Electronic equipment, Beidou signal receiver and narrowband radio frequency circuit thereof
By designing a narrowband radio frequency circuit in the Beidou receiver to filter out non-Beidou satellite signals, the problem that the receiver is susceptible to interference from other systems is solved, the accurate reception and processing of Beidou satellite signals is achieved, and the reliability of positioning and speed measurement is improved.
Patent Information
- Application Number
- CN202420095404.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-01-12
AI Technical Summary
The existing Beidou receiver is susceptible to other systems, resulting in abnormal positioning, speed measurement and time results, and even failing to work properly at critical moments.
A narrowband radio frequency circuit is designed, including matching circuit, power divider, first filter circuit, second filter circuit and circuit combiner. Through these circuits, non-Beidou satellite signals are filtered out, and only 1268.098MHz±10.23MHz of Beidou satellite signals are retained. and the signal in the 1561.098MHz ±1.023MHz frequency band ensures that the Beidou satellite signal is received.
Effectively filter out other satellite signals to ensure that the receiver only receives Beidou satellite signals, improves the accuracy and reliability of positioning, speed measurement and time results, and avoids receiver abnormalities caused by interference from other systems.
Smart Images
Figure CN222339389U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of Beidou system receivers, in particular to an electronic device, a Beidou signal receiver and a narrowband radio frequency circuit thereof. Background Art
[0002] Currently, most receivers on the market support multiple systems and multiple frequencies, and positioning adopts multi-system combined positioning. The existing technical solutions are affected by other systems, affecting the positioning, speed measurement and time results of the entire receiver.
[0003] The disadvantage of existing Beidou receivers is that they can be deceived by other systems, causing the receivers to malfunction and fail to work properly at critical moments. Utility Model Content
[0004] The purpose of the utility model is to provide an electronic device, a Beidou signal receiver and a narrowband radio frequency circuit thereof, so as to solve the problems mentioned in the above background technology.
[0005] The technical solution of the utility model is a narrowband radio frequency circuit, comprising: a matching circuit, a power divider, a first filter circuit, a second filter circuit and a combiner; the input end of the matching circuit is used to be connected to a radio frequency interface, the output end of the matching circuit is connected to the input end of the power divider, the first output end of the power divider is connected to the input end of the first filter circuit, the second output end of the power divider is connected to the input end of the second filter circuit, the output end of the first filter circuit is connected to the first input end of the combiner, the output end of the second filter circuit is connected to the second input end of the combiner, and the output end of the combiner is used to be connected to a radio frequency chip; the frequency bands of satellite signals filtered by the first filter circuit and the second filter circuit are different.
[0006] In one embodiment, the matching circuit includes a resistor R7, a resistor R8, a resistor R9 and a capacitor C7; the first end of the resistor R8 and the first end of the resistor R9 are used to connect to the radio frequency interface, the second end of the resistor R8 is connected to the first end of the capacitor C7, the second end of the capacitor C7 is connected to the input end of the power divider, the second end of the resistor R9 is used for grounding, the first end of the resistor R7 is used for grounding, and the second end of the resistor R7 is connected to the first end of the capacitor C7.
[0007] In one embodiment, the first filtering circuit includes: a first input circuit, a first surface acoustic wave filter and a first output circuit;
[0008] The input end of the first input circuit is connected to the first output end of the power divider, the output end of the first input circuit is connected to the input end of the first surface acoustic filter, the output end of the first surface acoustic filter is connected to the input end of the first output circuit, and the output end of the first output circuit is connected to the first input end of the combiner;
[0009] The first SAW filter is used to filter the satellite signals with frequencies outside the 1268.098 MHz±10.23 MHz frequency band, retain the signals in the 1268.098 MHz±10.23 MHz frequency band, and send the retained signals to the combiner.
