Radio frequency transmission line structure across printed circuit boards

Abstract

This disclosure relates to radio frequency (RF) transmission line structures across printed circuit boards. An electronic device may include one or more radio components and one or more antennas. RF transmission lines couple the radio components to corresponding antennas. To form RF transmission lines more efficiently, the RF transmission lines may be formed by interconnecting conductive traces distributed among multiple printed circuit boards. By integrating the transmission line structures onto printed circuit boards that also perform other functions, the device may require less space to implement the RF transmission lines. While one or more of these printed circuit boards may individually be unsuitable for implementing RF transmission lines with a specific impedance, the combined impedance of these transmission line structures across these printed circuit boards, when properly configured, can provide RF transmission lines with that specific impedance.

Description

[0001] This application claims priority to U.S. Patent Application No. 17 / 380491, filed July 20, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to electronic devices, including electronic devices having wireless circuitry. Background Technology

[0003] Electronic devices often possess wireless capabilities. Wireless electronic devices have wireless circuitry, which includes one or more antennas and one or more radio components, wherein corresponding radio frequency transmission lines transmit radio frequency signals between the antennas and the radio components.

[0004] Radio frequency (RF) transmission lines are typically implemented using coaxial cables. However, coaxial cables and their corresponding connectors are bulky and consume excessive space within electronic devices. Therefore, designing compact electronic devices while still providing transmission lines with satisfactory performance can be challenging. Summary of the Invention

[0005] Electronic devices may include wireless circuits having one or more radio components and one or more antennas. Radio frequency (RF) transmission lines can couple each antenna to the corresponding radio component. RF transmission lines can be integrated into a printed circuit structure across one or more overlapping printed circuits. If desired, these printed circuits may include flexible printed circuits, rigid printed circuit boards, interposers, package substrates, etc.

[0006] Conductive structures interconnected by solder or other conductive interconnects between these printed circuits can form portions of an RF transmission line. Each portion of the RF transmission line can individually exhibit an impedance offset from the target (composite or collective) impedance of the overall RF transmission line. By controlling the configuration of each printed circuit in the printed circuit (e.g., the thickness of conductive and insulating layers), the configuration between printed circuits (e.g., between conductive structures in the printed circuit) (e.g., distance), and the configuration of the printed circuits relative to other adjacent structures (e.g., structures or components adjacent to one or more of these printed circuits), these portions of the RF transmission line can collectively exhibit a target impedance appropriately impedance-matched for coupling radio components to an antenna and for operation of the overall RF transmission line at one or more corresponding operating frequencies.

[0007] RF transmission lines configured in this way can transmit RF signals to and from the antenna without mismatch loss. Therefore, since the RF transmission line itself inherently acts as an impedance matching structure, discrete components, such as inductors and capacitors used for impedance matching (e.g., impedance matching structures external to the printed circuit structure forming the RF transmission line), can be omitted. In other words, impedance mismatches between different portions of the RF transmission line (with respect to the target impedance) are not matched using discrete components. Instead, different portions of the RF transmission line on different printed circuits are configured or tuned relative to each other (e.g., by adjusting layer thickness, inter-layer spacing, layer geometry, layer materials, etc.) to directly achieve signal transmission without mismatch loss.

[0008] In this way, electronic devices can integrate RF transmission line structures using printed circuit structures (e.g., printed circuits that can also be used for other functions in electronic devices). This eliminates the need for bulky RF transmission line structures (e.g., coaxial cables and their connectors) and provides compact RF transmission lines with satisfactory performance. As an illustrative example and as described further in detail herein, the satisfactory performance of the RF transmission line is characterized at least by the impedance matching between the RF transmission line and the coupled antenna.

[0009] One aspect of this disclosure provides a radio frequency (RF) transmission line structure. The RF transmission line structure may exhibit composite impedance and may include a first printed circuit and a second printed circuit. The first printed circuit may have a first substrate and a first conductive trace on the first substrate. The first conductive trace may exhibit a first impedance. The second printed circuit may have a second substrate and a second conductive trace on the second substrate. The second conductive trace may exhibit a second impedance. The second printed circuit may at least partially overlap with the first printed circuit and may be separated from the first printed circuit by a certain distance. The first impedance, the second impedance, and the distance separating the second printed circuit from the first printed circuit may collectively define the composite impedance of the RF transmission line structure.

[0010] One aspect of this disclosure provides a radio frequency (RF) transmission line. The RF transmission line may include a signal conductor and a ground conductor. The signal conductor may include a first signal trace on a first printed circuit and a second signal trace on a second printed circuit. The ground conductor may include a first ground trace on a first printed circuit and a second ground trace on a second printed circuit. The first signal trace and the first ground trace on the first printed circuit may exhibit a first impedance. The second signal trace and the second ground trace on the second printed circuit may exhibit a second impedance. The RF transmission line may exhibit a characteristic impedance that is different from both the first and second impedances.

[0011] One aspect of this disclosure provides an electronic device. The electronic device may include radio components, an antenna, a first printed circuit board substrate, a second printed circuit board substrate at least partially overlapping the first printed circuit board substrate, and a radio frequency (RF) transmission line communicatively coupling the radio components to the antenna. The RF transmission line may have a first transmission line portion on the first printed circuit board substrate and a second transmission line portion on the second printed circuit board substrate. The first transmission line portion may exhibit a first impedance. The second transmission line portion may exhibit a second impedance. The RF transmission line may exhibit a collective impedance that is different from both the first and second impedances. Attached Figure Description

[0012] Figure 1 It is a block diagram of an exemplary electronic device with wireless circuitry according to some implementation schemes.

[0013] Figure 2 It is a block diagram of an exemplary wireless circuit with a transmission line structure according to some implementation schemes.

[0014] Figure 3 It is a cross-sectional view of an exemplary transmission line structure formed across multiple stacked substrates according to some implementation schemes.

[0015] Figure 4 This is a cross-sectional view of an exemplary system-in-package with wireless circuitry and transmission line structures according to some implementation schemes.

[0016] Figure 5 This is an exploded perspective view of an exemplary substrate and conductive structure for forming a transmission line structure for a radio frequency transmission line, based on some implementation schemes.

[0017] Figure 6 This is an exemplary side view of the substrate and conductive structure of the assembly forming the transmission line structure according to some implementation schemes.

[0018] Figure 7 This is a diagram of an exemplary electronic device that uses multiple stacked substrates to implement a transmission line structure for wireless circuits according to some implementation schemes. Detailed Implementation

[0019] Figure 1The electronic device 10 may be: a computing device, such as a laptop computer, desktop computer, computer monitor containing an embedded computer, tablet computer, cellular phone, media player, or other handheld or portable electronic device; a smaller device, such as a wristwatch, a hanging device, a headset or handset device (such as earbuds, a set of earbuds, or a set of earbuds with a corresponding housing for accommodating earbuds), a device embedded in glasses; or other equipment worn on the user's head; or other wearable or micro-devices, televisions, computer monitors without an embedded computer, gaming devices, navigation devices, embedded systems (such as systems in which electronic equipment with a display is installed in a kiosk or vehicle), voice-controlled speakers connected to the wireless Internet, home entertainment devices, remote control devices, game controllers, peripheral user input devices, wireless base stations or access points, equipment that enables the functionality of two or more of these devices; or other electronic equipment.

[0020] like Figure 1 As shown in the functional block diagram, device 10 may include components located on or within an electronic device housing, such as housing 12. Housing 12 (sometimes referred to as a shell) may be formed of plastic, glass, ceramic, fiber composite material, metal (e.g., stainless steel, aluminum, metal alloys, etc.), other suitable materials, or combinations of these materials. In some cases, housing 12 may be partially or entirely formed of dielectric or other low-conductivity materials (e.g., glass, ceramic, plastic, sapphire, etc.). In other cases, housing 12 or at least some of the structures constituting housing 12 may be formed of metallic elements.

[0021] Device 10 may include control circuitry 14. Control circuitry 14 may include storage devices, such as storage circuitry 16. Storage circuitry 16 may include hard disk drive storage devices, non-volatile memory (e.g., flash memory configured to form a solid-state drive or other electrically programmable read-only memory), volatile memory (e.g., static random access memory or dynamic random access memory), etc. Storage circuitry 16 may include storage devices and / or removable storage media integrated within device 10.

