Balancer with an Integrated Network, Wireless Device, and Method for Signal Conversion in the Balancer

Abstract

To provide baluns with integrated matching networks, a method of signal conversion, and a wireless device.SOLUTION: A balun 230 includes a first pair of coupled lines 211, a second pair of coupled lines 212, and a transmission line 213. A first port 221 of the balun 230 is connected to a reference voltage by way of a first line 215 of the first pair of coupled lines 211, the transmission line 213, and a first line 217 of the second pair of coupled lines 212. A second port 222 of the balun 230 is connected to the reference voltage by way of a second line 215 of the first pair of coupled lines 211, while a third port 223 of the balun 230 is connected to the reference voltage by way of a second line 218 of the second pair of coupled lines 212. The first port 221 serves as an unbalanced signal terminal, while the second port 222 and the third port 223 serve as positive and negative signal terminals.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] Embodiments of the present invention relate to electronic systems, and more particularly to radio frequency (RF) electronic devices.

Background Art

[0002] Baluns can be used to convert single-ended RF signals to differential RF signals or differential RF signals to single-ended RF signals. Examples of RF communication systems having one or more baluns include, but are not limited to, cellular phones, tablets, base stations, network access points, customer premise equipment (CPE), laptops, and wearable electronic devices.

[0003] Baluns can be included in RF communication systems that convert RF signals over a wide range of frequencies. For example, a balun can handle RF signals in the frequency range from about 30 kHz to 300 GHz, such as RF signals in the range from about 410 MHz to about 7.125 GHz for fifth generation (5G) communication using frequency range 1 (FR1) or in the range from about 24.25 GHz to 52.6 GHz for 5G communication using frequency range 2 (FR2).

Summary of the Invention

[0004] In certain embodiments, the present disclosure relates to a balun that includes a first pair of coupled lines including a first conductive line and a second conductive line, a second pair of coupled lines including a third conductive line and a fourth conductive line, and a transmission line connecting the first conductive line of the first pair of coupled lines to the third conductive line of the second pair of conductive lines.

[0005] In some embodiments, the first pair of conductive lines and the second pair of conductive lines have different lengths.

[0006] In various embodiments, the first pair of conductive lines and the second pair of conductive lines have different odd-mode impedances.

[0007] In some embodiments, the first pair of conductive lines and the second pair of conductive lines have different even-mode impedances.

[0008] In some embodiments, the first pair of conductive lines, the second pair of conductive lines, and the transmission line are implemented to provide input matching.

[0009] In various embodiments, the first pair of conductive lines, the second pair of conductive lines, and the transmission line are implemented to provide output matching.

[0010] In a number of embodiments, the transmission line includes a coil.

[0011] In some embodiments, the balun further includes a first port connected to one end of the first conductive line on the side opposite to the transmission line, a second port connected to the second conductive line of the first pair of conductive lines, and a third port connected to the fourth conductive line of the second pair of conductive lines.

[0012] According to a number of embodiments, the first port exists as an unbalanced terminal for a single-ended signal, the second port exists as a positive terminal for a differential signal, and the third port exists as a negative terminal for a differential signal.

[0013] According to some embodiments, the end of the third conductive line on the side opposite to the transmission line is connected to a reference voltage.

[0014] According to various embodiments, the end of the second conductive line on the side opposite to the second port is connected to a reference voltage.

[0015] According to a number of embodiments, the end of the fourth conductive line on the side opposite to the third port is connected to a reference voltage.

[0016] According to a number of embodiments, the first port is configured to receive a single-ended signal from an amplifier.

[0017] According to some embodiments, the first port is configured to output a single-ended signal to an amplifier.

[0018] According to various embodiments, the second port and the third port are configured to receive a differential signal from an amplifier.

[0019] According to a certain number of embodiments, the second port and the third port are configured to provide a differential signal to an amplifier.

[0020] In a predetermined embodiment, the present disclosure relates to a wireless device. The wireless device includes a transceiver and a front-end system coupled to the transceiver. The front-end system includes a balun, and the balun includes a first pair of coupled lines including a first conductive line and a second conductive line, a second pair of coupled lines including a third conductive line and a fourth conductive line, and a transmission line connecting the first conductive line of the first pair of coupled lines to the third conductive line of the second pair of conductive lines.

[0021] In various embodiments, the first pair of conductive lines and the second pair of conductive lines have different lengths.

[0022] In some embodiments, the first pair of conductive lines and the second pair of conductive lines have different odd-mode impedances.

[0023] In a certain number of embodiments, the first pair of conductive lines and the second pair of conductive lines have different even-mode impedances.

[0024] In some embodiments, the first pair of conductive lines, the second pair of conductive lines, and the transmission line are implemented to provide input matching.

[0025] In various embodiments, the first pair of conductive lines, the second pair of conductive lines, and the transmission line are implemented to provide output matching.

[0026] In some embodiments, the transmission line includes a coil.

[0027] In some embodiments, the balun further includes a first port connected to one end of the first conductive line on the side opposite to the transmission line, a second port connected to the second conductive line of the first pair of conductive lines, and a third port connected to the fourth conductive line of the second pair of conductive lines.

[0028] According to a certain number of embodiments, the first port exists as an unbalanced terminal for a single-ended signal, the second port exists as a positive terminal for a differential signal, and the third port exists as a negative terminal for a differential signal.

[0029] According to some embodiments, one end of the third conductive line on the side opposite to the transmission line is connected to a reference voltage.

[0030] According to various embodiments, one end of the second conductive line on the side opposite to the second port is connected to a reference voltage.

[0031] According to a certain number of embodiments, one end of the fourth conductive line on the side opposite to the third port is connected to a reference voltage.