[0010] In one embodiment, the first input circuit includes: a resistor R11, a resistor R12, a resistor R13 and a capacitor C15; the first end of the capacitor C15 is connected to the first output end of the power divider, the second end of the capacitor C15 is connected to the first end of the resistor R11, the second end of the resistor R11 is connected to the input end of the first surface acoustic filter, the first end of the resistor R12 is connected to the second end of the capacitor C15, the second end of the resistor R12 is used for grounding, the first end of the resistor R13 is used for grounding, and the second end of the resistor R13 is connected to the input end of the first surface acoustic filter.
[0011] In one embodiment, the first output circuit includes: a resistor R10, a resistor R14, a resistor R15 and a capacitor C16; the first end of the resistor R10 is connected to the output end of the first surface acoustic filter, the second end of the resistor R10 is connected to the first end of the capacitor C16, the second end of the capacitor C16 is connected to the first input end of the combiner, the first end of the resistor R14 is connected to the output end of the first surface acoustic filter, the second end of the resistor R14 is used for grounding, the first end of the resistor R15 is used for grounding, and the second end of the resistor R15 is connected to the first input end of the capacitor C16.
[0012] In one embodiment, the second filtering circuit includes: a second input circuit, a second SAW filter, and a second output circuit;
[0013] The input end of the second input circuit is connected to the second output end of the power divider, the output end of the second input circuit is connected to the input end of the second surface acoustic filter, the output end of the second surface acoustic filter is connected to the input end of the second output circuit, and the output end of the second output circuit is connected to the second input end of the combiner;
[0014] The second SAW filter is used to filter the satellite signals with frequencies outside the frequency band of 1561.098 MHz±1.023 MHz, retain the signals in the frequency band of 1561.098 MHz±1.023 MHz, and send the retained signals to the combiner.
[0015] In one embodiment, the second input circuit includes: a resistor R19, a resistor R21, a resistor R22 and a capacitor C18; the first end of the capacitor C18 is connected to the second output end of the power divider, the second end of the capacitor C18 is connected to the first end of the resistor R19, the second end of the resistor R19 is connected to the input end of the second surface acoustic filter, the first end of the resistor R21 is connected to the second end of the capacitor C19, the second end of the resistor R21 is used for grounding, the first end of the resistor R22 is used for grounding, and the second end of the resistor R22 is connected to the input end of the second surface acoustic filter.
[0016] In one embodiment, the second output circuit includes: a resistor R18, a resistor R23, a resistor R24 and a capacitor C19; the first end of the resistor R18 is connected to the output end of the second surface acoustic filter, the second end of the resistor R18 is connected to the first end of the capacitor C19, the second end of the capacitor C19 is connected to the second input end of the combiner, the first end of the resistor R23 is connected to the output end of the second surface acoustic filter, the second end of the resistor R23 is used for grounding, the first end of the resistor R24 is used for grounding, and the second end of the resistor R24 is connected to the first end of the capacitor C19.
[0017] A Beidou signal receiver comprises the narrowband radio frequency circuit, radio frequency interface and radio frequency chip described in any one of the above embodiments; the input end of the radio frequency interface is used to connect to an antenna, the output end of the radio frequency interface is connected to the input end of the narrowband radio frequency circuit, and the input end of the radio frequency chip is connected to the output end of the narrowband radio frequency circuit.
[0018] An electronic device comprises the Beidou signal receiver described in any one of the above embodiments.
[0019] The beneficial effect provided by the utility model is: by connecting an antenna to a radio frequency interface, it is used to receive satellite signals. The received satellite signal is matched and debugged by a matching circuit, and the debugged satellite signal is then split by a power divider. The split satellite signals enter the corresponding first filter circuit and the second filter circuit for filtering processing respectively, and the processed satellite signals are combined by a combiner, and finally the combined satellite signals are exported through a radio frequency chip. The satellite signal processed by the above narrowband radio frequency circuit can effectively filter out other satellite signals and only retain the Beidou satellite signal. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 A signal flow block diagram of a narrowband radio frequency circuit in an embodiment;
[0021] Figure 2 is a schematic diagram of a matching circuit in an embodiment;
[0022] Figure 3 is a schematic diagram of a first filtering circuit and a second filtering circuit in one embodiment.
