Measurement of interference due to antenna coupling

Abstract

A system for wireless communication includes a first radio frequency front end (RFFE) circuit coupled to a first antenna and a second RFFE coupled to a second antenna. The first RFFE circuit includes a first filter having a first passband spanning a first frequency band, a first low noise amplifier (LNA) coupled to the first filter, and a bypass circuit configured to bypass the first filter, the bypass circuit including an attenuator. The first RFFE also includes a first switching circuit configured to couple the first antenna to the first filter or the bypass circuit. The second RFFE circuit includes a power amplifier and a second filter coupled between the power amplifier and the second antenna, the second filter having a second passband that spans a second frequency band that is different from the first frequency band.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Non-Provisional Patent Application No. 18 / 363,321 filed in the U.S. Patent and Trademark Office on August 1, 2023, and Provisional Patent Application No. 63 / 395,265 filed in the U.S. Patent and Trademark Office on August 4, 2022, the contents of which are incorporated herein as if fully set forth below in their entirety and for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications, and more particularly to the measurement of jammer on wireless devices. Background Art

[0004] A wireless device may include multiple antennas for transmitting and / or receiving radio frequency (RF) signals. For example, the wireless device may receive a first RF signal via a first antenna and transmit a second RF signal via a second antenna. Due to antenna coupling between the first antenna and the second antenna, a portion of the energy of the second RF signal transmitted from the second antenna is coupled to the first antenna, which may potentially interfere with the reception of the first RF signal. Summary of the invention

[0005] The following content introduces a brief summary of one or more implementations to provide a basic understanding of such implementations. This overview is not an extensive overview of all expected implementations, and is neither intended to identify the key or important elements of all implementations, nor to describe the scope of any or all implementations. Its only purpose is to introduce some concepts of one or more implementations in a simplified form as a preface to the more detailed description that is subsequently introduced.

[0006] A first aspect relates to a system for wireless communication. The system includes a first radio frequency front end (RFFE) circuit coupled to a first antenna and a second RFFE coupled to a second antenna. The first RFFE circuit includes a first filter having a first passband spanning a first frequency band, a first low noise amplifier (LNA) coupled to the first filter, and a bypass circuit configured to bypass the first filter, the bypass circuit including an attenuator. The first RFFE also includes a first switching circuit, the first switching circuit configured to couple the first antenna to the first filter or the bypass circuit. The second RFFE circuit includes a power amplifier, and a second filter coupled between the power amplifier and the second antenna, the second filter having a second passband spanning a second frequency band different from the first frequency band.

[0007] A second aspect relates to a method for operating a wireless device, the wireless device comprising a first antenna and a second antenna. The method comprises: in a first mode, receiving a first radio frequency (RF) signal via the first antenna, and filtering the first RF signal using a filter. The method also comprises: in a second mode, sending a second RF signal via the second antenna, receiving the second RF signal via the first antenna, routing the second RF signal through a bypass circuit that bypasses the filter, and measuring a signal strength of the second RF signal.

[0008] A third aspect relates to a system including a first antenna and a second antenna. The system includes: means for receiving a first radio frequency (RF) signal via the first antenna, means for filtering the first RF signal, means for transmitting a second RF signal via the second antenna, means for receiving the first RF signal via the first antenna further including means for receiving the second RF signal via the first antenna, means for routing the second RF signal through a bypass circuit that bypasses the filter, and means for measuring a signal strength of the second RF signal.

[0009] A fourth aspect relates to a system for wireless communication. The system includes a first radio frequency front end (RFFE) circuit coupled to a first antenna, the first RFFE circuit being designed to condition signals for transmission and / or reception within a first frequency range, the first RFFE circuit including one or more circuits configured to provide a broadband bypass mode for received signals in a second frequency range different from the first frequency range. The system also includes a second RFFE circuit coupled to a second antenna, the second RFFE circuit being designed to condition signals for transmission and / or reception within the second frequency range.

[0010] A fifth aspect relates to a system for wireless communication. The system includes a modem integrated circuit, a transceiver integrated circuit coupled to the modem integrated circuit, and a first radio frequency front end (RFFE) circuit coupled between the transceiver integrated circuit and a first antenna. The first RFFE circuit includes: a first low noise amplifier (LNA) configured to amplify a first signal in a first frequency band; a first filter coupled to the first LNA, the first filter having a first passband spanning the first frequency band; a bypass circuit configured to bypass the first filter, the bypass circuit being configured to allow a second signal in a second frequency band different from the first frequency band to pass to the transceiver circuit; and a first switch circuit configured to couple the first antenna to the first filter or the bypass circuit. The system also includes a second RFFE circuit coupled between the transceiver integrated circuit and the second antenna. The second RFFE circuit includes: a first power amplifier; and a second filter coupled between the first power amplifier and the second antenna, the second filter having a second passband spanning the second frequency band.

[0011] A sixth aspect relates to a system for wireless communication. The system includes: a filter having a passband spanning a first frequency band; a first low noise amplifier (LNA) coupled to the filter, the first LNA being tuned to amplify a first signal in the first frequency band; a bypass circuit configured to bypass the filter, the bypass circuit including a second LNA tuned to amplify a second signal in a second frequency band different from the first frequency band; and a first switch circuit configured to couple a first antenna to the filter or the bypass circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1

[0013] An example of a wireless device including multiple antennas in accordance with certain aspects of the present disclosure is shown.

[0013] Figure 2 An example of a wireless device including a bypass circuit for measuring antenna coupling in accordance with certain aspects of the present disclosure is shown.

[0014] Figure 3 Another example of a wireless device including a bypass circuit in accordance with certain aspects of the present disclosure is shown.

[0015] Figure 4 Yet another example of a wireless device including a bypass circuit in accordance with certain aspects of the present disclosure is shown.

[0016] Figure 5 An example of a bypass circuit including a bypass low noise amplifier according to certain aspects of the present disclosure is shown.

[0017] Fig. 6A A first example use case of a wireless device in accordance with certain aspects of the present disclosure is shown.

[0018] Figure 6B A second example use case for a wireless device in accordance with certain aspects of the present disclosure is illustrated.

[0019] Figure 6C A third example use case for a wireless device in accordance with certain aspects of the present disclosure is illustrated.

[0020] Figure 7 An example environment including coexistence signals in accordance with certain aspects of the present disclosure is illustrated.

[0021] Figure 8 An example of a wireless device configured to detect coexistence signals in accordance with certain aspects of the present disclosure is shown.

[0022] Fig. 9 An example of a wireless device configured to simultaneously detect coexistence signals and receive RF signals for communication in accordance with certain aspects of the present disclosure is shown.

[0023] Fig.10 Another example of a wireless device configured to simultaneously detect coexistence signals and receive RF signals for communication in accordance with certain aspects of the present disclosure is shown.

[0024] Fig.11 An exemplary implementation of a switching circuit according to certain aspects of the present disclosure is shown.

[0025] Fig.12 is a flow chart illustrating a method for operating a wireless device in accordance with certain aspects of the present disclosure.

[0026] Fig.13 is a diagram of an environment including an electronic device including a transceiver in accordance with certain aspects of the present disclosure. DETAILED DESCRIPTION

[0027] The specific embodiments described below in conjunction with the accompanying drawings are intended as descriptions of various configurations, rather than being intended to represent the only configurations in which the concepts described herein may be practiced. The specific embodiments include specific details in order to provide a comprehensive understanding of the various concepts. However, it is apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, in order to avoid obscuring these concepts, well-known structures and components are shown in block diagram form.

[0028] Figure 1An example of a wireless device 110 according to certain aspects is shown. The wireless device 110 may be a cellular phone, a tablet computer, a laptop computer, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, etc. Figure 1 In the example shown, the wireless device 110 includes a first antenna 120, a second antenna 160, a receiver 115, and a transmitter 118. Although the examples are shown in FIG. Figure 1 Two antennas 120 and 160 are shown, but it should be understood that the wireless device 110 may include more than two antennas. In some aspects, the receiver 115 may be included in a first radio frequency front end (RFFE) circuit and the transmitter 118 may be included in a second RFFE circuit.

[0029] exist Figure 1 In the example shown, the receiver 115 includes a first filter 125 and a low noise amplifier 130. The low noise amplifier 130 has an input 132 and an output 134, and the first filter 125 is coupled between the first antenna 120 and the input 132 of the low noise amplifier 130.

[0030] In some aspects, the first filter 125 is a bandpass filter configured to pass a radio frequency (RF) signal in a first frequency band. For example, the first filter 125 may have a passband across the first frequency band. The first frequency band may be in a sub-6GHz band (e.g., any one of an LTE band, a 5G NR band, a wireless local area network (WLAN) band (e.g., WiFi 2 or 5GHz), etc.), a millimeter wave (mmWave) band, etc. The first filter 125 may include an acoustic filter, an inductor-capacitor (LC) filter, a cavity filter, a combination thereof, etc. Examples of acoustic filters include surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, etc. As used herein, a "bandpass filter" is a filter configured to pass an RF signal (e.g., with an attenuation of less than 3dB) within a frequency band.

[0031] The low noise amplifier 130 is configured to receive the RF signal from the first filter 125 at an input 132, amplify the RF signal, and output the amplified RF signal at an output 134. In one example, the low noise amplifier 130 may be configured (eg, tuned) to amplify RF signals in a first frequency band.

[0032] It should be understood that the receiver 115 may include Figure 1For example, in some implementations, the receiver 115 may include one or more additional filters (e.g., bandpass filters) coupled to the first antenna 120 for receiving RF signals in multiple frequency bands. In these implementations, the first filter 125 and the one or more additional filters may be coupled to the first antenna 120 via a duplexer and / or another circuit.

[0033] exist Figure 1 In the example of , the transmitter 118 includes a power amplifier 170 and a second filter 165. The power amplifier 170 has an input 172 and an output 174. The power amplifier 170 is configured to receive an RF signal (e.g., from a mixer) at the input 172, amplify the RF signal, and output the amplified RF signal at the output 174.

[0034] The second filter 165 is coupled between the output 174 of the power amplifier 170 and the second antenna 160. In some aspects, the second filter 165 is a bandpass filter configured to pass RF signals in the second frequency band. For example, the second filter 165 may have a passband across the second frequency band. The second frequency band may be in a sub-6GHz band (e.g., any one of the LTE band, the 5GNR band, the WLAN band (e.g., WiFi 2 or 5GHz), etc.), a millimeter wave (mmWave) band, etc. The second filter 165 may include an acoustic filter, an LC filter, a cavity filter, a combination thereof, etc. Examples of acoustic filters include SAW filters, BAW filters, etc. The second frequency band may be different from the first frequency band, or the same as the first frequency band.

[0035] It should be understood that the transmitter 118 may include Figure 1 For example, in some implementations, the transmitter 118 may include one or more additional filters (e.g., bandpass filters) coupled to the second antenna 160 for transmitting RF signals in multiple frequency bands. In these implementations, the second filter 165 and the one or more additional filters may be coupled to the second antenna 160 via a duplexer and / or another circuit.

