Communication circuit and terminal device

Abstract

The utility model discloses a communication circuit and a terminal device, relating to the technical field of communication, the communication circuit is applied to the terminal device, the terminal device comprises at least two antennas, the communication circuit comprises a detection control circuit and an antenna switching circuit, the detection control circuit is used for detecting the position between the terminal device and an external device, and the antenna switching circuit is used for switching the antenna. A corresponding antenna switching control signal is output; the input end of the antenna switching circuit is connected with the detection control circuit, the common end of the antenna switching circuit is used for receiving radio frequency signals accessed by the antennas or outputting the radio frequency signals to the antennas, and the number of the antenna access ends of the antenna switching circuit corresponds to the number of the antennas of the terminal equipment; and the antenna switching circuit is used for communicating a path between the common end and the corresponding antenna access end according to the antenna switching control signal. The utility model aims to solve the problem of disconnection of the terminal equipment and improve the working reliability of the terminal equipment.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication circuit and terminal equipment. Background Art

[0002] To ensure a wide enough signal coverage range, existing wireless communication devices such as APs (Access Points) or CPEs (Customer Premises Equipment) generally use relatively high power. When a terminal device is close to a communication device, due to the excessively high power, the antenna isolation between the terminal device and the communication device is attenuated, and the signal may still exceed the maximum input level of the communication chip in the terminal device, causing the terminal device to frequently disconnect, resulting in communication failure, or even burning the terminal device. Utility Model Content

[0003] The main purpose of the utility model is to provide a communication circuit and terminal equipment, aiming to improve the problem of terminal equipment disconnection and improve the reliability of the terminal equipment.

[0004] To achieve the above-mentioned object, the present invention provides a communication circuit, which is applied to a terminal device, wherein the terminal device includes at least two antennas, and the communication circuit includes:

[0005] A detection control circuit, used to detect the position between the terminal device and the external device and output a corresponding antenna switching control signal;

[0006] An antenna switching circuit, wherein the input end of the antenna switching circuit is connected to the detection control circuit, the common end of the antenna switching circuit is used to receive the radio frequency signal accessed by the antenna, or to output the radio frequency signal to the antenna, and the number of antenna access ends of the antenna switching circuit corresponds to the number of antennas of the terminal device; the antenna switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0007] In one embodiment, the detection control circuit includes:

[0008] A position detection circuit, configured to detect a distance between the terminal device and an external device and output a corresponding position detection signal to a controller;

[0009] A controller is electrically connected to the position detection circuit; the controller is used to output a corresponding antenna switching control signal according to the position detection signal, so that the antenna switching circuit connects the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0010] In one embodiment, the position detection circuit includes one or more combinations of a distance sensor, a proximity sensor, an inertial measurement sensor, and a visual sensor.

[0011] In one embodiment, the antenna switching circuit includes:

[0012] A switch circuit, the switch circuit having an input end, an antenna access end, and a common end, the input end of the switch circuit being connected to the detection control circuit, and the common end of the switch circuit being used to receive a radio frequency signal accessed by the antenna or output a radio frequency signal to the antenna;

[0013] The switch circuit is used to connect the path between its own common end and the antenna access end according to the antenna switching control signal.

[0014] In one embodiment, the number of the antennas is two, and the switching circuit includes a common terminal, a first antenna access terminal, a second antenna access terminal, and a controlled terminal:

[0015] A single-pole double-throw switch, wherein the common end of the single-pole double-throw switch is used to receive a radio frequency signal connected to the antenna or output a radio frequency signal to the antenna, and the controlled end is electrically connected to the output end of the detection control circuit;

[0016] The single-pole double-throw switch is used to connect the path between its own common terminal and the first antenna access terminal or the second antenna access terminal according to the antenna switching control signal.

[0017] In one embodiment, the communication circuit further includes:

[0018] A signal detection control circuit is used to detect the signal strength of the radio frequency signal output by the external device received by the terminal device, and output a corresponding antenna switching control signal to control the antenna switching circuit to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0019] In one embodiment, the antenna switching circuit further includes:

[0020] a transceiver, wherein a signal terminal of the transceiver is connected to a common terminal of the switch circuit, and a controlled terminal of the transceiver is electrically connected to the detection control circuit;

[0021] The switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal, so as to output the accessed RF signal to the transceiver, or output the RF signal output by the transceiver to the antenna.

[0022] The utility model provides a communication circuit applied to a terminal device, wherein the terminal device includes at least two antennas. The communication circuit includes:

[0023] A signal detection control circuit is used to detect the signal strength of the radio frequency signal output by the external device and received by the terminal device, and output a corresponding antenna switching control signal;

[0024] An antenna switching circuit, wherein the input end of the antenna switching circuit is connected to the signal detection control circuit, the common end of the antenna switching circuit is used to receive the radio frequency signal accessed by the antenna, or to output the radio frequency signal to the antenna, and the number of antenna access ends of the antenna switching circuit corresponds to the number of antennas of the terminal device; the antenna switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0025] In one embodiment, the signal detection control circuit includes:

[0026] Controller;

[0027] a signal detection circuit, configured to detect the signal strength of a radio frequency signal output by an external device and received by the terminal device, and output a corresponding signal strength detection signal to the controller;

[0028] The controller is electrically connected to the signal detection circuit; the controller is used to output a corresponding antenna switching control signal according to the signal strength detection signal, so that the antenna switching circuit connects the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0029] The present invention also provides a terminal device, which includes at least two antennas and a communication circuit as described in any one of the above items.

