Dual band operation of a radio

Abstract

In one embodiment, an integrated circuit includes a first radio frequency (RF) circuit configured to receive and process a first RF signal having a sub-gigahertz (GHz) frequency to output a first lower frequency signal and to transmit an RF signal having a sub-GHz frequency; a second RF circuit configured to receive and process a second RF signal having a frequency of at least substantially 2.4 GHz to output a second lower frequency signal and to transmit an RF signal at at least substantially 2.4 GHz; a shared analog circuitry coupled to the first RF circuit and the second RF circuit, the shared analog circuitry to receive at least one of the first RF signal or the second RF signal and to output a digital output signal; and a digital circuit coupled to the shared analog circuit, the digital circuit to recover message information from the digital output signal.

Description

Background Technology

[0001] As wireless-enabled devices become more prevalent, protocols that operate across a wide range of frequency bands are used. Some devices can provide operation across multiple frequency bands and can implement different radio frequency (RF) circuitry to communicate across these different bands.

[0002] One challenge in providing multiple RF circuits within a single integrated circuit is the size and complexity of the circuitry, such as the matching network required to interface the antenna with the RF circuitry. Therefore, some wireless-enabled devices may limit communication to a single frequency band or use separate integrated circuits for each band; others opt for increasing the cost, size, and power consumption of fully integrating the circuitry for multiple protocols. None of these scenarios offers the greatest flexibility. Summary of the Invention

[0003] In one aspect, an integrated circuit includes a semiconductor die that may include: a first radio frequency (RF) circuit including a first low-noise amplifier (LNA) and a first mixer, the first RF circuit being configured to receive and process a first RF signal having a sub-gigahertz (GHz) frequency to output a first lower frequency signal and to transmit an RF signal having a sub-GHz frequency; a second RF circuit including a second LNA and a second mixer, the second RF circuit being configured to receive and process a second RF signal having a frequency of at least substantially 2.4 GHz to output a second lower frequency signal and to transmit an RF signal at at least substantially 2.4 GHz; a shared analog circuit means coupled to the first RF circuit and the second RF circuit, the shared analog circuit means being configured to receive at least one of the first RF signal or the second RF signal and to output a digital output signal; and a digital circuit coupled to the shared analog circuit, the digital circuit being configured to recover message information from the digital output signal.

[0004] In one embodiment: a first RF circuit is coupled to a first matching network, which is configured to impedance match a first antenna for receiving a first RF signal; and a second RF circuit is coupled to a second matching network, which is configured to impedance match a second antenna for receiving a second RF signal. The integrated circuit can be coupled to the first matching network via a first pad of the semiconductor die and to the second matching network via a second pad of the semiconductor die, both of which are external to the integrated circuit. A programmable harmonic filter can be coupled to the second matching network, wherein when communication is via the first RF circuit, the programmable harmonic filter is enabled to prevent the first RF signal from being transmitted through the second matching network.

[0005] In one embodiment, the integrated circuit further includes a controller coupled to the first RF circuit and the second RF circuit, wherein in a first mode, the controller disables the first RF circuit and enables the second RF circuit, and the controller transmits onboarding information to network components of the network via the second RF circuit. After the integrated circuit is at least partially connected to the network based on the onboarding information, the controller disables the second RF circuit and enables the first RF circuit.

[0006] When the integrated circuit is integrated into the system, the first RF circuit and the second RF circuit are configured to operate at sub-GHz frequencies. The first RF circuit is coupled to a first antenna, and the second RF circuit includes a diversity path that is coupled to a diversity antenna, wherein the first antenna and the diversity antenna are configured for the same operating frequency band.

[0007] In one embodiment, the shared analog circuitry includes: a programmable gain amplifier for receiving a first lower frequency signal when a first RF circuit is active, and for receiving a second lower frequency signal when a second RF circuit is active; and an analog-to-digital converter (ADC) coupled to the output of the programmable gain amplifier, the ADC being used to output a digital output signal to the digital circuitry. The semiconductor die may further include a frequency synthesizer for generating a first mixed signal for a first mixer when the first RF circuit is active, and for generating a second mixed signal for a second mixer when the second RF circuit is active, wherein the first and second mixers include a shared complex mixer.

[0008] In another aspect, a method includes: performing impedance matching between a first RF circuit of an integrated circuit and at least one antenna using a first matching network, the first RF circuit being configured to process a first RF signal of a sub-GHz protocol; performing impedance matching between a second RF circuit of the integrated circuit and the at least one antenna using a second matching network, the second RF circuit being configured to process a second RF signal of a 2.4GHz protocol; using the first RF circuit to receive and process the impedance-matched first RF signal of the sub-GHz protocol; and using the second RF circuit to receive and process the impedance-matched second RF signal of the 2.4GHz protocol.

