Signal receiving circuit and wearable device

Abstract

The invention discloses a signal receiving circuit and a wearable device, the signal receiving circuit comprises a radio frequency receiver, a combiner and at least two receiving antennas, the at least two receiving antennas are used for receiving radio frequency signals of the same frequency band, and the at least two receiving antennas are electrically connected with the radio frequency receiver through the combiner; wherein the combiner is used for combining radio frequency signals received by the at least two receiving antennas and then outputting the combined radio frequency signals to the radio frequency receiver; and the absolute value of the phase difference of the radio frequency signals input by different input ports of the combiner is less than or equal to 90 degrees.

Description

Technical Field

[0001] This application relates to the field of electronic product technology, and in particular to a signal receiving circuit and wearable device. Background Technology

[0002] With the development of electronic products, wearable devices typically incorporate Global Positioning System (GPS) antennas. However, due to the relatively small size of wearable devices, the performance of GPS antennas is often poor. Therefore, existing technologies suffer from the problem of poor antenna performance in wearable devices. Summary of the Invention

[0003] This application provides a signal receiving circuit and a wearable device to solve the problem of poor antenna performance in wearable devices.

[0004] In a first aspect, embodiments of this application provide a signal receiving circuit, including: a radio frequency receiver, a combiner, and at least two receiving antennas, wherein the at least two receiving antennas are used to receive radio frequency signals of the same frequency band, and the at least two receiving antennas are electrically connected to the radio frequency receiver through the combiner;

[0005] The combiner is used to combine the radio frequency signals received by the at least two receiving antennas and output them to the radio frequency receiver; the absolute value of the phase difference of the radio frequency signals input to different input ports of the combiner is less than or equal to 90 degrees.

[0006] Secondly, embodiments of this application also provide a wearable device, including a signal receiving circuit. The signal receiving circuit includes a radio frequency receiver, a combiner, and at least two receiving antennas. The at least two receiving antennas are used to receive radio frequency signals of the same frequency band, and the at least two receiving antennas are electrically connected to the radio frequency receiver through the combiner.

[0007] The combiner is used to combine the radio frequency signals received by the at least two receiving antennas and output them to the radio frequency receiver; the absolute value of the phase difference of the radio frequency signals input to different input ports of the combiner is less than or equal to 90 degrees.

[0008] This application embodiment includes a signal receiving circuit comprising: a radio frequency (RF) receiver, a combiner, and at least two receiving antennas. The at least two receiving antennas are used to receive RF signals in the same frequency band, and are electrically connected to the RF receiver via the combiner. The combiner combines the RF signals received by the at least two receiving antennas and outputs the combined signals to the RF receiver. The absolute value of the phase difference between the RF signals input to different input ports of the combiner is less than or equal to 90 degrees. This improves the gain of the RF signal, thereby enhancing the antenna performance.

[0009] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0010] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0011] Figure 1 This is a schematic diagram of a signal receiving circuit provided in an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of another signal receiving circuit provided in an embodiment of this application;

[0013] Figure 3 This is one of the structural schematic diagrams of a combiner in a signal receiving circuit provided in this application embodiment;

[0014] Figure 4 This is the second schematic diagram of the combiner structure in a signal receiving circuit provided in this application embodiment. Detailed Implementation

[0015] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0016] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0017] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0019] It should be understood that watches have extremely limited space, resulting in poor antenna environments. The screen, battery, motor, speaker, and other tracking metal components are very close to the antenna, leading to poor antenna clearance. Due to the poor antenna environment and the limitations of antenna size, watches cannot fully meet the optimal radiation conditions of 1 / 4 wavelength. Therefore, the antenna performance of a watch is generally more than 6dB different from that of a mobile phone. In other words, the performance of a mobile phone's GPS antenna is more than four times that of a watch. Currently, the industry's GPS uses only a single-channel receiving circuit for each frequency band, unlike cellular networks which use a Multiple-Input Multiple-Output (MIMO) receiving scheme. Therefore, watches cannot compare with mobile phones in GPS positioning performance, leaving significant room for improvement. Furthermore, when running, the arm swings, causing the antenna's directionality to change, resulting in fluctuating signal strength and further deteriorating the GPS receiver's performance, leading to a worsened running trajectory. Therefore, this application proposes a signal receiving circuit and wearable device.