[0032] According to various embodiments, the front-end system further includes an amplifier configured to receive a single-ended signal from the first port.

[0033] According to some embodiments, the front-end system further includes an amplifier configured to provide a single-ended signal to the first port.

[0034] According to a certain number of embodiments, the front-end system further includes an amplifier configured to receive a differential signal from the second port and the third port.

[0035] According to some embodiments, the front-end system further includes an amplifier configured to provide a differential signal to the second port and the third port.

[0036] In certain embodiments, the present disclosure relates to a method of signal conversion in a balun. The method includes coupling a first conductive line and a second conductive line of a first pair of coupled lines, coupling a third conductive line and a fourth conductive line of a second pair of coupled lines, and providing a signal path from the first conductive line of the first pair of coupled lines to the third conductive line of the second pair of conductive lines using a transmission line.

[0037] In various embodiments, the first pair of conductive lines and the second pair of conductive lines have different lengths.

[0038] In some embodiments, the first pair of conductive lines and the second pair of conductive lines have different odd-mode impedances.

[0039] In a number of embodiments, the first pair of conductive lines and the second pair of conductive lines have different even-mode impedances.

[0040] In some embodiments, the method further includes providing input matching using the first pair of conductive lines, the second pair of conductive lines, and the transmission line.

[0041] In various embodiments, the method further includes providing output matching using the first pair of conductive lines, the second pair of conductive lines, and the transmission line.

[0042] In some embodiments, the method further includes providing a first port at one end of the first conductive line opposite the transmission line, providing a second port at one end of the second conductive line of the first pair of conductive lines, and providing a third port at one end of the fourth conductive line of the second pair of conductive lines.

[0043] According to a number of embodiments, the method further includes using the first port as an unbalanced terminal for a single-ended signal, using the second port as a positive terminal for a differential signal, and using the third port as a negative terminal for a differential signal.

[0044] According to some embodiments, the method further includes receiving a single-ended signal from an amplifier using the first port.

[0045] According to various embodiments, the method further includes providing a single-ended signal to an amplifier using a first port.

[0046] According to certain embodiments, the method further includes receiving a differential signal from an amplifier using a second port and a third port.

[0047] According to some embodiments, the method further includes providing a differential signal to an amplifier using a second port and a third port. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Embodiments of the present disclosure are described below through non-limiting examples with reference to the accompanying drawings.

[0049] [Figure 1] It is a schematic diagram of an example of a communication network. [Figure 2A] It is a schematic diagram of an embodiment of a communication system operating by beamforming. [Figure 2B] It is a schematic diagram of an embodiment of beamforming that provides a transmission beam. [Figure 2C] It is a schematic diagram of an embodiment of beamforming that provides a reception beam. [Figure 3A] It is a schematic diagram of a balun provided with an integrated matching network according to an embodiment. [Figure 3B] It is a schematic diagram of a balun provided with an integrated matching network according to another embodiment. [Figure 3C] It is a schematic diagram of a balun provided with an integrated matching network according to another embodiment. [Figure 3D] It is a schematic diagram of a balun provided with an integrated matching network according to another embodiment. [Figure 3E] It is a schematic diagram of a balun provided with an integrated matching network according to another embodiment. [Figure 4]Schematic diagram of a metallization layout for a balance with an integrated matching network according to other embodiments. [Diagram 5] Schematic diagram of a radio frequency (RF) amplification system according to one embodiment. [Figure 6] Schematic diagram of an RF amplification system according to other embodiments. [Figure 7] Schematic diagram of an RF amplification system according to other embodiments. [Figure 8] Schematic diagram of one embodiment of a mobile device. **DETAILED DESCRIPTION OF THE INVENTION**

[0050] The following detailed description of certain embodiments presents various descriptions of the particular embodiments. However, the innovations described herein can be embodied in many different ways, for example, as defined and covered by the claims. In this specification, drawings are referred to in which the same reference numbers indicate the same or functionally similar elements. It is understood that the elements shown in the drawings are not necessarily to scale. It is further understood that certain embodiments may include more elements than shown in the drawings and / or a subset of the elements shown in the drawings. Further, some embodiments may include any suitable combination of features from two or more of the drawings.

[0051] The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) and is responsible for global issues related to information and communication technologies, including the global sharing of radio frequency bands.

[0052] The Third Generation Partnership Project (3GPP) is a joint project among groups of telecommunications standards bodies around the world, such as the Association of Radio Industries and Businesses (ARIB), the Telecommunications Technology Committee (TTC), the China Communications Standards Association (CCSA), the Alliance for Telecommunications Industry Solutions (ATIS), the Telecommunications Technology Association (TTA), the European Telecommunications Standards Institute (ETSI), and the Telecom Standards Development Society of India (TSDSI).

[0053] Within the scope of ITU, 3GPP develops and maintains the technical specifications of various mobile communication technologies, for example, second-generation (2G) technologies (such as Global System for Mobile Communications (GSM) (registered trademark) and Enhanced Data Rates for GSM Evolution (EDGE)), third-generation (3G) technologies (such as Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA)), and fourth-generation (4G) technologies (such as Long Term Evolution (LTE) and LTE-Advanced).

[0054] The technical specifications managed by 3GPP can be extended and revised by specification releases. These specification releases can, over many years, well and widely specify new features and evolutions.

[0055] In one example, 3GPP introduced carrier aggregation (CA) for LTE in Release 10. 3GPP initially introduced two downlink carriers, but in Release 14, it was extended to include up to five downlink carriers and up to three uplink carriers. The new features and evolutions provided by 3GPP Releases include, but are not limited to, License-Assisted Access (LAA), Enhanced LAA (eLAA), Narrowband Internet of Things (NB-IoT), Vehicle-to-Everything (V2X), and High Power User Equipment (HPUE).