[0036] exist Figure 1In the example shown, the wireless device 110 also includes a mixer 140, an analog-to-digital converter (ADC) 145, and a processor 150. The mixer 140 is coupled to the output 134 of the low noise amplifier 130, and the ADC 145 is coupled between the mixer 140 and the processor 150. In some aspects, the mixer 140 is configured to mix the RF signal from the low noise amplifier 130 with a local oscillator signal (labeled as "LO_RX") to down-convert the RF signal to a baseband signal. The ADC 145 is configured to convert the baseband signal to a digital signal and output the digital signal to the processor 150.

[0037] The processor 150 is configured to process digital signals. The processing performed by the processor 150 may include one or more of the following: demodulation, decoding, filtering, etc. The processor 150 may include a baseband processor, a modem, a digital signal processor (DSP), a general processor, a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof.

[0038] It will be appreciated that the wireless device 110 may include one or more additional components (not shown) in the receive path between the low noise amplifier 130 and the processor 150. For example, in some implementations, the wireless device 110 may include an additional amplifier (not shown) between the low noise amplifier 130 and the mixer 140.

[0039] The wireless device 110 may support wireless communications in multiple frequency bands. For example, the wireless device 110 may receive a first RF signal in a first frequency band using a receiver 115 via a first antenna 120, and transmit a second RF signal in a second frequency band using a transmitter 118 via a second antenna 160, wherein the first frequency band and the second frequency band may be different. In this example, the wireless device 110 may receive the first RF signal from a base station or another wireless device.

[0040] The wireless device 110 may also support multiple wireless technologies, including any one or more of the following technologies: fourth generation (4G) (e.g., long term evolution (LTE)), fifth generation (5G), ultra-wideband (UWB), Bluetooth, WiFi, etc. In this example, the wireless device 110 may use different wireless technologies (e.g., different wireless technologies among the exemplary wireless technologies listed above) or the same wireless technology to send the first RF signal and receive the second RF signal.

[0041] The wireless device 110 may use time division duplex (TDD) and / or frequency division duplex (FDD) to send and receive RF signals. For TDD, the wireless device 110 sends and receives RF signals in separate time slots. For FDD, the wireless device 110 sends and receives RF signals on different frequencies. It should be understood that the wireless device 110 may support both TDD and FDD.

[0042] A challenge with using multiple antennas on the wireless device 110 is antenna coupling between the first antenna 120 and the second antenna 160, wherein a portion of the energy of the second RF signal transmitted from the second antenna 160 is coupled to the first antenna 120. The portion of the energy of the second RF signal coupled to the first antenna 120 may interfere with the reception of the first RF signal at the receiver 115 (i.e., act as an interfering signal at the receiver 115). Antenna coupling (also referred to as antenna-to-antenna coupling) may be unavoidable due to, for example, the compact form of the wireless device 100 where the antennas 120 and 160 are placed in close proximity to each other.

[0043] In the case when the first RF signal and the second RF signal are in different frequency bands, the interference from the second RF signal can be referred to as crosstalk between the antennas 120 and 160. In these cases, the first filter 125 can mitigate the interference by attenuating the second RF signal received by the first antenna 120 (i.e., the first filter 125 can be configured to suppress RF signals outside the first frequency band). However, even with attenuation, interference due to antenna coupling may still cause problems at the receiver 115. In the case when the first RF signal and the second RF signal are in the same frequency band (i.e., the first frequency band and the second frequency band are the same) or the first RF signal and the second RF signal are in the same 3GPP defined frequency band (e.g., the first RF signal is in the FDD TX portion of the 3GPP defined frequency band and the second RF signal is in the FDD RX portion of the 3GPP defined frequency band, or vice versa), the interference from the second RF signal can be referred to as self-interference or in-band interference.

[0044] The wireless device 110 may employ one or more features to mitigate the effects of interference due to antenna coupling. A filter may be used to mitigate interference due to antenna coupling. However, the filter suffers from a trade-off between interference suppression and filter insertion loss, wherein interference suppression attenuates the interference level to a sustainable value, and filter insertion loss may severely limit receiver sensitivity and thus limit cell coverage in all cases. To avoid this trade-off, several features may be used to mitigate interference due to antenna coupling. In one example, one or more components in the receiver 115 (e.g., a low noise amplifier 130) may be configured to selectively operate in a high linearity mode when certain conditions are met (e.g., a channel frequency combination that may fall in the frequency band of the desired signal and produce a loss of sensitivity). In this example, the wireless device 110 may enable a high linearity mode to mitigate interference due to antenna coupling. However, operating the one or more components in a high linearity mode may result in a higher noise figure (NF), which may reduce sensitivity.

[0045] In another example, the wireless device 110 may selectively perform nonlinear interference cancellation (NLIC). The NLIC may be performed by the processor 150 and / or another component on the wireless device 110. In this example, the wireless device 110 may enable NLIC to mitigate interference due to antenna coupling. However, enabling NLIC may result in increased power consumption.

[0046] Other features for mitigating the effects of interference due to antenna coupling may include increasing the ADC rate of ADC 145, employing a harmonic rejection mixer (HRM), and / or a strict second-order input intercept point (TxIIP2) specification at the receiver. However, employing any of these features may increase power consumption, receiver complexity, and / or degrade in major performance as a NF.

[0047] Thus, the wireless device 110 may employ one or more of the above features to mitigate the effects of interference due to antenna coupling. However, this is at the expense of higher NF in the high linearity mode case and increased power consumption for other features.

[0048] In some cases, antenna coupling between the first antenna 120 and the second antenna 160 may be relatively low (e.g., isolation between the first antenna 120 and the second antenna 160 may be better than expected). In these cases, since interference from the antenna coupling may be relatively low, this allows one or more of the above features to be disabled and / or relaxed to reduce NF and / or reduce power consumption. In other words, better isolation between the first antenna 120 and the second antenna 160 can be utilized to reduce NF and / or reduce power consumption by disabling and / or relaxing one or more of the above features. Accordingly, it is desirable to identify situations (i.e., scenarios) when antenna coupling is relatively low (i.e., antenna isolation is good).

[0049] In some other cases, antenna coupling may be high, resulting in a larger portion of the signal being passed from one antenna to one or more other antennas. However, additional filtering at the wireless device (e.g., phone) can reduce the interference power at the input of the low noise amplifier (LNA), which can allow some of the above features to be disabled, thereby reducing power consumption and improving performance. Therefore, it is desirable to measure the antenna coupling and the filtering effects of additional components to have a better estimate of the interference power affecting the receiver.

[0050] To address this, aspects of the present disclosure provide circuits that can be added to the wireless device 110 to measure antenna coupling between two or more antennas. For example, in some implementations, the circuit may be configured to measure antenna coupling for different frequency band combinations and / or antenna combinations, and store the measurement results in a memory (e.g., a non-volatile memory). These measurement results can be used to identify situations (i.e., scenarios) when antenna coupling is relatively low (i.e., antenna isolation is good). In these cases, one or more of the above-mentioned features (e.g., high linearity mode, NLIC, TxIIP2, HRM, etc.) for mitigating interference due to antenna coupling can be disabled and / or relaxed to reduce NF and / or reduce power consumption. In another example, the measurement results can be used to determine when to enable (i.e., activate) one or more of the above-mentioned features (e.g., high linearity mode, NLIC, TxIIP2, HRM, etc.). Circuits according to aspects of the present disclosure may also be used to measure filter suppression (e.g., for specific frequency band combinations and / or antenna combinations).

[0051] In some implementations, circuits according to aspects of the present disclosure may also be used to detect situations when the wireless device 110 is potentially interfering with a coexisting signal operating in a particular frequency band (e.g., a radio altimeter device, a UWB signal, etc.). In response to detecting the coexisting signal, the wireless device 110 may take measures to avoid interfering with the coexisting signal, such as suspending transmissions in the frequency band of the coexisting signal, or reducing transmission power in the frequency band of the coexisting signal.

[0052] The above features of the present disclosure and other features of the present disclosure are discussed further below.

[0053] Figure 2 An example is shown in which the wireless device 110 includes circuitry for measuring antenna coupling according to certain aspects. In this example, the wireless device 110 includes Figure 1 The wireless device 110 also includes a first switch circuit 210, a second switch circuit 220, a bypass circuit 230, a frequency synthesizer 240, and a control circuit 250 (also referred to as a controller). The bypass circuit 230 bypasses the first filter 125, as discussed further below.

[0054] The first switch circuit 210 has a first terminal 212, a second terminal 214, and a third terminal 216. "Terminal" may also be referred to as a port or another term. The first terminal 212 is coupled to the first antenna 120, the second terminal 214 is coupled to the first filter 125, and the third terminal 216 is coupled to the bypass circuit 230. The first switch circuit 210 is configured to selectively couple the first terminal 212 to the second terminal 214 or to the third terminal 216 under the control of the control circuit 250. The first switch circuit 210 may be implemented using, for example, a switch network (e.g., a switch transistor). The first switch circuit 210 may also be referred to as an antenna switch because it switches the first antenna 120 between the first filter 125 and the bypass circuit 230.

[0055] The second switch circuit 220 has a first terminal 222, a second terminal 224, and a third terminal 226. The first terminal 222 is coupled to the output 134 of the low noise amplifier 130, the second terminal 224 is coupled to the bypass circuit 230, and the third terminal 226 is coupled to the mixer 140. The second switch circuit 220 is configured to selectively couple the first terminal 222 to the third terminal 226 or the second terminal 224 to the third terminal 226 under the control of the control circuit 250. The second switch circuit 220 can be implemented, for example, using a switch network (e.g., a switch transistor). The second switch circuit 220 can also be referred to as a multiplexer or another term.

[0056] In this example, the first filter 125 and the low noise amplifier 130 are coupled in series between the second terminal 214 of the first switch circuit 210 and the first terminal 222 of the second switch circuit 220. In addition, the bypass circuit 230 is coupled between the third terminal 216 of the first switch circuit 210 and the second terminal 224 of the second switch circuit 220. In operation, the control circuit 250 can selectively couple the first filter 125 and the low noise amplifier 130 between the first antenna 120 and the mixer 140, or couple the bypass circuit 230 between the first antenna 120 and the mixer 140. In order to couple the first filter 125 and the low noise amplifier 130 between the first antenna 120 and the mixer 140, the control circuit 250 causes the first switch circuit 210 to couple the first terminal 212 to the second terminal 214, and causes the second switch circuit 220 to couple the first terminal 222 to the third terminal 226. To couple the bypass circuit 230 between the first antenna 120 and the mixer 140, the control circuit 250 causes the first switch circuit 210 to couple the first terminal 212 to the third terminal 216 and causes the second switch circuit 220 to couple the second terminal 224 to the third terminal 226. In this case, the bypass circuit 230 bypasses the first filter 125, thereby allowing the RF signal to be measured without filter rejection by the first filter 125, as discussed further below.

