Antenna switching circuit and communication equipment

Abstract

The utility model provides an antenna switching circuit and communication equipment, the antenna switching circuit comprises a switching module, the first end of the switching module is connected with a broadband control module, the second end of the switching module is connected with an external antenna, and the third end of the switching module is connected with a built-in antenna; and the in-place detection module is connected with the control end of the switching module, and the in-place detection module is configured to detect the in-place condition of the narrow-band board and control the switching module to conduct a signal path between the broadband control module and the external antenna or a signal path between the broadband control module and the internal antenna according to the in-place condition of the narrow-band board. By means of the mode, the broadband board and the narrowband board share one external antenna, and automatic switching of the antennas is achieved without software support.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to an antenna switching circuit and a communication device. Background Art

[0002] Wireless communication equipment contains internal antennas and external antennas. Internal antennas are usually hidden inside the equipment, which are limited in signal coverage and transmission distance. External antennas are installed outside the equipment, with wide signal coverage, long transmission distance, and easy adjustment of angles to adapt to different usage environments. Narrowband boards are usually used to process narrowband signals with low speed, low cost, and long-distance transmission, and often use external antennas, while broadband boards are used to process broadband signals with high speed, large data volume, and short-distance transmission, and often use internal antennas. However, in order to improve antenna performance, the broadband board and the narrowband board will share the external antenna, which involves antenna switching requirements in different situations.

[0003] In existing wireless communication devices, if the antenna cannot be switched, the communication device will be unable to connect between different RF signal paths. In communication devices that support antenna switching, additional detection circuits and software support are often required. Utility Model Content

[0004] In order to solve the above problems, the present application provides an antenna switching circuit and a communication device, which can realize the switching between an external antenna and a built-in antenna.

[0005] A technical solution adopted in the present application is: to provide an antenna switching circuit, which includes: a switching module, a first end of the switching module is connected to the broadband control module, a second end of the switching module is connected to the external antenna, and a third end of the switching module is connected to the built-in antenna; a presence detection module, connected to the control end of the switching module, the presence detection module is configured to detect the presence of a narrowband board, and control the switching module to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board.

[0006] In one embodiment, the presence detection module is configured to conduct the signal path between the broadband control module and the external antenna when it detects that the narrowband board is in place, and conduct the signal path between the broadband control module and the internal antenna when it detects that the narrowband board is not in place.

[0007] In one embodiment, the presence detection module includes: a first resistor, a first end of the first resistor is connected to the control end of the switching module, and a second end of the first resistor is connected to a suspended contact, and the suspended contact is configured to be grounded when the narrowband board is in place, or to be suspended when the narrowband board is not in place; a second resistor, a first end of the second resistor is connected to the control end of the switching module, and a second end of the second resistor is configured to input a high-level signal.

[0008] In one embodiment, the first resistor is a zero-ohm resistor.

[0009] In one embodiment, the second end of the second resistor is connected to the broadband control module, and the broadband control module is configured to output a high level signal.

[0010] In one embodiment, the antenna switching circuit further includes a high-pass filtering module, an input end of the high-pass filtering module is connected to the external antenna, and an output end of the high-pass filtering module is connected to the second end of the switching module.

[0011] In one embodiment, the antenna switching circuit also includes a low-pass filtering module, the input end of the low-pass filtering module is connected to the external antenna, and the output end of the low-pass filtering module is connected to the narrowband port. When the narrowband board is in place, the output end of the low-pass filtering module is connected to the narrowband board through the narrowband port.

[0012] In one embodiment, the antenna switching circuit further includes a bandpass filtering module, an input end of the bandpass filtering module is connected to the first end of the switching module, and an output end of the bandpass filtering module is connected to the broadband control module.

[0013] In one embodiment, the switching module is a radio frequency switch chip.

[0014] The present application also provides a communication device, which includes an external antenna; a built-in antenna; a broadband control module; an antenna switching circuit, which connects the external antenna, the built-in antenna and the broadband control module, and the antenna switching circuit is the antenna switching circuit as described above.