[0056] 3GPP introduced Phase 1 of the fifth-generation (5G) technology in Release 15 and Phase 2 of the 5G technology in Release 16. Subsequent 3GPP Releases will further evolve and expand the 5G technology. The 5G technology is also referred to here as 5G New Radio (NR).

[0057] 5G NR supports or is expected to support various features such as communication using millimeter - wave spectrum, beamforming capabilities, high - spectral - efficiency waveforms, low - latency communication, multiple radio numerologies, and / or non - orthogonal multiple access (NOMA). Despite such RF functions providing flexibility to the network and improving user data rates, there are a number of technical challenges in supporting such features.

[0058] The teachings herein are applicable to a wide variety of communication systems including, but not limited to, communication systems using advanced cellular technologies such as LTE - Advanced, LTE - Advanced Pro, and / or 5G NR.

[0059] FIG. 1 is a schematic diagram of an example of a communication network 10. The communication network 10 includes various examples of a macro - cell base station 1, a small - cell base station 3, and user equipment (UE). The user equipment (UE) includes a first mobile device 2a, a wireless - connected vehicle 2b, a laptop 2c, a stationary wireless device 2d, a wireless - connected train 2e, a second mobile device 2f, and a third mobile device 2g.

[0060] Despite specific examples of base stations and user equipment being shown in FIG. 1, the communication network may include a wide variety of types and / or numbers of base stations and user equipment.

[0061] For example, in the illustrated example, the communication network 10 includes a macro - cell base station 1 and a small - cell base station 3. The small - cell base station 3 may operate with relatively low power, short distance, and / or fewer simultaneous users compared to the macro - cell base station 1. The small - cell base station 3 may also be referred to as a femto - cell, pico - cell, or micro - cell. Despite the communication network 10 being shown as including two base stations, the communication network 10 may be implemented to include more or fewer base stations and / or other types of base stations.

[0062] Despite various examples of user equipment being shown, the teachings herein are applicable to a wide variety of user equipment including, but not limited to, mobile phones, tablets, laptops, Internet of Things (IoT) devices, wearable electronics, customer premise equipment (CPE), wirelessly connected vehicles, wireless relays, and / or a wide variety of other communication devices. Further, the user equipment includes not only currently available communication devices operating in cellular networks, but also later developed communication devices that can be easily implemented in the systems, processes, methods, and devices of the present invention described herein and claimed in the claims.

[0063] The exemplary communication network 10 of FIG. 1 supports communications using various cellular technologies including, for example, 4G LTE and 5G NR. In a given implementation example, the communication network 10 is further adapted to provide a wireless local area network (WLAN) such as WiFi. Despite various examples of communication technologies being given, the communication network 10 can be adapted to support a wide variety of communication technologies.

[0064] Various communication links of the communication network 10 are depicted in FIG. 1. The communication links can be duplexed (duplexing) in a wide variety of ways including, for example, using frequency division duplexing (FDD) and / or time division duplexing (TDD). FDD is a type of radio frequency communication that uses different frequencies for signal transmission and reception. FDD can provide a number of advantages such as high data rates and low latency. In contrast, TDD is a type of radio frequency communication that uses approximately the same frequency for signal transmission and reception, and the transmit communication and the receive communication switch over time. TDD can provide a number of advantages such as efficient use of the spectrum and variable allocation of throughput between the transmit and receive directions.

[0065] In a given implementation example, the user equipment can communicate with a base station using one or more of 4GLTE, 5GNR, and WiFi technologies. In a given implementation example, enhanced licensed assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (e.g., licensed 4GLTE and / or 5GNR frequencies) with one or more unlicensed carriers (e.g., unlicensed WiFi frequencies).

[0066] As shown in FIG. 1, the communication link includes not only the communication link between the UE and the base station, but also UE-to-UE communication and base station-to-base station communication. For example, the communication network 10 can be implemented to support a self-front-haul and / or a self-backhaul (such as between mobile device 412g and mobile device 412f).

[0067] The communication link can operate over a wide variety of frequencies. In a given implementation example, the communication is supported using 5GNR technology over one or more frequency bands below 6 gigahertz (GHz) and / or over one or more frequency bands above 6 GHz. For example, the communication link can provide a frequency range 1 (FR1), a frequency range 2 (FR2), or a combination thereof. In one embodiment, one or more of the mobile devices support the HPUE power class specification.

[0068] In a given implementation example, the base station and / or the user equipment communicate using beamforming. For example, beamforming can be used to converge the signal strength to overcome path losses, such as the high losses associated with communication over high signal frequencies. In a given embodiment, user equipment such as one or more mobile phones communicate using beamforming in the millimeter wave frequency band in the range of 30 GHz to 300 GHz and / or in the upper centimeter wave frequency in the range of 6 GHz to 30 GHz, specifically 24 GHz to 30 GHz.

[0069] Different users of communication network 10 may share available network resources, such as the available frequency spectrum, in a wide variety of ways. In one example, frequency division multiple access (FDMA) is used to divide a frequency band into multiple frequency carriers, with one or more carriers assigned to a particular user. Examples of FDMA include, but are not limited to, single-carrier FDMA (SC-FDMA) and orthogonal FDMA (OFDMA). OFDMA is a multi-carrier technique that divides the available bandwidth into multiple mutually orthogonal narrowband subcarriers that can be separately assigned to different users.

[0070] Other examples of shared access include, but are not limited to, time division multiple access (TDMA), in which users are assigned specific time slots to use the frequency resources, code division multiple access (CDMA), in which frequency resources are shared among different users by assigning each user a unique code, spatial division multiple access (SDMA), in which beamforming is used to provide shared access through spatial division, and non-orthogonal multiple access (NOMA), in which power domains are used for multiple access purposes. For example, NOMA may be used to serve multiple users with the same frequency, time, and / or code but at different power levels.