[0023] In the accompanying drawings, 10, narrowband RF circuit; 100, matching circuit; 200, power divider; 300, first filter circuit; 310, first input circuit; 320, first output circuit; 400, second filter circuit; 410, second input circuit; 420, second output circuit; 500, combiner; 600, RF interface; 700, RF chip. DETAILED DESCRIPTION
[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The technical solution of the present invention will be further described below in conjunction with the drawings of the embodiments of the present invention, and the present invention is not limited to the following specific implementation methods.
[0025] It should be understood that the same or similar numbers in the drawings of the embodiments correspond to the same or similar parts. In the description of the present utility model, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom" and the like indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0026] In one embodiment, Figure 1As shown, a narrowband radio frequency circuit 10 includes: a matching circuit 100, a power divider 200, a first filter circuit 300, a second filter circuit 400 and a combiner 500; the input end of the matching circuit 100 is used to connect to the radio frequency interface 600, the output end of the matching circuit 100 is connected to the input end of the power divider 200, the first output end of the power divider 200 is connected to the input end of the first filter circuit 300, the second output end of the power divider 200 is connected to the input end of the second filter circuit 400, the output end of the first filter circuit 300 is connected to the first input end of the combiner 500, the output end of the second filter circuit 400 is connected to the second input end of the combiner 500, and the output end of the combiner 500 is used to connect to the radio frequency chip 700; the frequency bands of satellite signals filtered by the first filter circuit 300 and the second filter circuit 400 are different.
[0027] Specifically, by connecting an antenna to the RF interface 600, the antenna is used to receive satellite signals. The received satellite signal is matched and debugged by the matching circuit 100, and the debugged satellite signal is then split by the power divider 200. The split satellite signals enter the corresponding first filter circuit 300 and the second filter circuit 400 for filtering respectively. The processed satellite signals are combined by the combiner 500, and finally the combined satellite signals are exported through the RF chip 700. The satellite signals processed by the narrowband RF circuit 10 can effectively filter out other satellite signals and only retain Beidou satellite signals.
[0028] In one embodiment, Figure 2 As shown, the matching circuit 100 includes a resistor R7, a resistor R8, a resistor R9 and a capacitor C7; the first end of the resistor R8 and the first end of the resistor R9 are used to connect to the RF interface 600, the second end of the resistor R8 is connected to the first end of the capacitor C7, and the second end of the capacitor C7 is connected to the power divider 200 (such as Figure 2 The first end of the resistor R7 is connected to the first end of the capacitor C7. Specifically, the satellite signal received from the radio frequency interface is matched and debugged by the matching circuit 100. The resistors R7, R8 and R9 with appropriate resistance values, and the capacitor C7 with appropriate capacitance value are selected according to actual needs. After the satellite signal is matched and adjusted by the matching circuit 100 set as above, a satellite signal of a suitable frequency band is obtained.
[0029] In one embodiment, the model of the power divider 200 includes PD1500U03W.
[0030] In order to filter out satellite signals in useless frequency bands, in one embodiment, Figure 3 As shown, the first filtering circuit 300 includes: a first input circuit 310, a first surface acoustic filter U3 and a first output circuit 320; the input end of the first input circuit 310 is connected to the first output end of the power divider 200, the output end of the first input circuit 310 is connected to the input end of the first surface acoustic filter U3, the output end of the first surface acoustic filter U3 is connected to the input end of the first output circuit 320, and the output end of the first output circuit 320 is connected to the combiner 500 (as shown in FIG. Figure 3 Specifically, after the satellite signal passes through the first filter circuit 300, satellite signals of other frequency bands can be filtered out, and the required signal frequency band is retained, thereby purifying the satellite signal.
[0031] Furthermore, the first SAW filter U3 is used to filter the satellite signal with a frequency other than the 1268.098 MHz ± 10.23 MHz frequency band, retain the signal in the 1268.098 MHz ± 10.23 MHz frequency band, and send the retained signal to the combiner 500. That is, the first SAW filter U3 is used to filter the signal other than the Beidou satellite B3 frequency point, and retain the signal of the Beidou satellite B3 frequency point.
