF module shown in Figures 13 to 17 can be an isolator.

[0176] The radio frequency modules shown in Figures 13 to 17 can be used for frequency division duplex (FDD) systems.

[0177] Among them, any of the impedance matching circuits mentioned above (any one of the first impedance matching circuit, second impedance matching circuit, third impedance matching circuit, fourth impedance matching circuit, fifth impedance matching circuit, and sixth impedance matching circuit) can be independently any one or a hybrid circuit of discrete circuits, microstrip matching circuits, integrated passive devices (IPDs), etc.

[0178] Please refer to Figure 18, which is a comparative schematic diagram of impedance matching methods between a conventional 50Ω matched RF module and a low-impedance matched RF module provided in this application embodiment. As shown in Figure 18, the impedance of the port of RF component A is low (i.e., less than 50Ω), and the impedance of the port of RF component B is also low. The left side shows the conventional 50Ω matched RF module, where port 2 of RF component A needs to be matched to 50Ω through a matching circuit, and port 1 of RF component B needs to be matched to 50Ω through another matching circuit. Then, the two 50Ω connections are connected through a 50Ω conversion interface. The right side shows the low-impedance matched RF module provided in this application embodiment, where port 2 of RF component A and port 1 of RF component B are connected through a low-impedance direct connection interface. Compared with the conventional 50Ω matched RF module, the low-impedance matched RF module provided in this application has the characteristics of low insertion loss, small area, and large bandwidth in its matching circuit.

[0179] This application also provides a communication device, which includes the radio frequency module described in the embodiments of this application.

[0180] Please refer to Figure 19, which is a schematic diagram of a communication device provided in an embodiment of this application. As shown in Figure 19, the communication device includes a radio frequency (RF) module. The RF module may include any one or more of the RF modules shown in Figures 7 to 17 above.

[0181] In this application embodiment, the communication device may include base station products or terminal equipment products. For example, base station products may include wireless base station products with wireless communication functions such as radio remote units (RRUs), massive multiple-input multiple-output (MASIVE MIMO), and outdoor units (ODUs). Terminal equipment products may include wireless terminal products with wireless communication functions such as mobile phones, laptops, tablets, wearable devices, routers, and customer premises equipment (CPEs).

[0182] It should be noted that the RF module architecture shown in Figures 7 to 17 is generally used in base station products. In terminal products, multi-channel switches, combiners, and other devices are usually adapted between the duplexer 70 / filter 40 and the antenna to achieve multi-band multiplexing in a hardware system.

[0183] The aforementioned communication device may also include other modules connected to the radio frequency module. The external ports of the radio frequency module are connected to the external ports of other modules. For example, in base station products, the external ports of the radio frequency module may also be connected to the external ports of units such as radio frequency integrated circuits (RFICs), system-on-chips (SOCs), and transceivers.

[0184] Optionally, the impedance of the external port of the RF module is less than the standard impedance.

[0185] The impedance of the external port of the RF module is less than the standard impedance. This allows for the design of a communication device where all modules have external ports with impedances less than the standard impedance, and the impedances of all modules' external ports can be the same or different. The impedance of the external port of the RF module can be defined as less than the standard impedance. This is suitable for low-impedance connection scenarios. It reduces the complexity of the matching circuits connecting various modules in the communication device, reduces insertion loss in the matching circuits, and enables miniaturization of the communication device.

[0186] The low-impedance circulator and RF module provided in this application are generally used in the RF section of base station / terminal equipment products. Because the symmetrical low-impedance circulator saves multiple port-to-50Ω matching circuits compared to traditional 50Ω or asymmetrical (only port 1 is low-impedance) circulators, the symmetrical circulator has a smaller size and lower insertion loss. Simultaneously, because the impedances of each port in the symmetrical low-impedance circulator are more symmetrical, its isolation and port VSWR are better than those of the asymmetrical low-impedance circulator. Furthermore, some RF components (such as power amplifiers) in the RF module have naturally low-impedance ports (ports with impedances less than the standard impedance). Using direct matching or low-impedance matching for the low-impedance ports of these RF components is simpler, smaller in area, and has lower insertion loss than first converting the low impedance to 50Ω and then matching it with 50Ω, offering advantages such as miniaturization, low loss, and high bandwidth. Similarly, the low-impedance isolator and RF module in this application also have the advantages of miniaturization and low loss.

[0187] The above description merely illustrates exemplary embodiments of this application, and while the description is specific and detailed, it should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0188] It should be understood that the first, second, third, etc. numbers used in this document are for descriptive convenience only and should not be construed as indicating or implying the number of technical features indicated.

[0189] In the description of this application, unless otherwise expressly specified and limited, the terms “connected” and “linked” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two elements.

[0190] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0191] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one" means one or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0192] Furthermore, the numerical range indicated by "-" in this application refers to the range including the values ​​before and after "-", which are respectively taken as the minimum and maximum values. Expressions of parameter ranges in this application, such as "greater than or equal to (≥)", "less than or equal to (≤)", "above", and "below", all include the stated number.

Claims

1. An irreversible device, characterized in that, The non-reversible device includes a first port and a second port, the impedance of the first port and the impedance of the second port are equal, and both the impedance of the first port and the impedance of the second port are less than the standard impedance.

2. The non-reversible device according to claim 1, characterized in that, The non-reversible device further includes a third port; the impedance of the third port is less than the standard impedance, or the impedance of the third port is the standard impedance.

