Transformer, Method for Operating Transformer, Radio Frequency Chip, and Electronic Device

A transformer includes a first inductor and a second inductor that are coupled to each other. The first inductor includes a plurality of parallel-connected induction coils. The second inductor includes a plurality of serial-connected induction coils. At least one of the plurality of parallel-connected induction coils and at least one of the plurality of serial-connected induction coils are adjacently disposed in a coupling manner.

TECHNICAL FIELD

This disclosure relates to the field of radio frequency technologies, and in particular, to a transformer, a method for operating the transformer, a radio frequency chip, and an electronic device.

BACKGROUND

Rapid development of wireless communication technologies greatly changes people's lives. Currently, electronic devices such as smartphones and tablet computers that support applications such as third generation (3G)/fourth generation (4G)/fifth generation (5G) mobile communication, a wireless local area network (WLAN), and a Wireless Interoperability for Microwave Access (WiMAX) have become standard configurations in people's daily lives, and a radio frequency chip is an important component for the electronic device to complete interaction.

A transformer is often used in the design of a radio frequency chip and the like, to realize impedance conversion for designing a matching network. How to meet a current demand for high performance of the transformer is a big challenge at present.

SUMMARY

Embodiments of this disclosure provide a transformer, a method for operating the transformer, a radio frequency chip, and an electronic device, to improve performance of the transformer.

To achieve the foregoing objective, this disclosure uses the following technical solutions.

According to a first aspect of embodiments of this disclosure, a transformer is provided. The transformer includes a first inductor and a second inductor that are coupled to each other. The first inductor includes a plurality of parallel-connected induction coils. The second inductor includes a plurality of serial-connected induction coils. At least one of the plurality of parallel-connected induction coils and at least one of the plurality of serial-connected induction coils are adjacently disposed in a coupling manner.

According to the transformer provided in this embodiment of this disclosure, after the first inductor in the transformer is set to include the plurality of parallel-connected induction coils, an inductance value of the first inductor is a sum of reciprocals of inductance values of the induction coils included in the first inductor, and a small inductance value of the first inductor may be obtained. After the second inductor in the transformer is set to include the plurality of serial-connected induction coils, an inductance value of the second inductor is a sum of inductance values of the induction coils included in the second inductor, and a large inductance value of the second inductor may be obtained. Therefore, an inductance ratio (namely, an impedance ratio) of the transformer is large. Based on this, the induction coil of the first inductor and the induction coil of the second inductor may be electromagnetically coupled, so that different quantities of induction coils of the first inductor and different quantities of induction coils of the second inductor may be electromagnetically coupled by adjusting an arrangement manner of the induction coils of the first inductor and the induction coils of the second inductor as required, so as to meet a requirement of the transformer for a high coupling coefficient. Therefore, the transformer may implement both a large inductance ratio (namely, impedance ratio) and a high coupling coefficient. In addition, quality factors of the first inductor and the second inductor are also high, and a loss of the transformer is small. When the transformer is used in a radio frequency chip, high performance requirements of the radio frequency chip for a large inductance ratio (namely, impedance ratio) and a high coupling coefficient in a scenario of impedance conversion with a large impedance ratio can be met.

In a possible implementation, the at least one of the plurality of parallel-connected induction coils and the at least one of the plurality of serial-connected induction coils are adjacently disposed in a nested manner at a same layer. The induction coil in the first inductor and the induction coil in the second inductor that are electromagnetically coupled are disposed at a same layer, to reduce a distance between the induction coil in the first inductor and the induction coil in the second inductor, so as to improve effect of electromagnetic coupling between the first inductor and the second inductor.

In a possible implementation, the induction coils of the first inductor include a first induction coil and a second induction coil, the induction coils of the second inductor include a third induction coil, and the third induction coil is disposed between the first induction coil and the second induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the second inductor further includes a fourth induction coil, and the second induction coil is disposed between the third induction coil and the fourth induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the first inductor further includes a fifth induction coil, and the fourth induction coil is disposed between the second induction coil and the fifth induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the plurality of parallel-connected induction coils and the plurality of serial-connected induction coils are disposed at a same layer, and both an outermost ring and an innermost ring of the transformer are induction coils in the first inductor. In this way, a quantity of induction coils in the first inductor can be maximized, effect of coupling between the first inductor and the second inductor is improved, and a high coupling coefficient and a large impedance ratio can be implemented. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the at least one of the plurality of parallel-connected induction coils and the at least one of the plurality of serial-connected induction coils are adjacently disposed in a stacked manner. The induction coil of the first inductor and the induction coil of the second inductor are disposed at different layers, so that a projection area of the transformer20may be small, and in addition, a distance between the induction coil of the first inductor and the induction coil of the second inductor may be small, to improve effect of electromagnetic coupling between the induction coil of the first inductor and the induction coil of the second inductor.

In a possible implementation, the induction coils of the first inductor include the first induction coil and the second induction coil, the induction coils of the second inductor include the third induction coil, and a projection of the first induction coil overlaps a projection of the third induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the induction coils of the first inductor include the first induction coil and the second induction coil, the induction coils of the second inductor include the third induction coil, and a projection of the second induction coil overlaps a projection of the third induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the induction coils of the first inductor include the first induction coil and the second induction coil, the induction coils of the second inductor include the third induction coil, and a projection of the first induction coil and a projection of the second induction coil overlap a projection of the third induction coil. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, at least a part of the plurality of parallel-connected induction coils are disposed at a same layer. In this way, the first inductor has a simple structure and is convenient to prepare.

In a possible implementation, at least a part of the plurality of serial-connected induction coils are disposed at a same layer. In this way, the first inductor has a simple structure and is convenient to prepare.

In a possible implementation, the first inductor further includes an induction coil connected in series to the plurality of parallel-connected induction coils. This is a possible implementation, and is used to meet requirements for different impedance ratios and coupling coefficients.

In a possible implementation, the transformer further includes a first capacitor and a second capacitor. The first capacitor is connected in parallel to the first inductor, and the second capacitor is connected in parallel to the second inductor. The first capacitor and the second capacitor are disposed, to adjust an operating frequency of the transformer.

In a possible implementation, the first inductor and the second inductor serve as one inductor group, and the transformer includes a plurality of inductor groups. First inductors in the plurality of inductor groups are connected in parallel, and second inductors in the plurality of inductor groups are connected in series. Compared with a case in which the transformer includes only one inductor group, in a case in which the transformer includes a plurality of inductor groups, inductance values of the first inductors of the transformer are smaller, and inductance values of the second inductors of the transformer are larger. Therefore, the transformer can obtain a larger inductance ratio (namely, impedance ratio). When a coupling coefficient of each inductor group is high, a high coupling coefficient of the transformer may still be maintained. Therefore, in a case in which a process is difficult to implement because a quantity of coils of the first inductor and a quantity of coils of the second inductor included in one inductor group are large, a plurality of inductor groups may be disposed to further improve the inductance ratio (namely, the impedance ratio) of the transformer.

According to a second aspect of embodiments of this disclosure, a radio frequency chip is provided, including a substrate and the transformer according to any one of the first aspect. The transformer is disposed on the substrate. The radio frequency chip provided in the second aspect of embodiments of this disclosure includes the transformer according to any one of the first aspect. Beneficial effects of the radio frequency chip are the same as the beneficial effects of the transformer. Details are not described herein again.

In a possible implementation, the radio frequency chip further includes a low impedance matching network and a high impedance matching network. The low impedance matching network is coupled to a first inductor of the transformer, and the high impedance matching network is coupled to a second inductor of the transformer. This is an application scenario.

According to a third aspect of embodiments of this disclosure, an electronic device is provided, including the radio frequency chip according to the second aspect and a circuit board. The radio frequency chip is disposed on the circuit board. The electronic device provided in the third aspect of embodiments of this disclosure includes the radio frequency chip according to any one of the second aspect. Beneficial effects of the radio frequency chip are the same as the beneficial effects of the radio frequency chip. Details are not described herein again.

According to a fourth aspect of embodiments of this disclosure, a method for operating a transformer is provided, including a transformer. The transformer includes a first inductor and a second inductor that are coupled to each other, the first inductor includes a plurality of parallel-connected induction coils, the second inductor includes a plurality of serial-connected induction coils, and at least one of the plurality of parallel-connected induction coils and at least one of the plurality of serial-connected induction coils are adjacently disposed in a coupling manner. The method for operating a transformer includes: electromagnetically coupling the first inductor and the second inductor, to couple a signal received by the first inductor to the second inductor and output the signal from the second inductor, or couple a signal received by the second inductor to the first inductor and output the signal from the first inductor. Beneficial effects of the method for operating a transformer provided in the fourth aspect of embodiments of this disclosure are the same as the beneficial effects of the transformer according to any one of the first aspect. Details are not described herein again.