[0009] In one embodiment, the method further includes: coupling a first RF signal from the at least one antenna to a first RF circuit via a first matching network including a first off-chip matching network and a first input pad of the integrated circuit coupled to the first off-chip matching network; and coupling a second RF signal from the at least one antenna to a second RF circuit via a second matching network including a second off-chip matching network and a second input pad of the integrated circuit coupled to the second off-chip matching network. The method may further include: in a first mode, disabling the first RF circuit and enabling the second RF circuit to transmit access information with network components of the network. After the integrated circuit is at least partially connected to the network based on the access information, the method may include disabling the second RF circuit and enabling the first RF circuit to communicate according to a sub-GHz protocol.

[0010] In another aspect, a system includes: at least one antenna for receiving sub-GHz protocol RF signals and 2.4GHz protocol RF signals; a first matching network coupled to the at least one antenna for impedance matching of the at least one antenna and a first RF circuit of an integrated circuit; a second matching network coupled to the at least one antenna for impedance matching of the at least one antenna and a second RF circuit of the integrated circuit; an integrated circuit coupled to the first and second matching networks, the integrated circuit including: a first RF circuit including a first LNA configured to receive and process sub-GHz protocol RF signals; a second RF circuit including a second LNA configured to receive and process 2.4GHz protocol RF signals; a shared circuit device coupled to the first and second RF circuits for receiving at least one of the sub-GHz protocol RF signals or the 2.4GHz protocol RF signals and outputting a digital output signal; and a digital circuit coupled to the shared circuit device for recovering message information from the digital output signal.

[0011] In one embodiment, at least one of the first matching network or the second matching network is external to the integrated circuit. The first matching network may include: a first matching network path having at least one first inductor coupled in series between the at least one antenna and the first RF circuit, and at least one first capacitor coupled in parallel to the at least one first inductor; and a second matching network path having at least one second inductor coupled in series between the at least one antenna and at least one power amplifier of the first RF circuit, and at least one second capacitor coupled in parallel to the at least one second inductor.

[0012] In one embodiment, the system may further include a controller coupled to the first RF circuit and the second RF circuit, wherein in a first mode, the controller disables the first RF circuit and enables the second RF circuit, and the controller transmits access information to network components of the network via the second RF circuit. After the system has been at least partially connected to the network based on the access information, the controller may disable the second RF circuit and enable the first RF circuit.

[0013] In one embodiment, the system further includes a programmable harmonic filter coupled to a second matching network, wherein the programmable harmonic filter is enabled when communication is via the first RF circuit to prevent harmonics of sub-GHz protocol RF signals from being transmitted through the second matching network. The programmable harmonic filter may have a programmable capacitor included in the integrated circuit and an inductor coupled between the programmable capacitor and the at least one antenna, wherein the programmable capacitor is decoupled from the inductor when communication is via the second RF circuit.

[0014] In one embodiment, the system may further include an RF switch coupled between the at least one antenna and the first and second matching networks. The system may further include a controller coupled to the first and second RF circuits, wherein, when the system includes a vehicle system, the controller is used to configure the first and second RF circuits to receive and process sub-GHz protocol RF signals. Attached Figure Description

[0015] Figure 1 This is a block diagram of a system according to one embodiment.

[0016] Figure 2 This is a block diagram showing further details of the circuitry within an integrated circuit according to one embodiment.

[0017] Figure 3A This is a schematic diagram of multiple matching networks according to one embodiment.

[0018] Figure 3B This is a schematic diagram of a matching network according to another embodiment.

[0019] Figure 4 This is a flowchart of a method according to one embodiment.

[0020] Figure 5 This is a block diagram of a representative integrated circuit according to one embodiment.

[0021] Figure 6 This is a block diagram of a system according to one embodiment. Detailed Implementation

[0022] In various embodiments, the integrated circuit (IC) includes transceiver circuitry to enable wireless communication. This transceiver circuitry may include both transmitting and receiving circuitry, at least some of which may be shared. In embodiments herein, the integrated circuit may include multiple independent radio frequency (RF) signal processing paths to enable communication at different operating frequency bands. In a particular embodiment, the integrated circuit may be configured for dual-band operation, wherein a first RF signal processing path is configured to operate at a relatively high frequency range (e.g., 2.4 GHz), such as for Bluetooth protocols (e.g., Bluetooth or Bluetooth Low Energy (BLE) protocol), protocols according to the IEEE 802.11 standard, or another protocol.