[0032] In one embodiment, Figure 3 As shown, the first input circuit 310 includes: a resistor R11, a resistor R12, a resistor R13 and a capacitor C15; the first end of the capacitor C15 is connected to the first output end of the power divider 200, the second end of the capacitor C15 is connected to the first end of the resistor R11, the second end of the resistor R11 is connected to the input end of the first surface acoustic filter U3, the first end of the resistor R12 is connected to the second end of the capacitor C15, the second end of the resistor R12 is used for grounding, the first end of the resistor R13 is used for grounding, and the second end of the resistor R13 is connected to the input end of the first surface acoustic filter U3. Specifically, a section of satellite signal branched by the power divider 200 first passes through the first input circuit 310, and then enters the first surface acoustic filter U3 for filtering. The resistors R11, R12 and R13 with appropriate resistance values, and the capacitor C15 with appropriate capacitance values are selected according to actual needs. After the satellite signal passes through the above-mentioned first input circuit 310, the signal strength can be improved and enter the first surface acoustic filter U3.
[0033] In one embodiment, Figure 3As shown, the first output circuit 320 includes: a resistor R10, a resistor R14, a resistor R15 and a capacitor C16; the first end of the resistor R10 is connected to the output end of the first surface acoustic filter U3, the second end of the resistor R10 is connected to the first end of the capacitor C16, the second end of the capacitor C16 is connected to the first input end of the combiner 500, the first end of the resistor R14 is connected to the output end of the first surface acoustic filter U3, the second end of the resistor R14 is used for grounding, the first end of the resistor R15 is used for grounding, and the second end of the resistor R15 is connected to the first input end of the capacitor C16. Specifically, the satellite signal filtered by the first surface acoustic filter U3 first passes through the first output circuit 320, and then enters the combiner 500 for signal merging processing. The resistors R10, R14 and R15 with appropriate resistance values, and the capacitor C16 with appropriate capacitance values are selected according to actual needs. After the satellite signal passes through the above-mentioned first output circuit 320, the signal strength can be improved and enter the combiner 500.
[0034] In order to filter out satellite signals in useless frequency bands, in one embodiment, Figure 3 As shown, the second filter circuit 400 includes: a second input circuit 410, a second surface acoustic filter U7 and a second output circuit 420; the input end of the second input circuit 410 is connected to the second output end of the power divider 200, the output end of the second input circuit 410 is connected to the input end of the second surface acoustic filter U7, the output end of the second surface acoustic filter U7 is connected to the input end of the second output circuit 420, and the output end of the second output circuit 420 is connected to the second input end of the combiner 500. Specifically, after the satellite signal passes through the second filter circuit 400, the satellite signals of other frequency bands can be filtered out, and the required signal frequency bands are retained, thereby purifying the satellite signal.
[0035] Furthermore, the second SAW filter U7 is used to filter the satellite signal with a frequency other than the 1561.098 MHz ± 1.023 MHz frequency band, retain the signal in the 1561.098 MHz ± 1.023 MHz frequency band, and send the retained signal to the combiner 500. That is, the second SAW filter U7 is used to filter the signal other than the Beidou satellite B1 frequency point, and retain the signal of the Beidou satellite B1 frequency point.
[0036] In one embodiment, Figure 3As shown, the second input circuit 410 includes: a resistor R19, a resistor R21, a resistor R22 and a capacitor C18; the first end of the capacitor C18 is connected to the second output end of the power divider 200, the second end of the capacitor C18 is connected to the first end of the resistor R19, the second end of the resistor R19 is connected to the input end of the second SAW filter U7, the first end of the resistor R21 is connected to the second end of the capacitor C19, the second end of the resistor R21 is used for grounding, the first end of the resistor R22 is used for grounding, and the second end of the resistor R22 is connected to the input end of the second SAW filter U7. Specifically, a section of satellite signal branched by the power divider 200 first passes through the second input circuit 410, and then enters the second SAW filter U7 for filtering. The resistors R19, R21 and R22 with appropriate resistance values, and the capacitor C18 with appropriate capacitance values are selected according to actual needs. After the satellite signal passes through the above-mentioned second input circuit 410, the signal strength can be improved and enter the second SAW filter U7.