In a possible implementation, the at least one of the plurality of parallel-connected induction coils and the at least one of the plurality of serial-connected induction coils are adjacently disposed in a nested manner at a same layer. That the first inductor and the second inductor are electromagnetically coupled includes: an induction coil in the first inductor and an induction coil that is in the second inductor and that is adjacent to the induction coil in the first inductor are electromagnetically coupled. This is an implementation.

In a possible implementation, the at least one of the plurality of parallel-connected induction coils and the at least one of the plurality of serial-connected induction coils are adjacently disposed in a stacked manner. That the first inductor and the second inductor are electromagnetically coupled includes: an induction coil in the first inductor and an induction coil that is in the second inductor and that is disposed in a stacked manner with the induction coil in the first inductor are electromagnetically coupled. This is an implementation.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions in embodiments of this disclosure with reference to the accompanying drawings in embodiments of this disclosure. It is clear that the described embodiments are merely a part rather than all of embodiments of this disclosure.

Terms such as “first” and “second” mentioned below in embodiments of this disclosure are merely used for ease of description, and shall not be understood as an indication or implication of relative importance or implicit indication of a quantity of indicated technical features. Therefore, a feature limited by “first”, “second”, or the like may explicitly or implicitly include one or more features. In the descriptions of this disclosure, unless otherwise stated, “a plurality of” means two or more.

In embodiments of this disclosure, “up”, “down”, “left”, and “right” are not limited to definitions relative to directions in which components are schematically placed in accompanying drawings. It should be understood that these directional terms may be relative concepts used for relative description and clarification, and may change correspondingly based on a change of a direction in which a component in an accompanying drawing is placed.

In embodiments of this disclosure, unless otherwise specified in the context, in the entire specification and claims, the term “include” is interpreted as “open and inclusive”, that is, “include, but not limited to”. In the description of the specification, terms such as “an embodiment”, “some embodiments”, “example embodiments”, “examples”, or “some examples” are intended to indicate that specific features, structures, materials, or characteristics related to the embodiments or examples are included in at least one embodiment or example of the present disclosure. The foregoing schematic representations of the terms do not necessarily refer to a same embodiment or example. Further, the particular feature, structure, material, or characteristic may be included in any one or more embodiments or examples in any appropriate manner.

When some embodiments are described, expressions of “coupling” and its extensions may be used. For example, when some embodiments are described, the term “coupling” may be used to indicate that two or more components are in direct physical contact or electrical contact. However, the term “coupling” may also indicate that two or more components do not directly contact each other, but still collaborate or interact with each other. Embodiments disclosed herein are not necessarily limited to content of this specification.

In embodiments of this disclosure, an example implementation is described with reference to a sectional view and/or a plane diagram and/or an equivalent circuit diagram that are/is used as idealized example accompanying drawings. In the accompanying drawings, for clarity, thicknesses of layers and regions are enlarged. Therefore, a change of a shape in the accompanying drawings due to, for example, a manufacturing technique and/or tolerance may be envisaged. Therefore, example implementations should not be construed as being limited to a shape of a region shown herein, but rather include shape deviations due to, for example, manufacturing. For example, an etching region shown as a rectangle typically has a bending characteristic. Therefore, the regions shown in the accompanying drawings are essentially examples, and their shapes are not intended to show actual shapes of regions of a device, and are not intended to limit a scope of the example implementations.

An embodiment of this disclosure provides an electronic device. The electronic device is, for example, a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, a financial terminal product, or a communication electronic product. The consumer electronic product is, for example, a mobile phone, a tablet computer (pad), a notebook computer, an e-reader, a personal computer (PC), a personal digital assistant (PDA), a desktop display, a smart wearable product (for example, a smartwatch or a smart band), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, or an uncrewed aerial vehicle. The home electronic product is, for example, an intelligent lock, a television, a remote control, a refrigerator, and a small rechargeable household appliance (such as a soy milk maker or a robot vacuum). The vehicle-mounted electronic product is, for example, a vehicle-mounted navigator, or a vehicle-mounted high-density digital video disc (DVD). The financial terminal product is, for example, an automated teller machine (ATM), or a terminal for self-service business handling. For example, the communication electronic product is a communication device like a server, a memory, a radar, or a base station.

FIG.1Ais a diagram of a structure of an example of an electronic device according to an embodiment of this disclosure. As shown inFIG.1A, an electronic device100may include a processor110, an external memory interface120, an internal memory121, a Universal Serial Bus (USB) interface130, a charging management module140, a power management module141, a battery142, a wired communication system150, a wireless communication system160, an audio module170, a speaker170A, a receiver170B, a microphone170C, a headset jack170D, a sensor module180, a button190, a motor191, an indicator192, a camera193, a display194, a SIM card interface195, an antenna1, an antenna2, and the like.

It may be understood that the structure shown in this embodiment of this disclosure does not constitute a specific limitation on the electronic device100. In some other embodiments of this disclosure, the electronic device100may include more or fewer components than those shown in the figure, a combination of some components, splits from some components, or a different component layout. The components shown in the figure may be implemented by using hardware, software, or a combination of software and hardware.

The processor110may include one or more processing units. For example, the processor110may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and/or a neural-network processing unit (NPU). Different processing units may be independent components, or may be integrated into one or more processors. The controller may generate an operation control signal based on instruction operation code and a time sequence signal, to complete control of instruction reading and instruction execution.

In some embodiments, the processor110may include one or more interfaces. The interface may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse-code modulation (PCM) interface, a universal asynchronous receiver/transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input/output (GPIO) interface, a SIM interface, a USB interface, and/or the like.

The USB interface130is an interface that conforms to a USB standard specification, and may be a mini USB interface, a micro USB interface, a USB type-C interface, or the like.

The charging management module140is configured to receive a charging input from a charger. The charger may be a wireless charger or a wired charger.

The power management module141is configured to connect to the battery142, the charging management module140, and the processor110. The power management module141receives an input from the battery142and/or the charging management module140, to supply power to the processor110, the internal memory121, the display194, the camera193, the wireless communication system160, and the like. The power management module141may be further configured to monitor parameters such as a battery capacity, a battery cycle count, and a battery health status (electric leakage or impedance).

The electronic device100implements a display function through the GPU, the display194, the application processor, and the like. The GPU is a microprocessor for image processing, and is connected to the display194and the application processor.

The display194is configured to display an image, a video, and the like. In some embodiments, the electronic device100may include one or N displays194, where N is a positive integer greater than 1.

The electronic device100may implement a shooting function through the ISP, the camera193, the video codec, the GPU, the display194, the application processor, and the like.

The ISP is configured to process data fed back by the camera193, the camera193is configured to capture a static image or a video, and the video codec is configured to compress or decompress a digital video.

The external memory interface120may be configured to connect to an external storage card, for example, a micro SD card, to extend a storage capability of the electronic device100.

The internal memory121may be configured to store computer-executable program code. The executable program code includes instructions.

The electronic device100may implement an audio function through the audio module170, the speaker170A, the receiver170B, the microphone170C, the headset jack170D, the application processor, and the like.

The audio module170is configured to convert digital audio information into an analog audio signal for output, and is also configured to convert an analog audio input into a digital audio signal. The speaker170A is configured to convert an audio electrical signal into a sound signal. The receiver170B is configured to convert an audio electrical signal into a sound signal. The microphone170C is configured to convert a sound signal into an electrical signal. The headset jack170D is configured to connect to a wired headset.

The sensor module180may include an image sensor, a pressure sensor, a magnetic sensor, a distance sensor, and the like. The image sensor may be, for example, a contact image sensor (CIS).

The button190includes a power button, a volume button, and the like. The motor191may generate a vibration prompt. The indicator192may be an indicator light, and may be configured to indicate a charging status and a power change, or may be configured to indicate a message, a missed call, a notification, and the like. The SIM card interface195is configured to connect to a SIM card.

A communication function of the electronic device100may be implemented through the antenna1, the antenna2, the wired communication system150, the wireless communication system160, the modem processor, the baseband processor, and the like.

The modem processor may include a modulator and a demodulator. The modulator is configured to modulate a to-be-sent low-frequency baseband signal into a medium-/high-frequency signal. The demodulator is configured to demodulate a received electromagnetic wave signal into a low-frequency baseband signal. Then, the demodulator transmits the low-frequency baseband signal obtained through demodulation to the baseband processor for processing. The baseband processor processes the low-frequency baseband signal, and then transmits a processed signal to the application processor. The application processor outputs a sound signal via an audio device (which is not limited to the speaker, the receiver, and the like), or displays an image or a video on the display194.