[0020] See Figure 1 and Figure 2This application provides a signal receiving circuit. For example... Figure 1 and Figure 2 The signal receiving circuit shown includes: a radio frequency receiver 10, a combiner 20, and at least two receiving antennas 30. The at least two receiving antennas 30 are used to receive radio frequency signals of the same frequency band. The at least two receiving antennas 30 are electrically connected to the radio frequency receiver 10 through the combiner 20.

[0021] The combiner 20 is used to combine the radio frequency signals received by the at least two receiving antennas 30 and output them to the radio frequency receiver 10; the absolute value of the phase difference of the radio frequency signals input to different input ports of the combiner 20 is less than or equal to 90 degrees.

[0022] In this embodiment of the application, the signal receiving circuit described above can be applied to wearable devices, such as smartwatches.

[0023] Optionally, the receiving antenna 30 can be used to receive radio frequency signals in the L1, L2, or L3 frequency bands. In some embodiments, the radio frequency receiver 10 may include two or more signal receiving ports, each of which is electrically connected to at least two receiving antennas 30 via a combiner 20. The receiving antennas 30 corresponding to different signal receiving ports are used to receive radio frequency signals in different frequency bands.

[0024] Optionally, the absolute value of the phase difference of the radio frequency signals input to different input ports of the combiner 20 being less than or equal to 90 degrees can be understood as: the absolute value of the phase difference of the radio frequency signals corresponding to any two input ports of the combiner 20 being less than or equal to 90 degrees.

[0025] It should be understood that each receiving antenna 30 corresponds to a signal receiving branch. The receiving antenna 30 can be electrically connected to an input port of the combiner 20 through the corresponding signal receiving branch. The combiner can be used to receive radio frequency signals for a frequency band using multiple receiving antennas. The combiner can also combine two radio frequency signals of the same frequency band, thereby improving the gain of the radio frequency signal and thus improving the performance of the antenna.

[0026] It should be noted that the absolute value of the phase difference between the RF signals input to different input ports of the combiner 20 is related to the gain of the RF signal. The smaller the absolute value of the phase difference between the RF signals input to different input ports of the combiner 20, the greater the gain of the corresponding RF signal. By setting the absolute value of the phase difference between the RF signals input to different input ports of the combiner to be less than or equal to 90 degrees, negative gain of the RF signal can be avoided.

[0027] This embodiment of the application includes a signal receiving circuit comprising: a radio frequency (RF) receiver 10, a combiner 20, and at least two receiving antennas 30. The at least two receiving antennas 30 are used to receive RF signals in the same frequency band, and are electrically connected to the RF receiver 10 via the combiner 20. The combiner 20 combines the RF signals received by the at least two receiving antennas 30 and outputs the combined signals to the RF receiver 10. The absolute value of the phase difference between the RF signals input to different input ports of the combiner 20 is less than or equal to 90 degrees. This improves the gain of the RF signal, thereby enhancing the antenna performance.

[0028] Alternatively, in some embodiments, such as Figure 1 and Figure 2 As shown, the signal receiving circuit further includes at least two phase modulators 40, each of which corresponds to one of the at least two receiving antennas 30. Each receiving antenna 30 is electrically connected to the combiner 20 through one of the phase modulators 40.

[0029] In this embodiment of the application, the phase tuner described above can be implemented by a transmission line and / or an LC matching network, wherein the transmission line can be understood or replaced by a microstrip line.

[0030] It should be understood that the phase modulator 40 modulates the phase of the radio frequency signal received by the receiving antenna 30 to reduce the phase difference of the radio frequency signal input to the combiner 20, thereby further improving the gain of the radio frequency signal.

[0031] It should be noted that, in related technologies, the phase difference of the radio frequency signals received by the same frequency receiving antenna is usually large, so it is not possible to directly combine the radio frequency signals received by different receiving antennas. In this embodiment, by setting a phase modulator 40, the radio frequency signals received by the receiving antenna 30 can be phase modulated, so that the phase difference of the radio frequency signals received by different receiving antennas 30 has a small phase difference before merging. Therefore, the radio frequency signals received by different receiving antennas 30 can be merged to improve the gain of the radio frequency signal.

[0032] Optionally, in some embodiments, the signal receiving circuit further includes an amplifier 50 disposed between the receiving antenna 30 and the phase tuner 40, or the amplifier 50 disposed between the combiner 20 and the radio frequency receiver 10.

[0033] In this embodiment of the application, the amplifier described above can be a low-noise amplifier (LNA).