[0037] In one embodiment, Figure 3 As shown, the second output circuit 420 includes: a resistor R18, a resistor R23, a resistor R24 and a capacitor C19; the first end of the resistor R18 is connected to the output end of the second surface acoustic filter U7, the second end of the resistor R18 is connected to the first end of the capacitor C19, the second end of the capacitor C19 is connected to the second input end of the combiner 500, the first end of the resistor R23 is connected to the output end of the second surface acoustic filter U7, the second end of the resistor R23 is used for grounding, the first end of the resistor R24 is used for grounding, and the second end of the resistor R24 is connected to the first end of the capacitor C19. Specifically, the satellite signal filtered by the second surface acoustic filter U7 first passes through the second output circuit 420, and then enters the combiner 500 for signal merging processing. The resistors R18, R23 and R24 with appropriate resistance values, and the capacitor C19 with appropriate capacitance values are selected according to actual needs. After the satellite signal passes through the above-mentioned second output circuit 420, the signal strength can be improved and enter the combiner 500.
[0038] A Beidou signal receiver comprises the narrowband radio frequency circuit 10, the radio frequency interface 600 and the radio frequency chip 700 described in any one of the above embodiments; the input end of the radio frequency interface 600 is used to connect to the antenna, the output end of the radio frequency interface 600 is connected to the input end of the narrowband radio frequency circuit 10, and the input end of the radio frequency chip 700 is connected to the output end of the narrowband radio frequency circuit 10. Specifically, the Beidou signal receiver adopts a narrowband radio frequency circuit design, suppresses the GPS (Global Positioning System) system frequency, the GLONASS system (GLONASS satellite navigation system) frequency, and the Galileo system (Galileo satellite navigation system) frequency, and only allows the Beidou satellite navigation system B3I frequency (1268.098MH±10.23MHz) and the Beidou satellite navigation system B1I frequency (1561.098MHz±1.023MHz) to pass, and filters out other frequency points, so as to achieve receiving only the satellite signal of the Beidou satellite navigation system. The Beidou signal receiver adopts a single Beidou system to effectively solve the invalidity of the receiver result caused by the satellite control station's control of the satellite signal, thereby ensuring the safety of positioning, speed measurement and time.
[0039] An electronic device comprises the Beidou signal receiver described in any one of the above embodiments. Specifically, the electronic device can receive only satellite signals of the Beidou satellite navigation system by installing the Beidou signal receiver inside.
[0040] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0041] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A narrowband radio frequency circuit, characterized in that: include: A matching circuit, a power divider, a first filter circuit, a second filter circuit and a combiner; The input end of the matching circuit is used to be connected to the RF interface, the output end of the matching circuit is connected to the input end of the power divider, the first output end of the power divider is connected to the input end of the first filter circuit, the second output end of the power divider is connected to the input end of the second filter circuit, the output end of the first filter circuit is connected to the first input end of the combiner, the output end of the second filter circuit is connected to the second input end of the combiner, and the output end of the combiner is used to be connected to the RF chip; the frequency bands of the satellite signals filtered by the first filter circuit and the second filter circuit are different.
2. The narrowband radio frequency circuit according to claim 1, characterized in that: The matching circuit includes a resistor R7, a resistor R8, a resistor R9 and a capacitor C7; The first end of the resistor R8 and the first end of the resistor R9 are used to connect to the RF interface, the second end of the resistor R8 is connected to the first end of the capacitor C7, the second end of the capacitor C7 is connected to the input end of the power divider, the second end of the resistor R9 is used for grounding, the first end of the resistor R7 is used for grounding, and the second end of the resistor R7 is connected to the first end of the capacitor C7.