[0057] In some aspects, the bypass circuit 230 can be broadband (e.g., typically implemented via an attenuator and a bypass path) to allow signals over a wide frequency range to pass, but at a gain level sufficient to allow downstream components (e.g., mixers, amplifiers, etc.) to process the signal. In some implementations, the bypass circuit 230 can include an attenuator. In this regard, Figure 2 An example is shown in which the bypass circuit 230 includes an attenuator 232 configured to attenuate the RF signal passing through the bypass circuit 230. The attenuator 232 can be implemented with a resistor attenuator including one or more resistors (e.g., arranged in an "L" configuration, a "T" configuration, a "pi" configuration, etc.), or another type of attenuator. In some aspects, the attenuator 232 can have a gain equal to or less than -3 dB, equal to or less than -6 dB, equal to or less than -12 dB, or equal to or less than -20 dB.

[0058] As discussed further below, attenuator 232 may be used to attenuate high amplitude RF signals that would otherwise saturate components in the receive path downstream of bypass circuit 230. Such components may include mixer 140 and / or additional amplifiers ( Figure 2230). Another advantage of attenuator 232 is that attenuator 232 (e.g., a resistor attenuator) has a wide (i.e., broad) frequency range. In other words, attenuator 232 provides broadband attenuation for bypass circuit 230. This allows antenna coupling to be measured over a wide (i.e., broad) frequency range, as discussed further below. In some aspects, attenuator 232 can be a variable attenuator with tunable attenuation that can be tuned by control circuit 250. In some implementations, downstream components in the receive path are able to process RF signals without saturation (e.g., the amplitude of the RF signal is not high enough to cause saturation). In these implementations, bypass circuit 230 can include a bypass path between the input and output of bypass circuit 230 that allows the RF signal to pass without attenuator 232 (e.g., the bypass path can have a gain of approximately 0 dB).

[0059] In this example, frequency synthesizer 240 is configured to generate a local oscillator signal (labeled “LO_RX”) for mixer 140. In some implementations, frequency synthesizer 240 may include one or more phase-locked loops (PLLs). In certain aspects, frequency synthesizer 240 may be configured to tune the frequency of the local oscillator signal under the control of control circuit 250. For example, frequency synthesizer 240 may be configured to set the frequency of the local oscillator signal to any one of a number of different frequencies under the control of control circuit 250.

[0060]

[0036] Example operation of the wireless device 110 according to certain aspects will now be discussed. In certain aspects, the control circuit 250 may selectively operate the wireless device 110 in the first mode or the second mode, as discussed further below.

[0061] In the first mode, the receiver 115 can receive a first RF signal in a first frequency band via the first antenna 120, wherein the first RF signal can be transmitted from a base station or another wireless device to the wireless device 110. In the first mode, as described above, the control circuit 250 causes the first switch circuit 210 and the second switch circuit 220 to couple the first filter 125 and the low noise amplifier 130 between the first antenna 120 and the mixer 140. In this mode, the first filter 125 (e.g., a bandpass filter) filters the first RF signal, and the low noise amplifier 130 amplifies the first RF signal. After filtering (e.g., bandpass filtering) and amplification, the mixer 140 mixes the first RF signal with a local oscillator signal to down-convert the first RF signal. For example, the frequency synthesizer 240 can set the frequency of the local oscillator signal to a first frequency in the first frequency band to down-convert the first RF signal to a baseband signal, which can then be converted to a digital signal by the ADC 145 and processed by the processor 150 (e.g., to recover data and control information). The first mode may also be referred to as a functional mode, a normal mode, or another term.

[0062] In the second mode, the receiver 115 can be used to measure the antenna coupling between the first antenna 120 and the second antenna 160. In the second mode, as described above, the control circuit 250 causes the first switch circuit 210 and the second switch circuit 220 to couple the bypass circuit 230 between the first antenna 120 and the mixer 140. This causes the receive path between the first antenna 120 and the mixer 140 to bypass the first filter 125. In this regard, the second mode may also be referred to as a bypass mode. As discussed further below, the second mode allows the antenna coupling to be measured without the filter suppression of the first filter 125.

[0063] In the second mode, the transmitter 118 transmits a second RF signal in a second frequency band via the second antenna 160. In one example, the second frequency band is different from the first frequency. However, it should be understood that in another example, the second frequency band may be the same as the first frequency band.

[0064] Due to antenna coupling between the first antenna 120 and the second antenna 160, a portion of the energy of the second RF signal is received by the first antenna 120. In the second mode, the second RF signal passes through the attenuator 232 in the bypass circuit 230. The attenuator 232 attenuates the second RF signal (i.e., attenuates the amplitude of the second RF signal). In this example, if the amplitude of the second RF signal entering the bypass circuit 230 is not attenuated by the attenuator 232, the amplitude of the second RF signal may be high and may saturate components in the receive path located downstream of the bypass circuit 230. The amplitude of the second RF signal may be high due to a lack of filter suppression, such as the first filter 125 (which is bypassed in the second mode) and / or the close proximity of the antennas 120 and 160. In some aspects, the attenuator 232 has a broadband response that is not limited by the filter (e.g., the filter 125) and the LNA tuned load.

[0065] After attenuation, the wireless device 110 may measure the signal strength (e.g., amplitude) of the second RF signal and use the measured signal strength to estimate the antenna coupling between the first antenna 120 and the second antenna 160. For example, the processor 150 may use the measured signal strength and the known attenuation of the attenuator 232 to estimate the power of the second RF signal at the first antenna 120. For example, the processor 150 may reference the measured signal strength of the second RF signal back to the first antenna 120 and estimate the power at the first antenna 120 based on the signal strength referenced to the first antenna 120. The processor 150 may reference the measured signal strength to the first antenna 120, for example, by subtracting the gain of the receive path between the measured location and the first antenna 120 from the measured signal strength. In this example, the gain of the receive path may be measured in advance as part of a reference gain measurement (e.g., performed in a test facility). Note that the gain of the receive path includes the gain of the attenuator 232, which may be given by -X dB, where X represents a number. The negative sign of the gain indicates that the attenuator 232 attenuates the RF signal. Thus, in this example, subtracting the gain of attenuator 232 may be equivalent to adding X dB. Since attenuator 232 is broadband, the gain of attenuator 232 is approximately constant over a wide frequency range and may therefore be reliably known over a wide frequency band.

[0066] The processor 150 may then estimate the antenna coupling based on a power difference between the power of the second RF signal at the first antenna 120 and the power of the second RF signal at the second antenna 160. In this example, the power at the second antenna 160 may be estimated using a power detector (not shown) coupled to the transmitter 118 and / or based on a gain or output power of the power amplifier 170. The processor 150 may store the antenna coupling in a memory 290 coupled to the processor 150.

[0067] The signal strength measurement may be performed by the processor 150 and / or a measurement circuit 280 coupled to the receive path between the mixer 140 and the processor 150. For example, the measurement circuit 280 may measure the signal strength (e.g., amplitude) of a baseband signal (generated from the RF signal) in the receive path and transmit the measured signal strength to the processor 150. In this example, the signal strength of the baseband signal provides a measure of the signal strength of the RF signal. In another example, the processor 150 may measure the signal strength in the digital domain after the ADC 145. In this example, the measurement circuit 280 may be omitted. Thus, the signal strength may be measured before or after the ADC 145.

[0068] In one example, the transmitter 118 may send a second RF signal to the base station in a sounding reference signal (SRS) time slot, wherein the second RF signal includes an SRS. In this example, the base station receives the second RF signal, and uses the SRS in the second RF signal to estimate the channel quality between the wireless device 110 and the base station. In this example, the wireless device 110 may also use the second RF signal to measure the antenna coupling between the first antenna 120 and the second antenna 160 in the manner described above. Therefore, in this example, the wireless device 110 may utilize the SRS time slot to measure the antenna coupling. As used herein, a "sounding reference signal" is a reference signal used by a base station (e.g., eNodeB, gNB, etc.) or an access point to estimate channel quality. It should be understood that in addition to the SRS, the second RF signal may also include one or more other signals.

[0069] Thus, in the second mode (i.e., bypass mode), the wireless device 110 routes the second RF signal received at the first antenna 120 through the bypass circuit 230 to measure the antenna coupling without the filter suppression of the first filter 125. After measuring the antenna coupling, the processor 150 may determine whether to disable and / or relax one or more of the features discussed above for mitigating interference due to antenna coupling (e.g., high linearity mode, NLIC, TxIIP2, HRM, etc.) based on the measured antenna coupling. For example, if the measured antenna coupling is equal to or below a certain threshold, the processor 150 may disable and / or relax one or more of the above features. In another example, one or more of the above features may be disabled (e.g., as a default setting), and the measured antenna coupling may be used to determine whether to enable (i.e., activate) one or more of the above features (e.g., high linearity mode, NLIC, TxIIP2, HRM, etc.). In this example, if the measured antenna coupling is above the threshold, the processor 150 may enable one or more of the above features.

[0070] Since the bypass circuit 230 bypasses the first filter 125, the bypass circuit 230 can also be used to estimate the frequency suppression characteristics of the first filter 125. For example, according to certain aspects, the frequency suppression characteristics of the first filter 125 in the second frequency band can be estimated as follows. First, the receiver 115 receives an RF signal in the second frequency band via the first antenna 120. The RF signal can be a second RF signal sent from the second antenna 160 or another RF signal in the second frequency band. In this example, the wireless device 110 uses the RF signal routed through the first filter 125 to make a first measurement of the signal strength of the RF signal, and uses the RF signal routed through the bypass circuit 230 to make a second measurement of the signal strength of the RF signal. The processor 150 can then characterize the filter suppression of the first filter 125 in the second frequency band based on the difference between the first measurement result and the second measurement result. Before taking the difference between the first measurement result and the second measurement result, the processor 150 can adjust the second measurement result to account for the attenuation in the attenuator 232. For example, if the attenuation of the attenuator 232 is -X dB, the processor can add X dB to the second measurement result to account for the attenuation.

[0071] In the above example, the control circuit 250 may route the RF signal through the first filter 125 for the first measurement by causing the first switch circuit 210 and the second switch circuit 220 to couple the first filter 125 between the first antenna 120 and the mixer 140, and route the RF signal through the bypass circuit 230 for the second measurement by causing the first switch circuit 210 and the second switch circuit 220 to couple the bypass circuit 230 between the first antenna 120 and the mixer 140. According to various aspects, the first measurement and the second measurement may be performed by the measurement circuit 280 and / or the processor 150. In addition, in this example, the control circuit 250 may cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency in the second frequency band to perform the measurement.

[0072] In some implementations, transmitter 118 may transmit in multiple frequency bands. In this regard, Figure 3An example is shown in which the transmitter 118 further includes a third filter 330, a first switch 310, and a second switch 320. In some aspects, the third filter 330 is a bandpass filter configured to pass RF signals in a third frequency band. The third frequency band may be within a sub-6GHz band (e.g., any one of an LTE band, a 5G NR band, a WLAN band (e.g., WiFi 2 or 5GHz), etc.), a millimeter wave (mmWave) band, etc. The third filter 330 may include an acoustic filter (e.g., SAW, BAW, etc.), an LC filter, a cavity filter, a combination thereof, etc. In one example, the third frequency band is different from the second frequency band. In this example, the power amplifier 170 may be configured (e.g., tuned) to amplify signals in both the second frequency band and the third frequency band.