[0022] Control circuitry 14 may include processing circuitry, such as processing circuitry 18. Processing circuitry 18 may be used to control the operation of device 10. Processing circuitry 18 may include one or more processors, microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application-specific integrated circuits, central processing units (CPUs), etc. Control circuitry 14 may be configured to perform operations in device 10 using hardware (e.g., dedicated hardware or circuitry), firmware, and / or software. Software code for performing operations in device 10 may be stored on storage circuitry 16 (e.g., storage circuitry 16 may include a non-transitory (tangible) computer-readable storage medium storing software code). This software code may sometimes be referred to as program instructions, software, data, commands, or code. The software code stored on storage circuitry 16 may be executed by processing circuitry 18.

[0023] Control circuitry 14 can be used to run software on device 10, such as satellite navigation applications, internet browsing applications, Voice over Internet Protocol (VoIP) telephone calling applications, email applications, media playback applications, operating system functions, etc. To support interaction with external equipment, control circuitry 14 can be used to implement communication protocols. Communication protocols that can be implemented using control circuitry 14 include Internet Protocol, Wireless Local Area Network (WLAN) protocols (e.g., IEEE 802.11 protocol—sometimes referred to as...). ), such as Protocols such as those used for other short-range wireless communication links, including wireless personal area network (WPAN) protocols, IEEE 802.11ad protocols (e.g., ultra-wideband protocols), cellular phone protocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP fifth-generation (5G) new radio (NR) protocols, etc.), antenna diversity protocols, satellite navigation system protocols (e.g., Global Positioning System (GPS) protocols, Global Navigation Satellite System (GLONASS) protocols, etc.), antenna-based spatial ranging protocols (e.g., radio detection and ranging (RADAR) protocols or other desired distance detection protocols for signals transmitted at millimeter-wave and centimeter-wave frequencies), or any other desired communication protocol. Each communication protocol may be associated with a corresponding radio access technology (RAT), which specifies the physical connection method used to implement the protocol.

[0024] Device 10 may include input-output circuitry 20. Input-output circuitry 20 may include input-output devices 22. Input-output devices 22 may be used to allow data to be supplied to device 10 and to allow data to be supplied from device 10 to external devices. Input-output devices 22 may include user interface devices, data port devices, and other input-output components. For example, input-output devices 22 may include touch sensors, displays (e.g., touch-sensitive displays and / or force-sensitive displays), light-emitting components such as displays without touch sensor capability, buttons (mechanical, capacitive, optical, etc.), scroll wheels, touchpads, keypads, keyboards, microphones, cameras, buttons, speakers, status indicators, audio jacks and other audio port components, digital data port devices, motion sensors (accelerometers, gyroscopes, and / or compasses for detecting motion), capacitive sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), temperature sensors, etc. In some configurations, keyboards, headphones, displays, pointing devices such as touchpads, mice and joysticks, and other input-output devices may be coupled to device 10 via wired or wireless connections (e.g., some input-output devices in input-output devices 22 may be peripheral devices coupled to the main processing unit or other parts of device 10 via wired or wireless links).

[0025] Input-output circuitry 20 may include wireless circuitry 24 to support wireless communication and / or radio-based spatial ranging operations. Wireless circuitry 24 may include one or more antennas 30. Wireless circuitry 24 may also include one or more radio components 26. Each radio component 26 may include circuitry for operating signals at a baseband frequency (e.g., baseband processor circuitry), signal generator circuitry, modulation / demodulation circuitry (e.g., one or more modems), radio frequency transceiver circuitry (e.g., radio frequency transmitter circuitry, radio frequency receiver circuitry, mixer circuitry for downconverting radio frequency signals to a baseband frequency or an intermediate frequency between radio frequency and baseband and / or upconverting signals at a baseband frequency or intermediate frequency to radio frequency), amplifier circuitry (e.g., one or more power amplifiers and / or one or more low-noise amplifiers (LNAs)), analog-to-digital converter (ADC) circuitry, digital-to-analog converter (DAC) circuitry, control paths, power paths, signal paths (e.g., radio frequency transmission lines, intermediate frequency transmission lines, baseband signal lines, etc.), switching circuitry, filter circuitry, and / or any other circuitry that uses antenna 30 to transmit and / or receive radio frequency signals. Each component of radio component 26 can be mounted on a corresponding substrate or integrated into a corresponding integrated circuit, chip, package (e.g., system-in-package), or system-on-a-chip (SoC). If desired, components of multiple radio components 26 can share a single substrate, integrated circuit, chip, package, or SoC.

[0026] Antenna 30 can be formed using any desired antenna structure. For example, antenna 30 may include antennas with resonant elements, formed from loop antenna structures, patch antenna structures, inverted F-shaped antenna structures, slot antenna structures, planar inverted F-shaped antenna structures, helical antenna structures, monopole antennas, dipoles, hybrids of these designs, etc. Adjustable filter circuits, switching circuits, impedance matching circuits, and / or other antenna tuning components can be used to adjust the frequency response and wireless performance of antenna 30 over time.

[0027] The transceiver circuitry in radio component 26 may use one or more antennas 30 to transmit radio frequency (RF) signals (e.g., antennas 30 may transmit RF signals for the transceiver circuitry). As used herein, the term "transmit RF signals" means the transmission and / or reception of RF signals (e.g., for performing one-way and / or two-way wireless communication with external wireless communication equipment). Antenna 30 may transmit RF signals by radiating them into free space (or through an intermediary device structure such as a dielectric overlay). Alternatively or otherwise, antenna 30 may receive RF signals from free space (e.g., through an intermediary device structure such as a dielectric overlay). The transmission and reception of RF signals by antenna 30 each involve the excitation or resonance of antenna currents on antenna resonant elements in the antenna by RF signals within the antenna's operating frequency band.

[0028] Radio component 26 can use antenna 30 to transmit and / or receive radio frequency signals in different frequency bands of radio frequency (sometimes referred to herein as communication bands or simply "bands"). The frequency bands processed by radio component 28 may include wireless local area network (WLAN) bands (e.g., (IEEE 802.11) or other WLAN communication bands, such as the 2.4 GHz WLAN band (e.g., 2400 MHz to 2480 MHz), the 5 GHz WLAN band (e.g., 5180 MHz to 5825 MHz), 6E band (e.g., 5925MHz to 7125MHz) and / or others Frequency bands (e.g., 1875MHz to 5160MHz); Wireless Personal Area Network (WPAN) frequency bands such as 2.4GHz Frequency bands or other WPAN communication bands; cellular telephone bands (e.g., bands from about 600 MHz to about 5 GHz, 3G bands, 4G LTE bands, 5G NR frequency range 1 (FR1) band below 10 GHz, 5G NR frequency range 2 (FR2) band between 20 GHz and 60 GHz, etc.); other centimeter or millimeter wave bands between 10 GHz and 300 GHz; near field communication (NFC) bands (e.g., 13.56 MHz); satellite navigation bands (e.g., GPS bands from 1565 MHz to 1610 MHz, GLONASS bands, BeiDou Navigation Satellite System (BDS) bands, etc.); ultra-wideband (UWB) bands operating under the IEEE 802.15.4 protocol and / or other ultra-wideband communication protocols; communication bands under the 3GPP wireless communication standard family; communication bands under the IEEE 802.XX standard family, and / or any other desired bands of interest.

[0029] Each radio component 26 may transmit and / or receive radio frequency signals according to a corresponding radio access technology (RAT) that determines the physical connection method for the components in the corresponding radio component. If desired, one or more radio components 26 may implement multiple RATs. As an example only, the radio components 26 in device 10 may include a UWB radio component for transmitting UWB signals using one or more antennas 30, a Bluetooth (BT) radio component for transmitting BT signals using one or more antennas 30, a Wi-Fi radio component for transmitting WLAN signals using one or more antennas 30, a cellular radio component for transmitting cellular phone signals using one or more antennas 30 (e.g., in the 4G band, 5G FR1 band, and / or 5G FR2 band), an NFC radio component for transmitting NFC signals using one or more antennas 30, and a wireless charging radio component for receiving wireless charging signals using one or more antennas 30 for charging the battery on device 10. This example is merely illustrative, and in general, radio components 26 may include any desired combination of radio components to cover any desired combination of RATs.