[0030] The present utility model proposes a communication circuit, which is applied to a terminal device, wherein the terminal device includes at least two antennas. The communication circuit includes a detection control circuit and an antenna switching circuit. The detection control circuit is used to detect the position between the terminal device and an external device and output a corresponding antenna switching control signal; the input end of the antenna switching circuit is connected to the detection control circuit, and the common end of the antenna switching circuit is used to receive a radio frequency signal accessed by the antenna or output a radio frequency signal to the antenna. The number of antenna access ends of the antenna switching circuit corresponds to the number of antennas of the terminal device; the antenna switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

[0031] In practical applications, at least two antennas can be set at different locations on the terminal device. The detection control circuit detects the position between the terminal device and the external device and outputs a corresponding antenna switching control signal, so that the antenna switching circuit connects the path between the common terminal and the corresponding antenna access terminal according to the antenna switching control signal. For example, a first antenna and a second antenna are set at different locations on the terminal device, with the first antenna serving as the main antenna and the second antenna serving as the auxiliary antenna. The antenna switching circuit includes a first antenna access terminal for accessing the first antenna and a second antenna access terminal for accessing the second antenna. If the detection control circuit determines that the isolation between the external device and the terminal device is good after detecting the position between the terminal device and the external device, and the terminal device does not drop the connection, the antenna switching circuit connects the path between the common terminal and the first antenna access terminal according to the antenna switching control signal. If the detection control circuit determines that the distance between the external device and the terminal device is close after detecting the position between the terminal device and the external device, the isolation is weak, and the sensitivity is reduced, the antenna switching circuit connects the path between the common terminal and the second antenna access terminal according to the antenna switching control signal to increase the physical distance between the terminal device and the antenna. In this way, the isolation between the external device and the terminal device is guaranteed, and the problem of terminal device dropouts is improved while ensuring a wide communication signal coverage range. In this way, the reliability of the terminal equipment is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 This is a schematic diagram of a circuit module of an embodiment of a communication circuit of the present utility model;

[0034] Figure 2 This is a schematic diagram of a circuit module of another embodiment of the communication circuit of the present utility model;

[0035] Figure 3 This is a schematic diagram of a circuit module of another embodiment of the communication circuit of the present utility model;

[0036] Figure 4 This is a schematic diagram of a circuit module of another embodiment of the communication circuit of the present utility model;

[0037] Figure 5 This is a schematic diagram of a circuit module of another embodiment of the communication circuit of the present utility model;

[0038] Figure 6This is a schematic diagram of a circuit module of another embodiment of the communication circuit of the present utility model;

[0039] Figure 7 This is a schematic structural diagram of an embodiment of the terminal device of the present utility model;

[0040] Figure 8 This is a structural diagram of another embodiment of the terminal device of the present utility model;

[0041] Figure 9 This is a structural diagram of another embodiment of the terminal device of the present utility model.

[0042] Description of Figure Numbers:

[0043] 10. Detection control circuit; 20. Antenna switching circuit; 30. Antenna access terminal; 40. Signal detection control circuit; 50. Transceiver; 60. Power amplifier circuit; 70. Filter circuit; 80. Frequency divider; 90. Power management circuit; 100. Oscillation circuit; 11. Position detection circuit; 12. Controller; 21. Switching circuit; 110. First frame; 120. Second frame; 130. First group of frames; 140. Second group of frames; 131. First side frame; 132. Second side frame; 141. Third side frame; 142. Fourth side frame.

[0044] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] In addition, in this utility model, the descriptions of "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0047] Existing wireless communication devices, such as APs (Access Points) and CPEs (Customer Premises Equipment), typically use high power to ensure sufficient signal coverage. When a terminal device is close to a communication device, the high power can cause the antenna isolation between the two devices to attenuate, but the signal may still exceed the maximum input level of the communication chip in the terminal device. This can cause the terminal device to frequently disconnect, leading to communication failures and even damage the terminal device.

[0048] For example, to ensure Wi-Fi signal coverage, Wi-Fi access points (APs) typically have high power, typically with a TRP > 15dBm. When a terminal device is operating next to the AP, the isolation between the AP antenna and the terminal is only around 10dB. Assuming Wi-Fi antenna efficiency is 50%, the maximum signal level received by the terminal is approximately 0-3dBm. This results in the terminal receiving a strong Wi-Fi signal, exceeding the maximum input level of the Wi-Fi receiver chip, causing the terminal to disconnect. Similarly, MIFI devices and mobile phones are often held close together, or POS terminals and charging docks with AP functions are often used together. This can easily cause frequent disconnections or communication failures for the terminal device. Reducing the transmit power of the Wi-Fi AP or lowering the receiving sensitivity of the terminal device will reduce the AP's signal coverage, preventing the terminal device from connecting to the Wi-Fi network. Furthermore, adjusting the AP's Wi-Fi antenna's directionality or repositioning the antenna to increase isolation between the AP and terminal antennas does not address the specific user habits of the terminal device, leading to arbitrary placement in practice and thus failing to resolve the issue.

[0049] For this purpose, refer to Figure 1 The present invention proposes a communication circuit, which is applied to a terminal device. The terminal device includes at least two antennas. The communication circuit includes:

[0050] The detection control circuit 10 is used to detect the position between the terminal device and the external device and output a corresponding antenna switching control signal;

[0051] The antenna switching circuit 20 has an input end connected to the detection control circuit 10, and a common end of the antenna switching circuit 20 is used to receive a radio frequency signal accessed by the antenna or output a radio frequency signal to the antenna. The number of antenna access ends 30 of the antenna switching circuit 20 corresponds to the number of antennas of the terminal device; the antenna switching circuit 20 is used to connect the path between the common end and the corresponding antenna access end 30 according to the antenna switching control signal.