[0034] Optionally, in some embodiments, the amplifier 50 is positioned between the receiving antenna 30 and the phase tuner 40, which can be understood as: one amplifier 50 is provided for each receiving antenna 30. In this way, by amplifying the radio frequency signal received by the receiving antenna 30, the amplitude of the radio frequency signal can be adjusted to obtain a radio frequency signal of a specific amplitude. Then, by passing it through the phase tuner 40, the phase of the radio frequency signal can be adjusted to obtain a radio frequency signal of a specific phase. Therefore, embodiments of this application can control the radio frequency signals input to the combiner 20 to have the same amplitude and phase, thereby improving the gain of the radio frequency signal output by the combiner 20.

[0035] It should be noted that, in related technologies, the amplitudes of the radio frequency signals received by the same frequency receiving antennas usually differ significantly, making it impossible to directly combine the radio frequency signals received by different receiving antennas. In this embodiment, by setting an amplifier 50, the radio frequency signals received by the receiving antenna 30 can be amplitude-divided, so that the amplitude difference of the radio frequency signals received by different receiving antennas 30 has a small amplitude difference before combining. Therefore, the radio frequency signals received by different receiving antennas 30 can be combined to improve the gain of the radio frequency signals.

[0036] Optionally, in some embodiments, the amplifier 50 is positioned between the combiner 20 and the radio frequency receiver 10. This can be understood as providing one amplifier 50 for each combiner 20, which simplifies the circuit structure and facilitates the miniaturization design of wearable devices. In this embodiment, it is assumed that the amplitude of the radio frequency signals received by each receiving antenna 30 is the same or similar, thus eliminating the need for an amplifier 50 at the front end for signal amplification. This reduces the number of amplifiers, simplifies the circuit structure, and facilitates the miniaturization design of wearable devices.

[0037] Optionally, in some embodiments, the signal receiving circuit further includes a first filter 60 and a second filter 70;

[0038] Wherein, when the amplifier 50 is disposed between the receiving antenna 30 and the phase tuner 40, the first filter 60 is disposed between the receiving antenna 30 and the amplifier 50, and the second filter 70 is disposed between the combiner 20 and the radio frequency receiver 10;

[0039] In the case where the amplifier 50 is disposed between the combiner 20 and the radio frequency receiver 10, the first filter 60 is disposed between the combiner 20 and the amplifier 50, and the second filter 70 is disposed between the amplifier 50 and the radio frequency receiver 10.

[0040] In this embodiment, the first filter 60 and the second filter 70 can be surface acoustic wave (SAW) filters. The first filter 60 and the second filter 70 can filter signals in frequency bands other than specific frequency bands, thereby reducing noise interference and improving communication quality.

[0041] Optionally, in some embodiments, the absolute value of the amplitude difference of the radio frequency signals input to different input ports of the combiner is less than or equal to 8 dB.

[0042] It should be noted that the absolute value of the amplitude difference of the RF signals input to different input ports of the combiner 20 is related to the gain of the RF signal. The smaller the absolute value of the amplitude difference of the RF signals input to different input ports of the combiner 20, the greater the gain of the corresponding RF signal. By setting the absolute value of the amplitude difference of the RF signals input to different input ports of the combiner to be less than or equal to 90 degrees, negative gain of the RF signal can be avoided.

[0043] Optionally, in some embodiments, the combiner 20 described above can be a Wilkinson combiner. In some embodiments, the combiner 20 can combine two radio frequency signals, for example, as... Figure 3 As shown, the combiner 20 includes: an output port PO1, a first resistor R1, a first input port PO2, and a second input port PO3, wherein...

[0044] The first input port PO2 is electrically connected to the output port PO1 via the first transmission line 201, and the second input port PO3 is electrically connected to the output port PO1 via the second transmission line 202; one end of the first resistor R1 is electrically connected to the first input port PO2, and the other end of the first resistor R1 is electrically connected to the second input port PO3.

[0045] In the embodiments of this application, such as Figure 3 As shown, the first transmission line 201 and the second transmission line 202 can be λ / 4 transmission lines, also known as λ / 4 microstrip lines, where λ is the wavelength of the radio frequency signal, i.e., the wavelength of the electromagnetic wave. For example, for the L1 band, it mainly includes the GPS band (e.g., 1.575 GHz), the BeiDou band (e.g., 1.561 GHz), and the GLONASS global navigation satellite system band (e.g., 1.602 GHz). Calculating based on 1.575 GHz, one-quarter of the electromagnetic wave wavelength is approximately 4.76 cm.