[0015] The present application provides an antenna switching circuit, which includes: a switching module, the first end of which is connected to a broadband control module, the second end of which is connected to an external antenna, and the third end of which is connected to a built-in antenna; a presence detection module, which is connected to the control end of the switching module, and the presence detection module is configured to detect the presence of a narrowband board, and control the switching module to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board. In the above manner, broadband and narrowband can share an external antenna, and automatic antenna switching can be achieved without software support. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] in:

[0018] Figure 1is a structural schematic diagram of a first embodiment of an antenna switching circuit provided by the present application;

[0019] Figure 2 is a structural schematic diagram of a second embodiment of an antenna switching circuit provided by the present application;

[0020] Figure 3 is a structural schematic diagram of a third embodiment of an antenna switching circuit provided by the present application;

[0021] Figure 4 is a structural schematic diagram of a fourth embodiment of an antenna switching circuit provided by the present application;

[0022] Figure 5 It is a structural diagram of an embodiment of a communication device provided by the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0024] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the first embodiment of the antenna switching circuit provided in the present application; the antenna switching circuit 100 includes a switching module 10 and a presence detection module 20 .

[0027] Among them, the first end of the switching module 10 is connected to the broadband control module, the second end of the switching module 10 is connected to the external antenna, and the third end of the switching module 10 is connected to the built-in antenna; the presence detection module 20 is connected to the control end of the switching module 10, and the presence detection module 20 is configured to detect the presence of the narrowband board, and control the switching module 10 to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board.

[0028] Optionally, the presence detection module 20 is configured to conduct the signal path between the broadband control module and the external antenna when it is detected that the narrowband board is in place, and conduct the signal path between the broadband control module and the internal antenna when it is detected that the narrowband board is not in place.

[0029] In one application scenario, a communication device includes an independent broadband board and an independent narrowband board. The switching module 10 is set on the broadband board and connected to the broadband control module. When the narrowband board is in place, that is, the narrowband board is installed at the corresponding position inside the device, the path between the broadband control module and the external antenna is connected; when the narrowband board is not in place, that is, the narrowband board is removed from the corresponding position inside the device, the path between the broadband control module and the built-in antenna is connected.

[0030] See also Figure 2 , Figure 2 1 is a schematic diagram of the structure of the second embodiment of the antenna switching circuit provided in the present application; the antenna switching circuit 100 includes a switching module 10 and a presence detection module 20.

[0031] Among them, the first end of the switching module 10 is connected to the broadband control module, the second end of the switching module 10 is connected to the external antenna, and the third end of the switching module 10 is connected to the built-in antenna; the presence detection module 20 is connected to the control end of the switching module 10, and the presence detection module 20 is configured to detect the presence of the narrowband board, and control the switching module 10 to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board.

[0032] Optionally, the switching module 10 is a radio frequency switch chip U1, which is a voltage-controlled switching device used to connect and disconnect radio frequency signals in radio frequency circuits. The radio frequency switch chip U1 contains a switch switching unit, which switches the radio frequency path under the control signal. For example, when the control terminal VC of the radio frequency switch chip U1 inputs a low-level signal, the switch switching unit conducts the first end ANT of the radio frequency switch chip U1 (i.e., the first end of the switching module 10) and the second end RF1 of the radio frequency switch chip U1 (i.e., the second end RF1 of the switching module 10); when the control terminal VC inputs a high-level signal, the switch switching unit conducts the first end ANT of the radio frequency switch chip U1 and the third end RF2 of the radio frequency switch chip U1 (i.e., the third end RF2 of the switching module 10), thereby switching the radio frequency signal.

[0033] Optionally, the presence detection module 20 includes a first resistor R1 and a second resistor R2, the first end of the first resistor R1 is connected to the control terminal VC of the RF switch chip U1, the second end of the first resistor R1 is connected to a suspended contact, the suspended contact is configured to be grounded when the narrowband board is in place, or suspended when the narrowband board is not in place; the first end of the second resistor R2 is connected to the control terminal VC of the RF switch chip U1, and the second end of the second resistor R2 is configured to input a high-level signal.

[0034] Optionally, the first resistor R1 is a zero-ohm resistor, which is a special resistor whose resistance is usually very small (close to but not zero) and can be used as a jumper to provide a flexible and easy-to-implement circuit connection method in the circuit.

[0035] Optionally, the second end of the second resistor R2 is connected to a broadband control module, and the broadband control module is configured to output a high level signal.