[0030] Radio component 26 may use antenna 30 to transmit and / or receive radio frequency signals, which are used to transmit wireless communication data between device 10 and external wireless communication equipment such as one or more electronic devices 10' (e.g., one or more other devices, such as device 10, a wireless access point, or a base station) via communication link 32. Wireless communication data may be transmitted bidirectionally or unidirectionally by radio component 26. Wireless communication data may include, for example, data encoded into corresponding data packets, such as wireless data associated with telephone calls, streaming media content, internet browsing, wireless data associated with software applications running on device 10, email messages, etc. Radio component 26 may also use antenna 30 to perform spatial ranging operations (e.g., to identify the distance between device 10 and external objects). If desired, radio component 26 performing spatial ranging operations may include radar circuitry (e.g., frequency modulated continuous wave (FMCW) radar circuitry, OFDM radar circuitry, FSCW radar circuitry, phase-coded radar circuitry, other types of radar circuitry).

[0031] Configurations in which device 10 is a headset, earphone, handset, or earbud are sometimes described herein as illustrative examples. In these configurations, device 10 performing wireless communication with one or more devices 10' may include device 10 being the master device of an accessory (e.g., a laptop computer, desktop computer, tablet computer, cellular phone, etc.). In an illustrative configuration where device 10 is an earbud in one ear of a user, device 10 may perform wireless communication with device 10', which may be an earbud in the other ear of the user. These configurations of devices 10 and 10' are merely illustrative. Devices 10 and 10' may include any number of electronic devices that communicate wirelessly with each other, if desired.

[0032] Figure 1 The examples are merely illustrative. Although for clarity, in Figure 1 In the example, control circuitry 14 is shown separate from wireless circuitry 24, but wireless circuitry 24 may include processing circuitry (e.g., one or more processors) and / or storage circuitry, the processing circuitry forming part of processing circuitry 18, and the storage circuitry forming part of storage circuitry 16 of control circuitry 14 (e.g., portions of control circuitry 14 may be implemented on wireless circuitry 24). Wireless circuitry 24 may include any desired number of antennas 30. Some or all of the antennas 30 in wireless circuitry 24 may be arranged as one or more phase-controlled antenna arrays (e.g., for transmitting radio frequency signals over a steerable signal beam). If desired, antennas 30 may be operated using multiple-input multiple-output (MIMO) schemes and / or carrier aggregation (CA) schemes.

[0033] Figure 2 yes Figure 1Functional block diagram of wireless circuit 24. (See attached diagram.) Figure 2 As shown, each radio component 26 can be coupled to one or more antennas 30 via one or more radio frequency transmission lines 36 (communication ground). As an illustrative example, each radio frequency transmission line 36 may include a ground conductor such as a ground conductor 38 and a signal conductor such as a signal conductor 40. The corresponding antenna 30 may include an antenna feed section such as an antenna feed section 46 having a ground antenna feed terminal 42 coupled to the ground conductor 38 and a positive antenna feed terminal 44 coupled to the signal conductor 40.

[0034] If necessary, one or more radio frequency transmission lines 36 may be shared between radio component 26 and / or antenna 30. A radio frequency front-end (RFFE) module may be interposed on one or more RF transmission lines 36. The RFFE module may include a substrate, integrated circuit, chip, or package separate from the radio component 26, and may include filter circuitry, switching circuitry, amplifier circuitry, impedance matching circuitry, RF coupler circuitry, and / or any other desired RF circuitry for operating on RF signals transmitted through the RF transmission line 36.

[0035] Coaxial cables are typically used to implement radio frequency (RF) transmission lines. However, with a large number of radio components and antennas (covering an ever-increasing number of RATs and frequency bands), a wireless system with RF transmission lines implemented in this way must employ a large amount of coaxial cable and corresponding connector structures, which can be large and bulky. This configuration is particularly undesirable for smaller form factor devices with limited internal space. In these devices, even including a single coaxial cable connector structure may be impractical, let alone multiple coaxial cable connector structures. While other transmission line structures can be used alternatively, their use faces similar space constraints in these smaller form factor devices and may lead to a degradation in wireless performance if adopted in compact wireless systems. Therefore, it may be desirable to provide RF transmission lines in a compact manner (e.g., for smaller form factor devices or other devices) while providing satisfactory wireless performance in the wireless system.

[0036] To provide a compact RF transmission line structure, wireless circuit 24 ( Figure 2The device may include one or more radio frequency (RF) transmission lines 36, which are implemented by RF transmission line structures (e.g., signal traces, ground traces, etc.) spanning one or more substrates 50 (e.g., one or more printed circuit substrates). Since electronic devices (e.g., device 10) typically include other device components (e.g., storage circuitry 16, processing circuitry 18, radio components 26, etc.) mounted on the (printed circuit) substrate, integrating the RF transmission line structure into these printed circuit structures requires fewer additional bulky structures (e.g., compared to configurations using dedicated coaxial cable connections). While RF transmission line structures spanning a single printed circuit (substrate) can be used (e.g., forming a single RF transmission line), the single printed circuit may require certain dimensions (e.g., specific minimum thickness or size) and / or other specialized properties to configure the corresponding RF transmission line to exhibit desired or satisfactory impedance at the operating frequency. As an illustrative example, the desired or satisfactory impedance refers to a transmission line impedance that matches the corresponding antenna impedance (e.g., the same, within 0.01%, within 0.1%, within 1%, within 2%, within 5%, etc.). Relying on such dedicated printed circuitry can be undesirably limiting in terms of available device space, device cost, etc., especially for devices with smaller form factor.

[0037] Therefore, the wireless circuit 24 may include one or more radio frequency transmission lines 36, each formed by a structure on a plurality of substrates 50 in the device 10. By forming the radio frequency transmission lines 36 using transmission line structures on a plurality of such structures (e.g., printed circuit boards and / or other substrates), the device 10 can forgo the need for bulky and / or dedicated printed circuit boards (substrates), which may result in increased device size and / or increased cost. A configuration in which one or more radio frequency transmission lines 36 are each freely formed across a plurality of substrates 50 (e.g., printed circuit boards and / or other substrates) is described as an illustrative example.

[0038] The transmission line structure integrated onto one or more substrates 50 may include one or more substrates for rigid printed circuit boards and / or flexible printed circuits. As an example, a flexible printed circuit may include a flexible printed circuit substrate formed of polyimide, liquid crystal polymer, other flexible polymer materials, or other suitable materials. If desired, the flexible printed circuit may include a multilayer laminated structure (e.g., layers of conductive materials such as copper and dielectric materials such as resin, laminated together without an intermediary adhesive). If desired, the multilayer laminated structure may be folded or bent in multiple dimensions (e.g., two-dimensional or three-dimensional) and may retain its bent or folded shape after bending (e.g., the multilayer laminated structure may be folded into a specific three-dimensional structural shape for wiring around other device components and may be rigid enough to retain its shape after folding without being held in place by reinforcements or other structures). As another example, a rigid printed circuit board may include a (rigid) printed circuit substrate formed of a rigid printed circuit board material such as glass fiber-filled epoxy or a glass fiber-epoxy laminate, ceramic, other rigid polymer materials, or other suitable materials. If desired, the printed circuit substrate may be formed from one or more of these flexible and / or rigid materials (e.g., at different portions of the substrate).

[0039] The transmission line structure integrated onto one or more substrates 50 may include one or more substrates for any suitable system. As an exemplary example, these substrates may include package substrates, such as substrates to which one or more components of a package system and / or integrated circuit (IC) dies are mounted (e.g., implementing a system-in-package (SiP)), interposer substrates such as substrates in which conductive routing structures are formed to route signals between two or more IC dies, package systems, printed circuits, etc. (e.g., implementing an interposer), or any other substrate. Because both exemplary SiPs and exemplary interposers may include conductive (routing) traces, vias, and other structures, a SiP or interposer may sometimes be referred to herein as a printed circuit.

[0040] Figure 3 This is a cross-sectional view of a wireless circuit 24 having an exemplary transmission line structure integrated onto multiple substrates (e.g., formed by a structure spanning multiple substrates). Figure 3In the example, four exemplary substrates 52, 54, 56, and 58 are shown. Each of substrates 52, 54, 56, and 58 can be any suitable type of substrate as described above (e.g., rigid printed circuit board substrate, flexible printed circuit board substrate, hybrid rigid-flexible printed circuit board substrate, interposer substrate, package, or SiP substrate, etc.). Substrate 52 is coupled to (e.g., mounted to or stacked on) substrate 56 via intercalating or interposer substrate 54. Substrate 56 is coupled to (e.g., mounted to or stacked on) substrate 58. Conductive structures such as conductive traces, conductive vias, metal traces, metal layers, metal vias, interconnect layers, routing layers, etc., may be disposed on each of substrates 52, 54, 56, and 58 (e.g., embedded in one or more outer surfaces, disposed on one or more outer surfaces, or otherwise disposed on one or more portions) to form conductive paths within each substrate and for transmitting signals between different substrates.