[0052] In this embodiment, the detection control circuit 10 can be implemented using a main controller 12, such as an MCU, DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), PLC, or SOC (System on Chip). The main controller 12 can be integrated with a position detection circuit 11 for detecting the position between the terminal device and the external device, thereby outputting an antenna switching control signal to the antenna switching circuit 20. The antenna switching circuit 20 connects the path between the common terminal and the corresponding antenna access terminal 30 according to the antenna switching control signal, thereby controlling the operation of the antenna corresponding to the antenna switching control signal. The antenna switching circuit 20 can be implemented using a switching circuit 21. For example, this can be implemented using a switching transistor such as a PIN diode switch or a field-effect transistor, or a switching device such as a relay or contactor, or an SPDT radio frequency switch. Terminal devices include electronic devices such as mobile phones, tablets, and computers, while external devices include communication devices such as CPE (Customer Premises Equipment) and APs (Access Points).

[0053] Specifically, multiple antennas can be installed at different locations on the terminal device. The detection control circuit 10 is configured to detect the position of the external device relative to each of the terminal device's multiple antennas in real time and output corresponding antenna switching control signals. For illustration, using a mobile phone as an example, assume that the mobile phone is equipped with two antennas, located at different sides of the phone, namely the first antenna and the second antenna. After the terminal device establishes a communication connection with the external device, the detection control circuit 10 detects the position of the first antenna, the second antenna, and the external device on the terminal device. Based on the position of the first antenna relative to the external device, and the position of the second antenna relative to the external device, the detection control circuit 10 selects the antenna farther from the external device for operation, thereby outputting a corresponding antenna switching control signal and controlling the antenna switching circuit 20 to open a path between the common terminal and the corresponding antenna access terminal 30. If the detection control circuit 10 detects that the first antenna is closer to the terminal device, the detection control circuit 10 selects the second antenna farther from the terminal device for operation, thereby outputting a corresponding antenna switching control signal to control the antenna switching circuit 20 to open a path between the common terminal and the antenna access terminal 30 connected to the second antenna. In this way, the physical distance between the terminal device and the antenna can be increased, improving the problem that when the terminal device is close to the communication device, the terminal device is frequently disconnected, resulting in communication failure or even burning the terminal device.

[0054] It is understood that, in order to reduce the power loss caused by frequent antenna switching, one of the multiple antennas on the terminal device can be used as the main antenna, and the remaining antennas can be used as auxiliary antennas. In this way, when the terminal device is communicating with an external device, the detection control circuit 10 can control the antenna switching circuit 20 to open the path between the common terminal and the antenna access terminal 30 for accessing the main antenna. When the terminal device and the external device are close, the detection control circuit 10 detects the position of the terminal device and selects one of the multiple auxiliary antennas to operate, thereby increasing the physical distance between the antenna and the external device and preventing the terminal device from being disconnected.

[0055] In actual applications, during the use of the external device and the terminal device, if the detection control circuit 10 determines that the isolation between the external device and the terminal device is good after detecting the position between the main antenna of the terminal device and the external device, the terminal device will not be disconnected. At this time, the antenna switching circuit 20 still connects the path between the common end and the antenna access end 30 for accessing the main antenna; when the detection control circuit 10 detects the position between the terminal device and the external device and determines that the distance between the external device and the terminal device is close, the isolation is not strong, and the sensitivity is reduced, the detection control circuit 10 outputs an antenna switching control signal to control the antenna switching circuit 20 to connect the path between the common end and the antenna access end 30 for accessing the auxiliary antenna, so as to increase the physical distance between the terminal device and the antenna. In this way, the isolation between the external device and the terminal device is guaranteed, and while meeting the large coverage range of the communication signal, the problem of terminal device disconnection is improved, the reliability of the terminal device operation is improved, and the user experience is improved.

[0056] In one embodiment of the present application, reference Figure 2 , the detection control circuit 10 includes:

[0057] A position detection circuit 11 is configured to detect the distance between the terminal device and an external device and output a corresponding position detection signal to the controller 12;

[0058] The controller 12 is electrically connected to the position detection circuit 11; the controller 12 is used to output a corresponding antenna switching control signal according to the position detection signal, so that the antenna switching circuit 20 connects the path between the common end and the corresponding antenna access end 30 according to the antenna switching control signal.

[0059] It should be noted that the position detection circuit 11 includes one or more combinations of a distance sensor, a proximity sensor, an inertial measurement sensor, and a visual sensor. The controller 12 can be implemented using the above-mentioned main controller 12. The controller 12 can be implemented using the above-mentioned main controller 12.

[0060] In this embodiment, a distance sensor SAR sensor (Specific Absorption Rate Sensor) is used as the position sensor.