[0036] Specifically, the second resistor R2 receives a high-level signal output from the broadband control module, so that the control end of the switching module 10 is pulled up to a high level, so that the first end and the third end of the switching module 10 are connected, and the broadband control module receives the RF signal input by the built-in antenna.

[0037] In one application scenario, the first end ANT of the RF switch chip U1 is connected to the broadband control module and the broadband transceiver, the second end RF1 of the RF switch chip U1 is connected to the external antenna, the third end RF2 of the RF switch chip U1 is connected to the internal antenna, the control end VC of the RF switch chip U1 is connected to the first resistor R1 and the second resistor R2, the first resistor R1 is connected to the suspended contact, when the suspended contact remains suspended, the voltage of the control end VC of the RF switch chip U1 is pulled up by the high-level signal received by the second resistor R2, the switch switching unit inside the RF switch chip U1 connects the first end ANT and the third end RF2 of the RF switch chip U1, so that the signal path between the broadband control module and the internal antenna is turned on; when the suspended contact is pressed by the ground of the narrowband board body or the external antenna body, the voltage of the control end VC of the RF switch chip U1 is pulled down, the switch switching unit inside the RF switch chip U1 connects the first end ANT and the second end RF1, so that the signal path between the broadband control module and the external antenna is turned on.

[0038] See also Figure 3 , Figure 3 1 is a schematic diagram of the structure of the third embodiment of the antenna switching circuit provided in the present application; the antenna switching circuit 100 includes a switching module 10 and a presence detection module 20 .

[0039] Among them, the first end of the switching module 10 is connected to the broadband control module, the second end of the switching module 10 is connected to the external antenna, and the third end of the switching module 10 is connected to the built-in antenna; the presence detection module 20 is connected to the control end of the switching module 10, and the presence detection module 20 is configured to detect the presence of the narrowband board, and control the switching module 10 to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board.

[0040] Figure 3 The antenna switching circuit 100 is shown with Figure 2 The main difference of the antenna switching circuit 100 shown in FIG. 1 is that the high-pass filter module 30, the low-pass filter module 40 and the band-pass filter module 50 are added. Therefore, the high-pass filter module 30, the low-pass filter module 40 and the band-pass filter module 50 are mainly described below. For other components in the antenna switching circuit 100, please refer to FIG. Figure 2 The relevant description of the embodiment shown, for example Figure 3 The switching module 10 in Figure 2 The description of the switching module 10 in will not be repeated here.

[0041] Optionally, the antenna switching circuit 100 further includes a high-pass filtering module 30 , an input end of the high-pass filtering module 30 is connected to the external antenna, and an output end of the high-pass filtering module 30 is connected to the second end of the switching module 10 .

[0042] Specifically, high-pass filtering is a frequency domain filtering method that retains high-frequency signals and suppresses low-frequency signals. The high-pass filtering module 30 is mainly composed of components such as capacitors, inductors and resistors, and is used to filter the high-frequency components in the signal and remove the low-frequency components and DC components. In one embodiment, when the narrowband board is in place, the high-pass filtering module 30 is used to filter out the signals with frequencies outside the range of 699-960MHz in the radio frequency signal input from the external antenna, and input the signals allowed to pass through to the broadband control module through the switching module 10.

[0043] Optionally, the antenna switching circuit 100 also includes a low-pass filtering module 40, the input end of the low-pass filtering module 40 is connected to the external antenna, and the output end of the low-pass filtering module 40 is connected to the narrowband port. When the narrowband board is in place, the output end of the low-pass filtering module 40 is connected to the narrowband board through the narrowband port.

[0044] Specifically, in contrast to high-pass filtering, low-pass filtering is used to filter out high-frequency signals and retain low-frequency signals. In one embodiment, when the narrowband board is in place, the low-pass filter module 40 is used to filter out signals with a frequency exceeding 470 MHz in the RF signal input from the external antenna, and input the signals allowed to pass into the narrowband control module.

[0045] Optionally, the antenna switching circuit 100 further includes a bandpass filtering module 50 , an input end of the bandpass filtering module 50 is connected to the first end of the switching module 10 , and an output end of the bandpass filtering module 50 is connected to the broadband control module.