[0071] Enhanced Mobile Broadband (eMBB) refers to technology that increases the system capacity of LTE networks. For example, eMBB may refer to communication with a peak data rate of at least 10 Gbps and a minimum of 100 Mbps for each user. Ultra-reliable low-latency communication (uRLLC) refers to technology for very low-latency communication, e.g., less than 2 milliseconds. uRLLC can be used for mission-critical communications, such as for autonomous driving and / or remote surgery applications. Massive Machine-Type Communication (mMTC) refers to low-cost, low-data-rate communications associated with wireless connections to everyday objects, e.g., communications associated with Internet of Things (IoT) applications.

[0072] The communication network 10 in FIG. 1 can be used to support a variety of advanced communication functions including, but not limited to, eMBB, uRLLC, and / or mMTC.

[0073] FIG. 2A is a schematic diagram of an embodiment of a communication system 110 that operates by beamforming. The communication system 110 includes a transceiver 105, signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn, and an antenna array 102. The antenna array 102 includes antenna elements 103a1, 103a2... 103an, 103b1, 103b2... 103bn, 103m1, 103m2... 103mn.

[0074] A communication system that communicates using millimeter wave carriers, centimeter wave carriers, and / or other frequency carriers can use an antenna array such as antenna array 102 to provide beamforming and directivity for signal transmission and / or reception.

[0075] For example, in the illustrated embodiment, the communication system 110 includes an array 102 of m×n antenna elements, each of which is coupled to a separate signal conditioning circuit in this embodiment. As indicated by the ellipsis, the communication system 110 can implement any suitable number of antenna elements and signal conditioning circuits.

[0076] For signal transmission, the signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn can provide the transmission signal to the antenna array 102 such that the signals radiated from the respective antenna elements combine using constructive and destructive interference to produce an aggregated transmission signal that exhibits a quality such as a beam having a strong signal intensity propagating in a given direction away from the antenna array 102.

[0077] In the context of signal reception, the signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn process the received signal (e.g., by separately controlling the received signal phase) so that when the signal arrives at the antenna array 102 from a specific direction, a large amount of signal energy is received. Thus, the communication system 110 also provides directivity for signal reception.

[0078] The relative concentration of signal energy that becomes a transmission beam or a reception beam can be increased by increasing the size of the array. For example, when there is more signal energy focused into a transmission beam, the signal can propagate over a long range while providing a sufficient signal level for RF communication. For example, a signal with a large ratio of signal energy focused into a transmission beam can exhibit a high effective isotropic radiated power (EIRP).

[0079] In the illustrated embodiment, the transceiver 105 transmits signals to the signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn and processes the signals received from the signal conditioning circuits.

[0080] As shown in FIG. 2A, the transceiver 105 generates control signals for the signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn. The control signals can be used for various functions such as controlling the gain and phase of the transmission signal and / or the reception signal to control beamforming. For example, each of the signal conditioning circuits 104a1, 104a2... 104an, 104b1, 104b2... 104bn, 104m1, 104m2... 104mn can include a phase shifter implemented according to the teachings herein.

[0081] 2B is a schematic diagram of one embodiment of beamforming to provide a transmit beam. FIG. 2B shows a portion of a communication system including first signal conditioning circuit 114a, second signal conditioning circuit 114b, first antenna element 113a, and second antenna element 113b.

[0082] Although shown as including two antenna elements and two signal conditioning circuits, the communication system may include additional antenna elements and / or signal conditioning circuits. For example, Figure 2B shows one embodiment of a portion of communication system 110 of Figure 2A.

[0083] The first signal conditioning circuit 114a includes a first phase shifter 130a, a first power amplifier 131a, a first low-noise amplifier (LNA) 132a, and a switch that controls the selection of power amplifier 131a or LNA 132a. Additionally, the second signal conditioning circuit 114b includes a second phase shifter 130b, a second power amplifier 131b, a second LNA 132b, and a switch that controls the selection of power amplifier 131b or LNA 132b. The first phase shifter 130a and the second phase shifter 130b may be implemented according to any of the embodiments herein.

[0084] Although one embodiment of a signal conditioning circuit is shown, other implementations of the signal conditioning circuit are possible, for example, in one example, the signal conditioning circuit includes one or more bandpass filters, duplexers, diplexers, and / or other components.

[0085] In the illustrated embodiment, the first antenna element 113a and the second antenna element 113b are separated by a distance d. Additionally, Figure 2B is annotated with an angle θ. In this example, θ has a value of approximately 90° when the transmit beam direction is substantially perpendicular to the plane of the antenna array and a value of approximately 0° when the transmit beam direction is substantially parallel to the plane of the antenna array.

[0086] By controlling the relative phase of the transmit signals applied to the antenna elements 113a, 113b, a desired transmit beam angle θ can be achieved. For example, the first phase shifter 130a may have a reference value of 0°, and the second phase shifter 130b may be controlled to impart a phase shift of approximately −2πf(d / ν) cos θ radians, where f is the fundamental frequency of the transmit signal, d is the distance between the antenna elements, ν is the velocity of the radiated wave, and π is the mathematical constant pi.

[0087] In certain implementations, the distance d is approximately λ / 2, where λ is the wavelength of the fundamental component of the transmit signal. In such implementations, the second phase shifter 130b can be controlled to provide a phase shift of approximately −π cos θ radians to achieve the transmit beam angle θ.