[0073] The first switch 310 is coupled between the second filter 165 and the output 174 of the power amplifier 170, and the second filter 165 is coupled between the first switch 310 and the second antenna 160. The second switch 320 is coupled between the third filter 330 and the output 174 of the power amplifier 170, and the third filter 330 is coupled between the second switch 320 and the second antenna 160. Each of the switches 310 and 320 may be implemented with a switching transistor or another type of switch.

[0074] In this example, the transmitter 118 can selectively transmit RF signals in the second frequency band or the third frequency band. To transmit in the second frequency band, the control circuit 250 turns on the first switch 310 and turns off the second switch 320, which couples the second filter 165 between the power amplifier 170 and the second antenna 160. To transmit in the third frequency band, the control circuit 250 turns off the first switch 310 and turns on the second switch 320, which couples the third filter 330 between the power amplifier 170 and the second antenna 160.

[0075] In this example, the wireless device 110 can measure the antenna coupling between the antennas 120 and 160 for the second frequency band and the third frequency band. To measure the antenna coupling for the second frequency band, the control circuit 250 turns on the first switch 310 and turns off the second switch 320, and the transmitter 118 transmits a second RF signal in the second frequency band. The wireless device 110 can then use the bypass circuit 230 in the receiver 115 to measure the antenna coupling, as described above.

[0076] To measure the antenna coupling for the third frequency band, the control circuit 250 turns off the first switch 310 and turns on the second switch 320. The power amplifier 170 receives a third RF signal in the third frequency band (e.g., from a mixer), amplifies the third RF signal, and outputs the third RF signal to the third filter 330. The third RF signal is filtered by the third filter 330 and transmitted via the second antenna 160. The receiver 115 receives a portion of the energy of the third RF signal via the first antenna 120, routes the third RF signal through the bypass circuit 230, and measures the signal strength of the third RF signal in the manner discussed above according to certain aspects. The processor 150 can then estimate the antenna coupling for the third frequency band based on the measured signal strength, and store the antenna coupling for the third frequency band in the memory 290.

[0077] Figure 4 Another example of a wireless device 110 according to certain aspects is shown. In this example, the transmitter 118 includes the second filter 165, the third filter 330, the first switch 310, the second switch 320, and the power amplifier 170 discussed above. The transmitter 118 also includes a fourth filter 430, a fifth filter 435, a third switch 440, a fourth switch 445, a second power amplifier 450, and a duplexer 410. The second power amplifier 450 has an input 452 and an output 454, wherein the second power amplifier 450 is configured to receive an RF signal at the input 452, amplify the RF signal, and output the amplified RF signal at the output 454. In the following discussion, the power amplifier 170 is referred to as the first power amplifier.

[0078] In some aspects, the fourth filter 430 is a bandpass filter configured to pass RF signals in a fourth frequency band, and the fifth filter 434 is a bandpass filter configured to pass RF signals in a fifth frequency band. Each frequency band can be in a sub-6GHz frequency band (e.g., any one of an LTE frequency band, a 5G NR frequency band, a WLAN frequency band (e.g., WiFi 2 or 5GHz), etc.), a millimeter wave (mmWave) frequency band, etc. Each of the filters 430 and 435 may include an acoustic filter (e.g., SAW, BAW, etc.), an LC filter, a cavity filter, a combination thereof, etc. In one example, the fourth frequency band may be different from the fifth frequency band. In this example, the second power amplifier 450 may be configured (e.g., tuned) to amplify signals in both the fourth frequency band and the fifth frequency band.

[0079] The duplexer 410 has a first terminal 415, a second terminal 420, and a third terminal 425 coupled to the second antenna 160. In some aspects, the duplexer 410 is configured to couple the first terminal 415 to the third terminal 425 for RF signals within a first frequency range, and to couple the second terminal 420 to the third terminal 425 for RF signals within a second frequency range, wherein the first frequency range is different from the second frequency range. Therefore, the duplexer 410 is configured to couple RF signals in the first frequency range and RF signals in the second frequency range to a common antenna (i.e., the second antenna 160). In an example, the second frequency band and the third frequency band are within the first frequency range, and the fourth frequency band and the fifth frequency band are within the second frequency range.

[0080] In this example, the second filter 165 is coupled between the first switch 310 and the first terminal 415 of the duplexer 410 , and the third filter 330 is coupled between the second switch 320 and the first terminal 415 of the duplexer 410 .

[0081] Furthermore, in this example, the third switch 440 is coupled between the fourth filter 430 and the output 454 of the second power amplifier 450, and the fourth filter 430 is coupled between the third switch 440 and the second terminal 420 of the duplexer 410. The fourth switch 445 is coupled between the fifth filter 435 and the output 454 of the second power amplifier 450, and the fifth filter 435 is coupled between the fourth switch 445 and the second terminal 420 of the duplexer 410. Each of the switches 440 and 445 may be implemented with a switching transistor or another type of switch.

[0082] In this example, the transmitter 118 may selectively transmit RF signals in the second frequency band, the third frequency band, the fourth frequency band, or the fifth frequency band. Figure 3 Transmission in a second frequency band and a third frequency band is discussed. In this example, the second RF signal and the third RF signal are coupled to the second antenna 160 through a duplexer 410 .

[0083] To transmit in the fourth frequency band, the control circuit 250 turns on the third switch 440 and turns off the fourth switch 345, which couples the second power amplifier 450 to the fourth filter 340. To transmit in the fifth frequency band, the control circuit 250 turns off the third switch 440 and turns on the fourth switch 445, which couples the second power amplifier 450 to the fifth filter 435. In this example, the fourth filter 430 and the fifth filter 435 are coupled to the second antenna 160 through the duplexer 410.

[0084] In this example, wireless device 110 may measure antenna coupling between antennas 120 and 160 for the second frequency band and the third frequency band, as described above with reference to FIG. Figure 3 Wireless device 110 may also measure antenna coupling between antennas 120 and 160 for the fourth and fifth frequency bands.

[0085] To measure the antenna coupling for the fourth frequency band, the control circuit 250 turns on the third switch 440 and turns off the fourth switch 445. The second power amplifier 450 receives a fourth RF signal in the fourth frequency band (e.g., from a mixer), amplifies the fourth RF signal, and outputs the fourth RF signal to the fourth filter 430. The fourth RF signal is filtered by the fourth filter 430 and transmitted via the second antenna 160. The receiver 115 receives a portion of the energy of the fourth RF signal via the first antenna 120, routes the fourth RF signal through the bypass circuit 230, and measures the signal strength of the fourth RF signal in the manner discussed above according to certain aspects. The processor 150 can then estimate the antenna coupling for the fourth frequency band based on the measured signal strength, and store the antenna coupling for the fourth frequency band in the memory 290.

[0086] To measure the antenna coupling for the fifth frequency band, the control circuit 250 turns off the third switch 440 and turns on the fourth switch 445. The second power amplifier 450 receives a fifth RF signal in the fifth frequency band (e.g., from a mixer), amplifies the fifth RF signal, and outputs the fifth RF signal to the fifth filter 435. The fifth RF signal is filtered by the fifth filter 435 and transmitted via the second antenna 160. The receiver 115 receives a portion of the energy of the fifth RF signal via the first antenna 120, routes the fifth RF signal through the bypass circuit 230, and measures the signal strength of the fifth RF signal in the manner discussed above according to certain aspects. The processor 150 can then estimate the antenna coupling for the fifth frequency band based on the measured signal strength, and store the antenna coupling for the fifth frequency band in the memory 290.

[0087] Therefore, the wireless device 110 can measure the antenna coupling for each of the second, third, fourth, and fifth frequency bands, and store the antenna coupling for each frequency band in the memory 290. Since the attenuator 232 is broadband, the gain of the attenuator 232 can be approximately constant on the second, third, fourth, and fifth frequency bands. For each frequency band, the processor 150 can determine whether to disable and / or relax one or more of the features discussed above (e.g., high linearity mode, NLIC, TxIIP2, HRM, etc.) for mitigating interference due to antenna coupling based on the measured antenna coupling for the frequency band. For example, for each frequency band, if the measured antenna coupling for the frequency band is equal to or lower than a specific threshold, the processor 150 can disable and / or relax one or more of the above-mentioned features.

[0088] It should be understood that the transmitter 118 is not limited to Figure 2 , 3 and the exemplary implementations shown in .

[0089] It should be understood that in some implementations, the bypass circuit 230 may include one or more additional components in addition to the attenuator 232. In this regard, Figure 5 An example is shown in which bypass circuit 230 also includes bypass low noise amplifier 510. As discussed further below, bypass low noise amplifier 510 can be used to increase the sensitivity of bypass circuit 230 for certain signals and / or provide a replica of low noise amplifier 130 without the filter rejection of first filter 125.

[0090] The bypass low noise amplifier 510 has an input 512 and an output 514. Figure 5 In the example of , the input 512 is coupled to the third terminal 216 of the first switch circuit 210, and the output 514 is coupled to the second terminal 224 of the switch circuit 220. The bypass low noise amplifier 510 is configured to receive an RF signal at the input 512, amplify the RF signal, and output the amplified RF signal at the output 514. In some aspects, the bypass low noise amplifier 510 is configured (e.g., tuned) to amplify RF signals within a specific frequency band. In one example, the frequency band of the bypass low noise amplifier 510 includes a first frequency band. In this example, the bypass low noise amplifier 510 can be a copy of the low noise amplifier 130 with approximately the same gain. In another example, the frequency band of the bypass low noise amplifier 510 can be a wide (i.e., broad) frequency band covering multiple frequency bands (e.g., any one or more frequency bands of the first, second, third, fourth, and fifth frequency bands).

[0091] exist Figure 5In the example of , the bypass circuit includes a switch 520, wherein the attenuator 232 and the switch 520 are coupled in series between the third terminal of the first switch circuit 210 and the second terminal 224 of the second switch circuit 220. As discussed further below, the control circuit 250 can use the switch 520 to selectively enable or disable the attenuation path of the bypass circuit 230.

[0092] In the second mode (i.e., bypass mode), the control circuit 250 controls whether the RF signal passing through the bypass circuit 230 is attenuated by the attenuator 232 or amplified by the bypass low noise amplifier 510. In one example, the control circuit 250 turns on the switch 520 and turns off the bypass low noise amplifier 510 to enable the attenuation path of the bypass circuit 230. In this case, the attenuator 232 attenuates the RF signal passing through the bypass circuit 230. In this example, the control circuit 250 turns off the switch 520 and enables the bypass low noise amplifier 510 to amplify the RF signal.