3. The narrowband radio frequency circuit according to claim 1, characterized in that: The first filtering circuit comprises: a first input circuit, a first surface acoustic wave filter and a first output circuit; The input end of the first input circuit is connected to the first output end of the power divider, the output end of the first input circuit is connected to the input end of the first surface acoustic filter, the output end of the first surface acoustic filter is connected to the input end of the first output circuit, and the output end of the first output circuit is connected to the first input end of the combiner; The first SAW filter is used to filter the satellite signals with frequencies outside the 1268.098 MHz±10.23 MHz frequency band, retain the signals in the 1268.098 MHz±10.23 MHz frequency band, and send the retained signals to the combiner.
4. The narrowband radio frequency circuit according to claim 3, characterized in that: The first input circuit includes: a resistor R11, a resistor R12, a resistor R13 and a capacitor C15; The first end of the capacitor C15 is connected to the first output end of the power divider, the second end of the capacitor C15 is connected to the first end of the resistor R11, the second end of the resistor R11 is connected to the input end of the first surface acoustic filter, the first end of the resistor R12 is connected to the second end of the capacitor C15, the second end of the resistor R12 is used for grounding, the first end of the resistor R13 is used for grounding, and the second end of the resistor R13 is connected to the input end of the first surface acoustic filter.
5. The narrowband radio frequency circuit according to claim 3, characterized in that: The first output circuit includes: a resistor R10, a resistor R14, a resistor R15 and a capacitor C16; The first end of the resistor R10 is connected to the output end of the first surface acoustic filter, the second end of the resistor R10 is connected to the first end of the capacitor C16, the second end of the capacitor C16 is connected to the first input end of the combiner, the first end of the resistor R14 is connected to the output end of the first surface acoustic filter, the second end of the resistor R14 is used for grounding, the first end of the resistor R15 is used for grounding, and the second end of the resistor R15 is connected to the first input end of the capacitor C16.
6. The narrowband radio frequency circuit according to claim 1, characterized in that: The second filtering circuit comprises: a second input circuit, a second surface acoustic wave filter and a second output circuit; The input end of the second input circuit is connected to the second output end of the power divider, the output end of the second input circuit is connected to the input end of the second surface acoustic filter, the output end of the second surface acoustic filter is connected to the input end of the second output circuit, and the output end of the second output circuit is connected to the second input end of the combiner; The second SAW filter is used to filter the satellite signals with frequencies outside the frequency band of 1561.098 MHz±1.023 MHz, retain the signals in the frequency band of 1561.098 MHz±1.023 MHz, and send the retained signals to the combiner.
7. The narrowband radio frequency circuit according to claim 6, characterized in that: The second input circuit includes: a resistor R19, a resistor R21, a resistor R22 and a capacitor C18; The first end of the capacitor C18 is connected to the second output end of the power divider, the second end of the capacitor C18 is connected to the first end of the resistor R19, the second end of the resistor R19 is connected to the input end of the second surface acoustic filter, the first end of the resistor R21 is connected to the second end of the capacitor C19, the second end of the resistor R21 is used for grounding, the first end of the resistor R22 is used for grounding, and the second end of the resistor R22 is connected to the input end of the second surface acoustic filter.
8. The narrowband radio frequency circuit according to claim 6, characterized in that: The second output circuit includes: a resistor R18, a resistor R23, a resistor R24 and a capacitor C19; The first end of the resistor R18 is connected to the output end of the second surface acoustic filter, the second end of the resistor R18 is connected to the first end of the capacitor C19, the second end of the capacitor C19 is connected to the second input end of the combiner, the first end of the resistor R23 is connected to the output end of the second surface acoustic filter, the second end of the resistor R23 is used for grounding, the first end of the resistor R24 is used for grounding, and the second end of the resistor R24 is connected to the first end of the capacitor C19.
9. A Beidou signal receiver, characterized in that: The invention comprises the narrowband radio frequency circuit, radio frequency interface and radio frequency chip as described in any one of claims 1 to 8; The input end of the radio frequency interface is used to connect to the antenna, the output end of the radio frequency interface is connected to the input end of the narrowband radio frequency circuit, and the input end of the radio frequency chip is connected to the output end of the narrowband radio frequency circuit.
10. An electronic device, characterized in that: Including the Beidou signal receiver as described in claim 9.