[0088] Thus, the relative phases of the phase shifters 130a, 130b can be controlled to provide transmit beamforming. In certain implementations, a transceiver (e.g., transceiver 105 of FIG. 2A) controls one or more phase shifter phase values to control beamforming.

[0089] Figure 2C is a schematic diagram of one embodiment of beamforming to provide a receive beam. Figure 2C is similar to Figure 2B, except that Figure 2C shows beamforming in the context of a receive beam rather than a transmit beam.

[0090] 2C, the relative phase difference between the first phase shifter 130a and the second phase shifter 130b can be selected to be approximately equal to −2πf(d / ν) cos θ radians to achieve a desired receive beam angle θ. In an implementation where the distance d corresponds to approximately λ / 2, the phase difference can be selected to be approximately equal to −π cos θ radians to achieve a receive beam angle θ.

[0091] Despite various equations having been provided for phase values that provide beamforming, other phase selection values are possible, such as phase values selected based on the implementation of the antenna array, the implementation of the signal conditioning circuitry, and / or the wireless environment.

[0092] Balun with integrated matching network

[0093] A balun is used in a radio frequency (RF) system to convert an unbalanced RF signal (also referred to as a single-ended RF signal) to a balanced RF signal (also referred to as a differential RF signal), or to convert a balanced RF signal to an unbalanced RF signal.

[0094] When designing an on-chip balun, the design of the balun can be simulated using an electromagnetic simulator (EM) and iteratively adjusted until the performance specifications are met. Such a trial-and-error approach may achieve a practical balun, but such a design process is long and cumbersome, and the results are not necessarily optimal in terms of area, loss, bandwidth, and / or balance. Furthermore, considering input matching and output matching, the design process can become complex. For example, it is typical for an explicit input matching network and / or an explicit output matching network to be present in the balun design.

[0095] A balun with an integrated matching network is provided herein. In a given embodiment, the balun structure includes a first pair of coupling lines, a second pair of coupling lines, and a transmission line. Additionally, a first port of the balun is connected to a reference voltage (e.g., ground) via a series connection of a first line of the first pair of coupling lines, the transmission line, and a first line of the second pair of coupling lines. Further, a second port of the balun is connected to the reference voltage via a second line of the first pair of coupling lines, while a third port of the balun is connected to the reference voltage via a second line of the second pair of coupling lines. The first port serves as an unbalanced terminal for an unbalanced RF signal, while the second and third ports serve as the positive and negative terminals for a balanced RF signal.

[0096] The differential-mode impedance, the common-mode impedance, and the length of the first pair of coupled lines can be adjusted separately during design from the differential-mode impedance, the common-mode impedance, and the length of the second pair of coupled lines. Further, the impedance and length of the transmission line can also be adjusted separately during design. Such parameters can be tuned to provide a methodology for on-die balun designs with low loss, small area, wide bandwidth, and / or improved balance. Since the number of design parameters is small, the balun can be easily modeled and designed very quickly.

[0097] Furthermore, such parameter tuning can be used to achieve desired input and output matching. That is, the balun here can operate by means of an integrated input matching network and / or an integrated output matching network. Such integration reduces loss and / or provides a compact chip layout.

[0098] The balun can further be tuned by one or more additional components such as a shunt capacitor between the second and third ports, a series capacitor at the first port, and / or a shunt capacitor at the first port.

[0099] The balun here can be used in a wide variety of applications including applications for converting (or vice versa) a single-ended signal to a differential signal at the input and / or output of an amplifier such as a power amplifier (PA), a low noise amplifier (LNA), and / or a variable gain amplifier (VGA). Further, the balun can be an on-chip fabricated using various chip manufacturing processes including but not limited to a silicon-on-insulator (SOI) process.

[0100] In a given implementation example here, the balun is configured to handle RF signals in the 5G frequency range 2 (FR2), such as from 24.25 GHz to 52.6 GHz. However, the balun here can also handle other RF signal frequencies.

[0101] FIG. 3A is a schematic diagram of a balun 230 with an integrated matching network according to an embodiment. The balun 230 includes a first pair of coupling lines 211, a second pair of coupling lines 212, a transmission line 213 (also referred to as a transmission line section), a first port 221, a second port 222, and a third port 223. The first port 221 serves as an unbalanced terminal for an unbalanced RF signal, the second port 222 serves as a positive terminal for a balanced RF signal, and the third port 223 serves as a negative terminal for a balanced RF signal.

[0102] As shown in FIG. 3A, the first pair of coupling lines 211 includes a first line 215 and a second line 216 that are electromagnetically coupled to each other (e.g., inductively coupled by the proximity arrangement of conductive lines). In addition, the second pair of coupling lines 212 includes a first line 217 and a second line 218 that are electromagnetically coupled to each other. While the first port 221 is connected to the first end of the first line 215, the second end of the first line 215 is connected to the first end of the transmission line 213. In addition, while the first end of the second line 216 is connected to a reference voltage (ground in this example), the second end of the second line 216 is connected to the second port 222. Further, while the first end of the first coupling line 217 is connected to the second end of the transmission line 213, the second end of the first line 217 is connected to the reference voltage. In addition, while the first end of the second coupling line 218 is connected to the third port 223, the second end of the second line 218 is connected to the reference voltage.

[0103] Accordingly, the first port 221 is connected to the reference voltage via the series connection of the first line 215 of the first pair of coupling lines 211, the transmission line 213, and the first line 217 of the second pair of coupling lines 212. Further, while the second port 222 is connected to the reference voltage via the second line 216 of the first pair of coupling lines 211, the third port 223 is connected to the reference voltage via the second line 218 of the second pair of coupling lines 212.