The wired communication module150may provide a wireless communication solution that is applied to the electronic device100and that includes 2G/3G/4G/5G, and the like. The wired communication module150may include one or more filters, switches, power amplifiers, low noise amplifiers (LNAs), and the like. The wired communication module150may receive an electromagnetic wave through the antenna1, perform processing such as filtering and amplification on the received electromagnetic wave, and transmit a processed electromagnetic wave to the modem processor for demodulation. The wired communication module150may further amplify a signal modulated by the modem processor, and convert an amplified signal into an electromagnetic wave for radiation through the antenna1. In some embodiments, at least some functional modules of the wired communication module150may be disposed in the processor110. In some embodiments, at least some functional modules of the wired communication module150may be disposed in a same device as at least some modules of the processor110.

The wireless communication system160may provide a wireless communication solution that is applied to the electronic device100, and that includes a WLAN (for example, a WI-FI network), BLUETOOTH (BT), a global navigation satellite system (GNSS), frequency modulation (FM), near-field communication (NFC), an infrared (IR) technology, or the like. The wireless communication module160may be one or more components into which one or more communication processing modules are integrated. The wireless communication module160receives an electromagnetic wave through the antenna2, performs frequency modulation and filtering processing on the electromagnetic wave signal, and sends a processed signal to the processor110. The wireless communication module160may further receive a to-be-sent signal from the processor110, perform frequency modulation and amplification on the signal, and convert a processed signal into an electromagnetic wave for radiation through the antenna2.

In some embodiments, in the electronic device100, the antenna1and the wired communication module150are coupled, and the antenna2and the wireless communication module160are coupled, so that the electronic device100can communicate with a network and another device by using a wireless communication technology. The wireless communication technology may include a Global System for Mobile Communications (GSM), a General Packet Radio Service (GPRS), code-division multiple access (CDMA), wideband code-division multiple access (WCDMA), time-division synchronous code-division multiple access (TD-SCDMA), Long-term Evolution (LTE), BT, GNSS, WLAN, NFC, FM, an IR technology, and the like. The GNSS may include a Global Positioning System (GPS), a Global Navigation Satellite System (GLONASS), a BeiDou navigation satellite system (BDS), a quasi-ceiling satellite system (QZSS), and/or a satellite-based augmentation system (SBAS).

The foregoing electronic device100further includes a circuit board, for example, a printed circuit board (PCB). Some electronic components in the electronic device100such as the processor110, the internal memory121, and a radio frequency chip may be disposed on the circuit board.

An embodiment of this disclosure provides a radio frequency chip. As shown inFIG.1A, a radio frequency chip200may be used in the foregoing wireless communication system160. The radio frequency chip200is an electronic component/part that converts a radio signal into a specific radio signal waveform through communication, and sends the radio signal waveform through resonance via the antenna2. The radio frequency chip200is responsible for radio frequency receiving and sending, frequency synthesis, power amplification, and the like.

The antenna2may or may not be packaged inside the radio frequency chip200. In this embodiment of this disclosure, an example in which the antenna2is not packaged inside the radio frequency chip200is used for illustration.

For example, as shown inFIG.1B, a radio frequency chip200is provided, and a block diagram of a transmit channel, a receive channel, and a local oscillator channel of the radio frequency chip200is shown.

Transmit channel: After being amplified by an intermediate frequency amplifier TX-IFAMP 1/2, an intermediate frequency (or baseband) signal is sent to a transmit frequency mixer TX-mixer. The TX-mixer performs frequency mixing on the intermediate frequency (or baseband) signal and a local oscillator signal to obtain a radio frequency signal. After being amplified by a radio frequency amplifier TX-RFAMP and a power amplifier PA, the radio frequency signal is transmitted via the antenna2.

Receive channel: After being amplified by a low noise amplifier LNA and a radio frequency amplifier RX_RFAMP, the radio frequency signal from the antenna2is sent to a receive frequency mixer RX-mixer. The RX-mixer performs frequency mixing on the radio frequency signal and a local oscillator signal to obtain an intermediate frequency (or baseband) signal. After being amplified by an intermediate frequency amplifier RX_IFAMP 1/2, the signal is provided for a post-stage chip for signal processing.

Local oscillator channel: After being amplified by a local oscillator buffer (LO-buffer), a signal from a phase-locked loop PLL is provided for a receive frequency mixer and a transmit frequency mixer for frequency mixing of the received or transmitted signal.

In some embodiments, the radio frequency chip200may further include components such as a frequency multiplier, a variable gain amplifier, and an attenuator. Components included in the radio frequency chip200shown inFIG.1Bare merely examples. This is not limited.

FIG.2Ashows an equivalent impedance conversion network based on a transformer. One end of a transformer20is coupled to a low impedance matching network10, and the other end of the transformer20is coupled to a high impedance matching network30.

The low impedance matching network10is relative to the high impedance matching network30, and a specific value of an impedance of the low impedance matching network10does not need to be limited, provided that the impedance of the low impedance matching network10is less than an impedance of the high impedance matching network30. For example, as shown inFIG.2B, the impedance of the low impedance matching network10is R1, the impedance of the high impedance matching network30is R2, and R1<R2.

Specific structures of the low impedance matching network and the high impedance matching network are not limited in this embodiment of this disclosure, provided that the low impedance matching network and the high impedance matching network are properly disposed with reference to a specific structure of a component including the transformer20.

The transformer20includes a first inductor L1and a second inductor L2whose coupling coefficient is K. The first inductor L1and the second inductor L2are mutually a primary induction coil and a secondary induction coil, an end part of the first inductor L1is coupled to the low impedance matching network10, and an end part of the second inductor L2is coupled to the high impedance matching network30, to implement conversion between the impedance R1and the impedance R2.

When the first inductor L1is the primary induction coil and the second inductor L2is the secondary induction coil, the transformer20is configured to convert the impedance R1into the impedance R2(or understood as driving a high impedance by a low impedance). When the first inductor L1is the secondary induction coil and the second inductor L2is the primary induction coil, the transformer20is configured to convert the impedance R2into the impedance R1(or understood as driving a low impedance by a high impedance).

For example,FIG.2Cis a diagram of an application scenario in which a low impedance drives a high impedance (or a high impedance drives a low impedance). The low impedance matching network10may be a first-stage amplifier, and the high impedance matching network30may be a second-stage amplifier. A power P1input by the first-stage amplifier to the transformer20is equal to I1*R1, where I1is a radio frequency current input by the first-stage amplifier. After impedance conversion is performed by the transformer20, a power P2output by the second-stage amplifier is equal to I2*R2, where I2is a radio frequency current flowing into the second-stage amplifier. Alternatively, for example,FIG.2Dshows an application scenario in which a local oscillator buffer drives a mixer. The low impedance matching network10may be the local oscillator buffer, and the high impedance matching network30may be the mixer.

In the transformer-based impedance conversion network, generally, an impedance ratio R is equal to an inductance ratio L. To be specific, an impedance of the low impedance matching network10is R1, an impedance of the high impedance matching network30is R2, an inductance value of the first inductor L1is L1′, an inductance value of the second inductor L2is L2′, and R1/R2=L1′/L2′. It can be learned from the foregoing descriptions that, in a process of designing the radio frequency chip200, the foregoing impedance conversion network often needs to be used. In an application process, in one aspect, impedance conversion with a large impedance ratio R is often encountered, for example, between a LO-Buffer and a mixer, between voltage interface amplifiers during driving of a high impedance by a low impedance, and between voltage interface amplifiers during driving of a low impedance by a high impedance. Sometimes, the impedance ratio R is greater than 7 or even greater. In this case, a large impedance ratio R is required to implement impedance matching. In another aspect, during designing of the radio frequency chip200, it is expected to reduce a loss of the transformer20as much as possible, to improve performance of the radio frequency chip200. In this case, the coupling coefficient K of the transformer20needs to be large enough. In a radio frequency band, it is generally expected that the coupling coefficient K is greater than 0.7.

In other words, in a scenario of impedance conversion with a large impedance ratio R, both the impedance ratio R (namely, the inductance ratio L) and the coupling coefficient K need to be large to meet a requirement of the radio frequency chip200for performance design.

In view of this, an embodiment of this disclosure further provides a transformer20. The transformer20may be used in the foregoing radio frequency chip200, and is disposed on a substrate of the radio frequency chip200. One component in the radio frequency chip200may include the transformer20, or a plurality of components in the radio frequency chip200may include the transformer20, or two components in the radio frequency chip200may be coupled via the transformer20. This is not limited in embodiments of this disclosure.