[0061] In combination with the contents of the above embodiments, there is a certain physical distance between the main antenna and the auxiliary antenna. The main antenna is located on one side of the terminal device, and the auxiliary antenna is located on the other side of the terminal device. The physical distance between the main antenna and the auxiliary antenna is maintained above a preset range to ensure sufficient isolation. In the initial state, the antenna switching circuit 20 conducts the path between the common end and the antenna access end 30 for accessing the main antenna, so that the common end of the antenna switching circuit 20 receives the radio frequency signal accessed by the main antenna, or outputs the radio frequency signal to the main antenna. When the terminal device approaches an external device, such as an AP device, the SAR sensor detects the approach of the terminal device and causes a change in the electromagnetic field, and converts the electromagnetic field change into an electrical signal and transmits it to the controller 12. After receiving the signal transmitted by the SAR sensor, the controller 12 can analyze the signal strength or change trend to determine whether the distance between the terminal device and the external device will affect the communication quality, such as when the terminal device is disconnected or even damaged. If the controller 12 determines that the terminal device is very close to the AP device, the controller 12 will output an antenna switching control signal to the antenna switching circuit 20, so that the antenna switching circuit 20 opens the path between the common end and the antenna access end 30 of the auxiliary antenna to access the auxiliary antenna, so that the common end of the antenna switching circuit 20 receives the RF signal accessed by the auxiliary antenna, or outputs the RF signal to the auxiliary antenna. It should be noted that if there are multiple auxiliary antennas, the controller 12 can control the antenna switching circuit 20 to switch to the antenna farthest away. Because the distance between the terminal device and the external device is close enough at this time, even if an antenna farther away from the external device among the multiple auxiliary antennas is selected to work, sufficient signal strength can still be maintained without affecting the communication quality.

[0062] Through the above settings, when the terminal device establishes a communication connection with the external device, the position detection circuit 11 will output the corresponding position detection signal to the controller 12, so that the controller 12 controls the auxiliary antenna to work, increases the isolation between the external device and the antenna, and reduces the signal strength received by the terminal device, thereby improving the problem of terminal device disconnection caused by excessive signal strength.

[0063] In one embodiment, reference Figure 3 , the antenna switching circuit 20 includes:

[0064] A switch circuit 21 having an input terminal, an antenna access terminal 30, and a common terminal. The input terminal of the switch circuit 21 is connected to the detection control circuit 10. The common terminal of the switch circuit 21 is used to receive a radio frequency signal from the antenna or output a radio frequency signal to the antenna.

[0065] The switch circuit 21 is configured to connect a path between its own common terminal and the antenna access terminal 30 according to the antenna switching control signal.

[0066] Optionally, the number of the antennas is two, and the switching circuit 21 includes a common terminal, a first antenna access terminal 30, a second antenna access terminal 30, and a controlled terminal:

[0067] A single-pole double-throw switch, wherein the common end of the single-pole double-throw switch is used to receive a radio frequency signal connected to the antenna or output a radio frequency signal to the antenna, and the controlled end is electrically connected to the output end of the detection control circuit 10;

[0068] The single-pole double-throw switch is used to connect the path between its own common terminal and the first antenna access terminal 30 or the second antenna access terminal 30 according to the antenna switching control signal.

[0069] In this embodiment, two antennas are respectively provided at different positions of the terminal device. The antenna switching circuit 20 includes a first antenna access terminal 30 and a second antenna access terminal 30. The first antenna access terminal 30 is used to access the main antenna, and the second antenna access terminal 30 is used to access the auxiliary antenna. When the antenna switching circuit 20 (single-pole double-throw switch) conducts the path between its own common terminal and the first antenna access terminal 30, the common terminal of the single-pole double-throw switch is used to receive the radio frequency signal accessed by the main antenna, or output the radio frequency signal to the main antenna; when the antenna switching circuit 20 (single-pole double-throw switch) conducts the path between its own common terminal and the second antenna access terminal 30, the common terminal of the single-pole double-throw switch is used to receive the radio frequency signal accessed by the auxiliary antenna, or output the radio frequency signal to the auxiliary antenna.

[0070] Specifically, under normal circumstances, the RF signal output from the common terminal of the switching circuit 21 is transmitted through the main antenna and received by the first antenna access terminal 30 of the switching circuit 21. A SAR sensor is connected to the main antenna of the terminal device. When the terminal device is placed adjacent to the main antenna, the SAR sensor detects the distance between the antenna and the external device and outputs a position detection signal to the controller 12. The controller 12 can control the level of the GPIO pin. For example, the initial state is a low-level signal. When the terminal device is placed close to the main antenna, the GPIO pin outputs a high-level signal, controlling the switching logic of the single-pole double-throw switch (SPDT) to switch to the auxiliary antenna. Because the auxiliary antenna is designed at the other end of the terminal device, this ensures isolation between the AP device and the terminal device's main antenna. This ensures that the terminal device does not drop offline when the communication signal strength is strong, while also ensuring network coverage in weak signal areas, thereby improving the reliability and stability of the communication circuit.

[0071] In one embodiment, reference Figure 4 , the communication circuit further includes:

[0072] The signal detection control circuit 40 is used to detect the signal strength of the radio frequency signal output by the external device received by the terminal device, and output a corresponding antenna switching control signal to control the antenna switching circuit 20 to connect the path between the common end and the corresponding antenna access end 30 according to the antenna switching control signal.

[0073] In this embodiment, the signal strength detection control circuit 10 can be implemented using a dedicated integrated circuit, such as an ASIC chip, and is used to measure parameters such as the ratio of signal strength to noise strength SNR and the ratio of carrier signal to interference signal C / I to determine the signal strength of the radio frequency signal output by the external device received by the terminal device.