[0104] The even-mode impedance, odd-mode impedance, and length (Z e1 , Z o1 , length 1) of the first pair of coupled lines 211 can be adjusted separately from the even-mode impedance, odd-mode impedance, and length (Z e2 , Z o2 , length 2) of the second pair of coupled lines 212 during design. Further, the impedance and length (Z O-c , length c) of the transmission line 213 can also be adjusted separately during design.

[0105] Therefore, the balun 230 can be designed very quickly with a desired differential impedance at a given frequency and bandwidth.

[0106] The balun 230 can be designed in various ways. In one embodiment, the balun is initially designed by a pair of identical coupled lines. If EM simulation shows that there is an imbalance between the positive and negative terminals, the balance can be improved by changing one of the coupled line parameters (Z e , Z o , length). For example, if |S 31 | < |S 21 |, the balance is improved by increasing the coupling of the second pair of coupled lines 212. In another example, if the phase (S 31 ) - phase (S 21 ) is less than 180 degrees, the balance can be improved by increasing the length of length 2 of the second pair of coupled lines 212.

[0107] FIG. 3B is a schematic diagram of a balun 240 with an integrated matching network according to another embodiment.

[0108] The balun 240 in FIG. 3B is similar to the balun 230 in FIG. 3A, except that the balun 240 further includes a series capacitor 231 connected between the first port 221 and the first line 215 of the first pair of coupled lines 211.

[0109] Figure 3C is a schematic diagram of a balun 250 provided with an integrated matching network according to another embodiment.

[0110] The balun 250 in FIG. 3C is similar to the balun 230 in FIG. 3A, but the balun 250 is different in that it further includes a shunt capacitor 232 connected between the second port 222 and the third port 223.

[0111] Figure 3D is a schematic diagram of a balun 260 provided with an integrated matching network according to another embodiment.

[0112] The balun 260 in FIG. 3D is similar to the balun 230 in FIG. 3A, but the balun 260 is different in that it further includes a shunt capacitor 233 connected between the first port 221 and the reference voltage.

[0113] Figure 3E is a schematic diagram of a balun 270 provided with an integrated matching network according to another embodiment.

[0114] The balun 270 in FIG. 3E is similar to the balun 230 in FIG. 3A, but the balun 270 is different in that it further includes a series capacitor 231 connected between the first port 221 and the first line 215 of the first pair of coupling lines 211, and a shunt capacitor 232 connected between the second port 222 and the third port 223.

[0115] Referring to FIGS. 3B through 3E, one or more additional components can be added to the balun structure for the purpose of performance improvement such as matching improvement and / or wide bandwidth.

[0116] Despite the various examples of components, or various combinations of components, that have been depicted, a wide variety of components can be added to the balun here to obtain performance modification and / or improvement. That is, although four examples of additional components have been depicted in FIGS. 3B through 3E, other examples are possible.

[0117] FIG. 4 is a schematic diagram of a metallization layout for a balun 550 with an integrated matching network according to another embodiment. The metallization layout can be implemented on a semiconductor die including a first metal layer 501, a second metal layer 502, a third metal layer 503, and a fourth metal layer 504.

[0118] The balun 550 includes a first pair of bond lines 511, a second pair of bond lines 512, a transmission line 513, a first port 521, a second port 522, a third port 523, and a ground network 515.

[0119] In the illustrated embodiment, the bond lines are vertically coupled, for example, using vertical metal lines on adjacent metal layers or omitting one or more intervening metal layers. In other implementation examples, horizontal coupling is used (e.g., spaced-apart metal conductors on a common metal layer are used).

[0120] The transmission line section 513 includes a helix or coil 514 in this embodiment. Implementing the transmission line section 513 in this manner achieves a compact layout.

[0121] FIG. 5 is a schematic diagram of a radio frequency (RF) amplification system 510 according to one embodiment. The RF amplification system 510 includes a cascade of an input balun 601 and an RF amplifier 604.

[0122] In the illustrated embodiment, the input balun 601 converts a single-ended RF input signal RF IN (or unbalanced signal U) into a differential RF input signal. In addition, the RF amplifier 604 amplifies the differential RF input signal to generate an RF output signal RF OUT . This RF output signal RF OUT may be single-ended or differential as illustrated.

[0123] FIG. 6 is a schematic diagram of an RF amplification system 620 according to another embodiment. The RF amplification system 620 includes a cascade of an RF amplifier 614 and an output balun 611.

[0124] In the illustrated embodiment, the RF amplifier 614 amplifies the RF input signal RF IN . The RF input signal RF IN may be single-ended or differential as illustrated. The RF amplifier 614 provides a single-ended RF output signal to the output balun 611. The output balun 611 converts this single-ended RF output signal into a differential RF output signal RF OUT .

[0125] FIG. 7 is a schematic diagram of an RF amplification system 630 according to another embodiment. The RF amplification system 630 includes a cascade of an input balun 621, an RF amplifier 624, and an output balun 622.

[0126] In the illustrated embodiment, the input balun 621 converts a single-ended RF input signal RF IN into a differential RF input signal. In addition, the RF amplifier 624 amplifies the differential RF input signal to generate a differential RF output signal. Further, the output balun 622 converts the differential RF output signal into a single-ended RF output signal RF OUT .

[0127] Any of the baluns here can be implemented in the use cases of FIGS. 5 to 7. Despite the example of the use case of the balun being depicted, the baluns here can also be used in electronic systems of other configurations.

[0128] FIG. 8 is a schematic diagram of an embodiment of a portable device 800. The portable device 800 includes a baseband system 801, a transceiver 802, a front-end system 803, an antenna 804, a power management system 805, a memory 806, a user interface 807, and a battery 808.

[0129] The mobile device 800 can be used to communicate using a variety of communication technologies including, but not limited to, 2G, 3G, 4G (LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (e.g., Wi-Fi), WPAN (e.g., Bluetooth® and ZigBee®), WMAN (e.g., WiMax), and / or GPS technology.