As shown inFIG.3A, a first inductor L1of a transformer20includes one induction coil L1, and a second inductor L2of the transformer20includes a plurality of induction coils L2.

In embodiments of this disclosure, to distinguish an induction coil of the first inductor L1from an induction coil of the second inductor L2, an example in which the induction coil of the first inductor L1is an induction coil1L1and the induction coil of the second inductor L2is an induction coil2L2is used for schematic description.

For example, as shown inFIG.3A, the first inductor L1includes one induction coil1L1, and the second inductor L2of the transformer20includes three induction coils2L2.

If an inductance value of each induction coil1L1of the first inductor L1is L1, an inductance value L1′ of the first inductor L1is equal to L1. If inductance values of the three induction coils2L2of the second inductor L2are L2a, L2b, and L2c, respectively, an inductance value L2′ of the second inductor L2is equal to L2a+L2b+L2c.

Therefore, the induction coil1L1in the first inductor L1and the induction coils2L2in the second inductor L2are set to a one-to-many structure, to increase an inductance ratio L (namely, an impedance ratio R) of the first inductor L1to the second inductor L2.

Based on this, as shown inFIG.3A,FIG.3B,FIG.3C, andFIG.3D, a position of the induction coil1L1in the first inductor L1is adjusted, to change relative positions and overlapping areas of the induction coil1L1in the first inductor L1and the plurality of induction coils2L2in the second inductor L2, to attempt to adjust a coupling coefficient K of the first inductor L1and the second inductor L2. Equivalent circuit diagrams of the transformers20shown inFIG.3A,FIG.3B,FIG.3C, andFIG.3Dare the same, and are all as shown inFIG.3E.

For example, a structure of a transformer operating in 5 gigahertz (GHz) to 10 GHz is set. It is found through simulation that, in a structure of the transformer20, shown inFIG.3A, in which the induction coil1L1in the first inductor L1is located on an inner side of the plurality of induction coils2L2in the second inductor L2, the inductance value L1′ of the first inductor L1is equal to 210 pH, a quality factor Q1of the first inductor L1is equal to 11, the inductance value L2′ of the second inductor L2is equal to 1830 pH, and a quality factor Q2of the second inductor L2is equal to 14. The inductance ratio L (namely, the impedance ratio R) of the first inductor L i to the second inductor L2can reach about 8.7, but the coupling coefficient K of the first inductor L1and the second inductor L2can only reach about 0.38. The inductance ratio L (namely, the impedance ratio R) can meet the requirement of the radio frequency chip200for the performance design, but the coupling coefficient K is excessively small and cannot meet the requirement of the radio frequency chip200for the performance design.

In a structure, shown inFIG.3B, in which the induction coil1L1in the first inductor L1is located at a periphery of an innermost induction coil2L2, the inductance value L1′ of the first inductor L1is equal to 296 pH, a quality factor Q1of the first inductor L1is equal to 9.6, the inductance value L2′ of the second inductor L2is equal to 1890 pH, and a quality factor Q2of the second inductor L2is equal to 15. The inductance ratio L (namely, the impedance ratio R) of the first inductor L1to the second inductor L2can only reach about 6.4, and the coupling coefficient K of the first inductor L1and the second inductor L2can only reach about 0.66. Neither the inductance ratio L (namely, the impedance ratio R) nor the coupling coefficient K can meet the requirement of the radio frequency chip200for the performance design.

In a structure, shown inFIG.3C, in which the induction coil1L1in the first inductor L1is located on an inner side of an outermost induction coil2L2, the inductance value L1′ of the first inductor L1is equal to 402 pH, a quality factor Q1of the first inductor L1is equal to 10, the inductance value L2′ of the second inductor L2is equal to 2016 pH, and a quality factor Q2of the second inductor L2is equal to 15. The coupling coefficient K of the first inductor L1and the second inductor L2can reach about 0.72, but the inductance ratio L (namely, the impedance ratio R) of the first inductor L1to the second inductor L2can only reach about 5.0. The coupling coefficient K can meet the requirement of the radio frequency chip200for the performance design, but the inductance ratio L (namely, the impedance ratio R) cannot meet the requirement of the radio frequency chip200for the performance design.

In a structure, shown inFIG.3D, in which the induction coil1L1in the first inductor L1is located at a periphery of the plurality of induction coils2L2in the second inductor L2, the inductance value L1′ of the first inductor L1is equal to 507 pH, a quality factor Q1of the first inductor L1is equal to 12.5, the inductance value L2′ of the second inductor L2is equal to 2020 pH, and a quality factor Q2of the second inductor L2is equal to 12.5. The inductance ratio L (namely, the impedance ratio R) of the first inductor L1to the second inductor L2can only reach about 3.98, and the coupling coefficient K of the first inductor L1and the second inductor L2can only reach about 0.59. Neither the inductance ratio L (namely, the impedance ratio R) nor the coupling coefficient K can meet the requirement of the radio frequency chip200for the performance design.

Generally, to implement a large inductance ratio L (namely, impedance ratio R), a large inductance value L2′ and a small inductance value L1′ are required. To be specific, a ratio of a quantity of coils of the first inductor L1to a quantity of coils of the second inductor L2needs to be increased, the second inductor L2is implemented by using more coils, and the first inductor L1is implemented by using fewer coils. To implement a high coupling coefficient K, an overlapping and nesting area between the first inductor L1and the second inductor L2needs to be increased. To be specific, a ratio of a quantity of coils of the first inductor L1to a quantity of coils of the second inductor L2needs to be reduced. Therefore, based on the structures shown inFIG.3AtoFIG.3D, to implement both the large inductance ratio L (namely, impedance ratio R) and the high coupling coefficient K becomes a contradiction, only one of the conditions can be met, and it is difficult to meet both of the conditions.

In view of this, an embodiment of this disclosure further provides a transformer20. As shown inFIG.4A, the transformer20includes a first inductor L1and a second inductor L2. The first inductor L1includes a plurality of parallel-connected induction coils1L1, and the second inductor L2includes a plurality of serial-connected induction coils2L2.

There is a gap between the plurality of first induction coils1L1, and there is a gap between the plurality of second induction coils2L2. Centers (which may be understood as an air core of the transformer20) of the plurality of induction coils1L1and centers of the plurality of induction coils2L2are the same, and gaps exist between the plurality of induction coils1L1and the plurality of induction coils2L2. The gap may be a gap parallel to a plane direction in which the induction coil1L1is located, or the gap may be a gap vertical to a plane direction in which the induction coil1L1is located.

The first inductor L1and the second inductor L2are mutually a primary induction coil and a secondary induction coil. In a scenario in which the transformer20is configured to drive a high impedance with a low impedance, the first inductor L1serves as the primary induction coil of the transformer20, and the second inductor L2serves as the secondary induction coil of the transformer20. In a scenario in which the transformer20is configured to drive a low impedance with a high impedance, the second inductor L2serves as the primary induction coil of the transformer20, and the first inductor L1serves as the secondary induction coil of the transformer20.

Relative positions of a signal end of the first inductor L1and a signal end of the second inductor L2are not limited in embodiments of this disclosure. As shown inFIG.4A, the signal end of the first inductor L1is disposed opposite to the signal end of the second inductor L2. As shown inFIG.4B, the signal end of the first inductor L1and the signal end of the second inductor L2are located on a same side. As shown inFIG.4CtoFIG.4E, an included angle between the signal end of the first inductor L1and the signal end of the second inductor L2may be any angle less than 180°. For ease of description, the following describes a detailed structure of the transformer20by using an example in which the signal end of the first inductor L1is disposed opposite to the signal end of the second inductor L2.

The first inductor L1includes the plurality of induction coils1L1disposed in parallel, and the second inductor L2includes the plurality of induction coils2L2disposed in series.

As shown inFIG.4F, at least one of the plurality of parallel-connected induction coils1L1of the first inductor L1and at least one of the plurality of serial-connected induction coils2L2of the second inductor L2are adjacently disposed in a coupling manner.

To be specific, at least one of the plurality of parallel-connected induction coils1L1of the first inductor L1may be electromagnetically coupled to the induction coil2L2. In addition, when electromagnetic coupling occurs, the induction coil1L1may be electromagnetically coupled to at least one induction coil2L2, and the induction coil2L2electromagnetically coupled to the induction coil1L1and the induction coil1L1may be adjacently disposed in a nested manner at a same layer, or may be adjacently disposed in a stacked manner.