[0046] It should be noted that, assuming the impedance Z of ports PO1, PO2, and PO3 is 50 ohms each, then R = 2 * Z = 100 ohms, and the impedance of the λ / 4 transmission line is... It can meet the high isolation requirements of PO2 and PO3, and the impedance matching of PO1 and PO2 as well as PO1 and PO3 ports, ensuring that RF signals can pass through smoothly.

[0047] It should be understood that when the RF signal input to PO2 and the RF signal input to PO3 are RF signals with the same amplitude, frequency and phase, the amplitudes across the first resistor R1 are the same, there will be no voltage difference, so no current will flow and there will be no loss.

[0048] When the combiner 20 is in use, assuming the input voltage of PO2 is V2 and the input power is P2, and the input voltage of PO3 is V3 and the input power is P3, the output voltage V1 and output power P1 of PO1 can be calculated using the following formula:

[0049] ;

[0050] ;

[0051] in, This represents the absolute value of the phase difference between the two radio frequency signals input to the combiner 20.

[0052] Optionally, in some embodiments, the combiner 20 can combine multiple radio frequency signals, for example, such as... Figure 4 As shown, the combiner 20 includes: an output port PO1, a second resistor R2, a third resistor R3, a fourth resistor R4, a third input port PO4, a fourth input port PO5, a fifth input port PO6, and a sixth input port PO7, wherein...

[0053] The third input port PO4 is electrically connected to the output port PO1 via the third transmission line 203 and the fourth transmission line 204; the fourth input port PO5 is electrically connected to the output port PO1 via the fifth transmission line 205 and the fourth transmission line 204; the fifth input port PO6 is electrically connected to the output port PO1 via the sixth transmission line 206 and the seventh transmission line 207; and the sixth input port PO7 is electrically connected to the output port PO1 via the eighth transmission line 208 and the seventh transmission line 207.

[0054] One end of the second resistor R2 is electrically connected to the third input port PO4, and the other end of the second resistor R2 is electrically connected to the fourth input port PO5; one end of the third resistor R3 is electrically connected to the fifth input port PO6, and the other end of the third resistor R3 is electrically connected to the sixth input port PO7; one end of the fourth resistor R4 is connected to the end where the fourth transmission line 204 and the third transmission line 203 are connected, and the other end of the fourth resistor R4 is connected to the end where the seventh transmission line 207 and the sixth transmission line 206 are connected.

[0055] In this embodiment, the combiner 20 can first combine two radio frequency signals to obtain two new radio frequency signals, and then combine the two new radio frequency signals again to obtain the final radio frequency signal. This can further increase the antenna gain. It should be understood that the principle of combining two radio frequency signals to obtain gain is as described above. Figure 1 or Figure 2 The embodiments shown will not be described in detail here.

[0056] Optionally, in some embodiments, the radio frequency signal is a Global Positioning System (GPS) radio frequency signal.

[0057] In this embodiment of the application, the radio frequency receiver can be understood as a GPS chip, and the receiving antenna can be called a GPS antenna.

[0058] Optionally, in some embodiments, the phase and amplitude of the radio frequency signals input to different input ports of the combiner 20 are the same.

[0059] It should be noted that, assuming the signals at ports PO2 and PO3 are in phase but have significantly different amplitudes (e.g., PO3 is 0), according to the formula, the output power P1 = 1 / 2 P2, which is equivalent to the output power becoming 0.5 times the input power, resulting in a 3dB degradation of the signal. Conversely, assuming the input amplitudes at ports PO2 and PO3 are the same, both P... in However, if the phase difference is 180°, then the output power P1 = P in +P in -2P in =0, the amplitude will be completely canceled out, the PO1 port will have no output power, and the signal will be completely attenuated. Therefore, in this embodiment, by setting the phase and amplitude of the RF signals input to different input ports of the combiner 20 to be the same, the signal gain of the RF signal output after passing through the combiner 20 can be enhanced. For example, as Figure 1 As shown, the output RF signal of the combiner 20 can be increased by 3dB.

[0060] It should be understood that signals from the two receiving antennas first pass through the first filter, then through the combiner. If the amplitude does not meet the requirements, the worst-case scenario is that the combiner is used as a single channel, because the signal attenuates by 3dB after the first filter in the combiner stage. According to the noise figure cascade formula: F... total =F1+(F2−1) / G1, Even if F2 increases by 3dB, because the gain of the first filter is generally around 18dB, the actual increase in noise figure is approximately (3-1) / 18=0.11dB, which is a very small attenuation. By utilizing the noise figure suppression principle of the first filter, the problem of two signals needing to have the same amplitude is solved. It is only necessary to ensure that the two signals entering the combiner have the same phase, making it applicable to consumer electronics fields using multi-antenna combining. Where F... total F1 represents the total noise figure, F2 represents the first-stage noise figure, F2 represents the second-stage noise figure, and G1 represents the first-stage power gain.