[0093] In certain aspects, for situations where the RF signal has a high amplitude and would saturate components in the receive path downstream of the bypass circuit 230 if it is not attenuated, the control circuit 250 may cause the RF signal to be attenuated by the attenuator 232. For situations where the RF signal is relatively weak and increased sensitivity is desired, the control circuit 250 may cause the RF signal to be amplified by the bypass low noise amplifier 510. For examples where the bypass low noise amplifier 510 is a copy of the low noise amplifier 130, the bypass low noise amplifier 510 may be used to estimate the gain of the low noise amplifier without the filter suppression of the first filter 125 (which is bypassed in this case). In this example, the control circuit 250 may cause the bypass low noise amplifier 510 to amplify the RF signal. The wireless device 110 may then measure the signal strength of the amplified RF signal using any of the techniques discussed above, and the processor 150 may estimate the gain of the bypass low noise amplifier 510 based on the measured signal strength. Assuming that the low noise amplifier 130 and the bypassed low noise amplifier 510 have approximately the same gain, the estimated gain of the bypassed low noise amplifier 510 may be used as an estimate of the gain of the low noise amplifier 130 .

[0094] In one example, the estimated gain of the low noise amplifier 130 can be used to characterize the filter rejection of the first filter 125. In this example, the receiver 115 receives an RF signal via the first antenna 120. The RF signal can be any one of the RF signals discussed above or another RF signal. In this example, the wireless device 110 uses the RF signal routed through the first filter 125 and the low noise amplifier 130 to make a first measurement of the signal strength of the RF signal, and uses the RF signal routed through the attenuator 232 to make a second measurement of the signal strength of the RF signal. The processor 150 can then characterize the filter rejection of the first filter 125 based on the difference between the first measurement result and the second measurement result. Before taking the difference, the processor 150 can adjust the second measurement result to take into account the attenuation in the attenuator 232. For example, if the attenuation of the attenuator 232 is -X dB, the processor can add X dB to the second measurement result to take into account the attenuation. Before taking the difference, the processor 150 can also adjust the first measurement result to take into account the gain of the low noise amplifier 130. For example, the processor 150 may subtract the estimated gain of the low noise amplifier 130 from the first measurement result to account for the gain of the low noise amplifier 130 .

[0095] Examples of various use cases for the wireless device 110 will now be discussed according to certain aspects. However, it should be understood that the exemplary use cases discussed below are for illustration purposes only, and the wireless device 110 is not limited to these examples.

[0096] Fig. 6A An exemplary use case (i.e., scenario) is shown in which a transmitter 118 transmits in a low frequency band (LB) and a low noise amplifier 130 in a receiver 115 is tuned to operate in a mid-high frequency band (MHB). In this example, LB can cover a frequency range of 0.6 to 1 GHz, and MHB can cover a frequency range of 1.8 to 2.7 GHz. However, it should be understood that the present disclosure is not limited to this example. In this example, a first power amplifier 170 can be configured to amplify a signal in LB, and a second power amplifier 450 can be configured to amplify a signal in MHB. In this example, a duplexer 410 is configured to isolate the first power amplifier 170 from the second power amplifier 450.

[0097] In this example, the second frequency band of the second filter 165 and the third frequency band of the third filter 330 are in LB, and the fourth frequency band of the fourth filter 430 and the fifth frequency band of the fifth filter 435 are in MHB. Fig. 6A In the example shown, the second frequency band is n8, and the third frequency band is n71. However, it should be understood that the second frequency band and the third frequency band are not limited to this example, and may include other frequency bands in the LB.

[0098] In this example, the low noise amplifier 130 is tuned to operate in MHB, and the first frequency band (e.g., n25) of the first filter 125 is in MHB. It should be understood that the receiver 115 may also include one or more filters (not shown) and one or more low noise amplifiers (not shown) configured to operate in LB or another frequency band. In this example, the receiver 115 may include a duplexer (not shown) to isolate the low noise amplifier 130 and the first filter 125 from the one or more filters (not shown) and one or more low noise amplifiers (not shown) operating in LB.

[0099] In the first mode (i.e., functional mode), the receiver 115 receives an RF signal (e.g., a first RF signal) in the MHB (e.g., from a base station or another wireless device). In this mode, the control circuit 250 can cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency in the first frequency band (e.g., n25) to down-convert the received RF signal to a baseband signal.

[0100] In the second mode (i.e., bypass mode), the wireless device 110 can measure the antenna coupling between the first antenna 120 and the second antenna 160 for the scenario of LB transmission (i.e., LB interference). To this end, the transmitter 118 transmits the RF signal in the LB via the second antenna 160 using the first power amplifier 170 for amplification and the second filter 165 or the third filter 330 for filtering. Due to the antenna coupling between the first antenna 120 and the second antenna 160, a portion of the energy of the RF signal is received by the first antenna 120. The control circuit 250 routes the RF signal through the attenuator 232 in the bypass circuit 230, which provides broadband attenuation. The control circuit 250 can also cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency (e.g., 897.5 MHz) in the frequency band (e.g., the second frequency band or the third frequency band) of the transmitter 118 to perform antenna coupling measurement.

[0101] After attenuation, the wireless device 110 may measure the signal strength (e.g., amplitude) of the RF signal using any of the techniques discussed above, and use the measured signal strength to estimate antenna coupling between the first antenna 120 and the second antenna 160. For example, the processor 150 may use the measured signal strength and the known attenuation of the attenuator 232 to estimate the power of the second RF signal at the first antenna 120. For example, the processor 150 may reference the measured signal strength back to the first antenna 120 and estimate the power at the first antenna 120 based on the signal strength of the reference first antenna 120. As described above, the processor 150 may reference the measured signal strength back to the first antenna 120 using a reference gain measurement.

[0102] The processor 150 may then estimate the antenna coupling based on a power difference between the power of the second RF signal at the first antenna 120 and the power of the second RF signal at the second antenna 160. In this example, the power at the second antenna 160 may be estimated using a power detector (not shown) coupled to the transmitter 118 and / or based on a gain or output power of the first power amplifier 170. The processor 150 may store the antenna coupling in the memory 290.

[0103] exist Fig. 6A In the example in , the transmitter 118 transmits in LB and the low noise amplifier 130 operates in MHB. However, it should be understood that the present disclosure is not limited to this example. In another exemplary use case (i.e., scenario), the transmitter 118 transmits in MHB and the low noise amplifier 130 operates in MHB. In this regard, Figure 6B An exemplary use case (ie, scenario) is shown where the transmitter 118 transmits in MHB and the low noise amplifier 130 in the receiver 115 is tuned to operate in MHB.

[0104] exist Figure 6B In the example shown, the fourth frequency band is n25 and the fifth frequency band is n66. However, it should be understood that the fourth frequency band and the fifth frequency band are not limited to this example and may include other frequency bands in MHB.

[0105] In a first mode (i.e., functional mode), the receiver 115 receives an RF signal (e.g., a first RF signal) in MHB (e.g., from a base station or another wireless device). In this mode, the control circuit 250 can cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency in a first frequency band (e.g., n25) to down-convert the received RF signal to a baseband signal. In this example, the first frequency band is in MHB, as described above.

[0106] In the second mode (i.e., bypass mode), for the scenario of MHB transmission (i.e., MHB interference), the wireless device 110 can measure the antenna coupling between the first antenna 120 and the second antenna 160. To this end, the transmitter 118 transmits the RF signal in MHB via the second antenna 160 using the second power amplifier 450 for amplification and the fourth filter 430 or the fifth filter 435 for filtering. Due to the antenna coupling between the first antenna 120 and the second antenna 160, a portion of the energy of the RF signal is received by the first antenna 120. The control circuit 250 routes the RF signal through the attenuator 232 in the bypass circuit 230, which provides broadband attenuation. The control circuit 250 can also cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency (e.g., 1882.5 MHz) in the frequency band (e.g., the fourth frequency band or the fifth frequency band) of the transmitter 118 to perform antenna coupling measurement. The wireless device 110 may then measure the signal strength of the RF signal and estimate the antenna coupling based on the measured signal strength (e.g., as described above with reference to Fig. 6A discussed).

[0107] Figure 6C Another exemplary use case (ie, scenario) is shown where the transmitter 118 transmits in MHB and the low noise amplifier 130 in the receiver 115 is tuned to operate in the n77 band. Figure 6C In the example shown, the fourth frequency band is n3 and the fifth frequency band is n66. However, it should be understood that the fourth frequency band and the fifth frequency band are not limited to this example.

[0108] In the first mode (i.e., functional mode), the receiver 115 receives an RF signal (e.g., a first RF signal) in the n77 frequency band (e.g., from a base station or another wireless device). In this mode, the control circuit 250 can cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency in the n77 frequency band to down-convert the received RF signal to a baseband signal.

[0109] In the second mode (i.e., bypass mode), for the scenario of MHB transmission (i.e., MHB interference), the wireless device 110 can measure the antenna coupling between the first antenna 120 and the second antenna 160. To this end, the transmitter 118 transmits the RF signal in MHB via the second antenna 160 using the second power amplifier 450 for amplification and the fourth filter 430 or the fifth filter 435 for filtering. Due to the antenna coupling between the first antenna 120 and the second antenna 160, a portion of the energy of the RF signal is received by the first antenna 120. The control circuit 250 routes the RF signal through the attenuator 232 in the bypass circuit 230, which provides broadband attenuation. The control circuit 250 can also cause the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to a frequency (e.g., 1.747 GHz) in the frequency band (e.g., the fourth frequency band or the fifth frequency band) of the transmitter 118 to perform antenna coupling measurement. The wireless device 110 may then measure the signal strength of the RF signal and estimate the antenna coupling based on the measured signal strength (e.g., as described above with reference to Fig. 6A discussed).

[0110] The bypass circuit 230 may also be used to detect situations in which the wireless device 110 is potentially interfering with a coexistence signal operating in a particular frequency band. The coexistence signal may be a signal intended for another wireless device, a signal intended for another receiver on the wireless device 110, etc. In other words, the wireless device 110 may coexist with other wireless devices in the radio environment and may take steps to avoid interfering with the signals of the other wireless devices (i.e., the coexistence signal). The coexistence signal may include, for example, a radio altimeter signal, a UWB signal, a WiFi signal, a cellular vehicle-to-everything (CV2X) signal, and / or another signal.

[0111] In response to detecting the coexistence signal, the wireless device 110 may take action to avoid interfering with the coexistence signal, such as ceasing transmission in the frequency band of the coexistence signal or reducing transmission power in the frequency band of the coexistence signal. The detection of coexistence signals using the bypass circuit 230 is discussed below in terms of certain aspects of an example using a radio altimeter signal. However, it should be understood that the disclosure is not limited to this example, and the bypass circuit 230 may be used to detect other coexistence signals, such as, for example, a UWB signal.

[0112] Figure 7An exemplary environment 710 is shown in which the wireless device 110 may potentially interfere with a coexisting signal. In this example, the environment 710 may include a radio altimeter device 720 (e.g., on an aircraft or another vehicle). The radio altimeter device 720 may be configured to send a radio altimeter signal 725 to the ground 730, which reflects the radio altimeter signal 725 back to the radio altimeter device 720. The radio altimeter device 720 may then estimate the height from the ground 730 based on the time it takes for the radio altimeter signal 732 to return to the radio altimeter device 720. The radio altimeter signal 732 may have a frequency band of 4.2 to 4.4 GHz or another frequency band. In this environment 710, RF transmissions from the wireless device 110 may interfere with the radio altimeter device 720.