[0041] The transmission line structure (e.g., one or more signal traces, one or more ground traces, etc.) that communicatively couples the radio component 26 to the antenna 40 can be formed by these conductive traces, conductive vias, or other conductive structures on each of the substrates 52, 54, 56, and 58. Figure 3 In this example, radio component 26 is coupled (e.g., using or not using other intermediary interconnect structures) to conductive traces on substrate 52, such as conductive trace 62. Conductive trace 62 forms a radio frequency transmission line (e.g., Figure 2 The first portion of the RF transmission line 36 in the substrate 52. One or more conductive vias, such as conductive vias 63, on the substrate 52 electrically connect the conductive trace 62 to corresponding external contacts on the substrate 52, such as contact pads 71 ​​(e.g., implemented as bonding pads, solder pads, etc.). The contact pads 71 ​​are electrically connected to conductive structures on substrates 56 and 58 (forming another part of the transmission line structure) via conductive structures on the intercalated substrate 54 (forming another part of the transmission line structure). If necessary, the substrate 54 can be omitted (e.g., the contact pads on substrates 52 and 56 can be directly connected to each other using conductive interconnect materials such as solder, conductive bumps, conductive adhesives, etc., without the need for separate intercalated conductive structures on the substrate).

[0042] In an exemplary configuration including base 54 (e.g.) Figure 3As shown), conductive structures on substrate 54, such as conductive routing structures 64 (e.g., implemented based on one or more conductive vertical vias, one or more conductive horizontal routing layers, and / or other conductive structures), route external connections on a first side of substrate 54 to another external connection on a second side of substrate 54 opposite to the first side. Contact pads 71 ​​on substrate 52 are connected to corresponding contact pads 73 on the first side (e.g., the first surface) of substrate 54 via conductive interconnect structures 72, such as solder, conductive bumps or posts, conductive adhesive, etc. Contact pads 77 on substrate 56 are connected to corresponding contact pads 75 on the second side (e.g., the second surface) of substrate 54 via conductive interconnect structures 74, such as solder, conductive bumps or posts, conductive adhesive, etc.

[0043] exist Figure 3 In the exemplary configuration shown, conductive traces on substrate 56, such as conductive trace 66, form radio frequency transmission lines (e.g., Figure 2 The second part of the radio frequency transmission line 36 in the substrate 56. One or more conductive vias such as conductive vias 65 and 67 on the substrate 56 electrically connect the conductive trace 66 to corresponding external contacts on the substrate 56, such as contact pads 77 for via 65 and contact pads 79 for via 67 on opposite sides of the substrate 56.

[0044] exist Figure 3 In the illustrated configuration, contact pads 79 are electrically connected to conductive structures on substrate 58 using conductive interconnect structures 76, such as solder, conductive bumps or posts, conductive adhesive, etc. One or more conductive vias, such as conductive vias 69, on substrate 58 electrically connect conductive traces, such as conductive traces 68, on substrate 58 to corresponding external contacts, such as contact pads 81, on substrate 58. The conductive traces 68 on substrate 58 form radio frequency transmission lines (e.g., Figure 2 The third part of the radio frequency transmission line 36 in the substrate 58. The conductive trace 68 that at least partially forms the radio frequency transmission line portion on the substrate 58 is coupled to the antenna 30 (e.g., with or without other intermediary interconnect structures).

[0045] like Figure 3 The configuration shown for forming the RF transmission line is merely illustrative. If needed, it can be configured... Figure 3 One or more substrates may be omitted or added to a set of stacked substrates. As an example, antenna 30 may be electrically connected to conductive trace 66 on substrate 56 without intervening conductive structures on substrate 58, radio component 26 may be electrically connected to conductive trace 66 on substrate 56 without intervening conductive structures on interpolator 54 and substrate 52, etc.

[0046] Although Figure 3A limited number of conductive traces and vias are shown for each substrate (e.g., substrates 52, 54, 56, and 58), but any suitable number of conductive traces and vias can be implemented on each substrate if needed to form a suitable transmission line structure for RF transmission lines and any additional RF transmission lines formed across multiple substrates in a similar manner. As an example, one or more conductive traces and vias in each substrate may be associated with signal paths or conductors (e.g., Figure 2 The signal conductor 40 in each substrate is associated with one or more conductive traces and vias that may be connected to a ground path or conductor (e.g., Figure 2 The grounding conductor 38 in the circuit is associated with it. If necessary, other signal and grounding conductors can be formed in a similar manner (e.g., for the same RF transmission line or another RF transmission line).

[0047] In this manner, one or more radio frequency (RF) transmission lines may be formed from conductive structures (e.g., conductive layers, conductive vias, contact pads, etc.) on each substrate, from conductive structures (e.g., conductive interconnect structures, such as solder, bumps, etc.) between or outside corresponding substrates, from non-conductive structures (e.g., base layers and dielectric layers providing appropriate isolation and / or separation between corresponding conductive structures) on each substrate, and from non-conductive structures (e.g., spacer structures or other structures providing appropriate isolation and / or separation between corresponding substrates) between or outside corresponding substrates. Each of these structures may be described herein as part of forming an RF transmission line, wherein the conductive structure forms a signal conductor or a ground conductor.

[0048] Because the transmission line structure for the radio frequency transmission line is integrated onto a substrate that performs other functions in device 10 (e.g., a printed circuit board that already performs other functions in the device, such as a main printed circuit board that provides structural support and signal routing for one or more components in the device, a printed circuit board on which storage and processing circuitry and / or other circuitry is mounted, a printed circuit board on which an antenna is disposed, a substrate that provides routing between components on one printed circuit board and components on another printed circuit board, a substrate that performs other suitable functions, a substrate that performs a combination of these functions, etc.), a compact transmission line structure with impedance matching the corresponding antenna impedance can be implemented in the device without a large coverage area in the device (e.g., compared to a coaxial cable connector used to support a coaxial cable).

[0049] The configuration of the transmission line impedance matching with the coupled antenna is described herein as an illustrative example. Other characteristics of the transmission line can be tuned if needed to efficiently transmit signals between the radio components and the antenna. If necessary, the transmission line impedance does not need to be exactly the same as the antenna impedance for impedance matching, as some mismatch may exist. If needed, additional impedance matching components or structures can be used to resolve this mismatch. The configuration of the RF transmission line coupled to the antenna without these additional intermediary impedance matching components or structures is described herein as an illustrative example.

[0050] As a combination Figure 3 In the described example, substrate 52 may be a system-in-package (SiP) substrate, substrate 56 may be a flexible printed circuit substrate for main system printed circuitry, providing structural support and signal routing to and from different functional components or subsystems in device 10, and substrate 58 may be a flexible printed circuit substrate for flexible printed circuitry providing routing to one or more antennas. Using an exemplary antenna configuration, one or more antennas coupled to the flexible printed circuitry associated with substrate 58 may be disposed on an antenna carrier mounted to substrate 58 (e.g., one or more antennas patterned on laser direct-formed (LDS) plastic). One or more antennas implemented in other ways may also be used if desired. In the above exemplary example, substrate 54 may be an interposer substrate for interposer communication between the SiP and the main system printed circuitry (e.g., providing signal routing between one or more components on the SiP and one or more components on the main system printed circuitry).

[0051] Figure 4 It is installed on an exemplary SiP 53 (e.g., with...). Figure 3 An exemplary interpolator 55 (e.g., associated with the base 52) Figure 3 A cross-sectional view (as associated with base 54). Figure 4As shown, the SiP53 includes a package substrate 52 (sometimes referred to as a carrier substrate 52) to which components 80 are mounted (e.g., mounted on opposite sides of the package substrate 52 using solder, wire bonding, conductive bumps, or other conductive interconnect structures). As an example, components 80 may include one or more integrated circuit dies (e.g., each implementing one or more of a memory circuit 16, processing circuit 18, radio component 26, signal processing circuit, and driver circuit for one or more input-output devices, power management circuitry, clock management circuitry, etc.), other active components (e.g., input-output device 22, programmable device, diode, other semiconductor device, etc.), passive components (e.g., resistors, capacitors, inductors, etc.), electromechanical components, and any other suitable discrete devices.