[0061] It should be noted that, as Figure 1 As shown, at least two radio frequency signals of the same frequency are tuned to the same signal by a phase tuner. Combined with the suppression of noise figure by the first filter, they are combined into one signal by a combiner 20 to achieve signal enhancement (maximum increase of 3dB) and increase antenna directivity. At this time, multiple receiving antennas are sufficient, as long as one antenna can receive the signal.

[0062] This application also provides a wearable device, which includes a signal receiving circuit. The structure and working principle of the signal receiving circuit can be referred to the above embodiments, and will not be repeated here. Since the wearable device provided in this application includes the signal receiving circuit in the above embodiments, the signal receiving circuit provided in this application has all the beneficial effects of the signal receiving circuit in the above embodiments.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A signal receiving circuit, characterized in that, include: The radio frequency receiver, the combiner, and at least two receiving antennas, wherein the at least two receiving antennas are used to receive radio frequency signals of the same frequency band, and the at least two receiving antennas are electrically connected to the radio frequency receiver through the combiner; The combiner is used to combine the radio frequency signals received by the at least two receiving antennas and output them to the radio frequency receiver; the absolute value of the phase difference of the radio frequency signals input to different input ports of the combiner is less than or equal to 90 degrees.

2. The signal receiving circuit according to claim 1, characterized in that, The signal receiving circuit further includes at least two phase modulators, each corresponding to one of the at least two receiving antennas, and each receiving antenna is electrically connected to the combiner through one of the phase modulators.

3. The signal receiving circuit according to claim 2, characterized in that, The signal receiving circuit further includes an amplifier, which is disposed between the receiving antenna and the phase tuner, or between the combiner and the radio frequency receiver.

4. The signal receiving circuit according to claim 3, characterized in that, The signal receiving circuit also includes a first filter and a second filter; Wherein, when the amplifier is disposed between the receiving antenna and the phase tuner, the first filter is disposed between the receiving antenna and the amplifier, and the second filter is disposed between the combiner and the radio frequency receiver; In the case where the amplifier is disposed between the combiner and the radio frequency receiver, the first filter is disposed between the combiner and the amplifier, and the second filter is disposed between the amplifier and the radio frequency receiver.

5. The signal receiving circuit according to any one of claims 1 to 4, characterized in that, The absolute value of the amplitude difference of the radio frequency signals input to different input ports of the combiner is less than or equal to 8 dB.

6. The signal receiving circuit according to any one of claims 1 to 4, characterized in that, The combiner includes: an output port, a first resistor, a first input port, and a second input port, wherein, The first input port is electrically connected to the output port via a first transmission line, and the second input port is electrically connected to the output port via a second transmission line; one end of the first resistor is electrically connected to the first input port, and the other end of the first resistor is electrically connected to the second input port.

7. The signal receiving circuit according to any one of claims 1 to 4, characterized in that, The combiner includes: an output port, a second resistor, a third resistor, a fourth resistor, a third input port, a fourth input port, a fifth input port, and a sixth input port, wherein... The third input port is electrically connected to the output port via a third transmission line and a fourth transmission line; the fourth input port is electrically connected to the output port via a fifth transmission line and a fourth transmission line; the fifth input port is electrically connected to the output port via a sixth transmission line and a seventh transmission line; and the sixth input port is electrically connected to the output port via an eighth transmission line and a seventh transmission line. One end of the second resistor is electrically connected to the third input port, and the other end of the second resistor is electrically connected to the fourth input port; one end of the third resistor is electrically connected to the fifth input port, and the other end of the third resistor is electrically connected to the sixth input port; one end of the fourth resistor is connected to the end where the fourth transmission line connects to the third transmission line, and the other end of the fourth resistor is connected to the end where the seventh transmission line connects to the sixth transmission line.

8. The signal receiving circuit according to any one of claims 1 to 4, characterized in that, The radio frequency signal is a GPS radio frequency signal.

9. The signal receiving circuit according to any one of claims 1 to 4, characterized in that, The phase and amplitude of the radio frequency signals input to different input ports of the combiner are all the same.

10. A wearable device, characterized in that, Includes the signal receiving circuit as described in any one of claims 1 to 9.

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