InFIG.4F, an example in which each induction coil1L1and at least one induction coil2L2are adjacently disposed in a coupling manner is used for illustration.FIG.4Fis a diagram of a structure of an equivalent circuit of the transformer20. In a product structure, a person skilled in the art may use relative positions of the induction coil1L1in the first inductor L1and the induction coil2L2in the second inductor L2, to determine whether the induction coil1L1and the induction coil2L2may be electromagnetically coupled. Usually, when the induction coil1L1is close to the induction coil2L2, electromagnetic coupling may occur.

An embodiment of this disclosure further provides a signal transmission method. In a scenario in which the transformer20is configured to drive a high impedance with a low impedance, in a signal transmission process, a first inductor L1and a second inductor L2are electromagnetically coupled, to couple a signal received by the first inductor L1to the second inductor L2, and output the signal from the second inductor L2.

Alternatively, in a scenario in which the transformer20is configured to drive a low impedance with a high impedance, in a signal transmission process, a first inductor L1and a second inductor L2are electromagnetically coupled, to transmit and couple a signal received by the second inductor L2to the first inductor L1, and output the signal from the first inductor L1.

According to the transformer20provided in this embodiment of this disclosure, the transformer20shown inFIG.4Ais used as an example. Inductance values of four induction coils1L1of the first inductor L1are as follows: an inductance value of an induction coil1L1at an outer ring is approximately L1a, an inductance value of an induction coil1L1at a secondary outer ring is approximately L1b, an inductance value of an induction coil1L1at a secondary inner ring is approximately L1c, and an inductance value of an induction coil1L1at an inner ring is approximately L1d. Inductance values of three induction coils2L2in the second inductor L2are as follows: an inductance value of an induction coil2L2at an outer ring is approximately L2a, an inductance value of an induction coil2L2at a middle ring is approximately L2b, and an inductance value of an induction coil2L2at an inner ring is approximately L2c.

According to the transformer20provided in this embodiment of this disclosure, after the plurality of induction coils1L1in the first inductor L1are connected in parallel, an inductance value L1′ of the first inductor L1including the plurality of induction coils1L1is as follows: L1′

and a small inductance value L1′ of the first inductor L1may be obtained. After the plurality of induction coils2L2in the second inductor L2are connected in series, an inductance value L2′ of the second inductor L2including the plurality of induction coils2L2is as follows: L2′≈L2a+L2b+L2c, and a large inductance value L2′ of the second inductor L2may be obtained. Therefore, an inductance ratio L (namely, an impedance ratio R) of the transformer20provided in this embodiment of this disclosure is large. Based on this, the induction coil1L1in the first inductor L1and the induction coil2L2in the second inductor L2may be electromagnetically coupled, so that different quantities of induction coils1L1and different quantities of induction coils2L2may be electromagnetically coupled by adjusting an arrangement manner of the induction coils1L1in the first inductor L1and the induction coils2L2in the second inductor L2as required, so as to meet a requirement of the transformer20for a high coupling coefficient K. Therefore, the transformer20may implement both a large inductance ratio L (namely, impedance ratio R) and a high coupling coefficient K. In addition, quality factors of the first inductor L1and the second inductor L2are also high, and a loss of the transformer20is small.

Based on the transformer20shown inFIG.4A, it is found through simulation that, when operating at a frequency of 8 GHz, the transformer20has an inductance value L1′ of the first inductor L1is equal to 177 pH, an inductance value L2′ of the second inductor L2is equal to 1590 pH, a quality factor Q1of the first inductor L1is equal to 12.8, and a quality factor Q2of the second inductor L2is equal to 11. An inductance ratio L (namely, an impedance ratio R) of the transformer20can reach about 9, and a coupling coefficient K can reach about 0.75, so that both a large inductance ratio L (namely, impedance ratio R) and a high coupling coefficient K can be implemented. In addition, the quality factors of the first inductor L1and the second inductor L2are also high, and a loss of the transformer20is small. When the transformer20is used in a radio frequency chip200, performance requirements of the radio frequency chip200for a large inductance ratio L (namely, impedance ratio R) and a high coupling coefficient K in a scenario of impedance conversion with a large impedance ratio R can be met, and a loss of the transformer20is small.

A quantity of induction coils1L1in the first inductor L1and a quantity of induction coils2L2in the second inductor L2are not limited in embodiments of this disclosure. InFIG.4A, an example in which the first inductor L1of the transformer20includes the four induction coils1L1and the second inductor L2includes the three induction coils2L2is merely used for illustration.

When a layout of the transformer20is formed, the induction coil1L1in the first inductor L1and the induction coil2L2in the second inductor L2may be disposed at a same layer, or may be disposed at different layers. The plurality of induction coils1L1in the first inductor L1may be disposed at a same layer, or may be disposed at different layers. The plurality of induction coils2L2in the second inductor L2may be disposed at a same layer, or may be disposed at different layers. The following schematically describes disposing positions and arrangement manners of the plurality of induction coils1L1and the plurality of induction coils2L2.

In terms of a manner in which the first inductor L1and the second inductor L2are coupled, in a possible implementation, at least one of the plurality of parallel-connected induction coils1L1and at least one of the plurality of serial-connected induction coils2L2are adjacently disposed in a nested manner at a same layer.

In some embodiments, the plurality of parallel-connected induction coils1L1in the first inductor L1are disposed at a same layer, the plurality of serial-connected induction coils2L2in the second inductor L2are disposed at a same layer, and the first inductor L1and the second inductor L2are disposed at a same layer.

The plurality of induction coils1L1of the first inductor L1and the plurality of induction coils2L2of the second inductor L2are disposed in a nested manner, and an induction coil1L1in the first inductor L1and an induction coil2L2adjacent to the induction coil1L1in the second inductor L2are electromagnetically coupled.

Alternatively, it is understood as that the plurality of induction coils1L1in the first inductor L1and the plurality of induction coils2L2in the second inductor L2are arranged in a staggered manner, and are arranged outward in sequence in a direction away from a center of the transformer20, one coil covers another coil, and adjacent coils are not coupled.

It may be understood that, in a place where the induction coil1L1overlaps with the induction coil2L2, jumpering (at a different layer from the induction coil1L1and the induction coil2L2) may be performed at the overlapping place in a manner of an air bridge or a dielectric bridge, so as to avoid coupling between the induction coil1L1and the induction coil2L2. Similarly, in a place where the plurality of induction coils2L2overlap, jumpering may be performed at the overlapping place in a manner of an air bridge or a dielectric bridge, so as to avoid coupling between the plurality of induction coils2L2.

For example, as shown inFIG.4E, all jumpering parts are on the induction coils2L2in the second inductor L2, and a jumpering part with a thinner line in the induction coil2L2is a part that overlaps the induction coil1L1in the first inductor L1. The jumpering part is at a different layer from other parts of the induction coil1L1and the induction coil2L2. When two jumpering parts intersect, two jumpers are located at different layers. Certainly, alternatively, all the jumpering parts may be on the induction coils1L1, or on the induction coils2L2, or some jumpering parts are on the induction coil1L1, and some jumpering parts are on the induction coil2L2. This is not limited in embodiments of this disclosure, provided that the jumpering parts are properly disposed as required. The at least one induction coil1L1in the first inductor L1and the at least one induction coil2L2in the second inductor L2are adjacently disposed in a nested manner at a same layer, to reduce a distance between the induction coil1L1and the induction coil2L2. In addition, this avoids an insulation layer between the induction coil1L1and the induction coil2L2, thereby improving effect of electromagnetic coupling between the induction coil1L1and the induction coil2L2.

In some embodiments, the plurality of induction coils1L1and the plurality of induction coils2L2are arranged in a nested manner.

Optionally, at least one induction coil2L2is disposed between adjacent induction coils1L1.

For example, as shown inFIG.5A, the induction coils1L1of a first inductor L1include a first induction coil L11and a second induction coil L12, and the induction coils2L2of a second inductor L2include a third induction coil L23. The third induction coil L23is disposed between the first induction coil L11and the second induction coil L12.

As shown inFIG.5A, only one third induction coil L23may be disposed between the first induction coil L11and the second induction coil L12. As shown inFIG.5B, a plurality of third induction coils L23may be disposed between a first induction coil L11and a second induction coil L12.

Certainly, the first inductor L1may include a plurality of first induction coils L11disposed adjacent to each other, and the first inductor L1may also include a plurality of second induction coils L12disposed adjacent to each other. InFIG.5AandFIG.5B, an example in which there is one first induction coil L11and one second induction coil L12is merely used for illustration.

Alternatively, optionally, a plurality of induction coils1L1are disposed between adjacent induction coils2L2.

For example, as shown inFIG.5C, an induction coil1L1of a first inductor L1includes a plurality of first induction coils L11, and an induction coil2L2of a second inductor L2includes a third induction coil L23and a fourth induction coil L24. The plurality of first induction coils L11are disposed between the third induction coil L23and the fourth induction coil L24.