[0130] The transceiver 802 generates RF signals for transmission and processes incoming RF signals received from the antenna 804. As will be appreciated, the various functions associated with the transmission and reception of RF signals can be accomplished by one or more components collectively represented as the transceiver 802 in FIG. 8. In one example, separate components (e.g., separate circuits or dies) may be provided to handle a given type of RF signal.

[0131] The front-end system 803 assists in conditioning signals transmitted to and / or received from the antenna 804. In the illustrated embodiment, the front-end system 803 includes one or more phase shifters 810, a power amplifier (PA) 811, a low-noise amplifier (LNA) 812, a filter 813, a switch 814, and a balun 815.

[0132] Furthermore, one or more baluns 815 can be used in combination with any of these components to provide single-ended to differential or reverse signal conversion. Such baluns can be implemented according to any of the embodiments herein.

[0133] The front-end system 803 can provide a number of functions including, but not limited to, amplification of transmitted signals, amplification of received signals, filtering of signals, switching between different bands, switching between different power modes, switching between transmit and receive modes, duplexing of signals, multiplexing of signals (e.g., diplexing or triplexing), or any combination thereof.

[0134] The mobile device 800 operates with beamforming. For example, the front-end system 803 includes a phase shifter 810 that is variably phase-controlled by the transceiver 802. In a given implementation example, the transceiver 802 controls the phase of the phase shifter 810 based on the data received from the processor 801.

[0135] The phase shifter 810 is controlled to provide beamforming and directivity for signal transmission and / or reception using the antenna 804. For example, in the context of signal transmission, the phase of the transmission signal applied to the antenna array used for transmission is controlled such that the transmitted signals are combined using constructive and destructive interference, generating an aggregated transmission signal that exhibits qualities such as a strong signal intensity propagating in a given direction. In the context of signal reception, the phase is controlled such that more signal energy is received when the signal arrives at the antenna array from a specific direction.

[0136] In a given implementation example, since the mobile device 800 supports carrier aggregation, flexibility is obtained to increase the peak data rate. Carrier aggregation can be used for both frequency-division duplexing (FDD) and time-division duplexing (TDD), and thus may be used to aggregate (aggregate) multiple carriers or channels. Carrier aggregation includes adjacent aggregation in which contiguous carriers are aggregated within the same operating frequency band. Carrier aggregation may be discontinuous and may include carriers with separated frequencies within a common band or different bands.

[0137] The antenna 804 may include antennas used for a variety of types of communication. For example, the antenna 804 may include antennas for signal transmission and / or reception associated with a variety of frequencies and communication standards.

[0138] In certain implementations, the antennas 804 support MIMO and / or switched diversity communications. For example, MIMO communications use multiple antennas to communicate multiple data streams over a single radio frequency channel. MIMO communications benefit from high signal-to-noise ratios, improved coding, and / or reduced signal interference due to spatial multiplexing in the wireless environment. Switched diversity refers to communications in which a particular antenna is selected to operate at a particular time. For example, a switch can be used to select a particular antenna from a group of antennas based on various factors such as an observed bit error rate and / or signal strength indicator.

[0139] In certain implementations, antenna 804 includes one or more arrays of antenna elements to enhance beamforming.

[0140] The baseband system 801 is coupled to a user interface 807 that facilitates the processing of various user inputs and outputs (I / O), such as voice and data. The baseband system 801 provides a digital representation of a transmit signal to the transceiver 802, which processes it to generate an RF signal for transmission. The baseband system 801 also processes a digital representation of a receive signal that is provided by the transceiver 802. As shown in FIG. 8, the baseband system 801 is coupled to a memory 806 to facilitate operation of the mobile device 800.

[0141] The memory 806 may be used for a wide variety of purposes, such as storing data and / or instructions to facilitate operation of the mobile device 800 and / or provide storage of user information.

[0142] The power management system 805 provides a certain number of power management functions for the portable device 800. In a given implementation example, the power management system 805 includes a PA supply control circuit that controls the supply voltage of a plurality of power amplifiers 811. For example, the power management system 805 may be configured to vary the supply voltage provided to one or more of the plurality of power amplifiers 811 in order to improve efficiency such as power added efficiency (PAE).

[0143] As shown in FIG. 8, the power management system 805 receives a battery voltage from the battery 808. The battery 808 may be any suitable battery, such as a lithium-ion battery, for use in the portable device 800.

[0144] Application

[0145] The principles and advantages of the embodiments described herein can be used for a wide variety of applications.

[0146] For example, the balance can be included in various electronic devices including, but not limited to, consumer electronics products, electronic test equipment for consumer electronics products, etc. Examples of electronic devices include base stations, wireless network access points, mobile phones (e.g., smartphones), tablets, televisions, computer monitors, computers, handheld computers, personal digital assistants (PDAs), microwave ovens, refrigerators, automobiles, stereo systems, disc players, digital cameras, portable memory chips, washing machines, dryers, copiers, facsimile machines, scanners, multifunction peripheral devices, wristwatches, desk clocks, etc. Further, the electronic devices may include unfinished products.