[0023] Furthermore, another RF signal processing path can be configured to operate in the sub-GHz band. For example, wireless communication, such as wireless local area networks (WLANs) (e.g., automation networks), may operate between approximately 170 MHz and 900 MHz. Embodiments can be used in conjunction with many different types of sub-GHz wireless protocols, such as Z-Wave, Thread SubG, Wi-SUN, and / or Sidewalk protocols, among others. Of course, embodiments are not limited to dual-band operation, and in some cases, two or more RF signal processing paths can be used to implement more than two operating bands.

[0024] ICs can be designed with specific components to enable operation in these dual-band frequencies (2.4 GHz and sub-GHz, as an example implementation), such as by including matching components. However, in other cases, ICs may be designed to be more general-purpose. In these cases, the IC may include separate, independent RF signal processing paths and shared circuitry, which, depending on the use case, can be configured to operate in the same frequency band (e.g., for use in a diversity receiver scenario) or to operate in a wide range of different frequency bands (e.g., the 2.4 GHz and sub-GHz example), which will be the focus of this discussion. In this way, a single IC design can be implemented in many different use cases, by leveraging common on-chip hardware and using specific off-chip hardware (such as matching networks) to enable operation in the desired frequency band for a given use case.

[0025] Now for reference Figure 1 A block diagram of a system according to one embodiment is shown. Figure 1 As shown, system 100 can be any type of wireless-enabled device. While the embodiments described herein may be particularly well-suited for use in Internet of Things (IoT) devices, it is to be understood that the embodiments are not limited in this respect, and other wireless-enabled devices, such as various consumer portable devices including laptops, smartphones, media players, etc., may also utilize the embodiments.

[0026] exist Figure 1 At the high level shown, system 100 includes integrated circuit 110. In one embodiment, integrated circuit 110 may be the main controller of system 100, such as a microcontroller unit (MCU). In other cases, IC 110 may be implemented as a standalone transceiver with both transmit and receive capabilities. In any case, IC 110 has multiple independent RF signal processing paths, including a first RF front-end circuit 1200 and a second RF front-end circuit 1201. At the high level, RF front-end circuit 120 may (generally) include various circuitry to receive and transmit RF signals and further interface with additional signal processing circuitry. Thus, RF front-end circuit 120 may include mixer circuitry to downconvert / upconvert signals between RF and lower frequencies, such as intermediate frequency (IF) and / or baseband. Furthermore, RF front-end circuit 120 may further include signal conditioning circuitry, such as amplifiers and / or other gain control circuitry, filter circuitry, etc. In some cases, additional circuitry, such as mixers or other downconversion circuitry, may be present in the separate RF front-end circuitry.

[0027] Still referencing Figure 1 A control circuit 125 exists, and the control circuit 125 can be configured to control operation. For example, depending on the desired protocol for a given environment, the control circuit 125 can dynamically enable and disable one of the selected RF front-end circuits 120. This operation may be derived from negotiation with network components. Further details of the operation of the control circuit 125 are described below.

[0028] like Figure 1 As further shown, the RF front-end circuitry 120 is coupled to the baseband circuitry 130. Although shown as a single baseband circuit, it is to be understood that at least a portion of the baseband circuitry 130 can be implemented separately for different signal processing paths. For example, different modem circuitry arrangements can be provided to implement modulation and demodulation of signals for different wireless protocols. In some embodiments, the baseband circuitry 130 can be implemented as a digital signal processor (DSP) or other digital circuitry to recover message information from a digitized signal obtained from a received RF signal.

[0029] Furthermore, the baseband circuit 130 can transmit digital information with the processing circuit 135, which can be a main processor, such as the host processor of system 100. In other cases, it should be understood that the processing circuit 135 can reside within IC 110 and can be implemented as an MCU. Of course, additional circuitry can also exist in IC 110 and system 100, but for ease of explanation, it is not shown here. Figure 1 As shown in the image.

[0030] like Figure 1 As further shown, IC 110 is coupled to multiple independent matching networks 140 0,1 In a particular embodiment, the matching network 140 can be implemented off-chip. By providing an external matching network separate from IC 110, the size, complexity, and cost of IC 110 can be reduced. Furthermore, providing off-chip matching allows for greater flexibility, as a much larger frequency range can be accommodated in this way.

[0031] In the specific implementation described herein, matching network 1400 can be configured to provide sub-GHz matching, while matching network 1401 can be configured to provide 2.4GHz matching. Although different implementations of matching network 140 are possible, in... Figure 1 In this high-level view, it is important to understand that the matching network 140 can be implemented as an LC circuit.

[0032] As further shown, each matching network 140 is coupled to a separate antenna 150. 0,1In an embodiment, each antenna 150 can be configured to receive signals in one or more specific frequency bands, and can be configured differently. That is, antenna 150 can be configured to receive and transmit signals in different frequency bands, in contrast to a diversity arrangement in which multiple antennas are configured to operate in the same frequency band, albeit with different phases. It should be understood that although... Figure 1 This high-level illustration is shown in the embodiments, but many variations and alternatives are possible. For example, in some cases, at least one of the matching networks 140 may be included within IC 110. Moreover, a single antenna (e.g., a dual resonant antenna) may be used, with an RF switch coupled between the matching network 140 and the antenna.