[0074] Under normal circumstances, the RF signal output from the common terminal of the antenna switching circuit 20 is transmitted through the main antenna and received by the first antenna access terminal 30 of the antenna switching circuit 20. A SAR sensor, acting as a detection control circuit 10, is connected to the main antenna of the terminal device. The SAR sensor detects the distance between the antenna and the external device and outputs an antenna switching control signal. Furthermore, a signal detection control circuit 40 detects the signal strength of the RF signal output by the external device and receives it from the terminal device. The signal detection control circuit 40 compares the measured parameter value with a preset threshold. For example, if the RSSI value, representing the strength of the received signal, exceeds a certain threshold, the RF signal strength is considered excessive. The signal detection control circuit 40 outputs an antenna switching control signal to the antenna switching circuit 20. In this embodiment, the antenna switching circuit 20 operates based on the antenna switching control signal output by at least one of the detection control circuit 10 and the signal detection control circuit 40 to establish a path between the common terminal and the corresponding antenna access terminal 30. This improves the reliability of the communication circuit of the present invention.

[0075] In this embodiment, the signal detection control circuit 40 may include a signal detection circuit and a controller 12. In combination with the contents of the above embodiments, the controller 12 can control the level state of the GPIO pin. For example, the initial state is a low-level signal. When the controller 12 determines that the terminal device is placed close to the main antenna based on the signal strength detection signal output by the signal detection circuit and / or the position detection signal output by the position detection circuit 11, the GPIO pin outputs a high-level signal to control the switching logic of the single-pole double-throw switch SPDT to switch to the auxiliary antenna, and the auxiliary antenna communicates with the antenna of the AP device.

[0076] With this configuration, the auxiliary antenna is located at the other end of the terminal device, ensuring isolation between the AP and the terminal's main antenna. This ensures that the terminal device remains connected even when the communication signal strength is strong, while also ensuring network coverage in weak signal areas. This improves the reliability and stability of the communication circuit. The configuration of the signal detection control circuit 40 and the position detection control circuit 10 ensures that even if one detection circuit fails, the other will continue to operate, ensuring the reliability of the communication circuit.

[0077] In one embodiment, reference Figure 5 , the antenna switching circuit 20 further includes:

[0078] a transceiver 50 , wherein a signal terminal of the transceiver 50 is connected to a common terminal of the switch circuit 21 , and a controlled terminal of the transceiver 50 is electrically connected to the detection control circuit 10 ;

[0079] The switch circuit 21 is configured to connect the path between the common terminal and the corresponding antenna access terminal 30 according to the antenna switching control signal, so as to output the received RF signal to the transceiver 50, or output the RF signal output by the transceiver 50 to the antenna;

[0080] And one or more combinations of the following circuits:

[0081] a power amplifier circuit 60, wherein a first end of the power amplifier circuit 60 is electrically connected to the signal end of the transceiver 50, and a second end of the power amplifier circuit 60 is electrically connected to the common end of the switch circuit 21; and configured to amplify a signal received by the first end of the power amplifier circuit 60 and output the amplified signal to the switch circuit 21; and / or amplify a signal received by the second end of the power amplifier circuit 60 and output the amplified signal to the transceiver 50;

[0082] a filter circuit 70, wherein a first end of the filter circuit 70 is electrically connected to the signal end of the transceiver 50, and a second end of the filter circuit 70 is electrically connected to the common end of the switch circuit 21; and configured to filter a signal received by the first end of the filter circuit 70 and output it to the switch circuit 21; and / or filter a signal received by the second end of the filter circuit 70 and output it to the transceiver 50;

[0083] A frequency dividing circuit, wherein the first end of the frequency dividing circuit is electrically connected to the signal end of the transceiver 50, and the second end of the frequency dividing circuit is electrically connected to the common end of the switching circuit 21; is used to isolate the signal received by the first end of the frequency dividing circuit and output it to the switching circuit 21; and / or isolate the signal received by the second end of the frequency dividing circuit and output it to the transceiver 50.

[0084] In this embodiment, transceiver 50 is used to receive or transmit radio frequency signals. Power amplifier circuit 60 is used to amplify the signal strength of the radio frequency signal to ensure signal transmission quality. Filter circuit 70 is used to filter out unwanted frequency components in the radio frequency signal to improve signal quality. Frequency divider circuits are used to isolate different signal paths to reduce interference between signals.

[0085] refer to Figure 6 Optionally, the transceiver 50 is a Wi-Fi transceiver chip. Antenna 1 and Antenna 2 are both Wi-Fi antennas, with Antenna 1 serving as the terminal device's main antenna and Antenna 2 serving as the terminal device's auxiliary antenna. The CPU serves as the controller 12, the SAR sensor serves as the distance sensor, the DPX serves as the frequency divider 80, the power amplifier circuit 60 is implemented using a power amplifier PA, and the filter circuit 70 is implemented using a SAW filter. WLAN-I / Q and UART are two communication channels between the CPU and the Wi-Fi transceiver chip for data and control signal transmission.