[0147] Summary

[0148] Unless the context clearly requires otherwise, throughout the specification and claims, terms like "comprises," "comprises," and the like should be interpreted in an inclusive sense, i.e., "including, but not limited to," as opposed to an exclusive or exhaustive sense. The term "coupled," as generally used herein, refers to two or more elements being connected either directly or via one or more intermediate elements. Similarly, the term "connected," as generally used herein, also refers to two or more elements being connected either directly or via one or more intermediate elements. Additionally, when used in this application, the terms "herein," "above," "below," and words of similar import shall refer to this application as a whole, and not to any particular portions of this application. Where the context permits, terms in the above Detailed Description using singular or plural numbers may also include the plural or singular number, respectively. The terms "or" and "or" referring to a list of two or more items cover all of the following interpretations of that term: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0149] Furthermore, unless specifically stated or understood otherwise within the context of use, conditional language used herein, such as "can," "could," "may," "might," "for example," "such as," and the like, among others, generally intends that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not. That is, such conditional language is generally not intended to imply that features, elements, and / or conditions are present in any manner required in one or more embodiments, or that one or more embodiments necessarily include logic that determines, with or without authorial input or prompting, whether or not those features, elements, and / or conditions are included or should be performed in any particular embodiment.

[0150] The above description of the embodiments of the present invention is not intended to be exhaustive or to limit the invention to the exact form disclosed. Specific embodiments and examples of the present invention have been described above for illustrative purposes, but as will be recognized by those skilled in the art, various equivalent modifications are possible within the scope of the present invention. For example, while a process or block is presented in a given order, alternative embodiments can execute a routine having steps in a different order or use a system having blocks, and some processes or blocks can be deleted, moved, added, subdivided, combined, and / or modified. These processes or blocks can each be implemented in a variety of different manners. Also, while a process or block may be shown as being executed serially, these processes or blocks may instead be executed in parallel or at different times.

[0151] The teachings of the present invention provided herein can be applied to other systems that are not necessarily the systems described above. The elements and acts of the various embodiments described above may be combined to provide further embodiments.

[0152] Although certain embodiments of the present invention have been described, these embodiments have been presented by way of example only and are not intended to limit the scope of the disclosure. In fact, the novel methods and systems described herein may be embodied in a variety of other forms, and furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the disclosure.

Claims

1. A balun, comprising: a first pair of coupling lines including a first conductive line and a second conductive line; a second pair of coupling lines including a third conductive line and a fourth conductive line; a transmission line connecting the first conductive line of the first pair of coupling lines to the third conductive line of the second pair of coupling lines; wherein the first pair of coupling lines and the second pair of coupling lines have different lengths, different odd-mode impedances, and different even-mode impedances; and the transmission line includes a coil.

2. The balun according to claim 1, further comprising: a first port connected to one end of the first conductive line on the side opposite to the transmission line; a second port connected to the second conductive line of the first pair of coupling lines; and a third port connected to the fourth conductive line of the second pair of coupling lines.

3. The first port serves as an unbalanced terminal for a single-ended signal; the second port serves as a positive terminal for a differential signal; and the third port serves as a negative terminal for the differential signal.

4. The balun according to claim 2, wherein one end of the third conductive line on the side opposite to the transmission line is connected to a reference voltage.

5. The balun according to claim 2, wherein one end of the second conductive line on the side opposite to the second port is connected to a reference voltage.

6. The balun according to claim 2, wherein one end of the fourth conductive line on the side opposite to the third port is connected to a reference voltage.

7. A wireless device, comprising: a transceiver; and a front-end system coupled to the transceiver; wherein the front-end system includes a balun; and the balun includes a first pair of coupling lines including a first conductive line and a second conductive line; a second pair of coupling lines including a third conductive line and a fourth conductive line; and a transmission line connecting the first conductive line of the first pair of coupling lines to the third conductive line of the second pair of coupling lines; wherein the first pair of coupling lines and the second pair of coupling lines have different lengths, different odd-mode impedances, and different even-mode impedances; and the transmission line includes a coil.

8. The wireless device according to claim 7, wherein the balun further includes: a first port connected to one end of the first conductive line on the side opposite to the transmission line; a second port connected to the second conductive line of the first pair of coupling lines; and a third port connected to the fourth conductive line of the second pair of coupling lines.

9. The front-end system further includes an amplifier configured to provide a single-ended signal to the first port, the wireless device of claim 8.

10. The front-end system further includes an amplifier configured to provide a differential signal to the second port and the third port, the wireless device of claim 8.

11. The first pair of coupling lines, the second pair of coupling lines, and the transmission line are operable to provide input matching to the amplifier, the wireless device of claim 9 or 10.

12. The first pair of coupling lines, the second pair of coupling lines, and the transmission line are operable to provide output matching to the amplifier, the wireless device of claim 9 or 10.

13. A method for signal conversion in a balun, providing a coupling between a first conductive line and a second conductive line of a first pair of coupling lines, providing a coupling between a third conductive line and a fourth conductive line of a second pair of coupling lines, providing a signal path through a transmission line from the first conductive line of the first pair of coupling lines to the third conductive line of the second pair of coupling lines comprising, the first pair of coupling lines and the second pair of coupling lines have different lengths, different odd-mode impedances, and different even-mode impedances, the transmission line includes a coil, the method.

14. The balun further includes, a first port connected to one end of the first conductive line on the side opposite to the transmission line, a second port connected to the second conductive line of the first pair of coupling lines, a third port connected to the fourth conductive line of the second pair of coupling lines comprising, the method of claim 13.

15. further comprising providing input matching to an amplifier configured to provide a single-ended signal to the first port or an amplifier configured to provide a differential signal to the second port and the third port using the first pair of coupling lines, the second pair of coupling lines, and the transmission line, the method of claim 14.

16. further comprising providing output matching to an amplifier configured to provide a single-ended signal to the first port or an amplifier configured to provide a differential signal to the second port and the third port using the first pair of coupling lines, the second pair of coupling lines, and the transmission line, the method of claim 14.

17. further comprising providing a single-ended signal to the first port using an amplifier, the method of claim 14.

18. The method of claim 14, further comprising applying a differential signal to the second port and the third port using an amplifier.

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