[0033] Now for reference Figure 2 Further details of the circuit arrangement within an integrated circuit according to one embodiment are shown. Figure 2 As shown, IC 200 (which is Figure 1 A more detailed view of IC 110 (including a separate RF signal processing path) is available. Figure 2 In the higher levels shown, these independent RF signal processing paths (typically 2200 and 2201) include low-noise amplifiers (LNAs) 2220 and 2221 in the receiving direction to receive and amplify incoming RF signals in a given frequency band. As shown, LNA 222 is coupled to an input pin or pad (which in turn can be coupled to an external matching network). In this way, the incoming RF signal is impedance matched between the circuitry of RF signal processing path 220 and the external antenna.

[0034] The amplified RF signal is then provided to the mixer circuit 225. Figure 2 In the illustrated embodiment, the mixing circuitry 225 is implemented as a shared complex mixer. It is important to note that this shared circuitry includes separate mixing paths for independent RF signal processing paths. Mixer 225 can be configured to downconvert the RF signal to a lower frequency. In some implementations, this downconversion can be performed to downconvert the RF signal to an IF level, a low IF level, a zero IF level, or even baseband. Depending on the implementation, mixer 225 can instead be separated into dedicated mixers, each associated with one of the RF signal processing paths 220.

[0035] Continue to refer to Figure 2 The down-converted signal is provided to multiple paths, namely the in-phase (I) path and the quadrature-phase (Q) path. As shown, these paths include corresponding programmable gain amplifiers (PGA) 230 capable of performing additional gain control.0,1 The resulting signal is then processed by the corresponding analog-to-digital converter (ADC) 235. 0,1 China has been digitized.

[0036] It should be noted that the RF front-end circuitry 220 further includes a power amplifier in the transmit direction. Figure 2 In a high-level view, multiple power amplifiers (PAs) 2400-2403 can be provided, allowing signals with controllable power levels to be supplied to a given output path among multiple output paths, i.e., dual output paths in this implementation. In one embodiment, a corresponding low-power PA and a high-power PA can be provided for each path. As shown, PA 240 is coupled to an output pin or pad (which in turn can be coupled to an off-chip matching network as described herein).

[0037] like Figure 2 As further illustrated, a local oscillator (LO) 260 is present. In the embodiments herein, the ability to provide independent RF signal processing paths operating in a widely divergent operating frequency band can be achieved at least partially via the LO 260, which outputs the LO signal to an LO divider (LODIV) 265. These components can collectively form a frequency synthesizer that can be programmably controlled to output a mixer signal used for down-conversion of incoming RF signals over a wide frequency range (e.g., at least in the 2.4 GHz and sub-GHz range described above) and for up-conversion from baseband to these RF frequencies in the transmission direction. Thus, as shown, the LODIV 265 is coupled to the RF front-end circuitry 220. 0,1 Both the receiver path component and the transmitter path component. Utilizing Figure 2 The implementation shown achieves a certain amount of hardware sharing between the two paths, thereby reducing area and complexity.

[0038] By avoiding on-chip matching networks (one or more), the complexity of designing such components for a wide frequency range is avoided. In this way, a single IC can be implemented in many different systems to handle RF communications over a wide frequency band. Furthermore, it is worth noting that in other use cases, independent RF signal processing paths can be used for diversity operation, such that both signal processing paths are configured to operate in the same frequency band to process signals received by the diversity antenna. Such diversity use cases can include, for example, vehicle entertainment systems where the diversity antenna is present in the vehicle environment to enable smoother reception of RF signals while the vehicle is in motion.

[0039] In fact, in some embodiments, it is possible for the IC to be initially designed for diversity operation by providing redundant RF paths initially designed for sub-GHz operation. The designed IC can be incorporated into a dual-mode wireless-enabled device that can use this diversity hardware to communicate in both sub-GHz and 2.4GHz networks. In other words, in the case of an embodiment, the IC can be configured in a given system implementation to have one RF signal processing path coupled to an off-chip sub-GHz matching network and another RF signal processing path coupled to an off-chip 2.4GHz matching network. In this way, performance optimization can be achieved for each frequency band while allowing dual-band operation without adding any additional hardware. When configured in such a system, the IC can receive and transmit in both the sub-GHz and 2.4GHz bands non-simultaneously without compromising performance in either band.