[0086] It is understandable that if the radio frequency signal output by the WIFI transceiver chip or the radio frequency signal received by the antenna is a 5G signal, a power amplifier PA needs to be set between the WIFI transceiver chip and the frequency divider 80 to amplify the signal strength of the WIFI signal. That is, the signal received by the first end of the power amplifier circuit 60 is amplified and output to the switch circuit 21, so that the switch circuit 21 connects the path between the common end and the corresponding antenna access end 30 according to the corresponding antenna switching control signal, and outputs the amplified WIFI signal to the corresponding antenna. Alternatively, the signal received by the second end of the power amplifier circuit 60 is amplified and output to the transceiver 50, so that the WIFI transceiver chip receives the amplified WIFI signal. If the radio frequency signal output by the WIFI transceiver chip or the radio frequency signal received by the antenna is a 2.4G signal, a SAW filter needs to be set between the WIFI transceiver chip and the frequency divider 80 to filter out interference signals and ensure signal quality. Specifically, the filter circuit 70 filters the radio frequency signal outputted by the Wi-Fi transceiver chip to its first terminal and then outputs it to the switch circuit 21, so that the switch circuit 21 connects the path between the common terminal and the corresponding antenna access terminal 30 according to the corresponding antenna switching control signal and outputs the filtered Wi-Fi signal to the corresponding antenna. Furthermore, the filter circuit 70 filters the signal received by the antenna at the second terminal and then outputs it to the transceiver 50, so that the Wi-Fi transceiver chip receives the filtered Wi-Fi signal. The frequency divider 80 isolates the signal outputted by the filter circuit 70 or the power amplifier circuit 60 to the second terminal of the frequency divider 80 and then outputs it to the switch circuit 21 for transmission via the corresponding antenna. Furthermore, the frequency divider isolates the signal received by the antenna at the second terminal of the frequency divider 80 and then outputs it to the filter circuit 70 or the power amplifier circuit 60, i.e., after filtering by the filter circuit 70, outputs it to the transceiver 50, or after amplifying by the power amplifier circuit 60, outputs it to the transceiver 50, thereby improving the quality of the signal received by the Wi-Fi transceiver chip.

[0087] In conjunction with the above embodiments, the terminal device is equipped with two Wi-Fi antennas. The SAR sensor is connected to the terminal device's main antenna, which is used to detect the position of antenna 1. The GPIO pin of the controller 12 CPU is used to control the SPDT switch to switch the operating status of the main antenna and the auxiliary antenna. Under normal circumstances, that is, when the distance between the terminal device and the external device is not sufficient to affect signal isolation and will not cause the terminal device to be disconnected or damaged, the Wi-Fi signal transmitted by the Wi-Fi transceiver chip undergoes signal processing by the PA or SAW before being transmitted through the Wi-Fi main antenna. The Wi-Fi signal output by the external device is received by the Wi-Fi transceiver chip via antenna 1. When the WIFI terminal device is placed close to the antenna of the AP device, the SAR sensor is used to detect the antenna, that is, to detect the distance between the terminal device and the AP device, and output the distance detection signal to the controller 12CPU. The CPU then controls the level state of the GPIO pin to control the switching logic of the single-pole double-throw switch SPDT to switch to the WIFI auxiliary antenna. Since the WIFI auxiliary antenna is set at the other end of the terminal device, the distance between the auxiliary antenna and the antenna of the AP device is farther than the distance between the main antenna and the antenna of the AP device. Therefore, the isolation between the WIFI AP device antenna and the WIFI antenna of the terminal device can be guaranteed, so that the WIFI terminal device will not be disconnected in the strong signal area when the AP device and the terminal device are close. At the same time, the power can be made relatively large to meet the demand for large WIFI coverage in the weak signal area between the AP device and the terminal device.

[0088] The above settings can not only ensure a wide signal coverage range for the Wi-Fi AP device, but also enable users to use Wi-Fi terminal devices in different scenarios. Even if they are close to the AP device, they can still communicate normally without affecting the communication quality, thereby improving the user experience and product competitiveness.

[0089] In one embodiment, the communication circuit further includes:

[0090] A power management circuit 90 , wherein the input end of the power management circuit 90 is used to access the power supply voltage, and the output end of the power management circuit 90 is electrically connected to the detection control circuit 10 ;

[0091] The power management circuit 90 is used to convert the power supply voltage and output it to the detection control circuit 10 to supply power to the detection control circuit 10 .

[0092] The oscillation circuit 100 is electrically connected to the power management circuit 90 and is used to output an oscillation signal to the power management circuit 90 so that the power management circuit 90 provides a clock signal to the detection control circuit 10 .

[0093] In this embodiment, the power management circuit 90 may be implemented by a voltage stabilizer, a charging management chip, etc., and the oscillation circuit 100 may be implemented by a crystal oscillator (XTAL).

[0094] refer to Figure 6 The input end of the power management circuit 90 can be connected to the power interface or internal battery of the terminal device, and the output end of the power management circuit 90 is electrically connected to the controller 12 (CPU). The input end of the power management circuit 90 is used to receive the power supply voltage of the external device or battery to power the controller 12 (CPU). The oscillation signal output by the oscillation circuit 100 is multiplied or divided by the power management circuit 90 and then output to the clock input pin of the controller 12 (CPU). In other words, the oscillation signal provided by the XTAL oscillator is processed by the clock generator inside the power management circuit 90 (PMU) to generate a precise clock signal, which is output to the CPU, thereby ensuring that the CPU can synchronize its internal operations and control its operating speed through a stable clock signal to accurately execute tasks.

[0095] The configuration of the oscillation circuit 100 and the power management circuit 90 reduces the bit error rate and improves the quality of the wireless signal. At the same time, effective power management can extend the battery life, thereby ensuring the efficiency and reliability of communication between the AP device and the terminal device.

[0096] The utility model provides a communication circuit applied to a terminal device, wherein the terminal device includes at least two antennas. The communication circuit includes:

[0097] The signal detection control circuit 40 is used to detect the signal strength of the radio frequency signal output by the external device and received by the terminal device, and output a corresponding antenna switching control signal;

[0098] The antenna switching circuit 20 has an input end connected to the signal detection control circuit 40, and a common end of the antenna switching circuit 20 is used to receive a radio frequency signal accessed by the antenna or output a radio frequency signal to the antenna. The number of antenna access ends 30 of the antenna switching circuit 20 corresponds to the number of antennas of the terminal device; the antenna switching circuit 20 is used to connect the path between the common end and the corresponding antenna access end 30 according to the antenna switching control signal.