[0113] Figure 7 Also shown is an example of another wireless device 735 that may transmit a coexisting signal (e.g., a UWB signal) that the wireless device 735 may potentially interfere with due to the coexisting signal. In this example, the wireless device 110 may transmit an RF signal having a frequency close enough to the coexisting signal to interfere with the coexisting signal. Figure 7 Also shown is an example of a base station 740 that can communicate wirelessly (e.g., to provide wireless services) with the wireless device 110. In this example, the base station 740 can also potentially interfere with the coexisting signal.

[0114] To address interference with coexisting signals, bypass circuit 230 according to certain aspects can be used to monitor for coexisting signals, such as a radio altimeter signal or another coexisting signal (e.g., a UWB signal). If a coexisting signal is detected, wireless device 110 can take action to mitigate interference with the coexisting signal, as discussed further below.

[0115] In this regard, Figure 8 An example is shown in which the bypass circuit 230 can be used to monitor a coexistence signal (e.g., a radio altimeter signal). To monitor the coexistence signal, the control circuit 250 causes the first switch circuit 210 and the second switch circuit 220 to couple the bypass circuit 230 between the first antenna 120 and the mixer 140. The control circuit 250 also enables the bypass low noise amplifier 510 to increase sensitivity and disables the attenuation path in the bypass circuit 230 (e.g., turning off the switch 520). The sensitivity can be increased to increase the detection sensitivity of the coexistence signal that may be relatively weak. In this example, the bypass low noise amplifier 510 is configured (i.e., tuned) to amplify a signal in a frequency band that includes the frequency of the coexistence signal (e.g., the radio altimeter signal).

[0116] In this example, the coexistence signal may be undetectable if routed through the first filter 125. This is because the filter rejection of the first filter 125 may attenuate the coexistence signal too much, making the coexistence signal undetectable after filtering. Routing the coexistence signal through the bypass circuit 230 avoids this problem by bypassing the first filter 125. In addition, enabling the bypassed low noise amplifier 510 increases sensitivity, which improves detection of the coexistence signal (e.g., the radio altimeter signal).

[0117] In this example, the control circuit 250 causes the frequency synthesizer 240 to tune the local oscillator signal of the mixer 140 to the frequency of the coexistence signal to down-convert the coexistence signal to a baseband signal. Figure 8 The processor 150 may then measure the signal strength of the baseband signal to estimate the signal strength at the frequency of the coexistence signal. The processor 150 may detect whether the coexistence signal exists based on the measured signal strength. For example, if the measured signal strength is equal to or higher than a threshold, the processor 150 may detect the coexistence signal.

[0118] In response to detecting the coexistence signal, the processor 150 may take one or more of the following actions to mitigate interference with the coexistence signal. The processor 150 may cause the transmitter 118 to cease RF transmissions at frequencies within the frequency band of the coexistence signal. Alternatively, the processor 150 may cause the transmitter 118 to reduce RF transmission power at frequencies within the frequency band of the coexistence signal. In a particular aspect, the processor 150 may cause the transmitter 118 to send a message to a base station (e.g., base station 740) to notify the base station of the presence of the coexistence signal (e.g., radio altimeter signal). In response, the base station (e.g., base station 740) may avoid RF transmissions to the wireless device 110 at frequencies within the frequency band of the coexistence signal.

[0119] In some aspects, the wireless device 110 may be configured to simultaneously monitor the coexistence signal and receive the RF signal for communication. The RF signal for communication may also be referred to as a third RF signal. For example, this allows the wireless device 110 to monitor the coexistence signal (e.g., a radio altimeter signal) while receiving data traffic from the third RF signal. In this regard, Fig. 9 An example is shown in which the wireless device 110 includes a second mixer 910 coupled to the third terminal 226 of the second switch circuit 220. In the following discussion, the mixer 140 is referred to as the first mixer 140.

[0120] In this example, the frequency synthesizer 240 is configured to output a first local oscillator signal (labeled as "LO_RX1") to the first mixer 140 and to output a second local oscillator signal (labeled as "LO_RX2") to the second mixer 910. In addition, the bypass low noise amplifier 510 can be configured (i.e., tuned) to amplify signals in the frequency band of the coexistence signal and the frequency band of the RF signal used for communication (e.g., the n77 band). The RF signal can be sent from a base station (e.g., base station 740) to the wireless device 110.

[0121] like Fig. 9 As shown, the wireless device 110 may further include a first amplifier 920 and a second amplifier 930. The first amplifier 920 has an input 922 coupled to the third terminal 226 of the second switch circuit 220 and an output 924 coupled to the first mixer 140. The second amplifier 930 has an input 932 coupled to the third terminal 226 of the second switch circuit 220 and an output 934 coupled to the second mixer 910. In this example, the first amplifier 920 and the second amplifier 930 may be used to provide different gains for the first mixer 140 and the second mixer 910.

[0122] During operation, the control circuit 250 causes the first switch circuit 210 and the second switch circuit 220 to couple the bypass circuit 230 between the first antenna 120 and the mixer 140. The control circuit 250 also enables the bypass low noise amplifier 510. Therefore, in this example, the RF signal and the coexistence signal received concurrently (i.e., simultaneously) via the first antenna 120 are routed through the bypass circuit 230 and amplified by the bypass low noise amplifier 510.

[0123] In this example, the frequency synthesizer 240 can tune the first oscillator signal (labeled as "LO_RX1") of the first mixer 140 to a frequency in the frequency band (e.g., n77) of the RF signal to down-convert the RF signal to a baseband signal. The baseband signal can then be converted into a digital signal by the ADC 145 and processed by the processor 150 (e.g., to recover data and / or control information).

[0124] The frequency synthesizer 240 can tune the second oscillator signal (labeled as "LO_RX2") of the second mixer 910 to the frequency of the coexistence signal (eg, 4.35 GHz) to down-convert the coexistence signal to a baseband signal. Fig. 9The processor 150 may then measure the signal strength of the baseband signal to estimate the signal strength at the frequency of the coexistence signal. The processor 150 detects whether a coexistence signal (e.g., a radio altimeter signal) is present based on the measured signal strength. For example, if the measured signal strength is equal to or higher than a threshold, the processor 150 may detect the coexistence signal. In response to detecting the coexistence signal, the processor 150 may take the actions described above with reference to Figure 8 One or more of the actions in question.

[0125] Fig.10 Another example is shown in which the wireless device 110 includes a power divider 1010. In this example, the power divider 1010 has an input 1012, a first output 1014 coupled to the input of the first amplifier 920, and a second output 1016 coupled to the input of the second amplifier 930. In this example, the bypass circuit 230 is coupled between the third terminal 216 of the first switch circuit 210 and the input 1012 of the power divider 1010. The power divider 1010 is configured to receive the RF signal and the coexistence signal from the bypass circuit 230 and divide the power thereof between the first output 1014 and the second output 1016.

[0126] Fig.11 2 shows an exemplary implementation of the second switch circuit 220 according to certain aspects. In this example, the second switch circuit 220 includes a first switch 1110 coupled between the first terminal 222 and the third terminal 226, and a second switch 1120 coupled between the second terminal 224 and the third terminal 226. The switches 1110 and 1120 can be controlled by the control circuit 250 ( Fig.11 In this example, the control circuit 250 turns on the first switch 1110 and turns off the second switch 1120 to couple the first terminal 222 to the third terminal 226, and turns on the second switch 1120 and turns off the first switch 1110 to couple the second terminal 224 to the third terminal 226. Each of the switches 1110 and 1120 can be implemented with a corresponding switching transistor or another type of switch. It should be understood that the second switch circuit 220 is not limited to Fig.11 For example, in other implementations, the second switch circuit 220 may include a different arrangement of switches.

[0127] Fig.12 A method 1200 for operating a wireless device in accordance with certain aspects is shown. The wireless device includes a first antenna (eg, the first antenna 120) and a second antenna (eg, the second antenna 160).

[0128] At block 1210 , in a first mode, a first radio frequency (RF) signal is received via a first antenna. For example, the first RF signal may be received by the receiver 115 .

[0129] At block 1220, in a first mode, a first RF signal is filtered using a filter. For example, the first filter may correspond to first filter 125. In some aspects, the filter may include a bandpass filter having a passband that spans a first frequency band. In some aspects, the first RF signal may be in the first frequency band.

[0130] At block 1230, in a second mode, a second RF signal is transmitted via the second antenna. For example, the second RF signal may be transmitted by the transmitter 118 via the second antenna. In some aspects, the second RF signal may be in a second frequency band, and the second frequency band is different from the first frequency band. In one example, the second frequency band may be outside the passband of the filter.

[0131] At block 1240 , in the second mode, a second RF signal is received via the first antenna. For example, the second RF signal may be received by the receiver 115 .

[0132] At block 1250 , the second RF signal is routed through the bypass circuit that bypasses the filter. For example, the second RF signal may be routed by the first switch circuit 210 .

[0133] At block 1260 , in the second mode, the signal strength of the second RF signal is measured. For example, the signal strength may be measured by the processor 150 and / or the measurement circuit 280 .

[0134] In certain aspects, the method 1200 may also include estimating antenna coupling between the first antenna and the second antenna based on the measured signal strength. For example, the antenna coupling may be estimated by the processor 150.

[0135] Fig.13 is a diagram of an environment 1300 including an electronic device 1302 and a base station 1304. The electronic device 1302 may include a wireless device 110 including antennas 120 and 160, a receiver 115, a transmitter 118, a mixer 140, a processor 150, and a control circuit 250.

[0136] In environment 1300, electronic device 1302 communicates with base station 1304 via wireless link 1306. As shown, electronic device 1302 is depicted as a smart phone. However, electronic device 1302 can be implemented as any suitable computing device or other electronic device, such as a cellular base station, a broadband router, an access point, a cellular or mobile phone, a gaming device, a navigation device, a media device, a laptop computer, a desktop computer, a tablet computer, a server computer, a network-attached storage (NAS) device, a smart appliance, a vehicle-based communication system, an Internet of Things (IoT) device, a sensor or security device, an asset tracker, etc.

[0137] Base station 1304 communicates with electronic device 1302 via wireless link 1306, which can be implemented as any suitable type of wireless link. Although base station 1304 is depicted as a base station tower of a cellular radio network, base station 1304 can represent or be implemented as another device, such as a satellite, a terrestrial broadcast tower, an access point, a peer device, a mesh network node, a fiber optic line, another electronic device generally as described above, etc. Therefore, electronic device 1302 can communicate with base station 1304 or another device via a wired connection, a wireless connection, or a combination thereof. Wireless link 1306 may include a downlink of data or control information transmitted from base station 1304 to electronic device 1302, and an uplink of other data or control information transmitted from electronic device 1302 to base station 1304. The wireless link 1306 may be implemented using any suitable communication protocol or standard (e.g., 3rd Generation Partnership Project Long Term Evolution (3GPP LTE, 3GPP NR 5G), IEEE 1302.13, IEEE1302.13, Bluetooth™, etc.).