Alternatively, optionally, as shown inFIG.6AandFIG.6B, an induction coil1L1of a first inductor L1includes a first induction coil L11and a second induction coil L12, and an induction coil2L2of a second inductor L2includes a third induction coil L23and a fourth induction coil L24. The third induction coil L23is disposed between the first induction coil L11and the second induction coil L12, and the second induction coil L12is disposed between the third induction coil L23and the fourth induction coil L24.

As shown inFIG.6AandFIG.6B, the first induction coil L11may be located in an innermost ring. As shown inFIG.6CandFIG.6D, the first induction coil L11may alternatively be located in an outermost ring.

Certainly, the first inductor L1may include a plurality of first induction coils L11disposed adjacent to each other, and the first inductor L1may also include a plurality of second induction coils L12disposed adjacent to each other. The second inductor L2may include a plurality of third induction coils L23disposed adjacent to each other, and the second inductor L2may also include a plurality of fourth induction coils L24disposed adjacent to each other.FIG.6AtoFIG.6Dare merely examples. This is not limited.

Alternatively, optionally, as shown inFIG.7AandFIG.7B, an induction coil1L1of a first inductor L1includes a first induction coil L11, a second induction coil L12, and a fifth induction coil L15. An induction coil2L2of a second inductor L2includes a third induction coil L23and a fourth induction coil L24.

The third induction coil L23is disposed between the first induction coil L11and the second induction coil L12, the second induction coil L12is disposed between the third induction coil L23and the fourth induction coil L24, and the fourth induction coil L24is disposed between the second induction coil L12and the fifth induction coil L15.

Certainly, the first inductor L1may include a plurality of first induction coils L11disposed adjacent to each other, the first inductor L1may also include a plurality of second induction coils L12disposed adjacent to each other, and the first inductor L1may also include a plurality of fifth induction coils L15disposed adjacent to each other. The second inductor L2may include a plurality of third induction coils L23disposed adjacent to each other, and the second inductor L2may also include a plurality of fourth induction coils L24disposed adjacent to each other.FIG.7AandFIG.7Bare merely examples. This is not limited.

Alternatively, optionally, as shown inFIG.7CandFIG.7D, an induction coil1L1of a first inductor L1includes a first induction coil L11and a second induction coil L12. An induction coil2L2of a second inductor L2includes a third induction coil L23, a fourth induction coil L24, and a sixth induction coil L26.

The third induction coil L23is disposed between the first induction coil L11and the second induction coil L12, the second induction coil L12is disposed between the third induction coil L23and the fourth induction coil L24, and the first induction coil L11is disposed between the third induction coil L23and the sixth induction coil L26.

Certainly, the first inductor L1may include a plurality of first induction coils L11disposed adjacent to each other, and the first inductor L1may also include a plurality of second induction coils L12disposed adjacent to each other. The second inductor L2may include a plurality of third induction coils L23disposed adjacent to each other, the second inductor L2may also include a plurality of fourth induction coils L24disposed adjacent to each other, and the second inductor L2may also include a plurality of sixth induction coils L26disposed adjacent to each other.FIG.7CandFIG.7Dare merely examples. This is not limited.

Certainly, as shown inFIG.8AtoFIG.8D, induction coils1L1in a first inductor L1and induction coils2L2in a second inductor L2may further be arranged in a nested manner based on any one of the foregoing layout structures. This is not limited in embodiments of this disclosure. In some embodiments, as shown inFIG.8AandFIG.8B, an innermost ring of a transformer20is an induction coil1L1, and an outermost ring of the transformer20is an induction coil2L2.

In some other embodiments, as shown inFIG.8C, an innermost ring of a transformer20is an induction coil2L2, and an outermost ring of the transformer20is an induction coil1L1.

In still another some embodiments, as shown inFIG.8D, both an innermost ring and an outermost ring of a transformer20are induction coils1L1.

To be specific, the induction coils1L1and the induction coils2L2are alternately arranged, and along an arrangement direction of the induction coils1L1and the induction coils2L2, both the outermost ring and the innermost ring of the transformer20are the induction coils1L1in the first inductor L1.

In this way, the plurality of induction coils1L1and the plurality of induction coils2L2are nested with each other, the induction coil1L1located in an outermost ring is electromagnetically coupled to one induction coil2L2, the induction coil1L1located in an innermost ring is electromagnetically coupled to one induction coil2L2, and other induction coils1L1may be electromagnetically coupled to two induction coils2L2, so that an overlapping and nesting area of the first inductor L1and the second inductor L2is largest, and electromagnetic coupling between the induction coils1L1and the induction coils2L2may be increased. When a quantity of the induction coils1L1and a quantity of the induction coils2L2are fixed (that is, an inductance ratio L and an impedance ratio R are fixed), an arrangement manner in which one induction coil1L1is disposed on each of the two sides of each induction coil2L2can maximize a coupling coefficient K of the transformer20.

In some embodiments, the induction coils1L1and the induction coils2L2are disposed adjacent to each other, and any two induction coils1L1are not adjacent to each other.

To be specific, each of the plurality of parallel-connected induction coils1L1and at least one of the plurality of serial-connected induction coils2L2are adjacently disposed in a stacked manner.

In this way, each induction coil1L1may be electromagnetically coupled to induction coils2L2located on the inner and outer sides of the induction coil1L1, so that electromagnetic coupling between the induction coil1L1and the induction coils2L2can be enhanced, to increase a coupling coefficient K of a transformer20.

Optionally, the plurality of induction coils1L1are four induction coils1L1, the plurality of induction coils2L2are three induction coils2L2, and the induction coils1L1and the induction coils2L2are alternately arranged and disposed in a nested manner.

In this way, when a transformer20is prepared, a process is easy to implement, and the transformer20is easy to prepare.

Regardless of how the induction coil1L1and the induction coil2L2are arranged, when the induction coil1L1and the induction coil2L2are disposed at a same layer, a gap may be provided between adjacent induction coils to reduce interference between the adjacent induction coils. To be specific, gaps may be provided between adjacent induction coils1L1, between adjacent second induction coils2L2, and between an induction coil1L1and an induction coil2L2that are adjacent to each other, to reduce interference between the adjacent induction coils1L1, between the adjacent second induction coils2L2, and between the induction coil1L1and the induction coil2L2that are adjacent to each other.

A smaller gap between the induction coil1L1and the induction coil2L2indicates better effect of electromagnetic coupling between the induction coil1L1and the induction coil2L2. Therefore, during design, electromagnetic coupling effect and process difficulty may be comprehensively considered to determine a size of the gap between the induction coil1L1and the induction coil2L2.

In some other embodiments, a part of the plurality of parallel-connected induction coils1L1in the first inductor L1are disposed at a same layer, and a part of the plurality of serial-connected induction coils2L2in the second inductor L2are disposed at a same layer.

The plurality of parallel-connected induction coils1L1in the first inductor L1are distributed at a plurality of layers, and the induction coil1L1and the induction coil2L2that are electromagnetically coupled are arranged in at least one layer, and the induction coil1L1and the induction coil2L2that are located at a same layer are disposed in a nested manner.

For an arrangement manner of the induction coils1L1located at a same layer and the induction coils2L2located at a same layer, refer to the foregoing arrangement manner of the induction coils1L1and the induction coils2L2. Details are not described herein again.

Projections of induction coils1L1located at different layers may at least partially overlap, or may not overlap. Projections of induction coils2L2located at different layers may at least partially overlap, or may not overlap. Projections of an induction coil1L1and an induction coil2L2that are located at different layers may at least partially overlap, or may not overlap.

The induction coil1L1and the induction coil2L2that are located at different layers may be coupled or may not be coupled. When the induction coil1L1and the induction coil2L2that are located at different layers are not coupled, an induction coil1L1and an induction coil2L2that are coupled in a transformer20are located at a same layer and disposed in a nested manner. When the induction coil1L1and the induction coil2L2that are located at different layers are coupled, an induction coil1L1and an induction coil2L2that are coupled in a transformer20are partially located at a same layer and disposed in a nested manner. The induction coil1L1and the induction coil2L2that are coupled in the transformer20are partially located at different layers and disposed in a stacked manner.

For an arrangement manner of the induction coil1L1and the induction coil2L2in a case in which the induction coil1L1and the induction coil2L2that are located at different layers are electromagnetically coupled, refer to the following related descriptions of stacked coupling between the induction coil1L1and the induction coil2L2.