[0099] In this embodiment, the signal strength detection control circuit 10 can be implemented using a dedicated integrated circuit, such as an ASIC chip, and is used to measure parameters such as the signal strength to noise strength ratio SNR, the carrier signal to interference signal ratio C / I, and the signal strength RSSI value to determine the signal strength of the radio frequency signal output by the external device received by the terminal device.

[0100] Under normal circumstances, the RF signal output from the common terminal of the antenna switching circuit 20 is transmitted through the main antenna and received by the first antenna access terminal 30, which is connected to the main antenna. The signal detection control circuit 40 is used to detect the signal strength of the RF signal output by the external device and output a corresponding antenna switching control signal. For example, the signal strength detection control circuit 10 compares the measured parameter with a preset threshold. The preset threshold is set in advance by the R&D personnel. For example, when the RSSI value representing the strength of the received signal exceeds the preset threshold, it indicates that the signal strength of the RF signal is too strong. The signal strength detection control circuit 10 outputs a corresponding antenna switching control signal to the antenna switching circuit 20. The antenna switching circuit 20 operates according to the antenna switching control signal to connect the common terminal to the corresponding antenna access terminal 30. For example, when the main antenna is close to the AP device, the antenna switching circuit 20 switches to the auxiliary antenna, thereby increasing the isolation between the terminal device antenna and the AP device antenna. This improves the reliability of the communication circuit of the present invention.

[0101] Optionally, the signal detection control circuit 40 includes:

[0102] Controller 12;

[0103] a signal detection circuit, configured to detect the signal strength of a radio frequency signal output by an external device and received by the terminal device, and output a corresponding signal strength detection signal to the controller 12;

[0104] The controller 12 is electrically connected to the signal detection circuit; the controller 12 is used to output a corresponding antenna switching control signal according to the signal strength detection signal, so that the antenna switching circuit 20 connects the path between the common end and the corresponding antenna access end 30 according to the antenna switching control signal.

[0105] In this embodiment, the signal detection control circuit 40 includes a signal detection circuit and a controller 12. In conjunction with the above embodiments, the controller 12 can control the level of a GPIO pin. For example, in the initial state, the signal level is low. When the controller 12 determines, based on the signal strength detection signal output by the signal detection circuit, that the terminal device is positioned close to the primary antenna, that is, when the signal strength detection circuit detects that the signal strength exceeds a preset range, the controller 12 outputs a high signal via the GPIO pin, controlling the switching logic of the single-pole double-throw switch (SPDT) to switch to the auxiliary antenna, thereby enabling communication between the auxiliary antenna and the antenna of the AP device. The preset range is set in advance by R&D personnel. When the controller 12 determines, based on the signal strength detection signal, that the terminal device is far from the AP device, the controller 12 outputs an antenna switching control signal via the GPIO pin, for example, changing the high signal level to a low signal, controlling the switching logic of the single-pole double-throw switch (SPDT) to switch to the primary antenna. That is, when the signal strength detection circuit detects that the signal strength has dropped to within a preset range, the controller 12 controls the SPDT switch to return to the primary antenna state to maintain optimal signal coverage.

[0106] With the above settings, since the auxiliary antenna is designed at the other end of the terminal device, when the isolation between the AP device and the terminal device's main antenna is low, it switches to the auxiliary antenna to work, ensuring that the terminal device does not drop the line when the communication signal strength is strong, and can also meet the network coverage in weak signal areas, thereby improving the reliability and stability of the communication circuit operation.

[0107] The present application proposes a terminal device, which includes at least two antennas and a communication circuit as described in any one of the above items.

[0108] Optionally, the terminal device further includes a frame, and at least two of the antennas are respectively arranged at different positions of the frame.

[0109] In this embodiment, the frame includes a first frame 110 and a second frame 120, and the first frame 110 and the second frame 120 are arranged opposite to each other; the number of the antennas is two, and the two antennas are respectively a first antenna and a second antenna;

[0110] Optionally, refer to Figure 7 The frame includes a first frame 110 and a second frame 120 that are arranged opposite to each other along the length direction of the terminal device. Figure 8The frame includes a first frame 110 and a second frame 120 disposed opposite each other along the width of the terminal device. In this embodiment, there are two antennas, namely a first antenna and a second antenna. The first antenna is disposed on the first frame 110; the second antenna is disposed on the second frame 120 disposed opposite the first frame 110. Alternatively, the first antenna is disposed on the second frame 120; the second antenna is disposed on the first frame 110 disposed opposite the second frame 120. For example, the first antenna is disposed on the first frame 110. In this manner, the first antenna and the second antenna are disposed on different frames. One of the first antenna or the second antenna is pre-set as the main antenna, and the other antenna is pre-set as the auxiliary antenna. When the distance between the external device and the terminal device's main antenna is greater than a preset distance, the main antenna transmits or receives radio frequency signals. When the distance between the external device and the terminal device's main antenna is less than the preset distance, the auxiliary antenna on the other frame transmits or receives radio frequency signals. This increases isolation between the terminal device's antenna and the external device, improves the problem of terminal device disconnection caused by the terminal device and an external device (e.g., an AP) being used in close proximity, and improves the reliability of the terminal device.

[0111] Optionally, refer to Figure 9 The frame includes a first group of frames 130 and a second group of frames 140, and the first group of frames 130 and the second group of frames 140 are arranged along the diagonal line; the number of the antennas is two, and the two antennas are the first antenna and the second antenna respectively; the first group of frames 130 includes a first side frame 131 and a second side frame 132, and the second group of frames 140 includes a third side frame 141 and a fourth side frame 142; the first antenna is arranged on the first side frame 131 or the second side frame 132; the second antenna is arranged on the third side frame 141 or the fourth side frame 142.