[0040] Now for reference Figure 3A A schematic diagram of multiple matching networks according to one embodiment is shown. Figure 3A As shown, a device 300, such as a given IoT device, includes multiple matching networks, namely matching networks 3100 and 3101. In embodiments herein, matching network 310 (generally) can be implemented as an off-chip component, thereby enabling greater flexibility for use with ICs that can operate in a wide frequency range across multiple frequency bands.

[0041] In one embodiment, when the device is configured such that one RF path operates at a sub-GHz frequency while the other operates in the 2.4GHz frequency range, a situation may arise where the harmonic frequencies of one band are close to the fundamental frequency of the other band. For example, the sub-GHz path may transmit in the 868MHz band, and the 2.4GHz path is configured to transmit in the 2.4GHz band, where 3*868 (2.6GHz) is close to 2.4GHz. In this case, the matching network of one path provides a good transmission path for the harmonic frequencies of the other path, and may lead to harmonic emission problems.

[0042] Different implementation methods can be used to alleviate this scenario. Figure 3A In this configuration, the RF switch 330 (which is further coupled to the antenna 350) can decouple the inactive matching network.

[0043] For details, please refer to the following: Figure 3AThe first matching network 3100 has different matching network paths for transmission and reception, both coupled between the RF switch 330 and the respective transmission and reception paths. It should be noted that the components of the matching network 3100 can be implemented on a circuit board coupled to an integrated circuit (such as IC 110). In the reception direction, the first matching network 3100 has an LC network formed by a series inductor L8 and a capacitor C12 connected in parallel between the reception path of the matching network 3100 and a reference voltage node (e.g., ground). In the transmission direction, the first matching network 3100 has multiple series-connected inductors L4-L6 and series-connected capacitors C10, along with parallel-connected capacitors C5-C8.

[0044] Similarly, the second matching network 3101 has different matching network paths for transmission and reception, both coupled between the RF switch 330 and the corresponding transmission and reception paths. As described above, the components of the matching network 3101 can be implemented on a circuit board. In the reception direction, the second matching network 3101 has an LC network formed by a series inductor L7 and a capacitor C11 connected in parallel. In the transmission direction, the second matching network 3101 has multiple series-connected inductors L1-L3 and series-connected capacitors C9, along with capacitors C1-C4 connected in parallel. It should be noted that in other implementations, C11 can be replaced by another inductor.

[0045] Referring now to Table 1, example values ​​for different inductors and capacitors in a matching network according to one embodiment are shown.

[0046] Table 1 .

[0047] In the table above, it is important to note that "NP" represents unpopulated (open circuit) and "OR" represents a zero-ohm resistor (short circuit). It should be understood that while these specific values ​​are shown for illustrative purposes, embodiments are not limited to these values, and different values ​​may be used in other embodiments. Furthermore, although... Figure 3A The diagram illustrates a specific implementation of the matching network, but it is to be understood that other topologies of the LC matching network may be used in other embodiments.

[0048] In the absence of RF switch 330, it is possible that... Figure 3AIn such an arrangement, standing alone can lead to leakage from inactive antennas. That is, harmonics from the sub-GHz band (e.g., the third harmonic) may fall within the operating frequency of the 2.4GHz band and, if coupled through ground, printed circuit board traces, and bonding wires, may leak directly through the closed antenna without any attenuation from the matching network 310, violating FCC or ETSI radiated emission limits.

[0049] In this scenario, a matching network for one path provides a good transmission path for the harmonic frequencies of another path, potentially leading to harmonic emission problems. Different implementation methods can be used to mitigate this situation. Figure 3A In this configuration, RF switch 330 can decouple inactive matching networks, thereby providing isolation between the "off" path and the antenna. Furthermore, by implementing a single-pole double-throw (SPDT) RF switch, only a single antenna is required. In other cases where two antennas are desired (e.g., for diversity purposes), a double-pole double-throw (DPDT) RF switch can be used.

[0050] In another scenario, a programmable harmonic filter trap can be included. (See now for reference.) Figure 3B A schematic diagram of a matching network according to another embodiment is shown. Figure 3B As shown, in device 300', only the matching network 3101 (to be used for the 2.4 GHz path) is shown for ease of illustration. In this implementation, the programmable harmonic filter 360 is shown as an optional component (in the dashed box). As shown, the programmable harmonic filter 360 includes a programmable capacitor C5 coupled between the antenna pin and the reference voltage node, and an inductor L5. Note that the capacitor C5 can be implemented on the die to provide flexibility for different frequencies and to controllably turn it on or off (as described below). In the embodiment, the values ​​of L5 and C5 can satisfy the relationship ω 2 =1 / √(L5*C5), where ω refers to the frequency where harmonic emission is problematic.