[0052] exist Figure 4 In the example, a specific component 80 implements a radio component 26 covering one or more RATs (e.g., an integrated circuit die including one or more radio components). Radio frequency transmission lines, such as radio frequency transmission line 36, and one or more additional radio frequency transmission lines, can couple the radio component 26 mounted to the substrate 52 to one or more antennas if needed. Figure 3 Similarly described, the conductive structures on the package substrate 52, the conductive structures on the substrate 54, and the conductive structures between the substrates 52 and 54 (e.g., conductive interconnect structure 72) form a radio frequency transmission line 36 coupled to the radio component 26. Specifically, the signal conductor 38 can use cross-channel... Figure 3 The first set of conductive structures in substrates 52 and 54, and substrates 56 and 58, are used to implement this, while the grounding conductor 40 can be implemented using cross-... Figure 3 The second set of conductive structures, implemented using substrates 52 and 54 and substrates 56 and 58, is used for implementation. If necessary, one or more additional signal conductors may share some of the conductive structures in the first set, and one or more additional ground conductors may share some of the conductive structures in the second set.

[0053] Since one or more RF transmission lines 36 are constructed using structures associated with SiP 53 and interposers 55, such as flexible printed circuits (e.g., made of...) Figure 3 The SiP is implemented using bases 56 and 58 (instead of using coaxial cables), thus eliminating the need for one or more coaxial cable connectors. Eliminating bulky coaxial cable connectors not only provides internal space savings but also allows the SiP to be fully encapsulated (e.g., compared to situations where exposed coaxial cable connectors are required to provide a coaxial cable connection, resulting in one side of the SiP not being encapsulated, thereby making that side of the component susceptible to unwanted weathering).

[0054] like Figure 4As shown, the components 80 on both sides of the substrate 52 and the connection between the SiP 53 and the interposer 54 are covered by encapsulations 82 and 84. If desired, an electromagnetic shielding layer can be disposed on the encapsulations 82 and 84, which protect the components on the SiP 53 from unwanted electromagnetic interference. Encapsulations 82 and 84 can be formed from any suitable amount and type of encapsulating material, such as plastic or specifically thermoplastic, ceramic, etc. Similarly, any suitable process (e.g., spin coating, molding, underfill, etc.) can be used to form the encapsulations 82 and 84 and the shielding layer.

[0055] When the SiP 53 is fully encapsulated and shielded to prevent unwanted weathering, temperature, and electromagnetic effects, the interposer 55 can act as an exclusive electrical interface through which components on the SiP 53 are connected. Specifically, a connection to components on the SiP 53 can be formed via external contacts (e.g., contact pads 75) on one side of the substrate 54. As an example, one or more additional printed circuits (e.g., with corresponding contact pads) can also be used. Figure 3 The flexible printed circuit associated with the substrate 56 can be electrically connected to the contact pad 75 via the conductive interconnect structure 74.

[0056] As mentioned above Figure 3 and Figure 4 The described substrate configuration is merely illustrative. Each of substrates 52, 54, 56, and 58 may serve other functions (e.g., in addition to supporting the integration of transmission line structures) if desired, and may have corresponding structures disposed thereon to perform those functions. As an illustrative example, Figure 4 The substrate 52 may include additional structures (e.g., conductive routing or interconnect layers, vias, etc.) for performing signal routing for other components 80 (e.g., in addition to radio component 26), and similarly, Figure 4 The substrate 54 may include additional structures (e.g., conductive routing or interconnect layers, vias, etc.) for forming a suitable signal routing path from an external contact on one side of the interposer 55 for other components 80 to an external contact on the other side of the interposer 55. Substrates 56 and 58 may similarly have corresponding additional structures thereon that perform any suitable routing function.

[0057] Figure 5 It is an exploded perspective view of an exemplary transmission line structure for radio frequency transmission lines, distributed or integrated across multiple substrates. Figure 5 In the example, the transmission line structure used for the radio frequency transmission line is formed by three sets of exemplary stacked metals and a substrate layer.

[0058] like Figure 5As shown, the first set of metal and substrate layers 90 includes a substrate 100 and metal layers 101 and 102 on the substrate 100 (e.g., where metal layer 102 is located on the top surface of the substrate 100, and metal layer 101 is embedded within the substrate 100 or located on the bottom surface of the substrate 100). The second set of metal and substrate layers 92 includes substrate layers 110 and 118 (sometimes collectively referred to herein as the substrate, which may have multiple substrate layers laminated or adhered together) and a metal layer having metal traces 112, 114, and 116 between substrate layers 110 and 118 (e.g., metal traces 112, 114, and 116 embedded within a multilayer substrate). Metal trace 112 may be laterally separated from and electrically isolated from metal trace 114 by gaps filled with non-conductive material (e.g., a portion of a multilayer substrate, or a substrate layer, dielectric layer, adhesive, insulator, etc.). Similarly, metal trace 116 can be laterally separated from and electrically isolated from metal trace 114 by gaps filled with non-conductive material.

[0059] The third group of metals and substrate layers 94 includes substrate layers 120 and 124 (sometimes referred to herein as a substrate, which may have multiple substrate layers laminated or adhered together), a metal layer 122 between substrate layers 120 and 124 (e.g., embedded within a multilayer substrate), and a metal layer 126 located on substrate layer 124 (e.g., on the top surface of the multilayer substrate). If desired, a non-conductive material (e.g., a portion of the multilayer substrate, or a substrate layer, dielectric layer, adhesive, etc.) may also fill the gap between substrate layers 120 and 124 and located in the same lateral plane as metal layer 122. If desired, one or more substrate layers (e.g., substrates) may sometimes be referred to herein as insulators or insulating layers (e.g., separating and providing insulation between ground traces and signal traces, between different ground traces, between different signal traces, etc.).

[0060] By tuning the relative configurations (e.g., distance, thickness, geometry, materials) between different groups of metal layers and the substrate, the overall RF transmission line can inherently act as an impedance matching structure that allows signals to and from the antenna to be transmitted without mismatch loss (e.g., the RF transmission line inherently does not suffer mismatch loss when transmitting signals to and from the antenna). In other words, any separate intermediary impedance matching structures (e.g., discrete components located outside the RF transmission line structure, such as capacitors, inductors, etc.) can be omitted because additional impedance matching is not required.

[0061] In one exemplary configuration, layer group 94 forms a first flexible printed circuit (e.g., a flexible printed circuit having a multilayer laminated structure or substrate, and...). Figure 3The layer group 92 forms part of a second flexible printed circuit (e.g., a flexible printed circuit having a multilayer laminated structure or substrate, and associated with a flexible printed circuit, etc.). Figure 3 The overlapping portion of the substrate 56 (associated with flexible printed circuits, etc.) and the layer group 90 forms a SiP or SiP substrate (e.g., with...). Figure 3 The substrate 52 associated with SiP, used for Figure 4 The overlapping portion of the SiP 53 packaging substrate 52, etc. For clarity, from... Figure 5 The SiP or SiP substrate portion is omitted in the layer group 90 shown.

[0062] Conductive structures (e.g., metal layers, metal traces, etc.) on each layer group 90, 92, and 94 are interconnected to collectively form a transmission line structure for radio frequency transmission lines.

[0063] Generally, it may be desirable for RF transmission lines to exhibit a specific, satisfactory characteristic impedance (e.g., a 50-ohm impedance transmission line) to minimize antenna signal loss (e.g., signal reflection) between the antenna and the RF transmission line. The characteristic impedance of the transmission line can be at least partially matched to the corresponding impedance of the antenna to which the transmission line is coupled (e.g., identical, within 0.01%, within 0.1%, within 1%, within 2%, within 5%, etc.), thus minimizing mismatch losses. However, in devices with relatively small printed circuitry (e.g., thickness), it may be difficult to provide RF transmission lines exhibiting a specific impedance due to the size (e.g., thickness) constraints of the smaller printed circuitry.

[0064] To mitigate these issues and provide an RF transmission line with impedance matched to the antenna impedance, conductive structures from multiple printed circuits, as well as other structures, can be selectively configured and connected to tune the composite or collective characteristic impedance of the RF transmission line. In other words, the relative configuration of layers within groups 90, 92, and 94 (and other adjacent or neighboring structures) can collectively contribute to the composite or collective impedance of the overall RF transmission line.