In terms of a manner in which the first inductor L1and the second inductor L2are coupled, in another possible implementation, at least one of the plurality of parallel-connected induction coils1L1and at least one of the plurality of serial-connected induction coils2L2are adjacently disposed in a stacked manner.

The first inductor L1and the second inductor L2are disposed in a stacked manner, and an induction coil1L1in the first inductor L1and an induction coil2L2that is in the second inductor L2and that is disposed in a stacked manner with the induction coil1L1are electromagnetically coupled.

It should be noted herein that, when the plurality of induction coils1L1and the plurality of induction coils2L2are disposed at different layers, seen from a top view, projections of an induction coil1L1and an induction coil2L2that are coupled may overlap, or may have a gap. Alternatively, it is understood as that a projection of the induction coil1L1on a substrate and a projection of the induction coil2L2on the substrate may overlap, or may have a gap.

In some embodiments, a projection of the induction coil1L1in the first inductor L1and a projection of the induction coil2L2in the second inductor L2does not overlap.

An arrangement sequence of the projection of the induction coil1L1in the first inductor L1and the projections of the induction coil2L2in the second inductor L2may be the same as the arrangement sequences shown inFIG.5AtoFIG.8D. For details, refer to the foregoing related descriptions. Details are not described herein again.

It should be emphasized that, in this example, only an example in which the induction coil1L1and the induction coil2L2are borne by the substrate is used for description. When the induction coil1L1and the second induction coil L2are borne by another bearing layer, a projection on the substrate described in this example may be understood as a projection on the bearing layer.

In some other embodiments, as shown inFIG.9A, projections of at least a part of the plurality of induction coils1L1in the first inductor L1and projections of at least a part of the plurality of induction coils2L2in the second inductor L2overlap.

To be specific, at least a part of the induction coil1L1is located above at least a part of the induction coil2L2, or at least a part of the induction coil2L2is located above at least a part of the induction coil1L1. Seen from a top view, at least a part of the induction coil1L1overlaps at least a part of the induction coil2L2.

For example, as shown inFIG.9A, the induction coil1L1of the first inductor L1includes a first induction coil L11and a second induction coil L12, and the induction coil2L2of the second inductor L2includes a third induction coil L23. A projection of the first induction coil L11overlaps a projection of the third induction coil L23.

Alternatively, for example, as shown inFIG.9B, the induction coil1L1of the first inductor L1includes a first induction coil L11and a second induction coil L12, and the induction coil2L2of the second inductor L2includes a third induction coil L23. A projection of the second induction coil L12overlaps a projection of the third induction coil L23.

Alternatively, for example, as shown inFIG.9C, the induction coil1L1of the first inductor L1includes a first induction coil L11and a second induction coil L12, and the induction coil2L2of the second inductor L2includes a third induction coil L23. Both a projection of the first induction coil L11and a projection of the second induction coil L12overlap a projection of the third induction coil L23.

The overlapping may be that the induction coil1L1in the first inductor L1at least partially covers the induction coil2L2in the second inductor L2, or the overlapping may be that the induction coil2L2in the second inductor L2at least partially covers the induction coil1L1in the first inductor L1, or the overlapping may be that the induction coil1L1in the first inductor L1coincides with the induction coil2L2in the second inductor L2.

The induction coil1L1and the induction coil2L2are disposed at different layers, and the projection of the induction coil1L1overlaps the projection of the induction coil2L2, so that a projection area of a transformer20may be small, and in addition, a distance between the induction coil1L1and the induction coil2L2may be minimized, to improve effect of electromagnetic coupling between the induction coil1L1and the induction coil2L2.

In some embodiments, each of the plurality of parallel-connected induction coils1L1is coupled to at least one induction coil2L2.

Optionally, as shown inFIG.10A, a projection of the induction coil1L1on the substrate covers a projection of the induction coil2L2on the substrate.

Alternatively, optionally, as shown inFIG.10B, a projection of the second induction coil L2on the substrate covers a projection of the induction coil1L1on the substrate.

Alternatively, optionally, as shown inFIG.10C, a projection of the induction coil1L1on the substrate coincides with a projection of the induction coil2L2on the substrate.

FIG.10Cuses an example in which the induction coil1L1is located above the induction coil2L2. When the projection of the induction coil1L1on the substrate coincides with the projection of the induction coil2L2on the substrate, the induction coil2L2is not displayed in a top view.

It should be noted that, the foregoing overlapping ignores connection parts used to implement serial connection of the plurality of induction coils1L1and parallel connection of the plurality of induction coils2L2, is an equivalent result, and is not complete covering or coinciding in a strict sense. In a strict sense, it may be understood as that the projection of the induction coil1L1on the substrate at least partially overlaps the projection of the induction coil2L2on the substrate.

Effect of overlapping between the induction coil1L1and the induction coil2L2may be adjusted by adjusting a line width of the induction coil1L1and a line width of the induction coil2L2.

Based on this, for example, as shown inFIG.10AtoFIG.10C, a quantity of induction coils1L1in the first inductor L1is equal to a quantity of induction coils2L2in the second inductor L2, and the induction coils1L1and the induction coils2L2are disposed in a one-to-one correspondence.

In this way, the induction coils1L1and the induction coils2L2can be electromagnetically coupled in a one-to-one correspondence manner, and cost-effectiveness is high.

Alternatively, for example, a quantity of induction coil1L1in the first inductor L1is not equal to a quantity of induction coil2L2in the second inductor L2.

For example, as shown inFIG.10D, projections of at least two induction coils1L1in the first inductor L1(FIG.10Duses two induction coils1L1as an example for illustration) on the substrate overlap a projection of a same induction coil2L2in the second inductor L2on the substrate. In other words, a plurality of induction coils1L1in the first inductor L1are disposed corresponding to one induction coil2L2in the second inductor L2.

In this way, when a quantity of induction coils2L2remains unchanged (an inductance value L2′ of the second inductor L2remains unchanged), a quantity of induction coils1L1may be increased. Because a plurality of induction coils1L1are connected in parallel, increasing the quantity of induction coils1L1is equivalent to reducing an inductance value L1′ of the first inductor L1, to increase an inductance ratio L (namely, an impedance ratio R) of the transformer20. In addition, a quantity of the induction coils1L1is increased, and each induction coil1L1is electromagnetically coupled to the induction coil2L2, so that an overlapping and nesting area of the induction coils1L1and the induction coil2L2may be increased, thereby increasing a coupling coefficient K of the transformer20.

Alternatively, for example, projections of a plurality of induction coils2L2in the second inductor L2on the substrate overlap a projection of a same induction coil1L1in the first inductor L1on the substrate. In other words, a plurality of induction coils2L2are disposed corresponding to one induction coil1L1.

In this way, the quantity of induction coils2L2is increased, to increase an inductance value L2′ of the second inductor L2, so as to increase an inductance ratio L (namely, an impedance ratio R) of the transformer20. In addition, each induction coil1L1is electromagnetically coupled to the plurality of induction coils2L2, so that an overlapping and nesting area of the induction coil1L1and the induction coils2L2may be increased, thereby increasing a coupling coefficient K of the transformer20.

In some other embodiments, a part of the plurality of parallel-connected induction coils1L1are coupled to at least one induction coil2L2, and a part of the induction coils1L1are not coupled to the induction coil2L2.

For example, as shown inFIG.10E, projections of a part of the plurality of induction coils1L1in the first inductor L1on the substrate overlap projections of the induction coils2L2in the second inductor L2on the substrate, and projections of a part of the induction coils1L1on the substrate do not overlap the projections of the induction coils2L2on the substrate.

For example, a quantity of induction coils1L1in the first inductor L1may be greater than a quantity of induction coils2L2in the second inductor L2. An extra-disposed induction coil1L1may be disposed in an outermost ring, or may be disposed in an innermost ring, or extra-disposed induction coils1L1may be disposed in both an outermost ring and an innermost ring.

The quantity of induction coils1L1is greater than the quantity of induction coils2L2, so that the extra-disposed induction coil1L1can reduce an inductance value L1′ of the first inductor L1and increase an inductance ratio L (namely, an impedance ratio R) of a transformer20. In addition, the extra-disposed induction coil1L1may be electromagnetically coupled to an induction coil2L2adjacent to the extra-disposed induction coil1L1, to increase an overlapping and nesting area between the induction coil1L1and the induction coil2L2, so as to increase a coupling coefficient K of the transformer20, thereby meeting different requirements.

It should be noted that the plurality of induction coils1L1in the first inductor L1may be disposed at a same layer, or may be disposed at different layers, or may be partially disposed at a same layer. The plurality of induction coils2L2in the second inductor L2may be disposed at a same layer, or may be disposed at different layers, or may be partially disposed at a same layer.