[0051] Using this arrangement, when the device transmits on ANT0 (i.e., for the sub-GHz band), the programmable harmonic filter 360 can be configured according to the above relationship. Therefore, most of the harmonic energy from the transmission flows through L5 / C5 and is not emitted from ANT1. However, configuring L5 / C5 according to the above relationship is undesirable when transmission on ANT1 at frequencies close to the harmonics (e.g., 2.4 GHz). Instead, the programmable capacitor C5 can be turned off. In this way, the impedance presented by L5 and C5 (with C5 turned off) can be absorbed into the matching network 3101. Although... Figure 3B This implementation is illustrated in the example, but other configurations are possible. Additionally, it's important to note that separate RF paths on the chip can be implemented using separate grounds to reduce coupling through a shared ground.

[0052] Now for reference Figure 4 A flowchart of a method according to one embodiment is shown. More specifically, Figure 4 Method 400 is a high-level method for operating a dual-mode wireless device according to one embodiment. Therefore, method 400 can be performed using an IC as described herein, which may include hardware circuitry such as a controller that can execute programmable instructions, alone or in combination with firmware and / or software, for controlling the IC implemented in the end-user equipment to operate in multiple modes.

[0053] As illustrated, method 400 begins by detecting the presence of one or more 2.4 GHz and sub-GHz networks (box 410). For example, a scan can be performed to identify the presence of such a network when the IoT device is powered on. Based on this detection, it is determined at diamond box 420 whether only a 2.4 GHz network is present. If so, control is passed to box 430, where the device can be configured for 2.4 GHz operation. As part of this configuration, unused circuitry, such as one or more other RF circuits, can be disabled to reduce power consumption. In this network environment, communication can be performed using 2.4 GHz protocols (box 440).

[0054] Still referencing Figure 4 Instead, if it is determined that only a sub-GHz network exists, as determined at diamond 450, control is passed to box 460, where the device can be configured for sub-GHz operation and unused circuitry can be disabled. In this network environment, communication can be performed using sub-GHz protocols (box 470). It should be noted that in some cases, the determinations at diamonds 420 and 450 may be performed in reverse order.

[0055] Continue to refer to Figure 4 If it is determined that multiple networks exist, including at least one 2.4 GHz network and at least one sub-GHz network, control is passed to box 480. At box 480, the device can be connected to the sub-GHz network using a 2.4 GHz protocol. For example, a BLE access procedure can be performed to connect the device to the sub-GHz network. Once connected, control is then passed to box 460, configuring the device to operate within the sub-GHz network. In this way, a BLE access procedure can be performed to include the device in the sub-GHz network. Continued operation then takes place within the sub-GHz network. Therefore, unused circuitry (e.g., at least one RF circuit) can be shut down.

[0056] Although described in this access example, it is to be understood that other implementations are possible, where operation can dynamically switch modes between sub-GHz and 2.4GHz protocols, for example, depending on network activity. In all these cases, the determination of the mode (including the frequency band for a given protocol) can be based at least in part on communication with network components, such as the network controller of a wireless control network.

[0057] Implementation examples can be carried out in many different environments. Reference now. Figure 5 A block diagram of a representative integrated circuit 500 is shown, which can be configured for dual-band operation using a matching network as described herein. Figure 5 In the illustrated embodiment, the integrated circuit 500 may be, for example, a microcontroller, a wireless transceiver that can operate according to one or more wireless protocols (e.g., WLAN-OFDM, WLAN-DSSS, Bluetooth, etc.), or other devices that may be used in a variety of use cases including sensing, metering, monitoring, embedded applications, communications, applications, etc., and may be particularly suitable for use in IoT devices.

[0058] In the illustrated embodiment, integrated circuit 500 includes a memory system 510, which in one embodiment may include non-volatile memory (such as flash memory) and volatile storage devices (such as RAM). In one embodiment, the non-volatile memory may be implemented as a non-transitory storage medium capable of storing instructions and data. Such non-volatile memory may store instructions, including instructions for determining an appropriate configuration of a matching network according to an embodiment of a given operating mode.

[0059] The memory system 510 is coupled to a digital core 520 via a bus 550. The digital core 520 may include one or more cores and / or a microcontroller that serve as the main processing unit of the integrated circuit. Furthermore, the digital core 520 may be coupled to a clock generator 530, which may provide one or more phase-locked loops or other clock generator circuitry to generate various clocks for use by the circuitry of the IC.

[0060] As further illustrated, IC 500 further includes a power circuitry 540, which may include one or more voltage regulators. Depending on the specific implementation, additional circuitry may optionally be present to provide various functions and interaction with external devices. Such circuitry may include: an interface circuitry 560 that provides an interface to various off-chip devices; and a sensor circuitry 570 that may include various on-chip sensors, including digital and analog sensors, to sense desired signals, such as for metering applications.