[0138] The electronic device 1302 includes a processor 1380 and a memory 1382. The processor 1380 may include the processor 150, and the memory 1382 may include the memory 290. The memory 1382 may be or form part of a computer-readable storage medium. The processor 1380 may include any type of processor, such as an application processor or a multi-core processor, which is configured to execute processor-executable instructions (e.g., code) stored in the memory 1382. The memory 1382 may include any suitable type of data storage medium, such as volatile memory (e.g., random access memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., disk or tape), etc. In the context of the present disclosure, the memory 1382 is implemented to store instructions 1384, data 1386, and other information of the electronic device 1302.

[0139] The electronic device 1302 may also include an input / output (I / O) port 1390. The I / O port 1390 enables data exchange or interaction with other devices, networks, or users, or between components of the device.

[0140] The electronic device 1302 may also include a signal processor (SP) 1392 such as, for example, a digital signal processor (DSP). The signal processor 1392 may function similarly to the processor 1380 and may be capable of executing instructions and / or processing information in conjunction with the memory 1382 .

[0141] For communication purposes, the electronic device 1302 also includes a modem 1394 (e.g., processor 150), a wireless transceiver 1396 (e.g., receiver 115 and transmitter 118), and one or more antennas (e.g., antennas 120 and 160). The wireless transceiver 1396 provides a connection to a corresponding network and other electronic devices connected thereto using RF wireless signals. The wireless transceiver 1396 can facilitate communication over any suitable type of wireless network, such as a wireless local area network (LAN) (WLAN), a peer-to-peer (P2P) network, a mesh network, a cellular network, a wireless wide area network (WWAN), a navigation network (e.g., a global positioning system (GPS) or another global navigation satellite system (GNSS) in North America), and / or a wireless personal area network (WPAN).

[0142] As used herein, the "passband" of a filter can be a frequency range within which the filter passes a signal with an attenuation of less than 3 dB (e.g., the gain of the filter in the frequency range is greater than -3 dB). In some aspects, the second frequency band discussed above can be outside the passband of the first filter 125 (e.g., the first filter 125 attenuates the signal in the second frequency band by more than 3 dB). However, it should be understood that the disclosure is not limited to this example. In some aspects, the first filter 125 can attenuate the signal in the second frequency band by more than 20 dB, more than 30 dB, or more than 40 dB (e.g., the gain of the filter 125 in the second frequency band is less than -20 dB, less than -30 dB, or less than -40 dB).

[0143] Examples of implementations are described in the following numbered clauses:

[0144] 1. A system for wireless communication, comprising:

[0145] A first radio frequency front end (RFFE) circuit coupled to the first antenna and comprising:

[0146] a first filter having a first passband spanning a first frequency band;

[0147] a first low noise amplifier (LNA) coupled to the first filter;

[0148] a bypass circuit configured to bypass the first filter, the bypass circuit comprising an attenuator; and

[0149] a first switching circuit configured to couple the first antenna to the first filter or the bypass circuit; and

[0150] A second RFFE circuit coupled to the second antenna and comprising:

[0151] power amplifier; and

[0152] A second filter is coupled between the power amplifier and the second antenna, the second filter having a second passband spanning a second frequency band different from the first frequency band.

[0153] 2. The system according to clause 1 further includes a controller configured to: cause the first switching circuit to couple the first antenna to the bypass circuit during a time period when the system is configured to transmit a signal in the second frequency band via the second RFFE circuit and the second antenna.

[0154] 3. The system of clause 2, further comprising a processor configured to measure a signal level of the signal based on an output of the bypass circuit.

[0155] 4. The system of clause 2 or 3, wherein the controller is configured to cause the first switch circuit to couple the first antenna to the first filter during a time period when the first antenna receives signals in the first frequency band.

[0156] 5. A system according to any one of clauses 1 to 4, further comprising:

[0157] mixer; and

[0158] A second switch circuit is configured to couple the mixer to an output of the first LNA or an output of the bypass circuit.

[0159] 6. The system according to clause 5, further comprising a controller configured to:

[0160] In a first mode, causing the first switch circuit to couple the first antenna to the first filter and causing the second switch circuit to couple the mixer to the output of the first LNA; and

[0161] In a second mode, the first switch circuit is caused to couple the first antenna to the bypass circuit, and the second switch circuit is caused to couple the mixer to an output of the bypass circuit.

[0162] 7. The system of clause 6, further comprising a frequency synthesizer coupled to the mixer, wherein the frequency synthesizer is configured to output an oscillator signal to the mixer.

[0163] 8. The system of clause 7, wherein the controller is configured to:

[0164] causing the frequency synthesizer to set the frequency of the oscillator signal to a first frequency in the first frequency band in the first mode; and

[0165] In the second mode, the frequency synthesizer is caused to set the frequency of the oscillator signal to a second frequency in the second frequency band.

[0166] 9. The system according to any one of clauses 1 to 8 further includes a processor configured to measure a signal level of a signal in the second frequency band received via the bypass circuit and the first antenna, the signal being sent via the second antenna and the second RFFE circuit.

[0167] 10. The system of clause 9, wherein the processor is configured to determine an antenna coupling level between the first antenna and the second antenna based on the measured signal level of the signal.

[0168] 11. A system according to any one of clauses 1 to 10, wherein the first RFFE circuit is included in a first RFFE module and the second RFFE circuit is included in a second RFFE module different from the first RFFE module, and the first RFFE module and the second RFFE module are coupled to a transceiver integrated circuit.

[0169] 12. The system of any one of clauses 1 to 11, wherein the bypass circuit further comprises:

[0170] a second LNA having an input and an output; and

[0171] A switch, wherein the attenuator and the switch are coupled in series between the input of the second LNA and the output of the second LNA.

[0172] 13. The system of clause 12, wherein the second LNA is tuned to a frequency of a coexistence signal received via the first antenna.

[0173] 14. The system of clause 13, wherein the frequency of the coexistence signal is within a frequency range of 4.2 GHz to 4.4 GHz.

[0174] 15. The system of clause 13 or 14, further comprising a controller configured to: turn on the switch and cause the first switch circuit to couple the first antenna to the bypass circuit during a time period when the first antenna receives the coexistence signal.

[0175] 16. A system according to clause 15, wherein the controller is configured to: turn off the switch and cause the first switch circuit to couple the first antenna to the bypass circuit during a time period when the system is configured to transmit a signal in the second frequency band via the second RFFE circuit and the second antenna.

[0176] 17. A method for operating a wireless device, the wireless device comprising a first antenna and a second antenna, the method comprising:

[0177] In the first mode,

[0178] receiving a first radio frequency (RF) signal via the first antenna; and

[0179] filtering the first RF signal using a filter;

[0180] In the second mode,

[0181] transmitting a second RF signal via the second antenna;

[0182] receiving the second RF signal via the first antenna;

[0183] routing the second RF signal through a bypass circuit that bypasses the filter; and

[0184] The signal strength of the second RF signal is measured.

[0185] 18. The method of clause 17, wherein the filter comprises a bandpass filter having a passband spanning the first frequency band.

[0186] 19. The method of clause 18, wherein the second RF signal is in a second frequency band, and the second frequency band is different from the first frequency band.

[0187] 20. The method of any of clauses 17 to 19, further comprising attenuating the second RF signal using an attenuator in the bypass circuit.

[0188] 21. The method of any of clauses 17 to 20, further comprising, in the second mode, estimating antenna coupling between the first antenna and the second antenna based on the measured signal strength.

[0189] 22. A method according to any of clauses 17 to 21, wherein the first RF signal is sent from a base station.

[0190] 23. A method according to any one of clauses 17 to 22, further comprising:

[0191] measuring a signal strength of the first RF signal after filtering by the filter; and

[0192] A filter rejection of the filter is characterized based on a difference between a measured signal strength of the first RF signal and a measured signal strength of the second RF signal.

[0193] 24. A method according to any one of clauses 17 to 23, further comprising:

[0194] In the second mode,

[0195] receiving a coexistence signal via the first antenna;

[0196] routing the coexistence signal through the bypass circuit;

[0197] amplifying the coexistence signal using a low noise amplifier in the bypass circuit;

[0198] measuring the signal strength of the coexistence signal; and

[0199] The coexistence signal is detected based on a measured signal strength of the coexistence signal.

[0200] 25. A method according to clause 24, wherein the coexistence signal comprises a radio altimeter signal.

[0201] 26. A method according to clause 24 or 25, further comprising:

[0202] receiving a third RF signal concurrently with the coexistence signal via the first antenna; and

[0203] Data is recovered from the third RF signal.

[0204] 27. The method of any one of clauses 24 to 26, further comprising: in response to detecting the coexistence signal, causing a transmitter on the wireless device to stop transmitting in a frequency band of the coexistence signal or reduce transmission power in the frequency band of the coexistence signal.

[0205] 28. A method according to any of clauses 24 to 27, wherein the coexistence signal has a frequency in the frequency range of 4.2 GHz to 4.4 GHz.

[0206] 29. A method as described in any of clauses 24 to 27, wherein the coexistence signal comprises an ultra-wideband (UWB) signal.

[0207] 30. A method according to any of clauses 17 to 29, further comprising, in the first mode, recovering data from the first RF signal after filtering using the filter.

[0208] 31. A system comprising a first antenna and a second antenna, the system comprising:

[0209] means for receiving a first radio frequency (RF) signal via the first antenna;

[0210] means for filtering the first RF signal;

[0211] means for transmitting a second RF signal via the second antenna, the means for receiving the first RF signal via the first antenna further comprising means for receiving the second RF signal via the first antenna;

[0212] means for routing the second RF signal through a bypass circuit that bypasses the means for filtering; and

[0213] Means for measuring a signal strength of the second RF signal.

[0214] 32. A system for wireless communication, comprising:

[0215] a first radio frequency front end (RFFE) circuit coupled to the first antenna, the first RFFE circuit being designed to condition signals for transmission and / or reception within a first frequency range, the first RFFE circuit comprising one or more circuits configured to provide a wideband bypass mode for received signals within a second frequency range different from the first frequency range; and

[0216] A second RFFE circuit is coupled to the second antenna, and the second RFFE circuit is designed to condition signals for transmission and / or reception within the second frequency range.

[0217] 33. The system of clause 32 further comprises a processor configured to measure an antenna coupling level between the first antenna and the second antenna based on an output of the first RFFE circuit in response to a transmit signal transmitted via the second antenna via the second RFFE circuit.

[0218] 34. A system for wireless communication, comprising:

[0219] Modem integrated circuits;

[0220] a transceiver integrated circuit coupled to the modem integrated circuit;

[0221] A first radio frequency front end (RFFE) circuit coupled between the transceiver integrated circuit and the first antenna, the first RFFE circuit comprising:

[0222] a first low noise amplifier (LNA) configured to amplify a first signal in a first frequency band;

[0223] a first filter coupled to the first LNA, the first filter having a first passband spanning the first frequency band;

[0224] a bypass circuit configured to bypass the first filter, the bypass circuit configured to pass a second signal in a second frequency band different from the first frequency band to the transceiver circuit; and

[0225] a first switching circuit configured to couple the first antenna to the first filter or the bypass circuit; and

[0226] A second RFFE circuit is coupled between the transceiver integrated circuit and the second antenna and includes:

[0227] a first power amplifier; and

[0228] A second filter is coupled between the first power amplifier and the second antenna, the second filter having a second passband spanning the second frequency band.