In some embodiments, the plurality of induction coils1L1in the first inductor L1are disposed at a same layer, and the plurality of induction coils2L2in the second inductor L2are disposed at a same layer. In this way, a structure is simple, preparation is convenient, and integration is high.

In some embodiments, as shown inFIG.11, on a basis that the first inductor L1includes the plurality of parallel-connected induction coils1L1, the first inductor L1further includes an induction coil3L3connected in series to the plurality of parallel-connected induction coils1L1.

A quantity of induction coils3L3connected in series to the induction coils1L1and arrangement positions of the induction coils3L3are not limited in embodiments of this disclosure, provided that the induction coils3L3are properly disposed as required.

This is an implementable solution, and is used to meet requirements for different inductance ratios L (namely, impedance ratios R) and coupling coefficients K.

Based on this, in terms of a shape of the induction coil1L1and a shape of the induction coil2L2, in some embodiments, the induction coil1L1and the induction coil2L2are circular.

In this way, impedance of the induction coil1L1and impedance of the induction coil2L2are continuous, a quality factor of the induction coil1L1and a quality factor of the induction coil2L2are high, and a loss of the transformer20is small.

In some other embodiments, the induction coil1L1and the induction coil2L2are polygonal. In this way, a preparation process of the induction coil1L1and the induction coil2L2is simple, and preparation is easy.

Optionally, an included angle between edges that enclose the induction coil1L1is greater than 90°. Similarly, an included angle between edges that enclose the induction coil2L2is greater than 90°. For example, the shape of the induction coil1L1and the shape of the induction coil2L2are octagons.

In this way, the preparation process of the induction coil1L1and the induction coil2L2is simple, and the preparation is easy. In addition, the impedance of the induction coil1L1and the impedance of the induction coil2L2may be continuous, the quality factor of the induction coil1L1and the quality factor of the induction coil2L2are high, and the loss of the transformer20is reduced.

In terms of a manner of connecting the plurality of induction coils1L1in parallel in the first inductor L1, in some embodiments, as shown inFIG.10E, endpoints of the induction coils1L1in the first inductor L1are located on a same straight line.

This can avoid that a part that is of the induction coil1L1and that cannot function as an induction coil is equivalent to a conducting wire. In this way, an effective area of each induction coil1L1is the largest, and an inductance ratio L (namely, an impedance ratio R) and a coupling coefficient K of the transformer20are the largest.

In some other embodiments, as shown inFIG.12, endpoints of the induction coils1L1in the first inductor L1are not located on a same straight line. A coupling position of each induction coil1L1may be adjusted based on an overall layout of a radio frequency chip200. This is not limited in embodiments of this disclosure.

It should be emphasized that regardless of how the induction coil1L1and the induction coil2L2are arranged, line widths, materials, and shapes of the induction coil1L1and the induction coil2L2are not limited in embodiments of this disclosure. A structure shown in this embodiment of this disclosure is merely an example. This is not limited.

Based on any one of the foregoing structures of a transformer20, in some embodiments, as shown inFIG.13, the first inductor L1and the second inductor L2shown above are used as one inductor group L′, and a transformer20includes a plurality of inductor groups L′. First inductors L1in the plurality of inductor groups L′ are connected in parallel, and a plurality of second inductors L2in the plurality of inductor groups L′ are connected in series.

InFIG.13, an example in which the transformer20includes two inductor groups L′ is used for illustration. However, the transformer20is not limited to including only two inductor groups L′ in this embodiment of this disclosure, provided that the inductor groups L′ are properly disposed as required.

Factors such as arrangement manners, quantities, shapes, and widths of the first inductors L1and the second inductors L2in the plurality of inductor groups L′ included in the transformer20may be the same, or may be different, and any combination of any one of the inductor groups L′ shown above may be used.

FIG.13is used as an example. A quantity of induction coils1L1that are disposed in parallel and that are included in the first inductors L1of the transformer20is a sum of quantities of a plurality of induction coils1L1in the two inductor groups L′. A quantity of induction coils2L2that are disposed in series and that are included in the second inductors L2of the transformer20is a sum of quantities of a plurality of induction coils2L2in the two inductor groups L′.

For example, inductance values of four induction coils1L1in the left inductor group L′ are L1a, L1b, L1c, and Lid, respectively, and inductance values of four induction coils1L1in the right inductor group L′ are L1a′, L1b′, L1c′ and L1d′, respectively. Inductance values of three induction coils2L2in the left inductor group L′ are L2a, L2b, and L2c, respectively, and inductance values of three induction coils2L2in the right inductor group L′ are L2a′, L2b′, L2c′, respectively. In this case, an inductance value L1′ of the first inductors L1of the transformer20is as follows:

and an inductance value L2′ of the second inductors L2is as follows: L2′˜(L2a+L2b+L2c)+(L2a′+L2b′+L2c′).

It can be learned from the foregoing descriptions that, compared with a case in which the transformer20includes only one inductor group L′, in a case in which the transformer20includes a plurality of inductor groups L′, inductance values L1′ of the first inductors L1of the transformer20are smaller, and inductance values L2′ of the second inductors L2of the transformer20are larger. Therefore, the transformer20can obtain a larger inductance ratio L (namely, impedance ratio R). When a coupling coefficient K of each inductor group L′ is high, a high coupling coefficient K of the transformer20may still be maintained. It is found through simulation that, when the transformer20includes two inductor groups L′, and a structure of each inductor group L′ is shown inFIG.4A, an inductance ratio L (namely, an impedance ratio R) of the transformer20can reach about 35, and a coupling coefficient K can reach about 0.73.

Therefore, in a case in which a process is difficult to implement because a quantity of induction coils1L1and a quantity of induction coils2L2included in one inductor group L′ are large, a plurality of inductor groups L′ may be disposed to further improve the inductance ratio L (namely, the impedance ratio R) of the transformer20.

Based on any one of the foregoing structures of a transformer20, as shown inFIG.14AandFIG.14B, a transformer20further includes a first capacitor C1and a second capacitor C2. The first capacitor C1is connected in parallel to a plurality of induction coils1L1, and the second capacitor C2is connected in parallel to a plurality of induction coils2L2.

That the first capacitor C1is connected in parallel to a plurality of induction coils1L1may be understood as that two ends of the first capacitor C1are correspondingly coupled to two output ends of the plurality of induction coils1L1. That the second capacitor C2is connected in parallel to a plurality of induction coils2L2may be understood as that two ends of the second capacitor C2are correspondingly coupled to two output ends of the plurality of induction coils2L2.

Disposal positions of the first capacitor C1and the second capacitor C2are not limited in embodiments of this disclosure. A plate of the first capacitor C1and a plate of the second capacitor C2may be at a same layer as the induction coil1L1and/or the induction coil2L2, or a plate of the first capacitor C1and a plate of the second capacitor C2may be at different layers from the induction coil1L1and/or the induction coil2L2, provided that the first capacitor C1and the second capacitor C2are properly disposed as required.

Therefore, in this disclosure, a small inductor is formed through parallel connection, and a large inductor is formed through series connection, so that the transformer20has a large inductance ratio L (namely, impedance ratio R). The induction coils1L1and the induction coils2L2are alternately arranged, so that the transformer20has a high coupling coefficient K. In this way, the transformer20can implement both a large inductance ratio L (namely, impedance ratio R) and a high coupling coefficient K, thereby well implementing low-insertion-loss impedance conversion performance in a scenario with a large impedance ratio matching requirement.

It should be emphasized that the transformer20provided in this embodiment of this disclosure is not only applicable to the foregoing radio frequency chip200, but also may be used in another structure.

An embodiment of this disclosure further provides a circuit board (for example, a PCB). The circuit board includes any one of the foregoing transformers20. In other words, a transformer20may be integrated into the circuit board. Certainly, a first inductor L1and a second inductor L2may be located at a same wiring layer in the circuit board, or may be located at different wiring layers, provided that the first inductor L1and the second inductor L2are properly disposed as required.

An embodiment of this disclosure further provides an electronic device, including the foregoing circuit board. The electronic device further includes a low impedance matching network10and a high impedance matching network30. The low impedance matching network10and the high impedance matching network30are disposed on the circuit board, end parts of a plurality of induction coils1L1in the transformer20are coupled to the low impedance matching network10, and end parts of a plurality of induction coils2L2in the transformer20are coupled to the high impedance matching network30, so as to implement conversion between the low impedance network10and the high impedance network30.

The circuit board and the electronic device provided in embodiments of this disclosure include any one of the foregoing transformers20. Beneficial effects of the circuit board and the electronic device are the same as the beneficial effects of the transformer20. Details are not described herein again.