[0065] As an illustrative example, the individual characteristic impedances of the first RF transmission line portion implemented on layer group 90, the second RF transmission line portion implemented on layer group 92, and the third RF transmission line portion implemented on layer group 94, when viewed individually (e.g., in isolation), exhibit corresponding individual impedances that are more capacitive (e.g., less than the target 50-ohm impedance line) or more inductive (e.g., greater than the target 50-ohm impedance line) than the target characteristic impedance of the RF transmission line (e.g., a 50-ohm impedance transmission line). However, collectively, the three RF transmission line portions, along with any corresponding interconnects and adjacent structures, will form an RF transmission line with the target characteristic impedance (e.g., a 50-ohm impedance transmission line). Similarly, as in combination... Figure 3 and Figure 4 The transmission line structures described across multiple substrates can also collectively exhibit the target overall characteristic impedance (sometimes referred to as collective or composite impedance in this paper), even if the transmission line structures do not individually exhibit the target impedance.

[0066] RF transmission lines configured in this way can transmit RF signals to and from the antenna without mismatch loss. Therefore, since the RF transmission line itself inherently acts as an impedance matching structure, discrete components, such as inductors and capacitors used for impedance matching (e.g., impedance matching structures external to the printed circuit structure forming the RF transmission line), can be omitted. In other words, impedance offsets between different sections of the RF transmission line and the target impedance are not matched using discrete components. Instead, different sections of the RF transmission line on different printed circuits are configured or tuned relative to each other (e.g., by adjusting layer thickness, inter-layer spacing, layer geometry, layer materials, etc.) to directly achieve signal transmission without mismatch loss.

[0067] The configuration in which the RF transmission line exhibits an impedance of 50 ohms is described herein as an illustrative example. The impedance of the RF transmission line is frequency-dependent (e.g., dependent on one or more frequencies of the RF signal transmitted between the antenna and radio components by the RF transmission line). If desired, at one or more operating frequencies (e.g., in one or more frequency bands), the RF transmission line can be configured to exhibit any suitable target input, output, and / or characteristic impedance, such as an impedance of 50 ohms, an impedance between 45 and 55 ohms, an impedance between 40 and 60 ohms, etc. Therefore, at one or more operating frequencies, each RF transmission line section in a separate RF transmission line section can exhibit an individual impedance that is more capacitive (e.g., less) or more inductive (e.g., greater) than the overall RF transmission line impedance. As an example, the individual impedance along each RF transmission line section (e.g., implemented on a single printed circuit) can exhibit input, output, and / or characteristic impedances within 1%, 2%, 5%, 10%, 20%, etc., of the overall RF transmission line impedance at one or more operating frequencies.

[0068] To aid in tuning the overall impedance of the RF transmission line, different metal layers can be selectively interconnected at corresponding contact locations (e.g., using vias and routing layers within the substrate, using contact pads or solder pads on the surface of the substrate, using solder blocks, other solder structures, or other conductive interconnect structures between substrates of different or identical layer groups, each group associated with printed circuits, packages, interposers, etc.). Additionally, the distance or separation between different printed circuits, packages, interposers, etc., can be controlled (e.g., between groups 90, 92, and 94, such as distance 150 between group 90 and group 92, and distance 152 between group 92 and group 94) to more predictably tune the overall RF transmission line impedance. The configuration (e.g., distance or separation) relative to adjacent structures can also be controlled to more predictably tune the overall RF transmission line impedance.

[0069] As an illustrative example, the individual (characteristic) impedance of a transmission line portion on a single printed circuit (e.g., at one of groups 90, 92, or 94) can be defined by the separation of the signal conductor and ground conductor by the insulating structure within that single printed circuit, and by the dimensions and geometry of the signal conductor and ground conductor, the properties of the insulating structure, and other characteristics of that single printed circuit. In some configurations, the characteristics of a single printed circuit may be too restrictive in providing the desired impedance of the overall transmission line (e.g., based solely on the transmission line portion on that single printed circuit). However, by utilizing the spacing relative to other adjacent elements and the structures on those other adjacent elements (e.g., other overlapping printed circuits, conductors and insulators on the printed circuit, spacers, or any other adjacent components), the characteristics of the transmission line portion on the single printed circuit can be adjusted or complemented by these adjacent elements to collectively achieve the desired impedance of the overall transmission line.

[0070] Still referencing Figure 5 One or more interconnect structures (e.g., vias and routing layers within the substrate, contact pads or solder pads on the surface of the substrate, solder blocks, other solder structures, or other conductive interconnect structures between substrates of different or the same layer groups, each group associated with a printed circuit, package, interposer, etc.) may connect the metal layer or trace 101 to the metal trace 114 across exemplary contact locations 130-1 and 130-2. One or more interconnect structures may connect the metal trace 114 to the metal layer or trace 126 across exemplary contact locations 144-1 and 144-2. The metal traces 101, 114, and 126 may form signal conductors for radio frequency transmission lines when interconnected (e.g., ...). Figure 2 (Signal conductor 40 in the middle). At one end of the signal conductor, a metal trace 101 can be coupled to a radio component, such as... Figure 2 The radio component 26 is located in the center, and at the other end of the signal conductor, a metal trace 126 can be coupled to an antenna, such as... Figure 2 Antenna 30 is located at the positive antenna feed terminal 44.

[0071] One or more interconnect structures may connect metal layer or trace 102 to metal trace 116 across exemplary contact locations 132-1 and 132-2. One or more interconnect structures may connect metal layer or trace 102 to metal trace 112 across exemplary contact locations 134-1 and 134-2. One or more interconnect structures may connect metal trace 112 to metal layer or trace 122 across one or more exemplary contact locations (e.g., across an exemplary group of three locations 140-1 and 140-2). One or more interconnect structures may connect metal trace 116 to metal layer or trace 122 across one or more exemplary contact locations (e.g., across an exemplary group of three locations 142-1 and 142-2). Metal traces 102, 112, 116, and 122 may form one or more ground conductor portions for radio frequency transmission lines when interconnected (e.g., Figure 2 The grounding conductor 38). At one end of the grounding conductor, a metal trace 102 can be coupled to a radio component, such as radio component 26 and other equipment structures (e.g., a battery, other grounding structures for equipment components, equipment housing, etc.), and at the other end of the grounding conductor, a metal trace 122 can be coupled to an antenna, such as... Figure 2 Antenna 30 is located at antenna feed terminal 42.

[0072] Figure 6 yes Figure 5 An illustrative side view of layers 90, 92, and 94 during assembly (e.g., interconnected, mounted, etc.). Configurations in which each group of 90, 92, and 94 forms different printed circuits with separate substrates are described as illustrative examples (e.g., sometimes referred to herein as printed circuit 90, printed circuit 92, and printed circuit 94).

[0073] like Figure 6 As shown, interconnect structure 131 electrically connects metal trace 101 to metal traces in metal layer 115 (e.g., electrically connects to traces that can be formed in the same metal layer 115 as metal traces 112 and 116). Figure 5 Metal trace 114 in the metal layer 115). Interconnection structure 131 electrically connects metal trace 102 to metal traces in metal layer 115 (e.g., electrically connects to traces that can be formed in the same metal layer 115 as metal traces 114 and 116). Figure 5 (Metal trace 112 in the middle). Similar additional interconnect structures can also electrically connect metal trace 102 to... Figure 5 In (in) Figure 6Metal traces 116 (in layer 115). Interconnect structures 131 and 133 and other interconnect structures may include conductive printed circuit routing structures located on printed circuit 90 and printed circuit 92, such as vias, interconnect layers, external contact pads, etc., and may include conductive structures located between printed circuit 90 and printed circuit 92, such as solder (balls, bumps, blocks, etc.) or other conductive materials connecting corresponding contact pads on printed circuit 90 and 92.

[0074] Interconnect structure 141 will connect the metal traces in metal layer 115 (e.g., Figure 5 Metal trace 112 is electrically connected to metal trace 122. Similar interconnect structures can also be used to... Figure 5 In or Figure 6 Metal trace 116 in layer 115 is electrically connected to metal trace 122. Interconnect structure 143 connects the metal traces in metal layer 115 (e.g., Figure 5 Metal trace 114 is electrically connected to metal trace 126. Interconnect structures 141 and 143 and other interconnect structures may include conductive printed circuit routing structures located on printed circuit 92 and printed circuit 94, such as vias, interconnect layers, external contact pads, etc., and may include conductive structures located between printed circuit 92 and printed circuit 94, such as solder (balls, bumps, blocks, etc.) or other conductive materials connecting corresponding contact pads on printed circuit 92 and 94.