3. The irreversible device according to claim 2, characterized in that, The impedance of the third port is equal to the impedance of the first port.

4. The irreversible device according to claim 2 or 3, characterized in that, The third port is connected to the load.

5. The irreversible device according to any one of claims 1 to 4, characterized in that, When the standard impedance is 50 ohms, the impedance less than the standard impedance includes: greater than 1 ohm and less than 50 ohms.

6. A radio frequency module, characterized in that, It includes a power amplifier and an irreversible device; the irreversible device includes a first port and a second port, the output port of the power amplifier is connected to the first port of the irreversible device, the impedance of the first port of the irreversible device and the impedance of the second port of the irreversible device are equal, and the impedance of the first port of the irreversible device and the impedance of the second port of the irreversible device are both less than the standard impedance.

7. The radio frequency module according to claim 6, characterized in that, The impedance of the output port of the power amplifier is less than the standard impedance.

8. The radio frequency module according to claim 7, characterized in that, The impedance of the output port of the power amplifier is equal to the impedance of the first port of the non-reversible device, and the output port of the power amplifier is directly connected to the first port of the non-reversible device.

9. The RF module according to claim 7, wherein the impedance of the output port of the power amplifier is not equal to the impedance of the first port of the non-reversible device, and the output port of the power amplifier is connected to the first port of the non-reversible device through a first impedance matching circuit.

10. The radio frequency module according to any one of claims 6 to 9, characterized in that, The radio frequency module also includes a low-noise amplifier and a filter; the second port of the non-reversible device is connected to the first port of the filter; the third port of the non-reversible device is connected to the input port of the low-noise amplifier; wherein the impedance of the third port of the non-reversible device is less than or equal to the standard impedance.

11. The radio frequency module according to claim 10, characterized in that, The impedance of the first port of the filter is equal to or less than the standard impedance; the impedance of the input port of the low-noise amplifier is equal to or less than the standard impedance.

12. The radio frequency module according to claim 11, characterized in that, The impedance of the second port of the non-reversible device is equal to the impedance of the first port of the filter, and the second port of the non-reversible device is directly connected to the first port of the filter.

13. The radio frequency module according to claim 11, characterized in that, The impedance of the second port of the non-reversible device is not equal to the impedance of the first port of the filter, and the second port of the non-reversible device is connected to the first port of the filter through a second impedance matching circuit.

14. The radio frequency module according to any one of claims 11 to 13, characterized in that, The impedance of the third port of the non-reversible device is equal to the impedance of the input port of the low-noise amplifier, and the third port of the non-reversible device is directly connected to the input port of the low-noise amplifier.

15. The radio frequency module according to any one of claims 11 to 13, characterized in that, The impedance of the third port of the non-reversible device is not equal to the impedance of the input port of the low-noise amplifier. The third port of the non-reversible device is connected to the input port of the low-noise amplifier through a third impedance matching circuit.

16. The radio frequency module according to any one of claims 10 to 15, characterized in that, The radio frequency module also includes an antenna unit; the second port of the filter is connected to the antenna unit.

17. The radio frequency module according to any one of claims 10 to 16, characterized in that, The radio frequency module is used in the time division duplex (TDD) system.

18. The radio frequency module according to any one of claims 6 to 9, characterized in that, The radio frequency module also includes a low-noise amplifier and a duplexer; the second port of the non-reversible device is connected to the first port 701 of the duplexer, and the second port of the duplexer is connected to the input port of the low-noise amplifier.

19. The radio frequency module according to claim 18, characterized in that, The impedance of the first port 701 of the duplexer is equal to or less than the standard impedance; the impedance of the second port of the duplexer is equal to or less than the standard impedance; the impedance of the input port of the low-noise amplifier is equal to or less than the standard impedance.

20. The radio frequency module according to claim 19, characterized in that, The impedance of the second port of the non-reversible device is equal to the impedance of the first port 701 of the duplexer; the second port of the non-reversible device is directly connected to the first port 701 of the duplexer.

21. The radio frequency module according to claim 19, characterized in that, The impedance of the second port of the non-reversible device is not equal to the impedance of the first port 701 of the duplexer; the second port of the non-reversible device is connected to the first port 701 of the duplexer through a fourth impedance matching circuit.

22. The radio frequency module according to any one of claims 18 to 21, characterized in that, The non-reversible device also includes a third port, which is connected to a load.

23. The radio frequency module according to claim 22, characterized in that, The impedance of the third port of the non-reversible device is equal to the impedance of the load; the third port of the non-reversible device is directly connected to the load.

24. The radio frequency module according to claim 22, characterized in that, The impedance of the third port of the non-reversible device is not equal to the impedance of the load; the third port of the non-reversible device is connected to the load through a fifth impedance matching circuit.

25. The radio frequency module according to any one of claims 18 to 24, characterized in that, The radio frequency module also includes an antenna unit; the second port of the duplexer is connected to the antenna unit.

26. The radio frequency module according to any one of claims 18 to 25, characterized in that, The radio frequency module is used in the frequency division duplex (FDD) system.

27. The radio frequency module according to any one of claims 9, 13, 15, 21, and 24, characterized in that, Each impedance matching circuit independently includes any one or a combination of discrete circuits, microstrip matching circuits, and integrated passive devices.

28. A communication device, characterized in that, Includes the radio frequency module as described in any one of claims 6 to 27.

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