[0229] 35. The system of clause 34, wherein the bypass circuit comprises an attenuator configured to attenuate the second signal in the second frequency band.

[0230] 36. The system of clause 34 or 35 further comprises a controller configured to cause the first switching circuit to couple the first antenna to the bypass circuit during a time period when the system is configured to transmit the second signal in the second frequency band via the second RFFE circuit and the second antenna.

[0231] 37. The system of clause 36, wherein the transceiver integrated circuit is configured to measure a signal level of the second signal based on an output of the bypass circuit.

[0232] 38. A system as claimed in clause 36 or 37, wherein the transceiver integrated circuit comprises a mixer configured to receive a local oscillator signal having a frequency in the second frequency band.

[0233] 39. A system according to any one of clauses 34 to 38, wherein the transceiver integrated circuit and / or the modem integrated circuit or a combination thereof is configured to measure a signal level of the second signal in the second frequency band received via the bypass circuit based on a transmit signal sent via the second antenna and the second RFFE circuit.

[0234] 40. The system of any of clauses 34 to 39, wherein the transceiver integrated circuit and / or the modem integrated circuit, or some combination thereof, is configured to determine an antenna coupling level between the first antenna and the second antenna based on an output of the bypass circuit.

[0235] 41. A system according to any of clauses 34 to 40, wherein the first RFFE circuit is a low-band (LB) RFFE module and the second RFFE circuit is a mid-high-band (MHB) RFFE module.

[0236] 42. A system according to any of clauses 34 to 40, wherein the first RFFE circuit is a mid-high band (MHB) RFFE module and the second RFFE circuit is a low-band (LB) RFFE module.

[0237] 43. A system for wireless communication, comprising:

[0238] a filter having a passband spanning a first frequency band;

[0239] a first low noise amplifier (LNA) coupled to the filter, the first LNA being tuned to amplify a first signal in the first frequency band;

[0240] a bypass circuit configured to bypass the filter, the bypass circuit comprising a second LNA tuned to amplify a second signal in a second frequency band different from the first frequency band; and

[0241] A first switching circuit is configured to couple a first antenna to the filter or the bypass circuit.

[0242] 44. The system of clause 43, wherein the second signal comprises a radio altimeter signal.

[0243] 45. A system according to clause 43 or 44, wherein the second signal has a frequency in the frequency range of 4.2 GHz to 4.4 GHz.

[0244] 46. ​​The system of clause 43, wherein the second signal comprises an ultra-wideband (UWB) signal.

[0245] 47. The system of clause 43, wherein the first frequency band is in a low frequency band (LB) and the second frequency band is in a mid-high frequency band (MHB).

[0246] 48. The system of clause 43, wherein the second frequency band is in a low frequency band (LB) and the first frequency band is in a mid-high frequency band (MHB).

[0247] 49. The system of clause 43, wherein the first frequency band is in a frequency range of 0.6 GHz to 1 GHz and the second frequency band is in a frequency range of 1.8 GHz to 2.7 GHz.

[0248] 50. The system of clause 43, wherein the second frequency band is in a frequency range of 0.6 GHz to 1 GHz and the first frequency band is in a frequency range of 1.8 GHz to 2.7 GHz.

[0249] 51. A system according to any of clauses 43 to 50, further comprising a controller configured to:

[0250] In a first mode, causing the first switching circuit to couple the first antenna to the filter; and

[0251] In a second mode, the first switch circuit is caused to couple the first antenna to the second LNA.

[0252] 52. The system of clause 51, further comprising a processor configured to:

[0253] in the first mode, recovering data in the first signal after the first signal is amplified by the first LNA; and

[0254] In the second mode, after the second signal is amplified by the second LNA, the signal strength of the second signal is measured.

[0255] 53. The system of clause 52, further comprising a transmitter coupled to the second antenna, wherein the processor is configured to detect the second signal based on the measured signal strength, and in response to detecting the second signal, cause the transmitter to cease transmission in the second frequency band or reduce transmission power in the second frequency band.

[0256] 54. A system according to clause 52 or 53, wherein the first signal is sent from a base station.

[0257] In this disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term "aspect" does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation. The term "coupled" is used herein to refer to a direct or indirect electrical coupling between two structures. It should also be understood that the term "grounded" can refer to either a DC ground or an AC ground, and thus the term "grounded" covers both possibilities.

[0258] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Therefore, the disclosure is not intended to be limited to the examples described herein, but should conform to the widest scope of the principles and novel features disclosed herein.

Claims

1. A system for wireless communication, comprising: A first radio frequency front end (RFFE) circuit coupled to the first antenna and comprising: a first filter having a first passband spanning a first frequency band; a first low noise amplifier (LNA) coupled to the first filter; a bypass circuit configured to bypass the first filter, the bypass circuit comprising an attenuator; and a first switching circuit configured to couple the first antenna to the first filter or the bypass circuit; and A second RFFE circuit coupled to the second antenna and comprising: power amplifier; and A second filter is coupled between the power amplifier and the second antenna, the second filter having a second passband spanning a second frequency band different from the first frequency band.

2. The system according to claim 1 further includes a controller, which is configured to: cause the first switching circuit to couple the first antenna to the bypass circuit during a time period when the system is configured to send a signal in the second frequency band via the second RFFE circuit and the second antenna. 3 . The system of claim 2 , further comprising a processor configured to measure a signal level of the signal based on an output of the bypass circuit.

4. The system according to claim 2, wherein: The controller is configured to cause the first switch circuit to couple the first antenna to the first filter during a time period when the first antenna receives signals in the first frequency band.

5. The system according to claim 1, further comprising: Mixer; as well as A second switch circuit is configured to couple the mixer to an output of the first LNA or an output of the bypass circuit.

6. The system of claim 5, further comprising a controller configured to: In a first mode, causing the first switch circuit to couple the first antenna to the first filter and causing the second switch circuit to couple the mixer to the output of the first LNA; and In a second mode, the first switch circuit is caused to couple the first antenna to the bypass circuit, and the second switch circuit is caused to couple the mixer to the output of the bypass circuit.

7. The system of claim 6, further comprising a frequency synthesizer coupled to the mixer, wherein: The frequency synthesizer is configured to output an oscillator signal to the mixer.

8. The system according to claim 7, wherein: The controller is configured to: causing the frequency synthesizer to set the frequency of the oscillator signal to a first frequency in the first frequency band in the first mode; and In the second mode, the frequency synthesizer is caused to set the frequency of the oscillator signal to a second frequency in the second frequency band.

9. The system of claim 1, further comprising a processor configured to measure a signal level of a signal in the second frequency band received via the bypass circuit and the first antenna, the signal being sent via the second antenna and the second RFFE circuit.

10. The system according to claim 9, wherein: The processor is configured to determine an antenna coupling level between the first antenna and the second antenna based on the measured signal level of the signal.

11. The system according to claim 1, wherein: The first RFFE circuit is included in a first RFFE module, and the second RFFE circuit is included in a second RFFE module different from the first RFFE module, and the first RFFE module and the second RFFE module are coupled to a transceiver integrated circuit.

12. The system of claim 1, wherein: The bypass circuit also includes: a second LNA having an input and an output; and A switch, wherein the attenuator and the switch are coupled in series between the input of the second LNA and the output of the second LNA.

13. The system according to claim 12, wherein: The second LNA is tuned to a frequency of a coexistence signal received via the first antenna.

14. The system according to claim 13, wherein: The frequency of the coexistence signal is in a frequency range of 4.2 GHz to 4.4 GHz.

15. The system of claim 13, further comprising a controller configured to, during a time period when the first antenna receives the coexistence signal, turn on the switch and cause the first switch circuit to couple the first antenna to the bypass circuit.

16. The system of claim 15, wherein: The controller is configured to, during a time period when the system is configured to transmit signals in the second frequency band via the second RFFE circuit and the second antenna, turn off the switch and cause the first switch circuit to couple the first antenna to the bypass circuit.

17. A method for operating a wireless device, the wireless device comprising a first antenna and a second antenna, the method comprising: In the first mode, receiving a first radio frequency (RF) signal via the first antenna; as well as filtering the first RF signal using a filter; In the second mode, transmitting a second RF signal via the second antenna; receiving the second RF signal via the first antenna; routing the second RF signal through a bypass circuit that bypasses the filter; as well as The signal strength of the second RF signal is measured.

18. The method according to claim 17, wherein: The filter comprises a bandpass filter having a passband spanning a first frequency band.

19. The method according to claim 18, wherein: The second RF signal is in a second frequency band, and the second frequency band is different from the first frequency band.

20. The method of claim 17, further comprising: The second RF signal is attenuated using an attenuator in the bypass circuit.

21. The method of claim 17, further comprising: In the second mode, antenna coupling between the first antenna and the second antenna is estimated based on the measured signal strength.

22. The method according to claim 17, wherein: The first RF signal is sent from a base station.

23. The method of claim 17, further comprising: measuring a signal strength of the first RF signal after being filtered by the filter; as well as A filter rejection of the filter is characterized based on a difference between a measured signal strength of the first RF signal and a measured signal strength of the second RF signal.

24. The method of claim 17, further comprising: In the second mode, receiving a coexistence signal via the first antenna; routing the coexistence signal through the bypass circuit; amplifying the coexistence signal using a low noise amplifier in the bypass circuit; measuring the signal strength of the coexistence signal; as well as The coexistence signal is detected based on a measured signal strength of the coexistence signal.

25. The method according to claim 24, wherein: The coexistence signal comprises a radio altimeter signal.

26. The method of claim 24, further comprising: receiving a third RF signal concurrently with the coexistence signal via the first antenna; as well as Data is recovered from the third RF signal.

27. The method of claim 24, further comprising: In response to detecting the coexistence signal, a transmitter on the wireless device is caused to stop transmission in a frequency band of the coexistence signal or to reduce transmission power in the frequency band of the coexistence signal.

28. A system comprising a first antenna and a second antenna, the system comprising: means for receiving a first radio frequency (RF) signal via the first antenna; means for filtering the first RF signal; means for transmitting a second RF signal via the second antenna, the means for receiving the first RF signal via the first antenna further comprising means for receiving the second RF signal via the first antenna; means for routing the second RF signal through a bypass circuit that bypasses the means for filtering; as well as Means for measuring a signal strength of the second RF signal.

29. A system for wireless communication, comprising: a first radio frequency front end (RFFE) circuit coupled to a first antenna, the first RFFE circuit being designed to condition signals for transmission and / or reception in a first frequency range, the first RFFE circuit comprising one or more circuits configured to provide a wideband bypass mode for received signals in a second frequency range different from the first frequency range; as well as A second RFFE circuit is coupled to the second antenna, and the second RFFE circuit is designed to condition signals for transmission and / or reception in the second frequency range.

30. The system of claim 29, further comprising a processor configured to measure an antenna coupling level between the first antenna and the second antenna based on an output of the first RFFE circuit in response to a transmit signal transmitted via the second antenna via the second RFFE circuit.

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