[0075] The dimensions (e.g., height and pitch) of interconnect structures 131 and 133 (e.g., solder blocks between printed circuits 90 and 92) can be controlled to maintain a desired distance between printed circuits 90 and 92 (e.g., between metal traces in printed circuits 90 and 92). Figure 5 The distance between the interconnect structures 131 and 133 is 150 mm, and the capacitive load between the different components forming the interconnect structures 131 and 133 (e.g., the capacitive load associated with the size of the solder pads at the corresponding interfaces of the printed circuits 90 and 92) is taken into account when controlling the overall impedance of the RF transmission lines. Similarly, the dimensions (e.g., height and pitch) of the interconnect structures 141 and 143 can also be controlled to maintain the desired distance between the printed circuits 92 and 94 (e.g., between the metal traces in the printed circuits 92 and 94). Figure 5 The distance 152 in the middle) and the capacitive load between the different components forming the interconnect structures 141 and 143 (e.g., the capacitive load associated with the size of the solder pads at the corresponding interfaces of the printed circuits 92 and 94) are taken into account when controlling the overall impedance of the RF transmission line.

[0076] If necessary, other components or structures such as components or structures 154 and 156 may be disposed between printed circuits 90, 92, and 94 to control and / or maintain the distance between printed circuits 90, 92, and 94. As an example, components or structures 154 and 156 may be dedicated spacer structures, components disposed on one or more of printed circuits 90, 92, and 94, or components separate from printed circuits 90, 92, and 94.

[0077] In an exemplary configuration where one or more printed circuits 90, 92, and 94 individually have dimensions (e.g., corresponding thicknesses) unsuitable for providing RF transmission lines with target impedance, Figure 6 The configuration of printed circuits 90, 92, and 94 provides a way to implement RF transmission lines across printed circuits 90, 92, and 94 to collectively represent a composite impedance that matches the corresponding antenna impedance. Additionally, as... Figure 6 As shown, the patterned grounding scheme (e.g., using conductive structures 133 and 141) connecting different reference ground layers in printed circuits 90, 92, and 94 helps to provide grounding connections, thereby allowing free flow of current across different ground portions, thus forming ground conductors in the RF transmission lines. If desired, conductive structures 133 and 141 (e.g., implemented at least partially by ground pads and solder blocks) can be positioned at any suitable location across any suitable overlap of metal traces 102, 112 in layer 115, 116 in layer 115, and 122 to ensure proper grounding across all these metal (ground) traces in the different printed circuits, thereby allowing return current to move freely along different portions of the ground conductors in the different printed circuits.

[0078] Such as combination Figure 5 and Figure 6 The described configuration of the transmission line structure integrated across printed circuits 90, 92, and 94 is merely illustrative. Figure 5 and Figure 6 The description can be similarly applied to combining Figures 2-4 The described transmission line structure (e.g., across) Figure 3 The transmission line structures of printed circuits 52, 54, 56, and 58 in the circuit can be controlled by combining... Figure 5 and Figure 6 The various characteristics described in the printed circuits 90, 92 and 94 together form an RF transmission line with an impedance matched to the antenna impedance.

[0079] Example electronic devices 10 include wristwatches, earphones, handsets, or combinations thereof. Figure 1 Any other device described in Figure 7 As shown, this exemplary electronic device has the following features: Figures 2-6The wireless circuit described is a radio frequency transmission line that is integrated across multiple printed circuits.

[0080] exist Figure 7 In the example, the housing 12 of device 10 includes a first portion 162 and a second portion 164. Housing 12 may include one or more ports, such as ports aligned with one or more internal components, such as a speaker 176 (e.g., a speaker port). Housing 12 separates the exterior of device 10 from the interior (e.g., interior 160) of device 10, within which components of device 10 are disposed. Components of device 10 may include a battery 178, a microphone 180, any other component 182, such as a connector... Figure 1 Those described. One or more of these components (e.g., processing circuitry 18, storage circuitry 16, radio component 26, antenna 30, input / output device 22, etc.) may be mounted on one or more printed circuits in device 10.

[0081] As an example, device 10 may include printed circuits (e.g., forming SiP 168) mounted in a package to radio components, processing circuitry, storage circuitry, etc.; printed circuits (e.g., forming system flexible printed circuit 166) that act as a system printed circuit extending across an interior 160 of device 10 (e.g., extending across a first portion 162 and a second portion 164) to provide structural support and connectivity across different subsystems in device 10; printed circuits (e.g., forming interposers 170) that act as a routing interface between components mounted to SiP 168 and system flexible printed circuit 166; and printed circuits (e.g., forming antenna flexible printed circuit 172) that provide routing to and from one or more antennas, such as antenna 30. As an illustrative example, antenna 30 may be patterned (e.g., using LDS process) on an antenna carrier 174 (e.g., LDS plastic) mounted on flexible printed circuit 172.

[0082] The radio components in SiP 168 can be coupled to antenna 30 using a transmission line structure having a transmission line structure extending across SiP 168, interposer 170, system flexible printed circuit 166, and antenna flexible printed circuit 172 and integrated with these devices (e.g., using a combination of...). Figures 2-6 The described configuration provides a compact RF transmission line exhibiting impedance matching with the antenna 30 without the need for separate intermediary impedance matching elements such as capacitors and / or inductors. The transmission line structure on the antenna flexible printed circuit 172 can be coupled to the antenna 30 on the carrier 174 via one or more suitable conductive interconnect structures (e.g., solder, weldment, conductive adhesive, screw, bracket, etc.) to feed the antenna 30.

[0083] According to one embodiment, a radio frequency transmission line structure is provided, including a first printed circuit having a first substrate and first conductive traces disposed on the first substrate, the first conductive traces exhibiting a first impedance; and a second printed circuit having a second substrate and second conductive traces disposed on the second substrate, the second conductive traces exhibiting a second impedance, the second printed circuit at least partially overlapping and being separated from the first printed circuit by a certain distance, and the first impedance, the second impedance, and the distance separating the second printed circuit from the first printed circuit together define the composite impedance of the radio frequency transmission line structure.

[0084] According to another embodiment, the composite impedance of the radio frequency transmission line structure is different from the first impedance exhibited by the first conductive trace and different from the second impedance exhibited by the second conductive trace.

[0085] According to another embodiment, the first conductive trace includes a ground trace and a signal trace separated from the ground trace by an insulator, and the ground trace, the signal trace, and the insulator at least partially define a first impedance associated with the first conductive trace.

[0086] According to another embodiment, the second conductive trace includes an additional ground trace and an additional signal trace separated from the additional ground trace by an additional insulator, and the additional ground trace, the additional signal trace, and the additional insulator at least partially define a second impedance associated with the second conductive trace.

[0087] According to another embodiment, the radio frequency transmission line structure includes a third printed circuit having a third substrate and a third conductive trace located on the third substrate, the third printed circuit at least partially overlapping with the second printed circuit and separated from the second printed circuit by an additional distance.

[0088] According to another embodiment, the third conductive trace exhibits a third impedance, and the third impedance, together with the additional distance separating the third printed circuit from the second printed circuit, further defines the composite impedance of the RF transmission line structure.

[0089] According to another embodiment, the first printed circuit includes a first flexible printed circuit, and the second printed circuit includes a second flexible printed circuit.

[0090] According to another embodiment, the radio frequency transmission line structure includes a component located between a first printed circuit and a second printed circuit and configured to maintain a distance separating the second printed circuit from the first printed circuit.

[0091] According to an embodiment, a radio frequency transmission line is provided, including a signal conductor comprising a first signal trace on a first printed circuit and a second signal trace on a second printed circuit; and a ground conductor comprising a first ground trace on a first printed circuit and a second ground trace on a second printed circuit, wherein the first signal trace and the first ground trace on the first printed circuit exhibit a first impedance, the second signal trace and the second ground trace on the second printed circuit exhibit a second impedance, and the radio frequency transmission line exhibits a characteristic impedance that is different from both the first and second impedances.

[0092] According to another embodiment, the radio frequency transmission line includes a conductive interconnect structure that couples a first ground trace located on a first printed circuit to a second ground trace on a second printed circuit at multiple locations.

[0093] According to another embodiment, the radio frequency transmission line includes additional conductive interconnect structures that couple a first signal trace on a first printed circuit to a second signal trace on a second printed circuit. The conductive interconnect structures and the additional conductive interconnect structures include solder located between the first printed circuit and the second printed circuit.

[0094] According to another embodiment, the conductive interconnect structure includes solder located between the first printed circuit and the second printed circuit, a first contact pad located on the first printed circuit, a second contact pad located on the second printed circuit, a first conductive via located on the first printed circuit, and a second conductive via located on the second printed circuit.