[0061] In addition, such as Figure 5 As shown, transceiver circuitry 580 can be provided to transmit and receive wireless signals, for example, according to one or more local area network or wide area network wireless communication schemes such as Zigbee, Bluetooth, IEEE 802.11, IEEE 802.15.4, cellular communication, etc. As illustrated, transceiver circuitry 580 includes dual RF paths 585 that can be coupled to an off-chip matching network as described herein. It should be understood that although shown in this high-level view, many variations and alternatives are possible.

[0062] It is important to note that the ICs described in this article can be implemented in a variety of different devices, such as IoT devices. As two examples, the IoT device could be a smart light bulb in a home or industrial automation network, or a smart utility meter used in a smart utility network, such as a mesh network that communicates according to the IEEE 802.15.4 specification or other such wireless protocols.

[0063] Now for reference Figure 6 A high-level diagram of a network according to one embodiment is shown. Figure 6 As shown, Network 600 includes various devices, including smart devices (such as IoT devices), routers, and remote service providers. Figure 6 In embodiments, the mesh network 605 may exist, for example, in a network with multiple IoT devices 610. 0-nIn a building. Such IoT devices may include dual RF paths and matching networks as described herein. As shown, at least one IoT device 610 is coupled to a router 630, which in turn communicates with a remote service provider 660 via a wide area network 650 (e.g., the Internet). In one embodiment, the remote service provider 660 may be a back-end server of a utility handling communications with the IoT device 610. It should be understood that, although... Figure 6 This high level is shown in the embodiments, but many variations and alternatives are possible.

[0064] While this disclosure has described a limited number of implementations, many modifications and variations will be apparent to those skilled in the art upon which this disclosure is made. The appended claims are intended to cover all such modifications and variations.

Claims

1. An integrated circuit for accessing sub-GHz networks using a 2.4GHz protocol, comprising: Semiconductor dies, including: A first radio frequency (RF) circuit includes a first low-noise amplifier (LNA) and a first mixer, the first RF circuit being configured to receive and process a first RF signal having a sub-gigahertz (GHz) frequency to output a first lower frequency signal, and to transmit an RF signal having a sub-GHz frequency. The second RF circuit includes a second LNA and a second mixer, the second RF circuit being configured to receive and process a second RF signal having a frequency of at least substantially 2.4 GHz to output a second lower frequency signal, and to transmit RF signals at at least substantially 2.4 GHz; A shared analog circuit device coupled to a first RF circuit and a second RF circuit, the shared analog circuit device being used to receive at least one of a first RF signal or a second RF signal and to output a digital output signal; Digital circuitry coupled to the shared analog circuitry, the digital circuitry being used to recover message information from the digital output signal; and A controller coupled to a first RF circuit and a second RF circuit, wherein in a first mode in which it is determined that there are multiple networks including at least one 2.4 GHz network and at least one sub-GHz network, the controller disables the first RF circuit and enables the second RF circuit, and the controller transmits access information to network components of the at least one 2.4 GHz network via the second RF circuit.

2. The integrated circuit according to claim 1, wherein: A first RF circuit is coupled to a first matching network, which is configured to impedance match a first antenna for receiving a first RF signal. as well as The second RF circuit is coupled to a second matching network, which is configured to match the impedance of the second antenna, which is used to receive the second RF signal.

3. The integrated circuit of claim 2, wherein the integrated circuit is coupled to a first matching network via a first pad of the semiconductor die and to a second matching network via a second pad of the semiconductor die, the first matching network and the second matching network being external to the integrated circuit.

4. The integrated circuit of claim 2, further comprising a programmable harmonic filter coupled to a second matching network, wherein the programmable harmonic filter is enabled when communication is via a first RF circuit to prevent the transmission of a first RF signal through the second matching network.

5. The integrated circuit of claim 1, wherein after the integrated circuit is at least partially accessed into the network based on the access information, the controller disables the second RF circuit and enables the first RF circuit.

6. The integrated circuit of claim 1, wherein when the integrated circuit is integrated in a system, the first RF circuit and the second RF circuit are configured to operate at sub-GHz frequencies, the first RF circuit being coupled to a first antenna, and the second RF circuit including a diversity path being coupled to a diversity antenna, wherein the first antenna and the diversity antenna are configured for the same operating frequency band.

7. The integrated circuit of claim 1, wherein the shared analog circuit comprises: A programmable gain amplifier for receiving a first lower frequency signal when a first RF circuit is active, and for receiving a second lower frequency signal when a second RF circuit is active; as well as An analog-to-digital converter (ADC) coupled to the output of the programmable gain amplifier is used to output the digital output signal to the digital circuit.

8. The integrated circuit of claim 1, wherein the semiconductor die further comprises a frequency synthesizer for generating a first mixing signal for a first mixer when the first RF circuit is active, and for generating a second mixing signal for a second mixer when the second RF circuit is active, wherein the first mixer and the second mixer comprise a shared complex mixer.