[0112] In this embodiment, the first antenna and the second antenna are both WIFI antennas. The external device is a WIFI AP device. When the first antenna is set on the first side frame 131, the second antenna can be set on the third side frame 141; when the first antenna is set on the second side frame 132, the second antenna can be set on the fourth side frame 142. In this way, the maximum physical distance between the first antenna and the second antenna on the terminal device can be guaranteed as much as possible to ensure the isolation between the antennas. When the terminal device is close to the WIFI AP device, so that the distance between the external device and the main antenna (first antenna) of the terminal device reaches the critical distance for the terminal device to be disconnected, it can be switched to the auxiliary antenna farther away from the external device to work. In this way, while meeting the large coverage range of the WIFI communication signal, the problem of terminal device disconnection is improved, and the reliability of the terminal device operation is improved.

[0113] It is worth noting that since the terminal device of the present application is based on the above-mentioned communication circuit, the embodiments of the terminal device of the present application include all technical solutions of all embodiments of the above-mentioned communication circuit, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0114] The present application also proposes a communication system, the communication system comprising the communication circuit as described in any one of the above items;

[0115] And / or, a terminal device as described in any of the above items, and an external device, wherein the external device is communicatively connected to the terminal device.

[0116] It is worth noting that since the communication system of the present application is based on the above-mentioned communication circuit and / or terminal equipment, the embodiments of the communication system of the present application include all technical solutions of all embodiments of the above-mentioned communication circuit and / or terminal equipment, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0117] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of the present invention.

Claims

1. A communication circuit, applied to a terminal device, wherein the terminal device includes at least two antennas, characterized in that: The communication circuit comprises: A detection control circuit, used to detect the position between the terminal device and the external device and output a corresponding antenna switching control signal; An antenna switching circuit, wherein the input end of the antenna switching circuit is connected to the detection control circuit, the common end of the antenna switching circuit is used to receive the radio frequency signal accessed by the antenna, or to output the radio frequency signal to the antenna, and the number of antenna access ends of the antenna switching circuit corresponds to the number of antennas of the terminal device; the antenna switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

2. The communication circuit according to claim 1, wherein: The detection control circuit includes: A position detection circuit, configured to detect a distance between the terminal device and an external device and output a corresponding position detection signal to a controller; A controller is electrically connected to the position detection circuit; the controller is used to output a corresponding antenna switching control signal according to the position detection signal, so that the antenna switching circuit connects the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

3. The communication circuit according to claim 2, wherein: The position detection circuit includes one or more combinations of a distance sensor, a proximity sensor, an inertial measurement sensor, and a visual sensor.

4. The communication circuit according to claim 1, wherein: The antenna switching circuit includes: A switch circuit, the switch circuit having an input end, an antenna access end, and a common end, the input end of the switch circuit being connected to the detection control circuit, and the common end of the switch circuit being used to receive a radio frequency signal accessed by the antenna or output a radio frequency signal to the antenna; The switch circuit is used to connect the path between its own common end and the antenna access end according to the antenna switching control signal.

5. The communication circuit according to claim 4, wherein: There are two antennas, and the switch circuit includes a common terminal, a first antenna access terminal, a second antenna access terminal, and a controlled terminal: A single-pole double-throw switch, wherein the common end of the single-pole double-throw switch is used to receive a radio frequency signal connected to the antenna or output a radio frequency signal to the antenna, and the controlled end is electrically connected to the output end of the detection control circuit; The single-pole double-throw switch is used to connect the path between its own common terminal and the first antenna access terminal or the second antenna access terminal according to the antenna switching control signal.

6. The communication circuit according to claim 1, wherein: The communication circuit further includes: A signal detection control circuit is used to detect the signal strength of the radio frequency signal output by the external device received by the terminal device, and output a corresponding antenna switching control signal to control the antenna switching circuit to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

7. The communication circuit according to claim 4, wherein: The antenna switching circuit further includes: a transceiver, wherein a signal terminal of the transceiver is connected to a common terminal of the switch circuit, and a controlled terminal of the transceiver is electrically connected to the detection control circuit; The switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal, so as to output the accessed RF signal to the transceiver, or output the RF signal output by the transceiver to the antenna.

8. A communication circuit, applied to a terminal device, the terminal device including at least two antennas, characterized in that: The communication circuit comprises: A signal detection control circuit is used to detect the signal strength of the radio frequency signal output by the external device and received by the terminal device, and output a corresponding antenna switching control signal; An antenna switching circuit, wherein the input end of the antenna switching circuit is connected to the signal detection control circuit, the common end of the antenna switching circuit is used to receive the radio frequency signal accessed by the antenna, or to output the radio frequency signal to the antenna, and the number of antenna access ends of the antenna switching circuit corresponds to the number of antennas of the terminal device; the antenna switching circuit is used to connect the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

9. The communication circuit according to claim 8, wherein: The signal detection control circuit includes: Controller; a signal detection circuit, configured to detect the signal strength of a radio frequency signal output by an external device and received by the terminal device, and output a corresponding signal strength detection signal to the controller; The controller is electrically connected to the signal detection circuit; the controller is used to output a corresponding antenna switching control signal according to the signal strength detection signal, so that the antenna switching circuit connects the path between the common end and the corresponding antenna access end according to the antenna switching control signal.

10. A terminal device, characterized in that: The terminal device includes at least two antennas and the communication circuit according to any one of claims 1 to 9.

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