[0095] According to another embodiment, a first conductive via couples a first ground trace to a first contact pad, a second conductive via couples a second ground trace to a second contact pad, and solder couples the first contact pad to the second contact pad.

[0096] According to another embodiment, the radio frequency transmission line is configured to transmit radio frequency signals at a certain frequency, the characteristic impedance exhibited by the radio frequency transmission line being between 40 ohms and 60 ohms at that frequency, a first individual impedance being greater than or less than 50 ohms, and a second impedance being greater than or less than 50 ohms.

[0097] According to one embodiment, an electronic device is provided, including a radio component; an antenna; a first printed circuit substrate; a second printed circuit substrate, the second printed circuit substrate at least partially overlapping the first printed circuit substrate; and a radio frequency transmission line that communicatively couples the radio component to the antenna, the radio frequency transmission line having a first transmission line portion on the first printed circuit substrate and a second transmission line portion on the second printed circuit substrate, the first transmission line portion exhibiting a first impedance, the second transmission line portion exhibiting a second impedance, and the radio frequency transmission line exhibiting a collective impedance different from both the first and second impedances.

[0098] According to another embodiment, the electronic device includes components adjacent to a first printed circuit substrate and a second printed circuit substrate, the components, the first transmission line portion and the second transmission line portion together exhibiting the collective impedance of the radio frequency transmission line.

[0099] According to another embodiment, the first printed circuit substrate includes a first flexible printed circuit substrate, the first transmission line portion includes conductive traces located on the first flexible printed circuit, the second printed circuit substrate includes a second flexible printed circuit, and the second transmission line portion includes additional conductive traces located on the second flexible printed circuit.

[0100] According to another embodiment, the electronic device includes a control circuit coupled to and configured to control the operation of the radio component, a first printed circuit substrate being a package substrate of a package, the control circuit and the radio component being mounted to the package substrate, and an encapsulating material being disposed on the package substrate and encapsulating the control circuit and the radio component.

[0101] According to another embodiment, the electronic device is a portable electronic device and includes a housing having a speaker port; a speaker aligned with the speaker port; a microphone; a battery; and control circuitry coupled to the radio components, speaker, microphone, and battery.

[0102] According to another implementation, the electronic device is a wireless earbud.

[0103] The foregoing is merely illustrative and various modifications can be made to the described implementation scheme. The aforementioned implementation scheme can be implemented independently or in any combination.

Claims

1. A radio frequency transmission line, comprising: a first printed circuit having a first substrate, a first signal trace on the first substrate, and a first ground trace on the first substrate; a second printed circuit at least partially overlapping the first printed circuit and having a second substrate, a second signal trace on the second substrate, and a second ground trace on the second substrate, wherein a characteristic impedance of the radio frequency transmission line is tuned by a spacing between the first printed circuit and the second printed circuit; a third printed circuit at least partially overlapping the first printed circuit and the second printed circuit and having a third substrate, a third signal trace on the third substrate, and a third ground trace on the third substrate; a first interconnect structure coupling the first signal trace to the second signal trace and coupling the second signal trace to the third signal trace, thereby forming a signal conductor of the radio frequency transmission line; and a second interconnect structure coupling the first ground trace to the second ground trace and coupling the second ground trace to the third ground trace, thereby forming a ground conductor of the radio frequency transmission line.

2. The radio frequency transmission line of claim 1, wherein the characteristic impedance of the radio frequency transmission line is tuned by a spacing between the second printed circuit and the third printed circuit.

3. The radio frequency transmission line of claim 2, wherein the first ground trace and the first signal trace are separated by an insulator, and wherein the first ground trace, the first signal trace, and the insulator exhibit an impedance different from the characteristic impedance of the radio frequency transmission line.

4. The radio frequency transmission line of claim 3, wherein the second ground trace and the second signal trace are separated by a further insulator, and wherein the second ground trace, the second signal trace, and the further insulator exhibit an impedance different from the characteristic impedance of the radio frequency transmission line.

5. The radio frequency transmission line of claim 1, wherein the first interconnect structure and the second interconnect structure comprise solder between the first printed circuit and the second printed circuit.

6. The radio frequency transmission line of claim 5, wherein the first interconnect structure and the second interconnect structure comprise contact pads on the first printed circuit and the second printed circuit.

7. The radio frequency transmission line of claim 1, wherein the first printed circuit comprises a first flexible printed circuit and the second printed circuit comprises a second flexible printed circuit.

8. The radio frequency transmission line of claim 1, further comprising: a component between the first printed circuit and the second printed circuit and configured to maintain a distance separating the second printed circuit from the first printed circuit.

9. A radio frequency transmission line, comprising: ​ a signal conductor comprising a first signal trace on a first printed circuit and a second signal trace on a second printed circuit; and a ground conductor comprising a first ground trace on the first printed circuit and a second ground trace on the second printed circuit, the first signal trace and the first ground trace on the first printed circuit exhibit a first impedance, the second signal trace and the second ground trace on the second printed circuit exhibit a second impedance, and the radio frequency transmission line exhibits a characteristic impedance different from the first impedance and different from the second impedance, wherein the characteristic impedance of the radio frequency transmission line is tuned by a spacing between the first printed circuit and the second printed circuit.

10. The radio frequency transmission line of claim 9, further comprising: a conductive interconnect structure coupling the first ground trace on the first printed circuit to the second ground trace on the second printed circuit at a plurality of locations.

11. The radio frequency transmission line of claim 10, further comprising: a further conductive interconnect structure coupling the first signal trace on the first printed circuit to the second signal trace on the second printed circuit, the conductive interconnect structure and the further conductive interconnect structure comprising solder between the first printed circuit and the second printed circuit.

12. The radio frequency transmission line of claim 10, wherein the conductive interconnect structure comprises solder between the first printed circuit and the second printed circuit, a first contact pad on the first printed circuit, a second contact pad on the second printed circuit, a first conductive via on the first printed circuit, and a second conductive via on the second printed circuit.

13. The radio frequency transmission line of claim 12, wherein the first conductive via couples the first ground trace to the first contact pad, the second conductive via couples the second ground trace to the second contact pad, and the solder couples the first contact pad to the second contact pad.

14. The radio frequency transmission line of claim 9, wherein the radio frequency transmission line is configured to convey radio frequency signals at a frequency, the characteristic impedance exhibited by the radio frequency transmission line is between 40 ohms and 60 ohms at the frequency, the first impedance is greater than or less than 50 ohms, and the second impedance is greater than or less than 50 ohms.

15. An electronic device, comprising: a radio; an antenna; a first printed circuit substrate; a second printed circuit substrate at least partially overlapping the first printed circuit substrate; and a radio frequency transmission line communicatively coupling the radio to the antenna, the radio frequency transmission line having a first transmission line portion on the first printed circuit substrate and a second transmission line portion on the second printed circuit substrate, the first transmission line portion exhibits a first impedance, the second transmission line portion exhibits a second impedance, and the radio frequency transmission line exhibits a collective impedance that is different from the first impedance and different from the second impedance, wherein the collective impedance of the radio frequency transmission line is tuned by a spacing between the first printed circuit substrate and the second printed circuit substrate.

16. The electronic device of claim 15, further comprising: a component adjacent to the first printed circuit substrate and the second printed circuit substrate, wherein the component, the first transmission line portion, and the second transmission line portion collectively exhibit the collective impedance of the radio frequency transmission line.

17. The electronic device of claim 15, wherein the first printed circuit substrate comprises a first flexible printed circuit substrate, the first transmission line portion comprises a conductive trace on the first flexible printed circuit substrate, the second printed circuit substrate comprises a second flexible printed circuit substrate, and the second transmission line portion comprises another conductive trace on the second flexible printed circuit substrate.

18. The electronic device of claim 15, further comprising: control circuitry coupled to the radio and configured to control operation of the radio, wherein the first printed circuit substrate is a package substrate of a package, wherein the control circuitry and the radio are mounted to the package substrate, and wherein an encapsulation material is disposed on the package substrate and encapsulates the control circuitry and the radio.

19. The electronic device of claim 15, wherein the electronic device is a portable electronic device and further comprising: a housing having a speaker port; a speaker aligned with the speaker port; a microphone; a battery; and control circuitry coupled to the radio, the speaker, the microphone, and the battery.

20. The electronic device of claim 15, wherein the electronic device is a wireless earbud. ​

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