9. A method for accessing a sub-GHz network using a 2.4GHz protocol, comprising: Impedance matching is performed between a first radio frequency (RF) circuit of an integrated circuit and at least one antenna using a first matching network. The first RF circuit is configured to process a first RF signal of a sub-gigahertz (GHz) protocol. Impedance matching is performed between the second RF circuit of the integrated circuit and the at least one antenna using a second matching network. The second RF circuit is configured to process the second RF signal of the 2.4 GHz protocol. The first RF circuit is used to receive and process the impedance-matched first RF signal of the sub-GHz protocol; A second RF circuit is used to receive and process the impedance-matched second RF signal of the 2.4 GHz protocol; and In a first mode where it is determined that there are multiple networks including at least one 2.4 GHz network and at least one sub-GHz network, a first RF circuit is disabled and a second RF circuit is enabled to transmit access information with network components of the at least one 2.4 GHz network.

10. The method of claim 9, further comprising: A first RF signal is coupled from the at least one antenna to the first RF circuit via a first matching network including a first off-chip matching network and a first input pad of the integrated circuit coupled to the first off-chip matching network. as well as The second RF signal is coupled from the at least one antenna to the second RF circuit via a second matching network including a second off-chip matching network and a second input pad of the integrated circuit coupled to the second off-chip matching network.

11. The method of claim 9, wherein after the integrated circuit is at least partially accessed into the network based on the access information, the second RF circuit is disabled and the first RF circuit is enabled to communicate according to the sub-GHz protocol.

12. A computer-readable storage medium comprising computer-readable instructions, which, when executed, are used to implement the method claimed in any one of claims 9 to 11.

13. A system for accessing a sub-GHz network using a 2.4GHz protocol, comprising: At least one antenna for receiving radio frequency (RF) signals of the sub-gigahertz (GHz) protocol and RF signals of the 2.4 GHz protocol; A first matching network coupled to the at least one antenna, the first matching network being used for impedance matching of the at least one antenna and a first RF circuit of the integrated circuit; A second matching network is coupled to the at least one antenna, and the second matching network is used to perform impedance matching between the at least one antenna and the second RF circuit of the integrated circuit; as well as The integrated circuit, coupled to a first matching network and a second matching network, includes: A first RF circuit includes a first low-noise amplifier (LNA) configured to receive and process RF signals of the sub-GHz protocol. A second RF circuit, including a second LNA, is configured to receive and process RF signals of the 2.4 GHz protocol. A shared circuit device coupled to a first RF circuit and a second RF circuit, the shared circuit device being used to receive at least one of the sub-GHz protocol RF signal or the 2.4GHz protocol RF signal and to output a digital output signal; Digital circuitry coupled to the shared circuitry, the digital circuitry being used to recover message information from the digital output signal; and A controller coupled to a first RF circuit and a second RF circuit, wherein in a first mode in which it is determined that there are multiple networks including at least one 2.4 GHz network and at least one sub-GHz network, the controller disables the first RF circuit and enables the second RF circuit, and the controller transmits access information to network components of the at least one 2.4 GHz network via the second RF circuit.

14. The system of claim 13, wherein at least one of the first matching network or the second matching network is external to the integrated circuit.

15. The system of claim 13, wherein the first matching network comprises: A first matching network path having at least one first inductor coupled in series between the at least one antenna and the first RF circuit, and at least one first capacitor coupled in parallel to the at least one first inductor; as well as The second matching network path has at least one second inductor coupled in series between the at least one antenna and at least one power amplifier of the first RF circuit, and at least one second capacitor coupled in parallel to the at least one second inductor.

16. The system of claim 13, wherein after the system is at least partially connected to the network based on the access information, the controller disables the second RF circuit and enables the first RF circuit.

17. The system of claim 13, further comprising a programmable harmonic filter coupled to a second matching network, wherein the programmable harmonic filter is enabled when communication is via a first RF circuit to prevent harmonics of the sub-GHz protocol RF signal from being transmitted through the second matching network.

18. The system of claim 17, wherein the programmable harmonic filter includes a programmable capacitor contained in the integrated circuit and an inductor coupled between the programmable capacitor and the at least one antenna, wherein the programmable capacitor is decoupled from the inductor when communication is via a second RF circuit.

19. The system of claim 13, further comprising an RF switch coupled between the at least one antenna and the first and second matching networks.

20. The system of claim 13, further comprising a controller coupled to the first RF circuit and the second RF circuit, wherein when the system includes a vehicle system, the controller is configured to configure the first RF circuit and the second RF circuit to receive and process the sub-GHz protocol RF signals.

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