[0046] Specifically, bandpass filtering is also a filtering method that can selectively pass signals within a certain frequency range. The bandpass filtering module 50 has a narrow frequency bandwidth, which can effectively filter out specific frequency signals and filter out other frequency signals. In one embodiment, the bandpass filtering module 50 receives the radio frequency signal received by the switching module 10 through the antenna, filters out the narrowband signal in the radio frequency signal, and outputs the broadband signal to the broadband control module.

[0047] See also Figure 4 , Figure 4 1 is a schematic diagram of the structure of the fourth embodiment of the antenna switching circuit provided in the present application; the antenna switching circuit 100 includes a switching module 10 and a presence detection module 20.

[0048] Among them, the first end of the switching module 10 is connected to the broadband control module, the second end of the switching module 10 is connected to the external antenna, and the third end of the switching module 10 is connected to the built-in antenna; the presence detection module 20 is connected to the control end of the switching module 10, and the presence detection module 20 is configured to detect the presence of the narrowband board, and control the switching module 10 to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the built-in antenna according to the presence of the narrowband board.

[0049] Figure 4 The antenna switching circuit 100 is shown with Figure 3 The main difference of the antenna switching circuit 100 shown in FIG. 1 is that the high-pass filter module 30 and the low-pass filter module 40 are added. Therefore, the components added to the high-pass filter module 30 and the low-pass filter module 40 are mainly described below. For other components in the antenna switching circuit 100, please refer to FIG. Figure 3 The relevant description of the embodiment shown, for example Figure 4 The switching module 10 in Figure 3 The description of the switching module 10 in will not be repeated here.

[0050] Optionally, the high-pass filter module 30 includes a first capacitor C1, a second capacitor C2, a third resistor R3, a first inductor L1, a third capacitor C3, a second inductor L2, a third inductor L3 and a fourth inductor L4. The first end of the first capacitor C1 is connected to the second end RF1 of the RF switch chip U1, the first end of the second capacitor C2 is connected to the second end of the first capacitor C1, the first end of the third resistor R3 is connected to the second end of the second capacitor C2, the first end of the first inductor L1 is connected to the second end of the third resistor R3, the third capacitor C3 is connected in parallel with the first inductor L1, the first end of the second inductor L2 is connected to the second end of the first capacitor C1, the second end of the second inductor L2 is grounded, the first end of the third inductor L3 is connected to the second end of the second capacitor C2, the second end of the third inductor L3 is grounded, the first end of the fourth inductor L4 is connected to the second end of the third resistor R3, and the second end of the fourth inductor L4 is grounded.

[0051] In one embodiment, the high-pass filter module 30 may further include: a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6, the fourth capacitor C4 is connected in parallel with the second inductor L2, the fifth capacitor C5 is connected in parallel with the third inductor L3, the first end of the sixth capacitor C6 is connected to the second end of the third resistor R3, and the second end of the sixth capacitor C6 is connected to the first end of the fourth inductor L4.

[0052] Optionally, the low-pass filter module 40 includes a seventh capacitor C7, a fourth resistor R4, a fifth inductor L5, a sixth inductor L6, an eighth capacitor C8 and a first TVS diode D1. The first end of the seventh capacitor C7 is connected to the narrowband control module, the first end of the fourth resistor R4 is connected to the second end of the seventh capacitor C7, the first end of the fifth inductor L5 is connected to the second end of the fourth resistor R4, the first end of the sixth inductor L6 is connected to the second end of the fifth inductor L5, the second end of the sixth inductor L6 is connected to the external antenna and the first end of the first TVS diode D1, the second end of the first TVS diode D1 is grounded, and the eighth capacitor C8 is connected in parallel with the fifth inductor L5.

[0053] In one embodiment, the low-pass filter module 40 may further include: a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11 and a twelfth capacitor C12. The first end of the ninth capacitor C9 is connected to the second end of the seventh capacitor C7, the second end of the ninth capacitor C9 is grounded, the first end of the tenth capacitor C10 is connected to the second end of the fifth inductor L5, the second end of the tenth capacitor C10 is grounded, the first end of the eleventh capacitor is connected to the second end of the first inductor L1 and the first end of the sixth inductor L6, the second end of the eleventh capacitor C11 is grounded, the first end of the twelfth capacitor is connected to the second end of the sixth inductor L6, and the second end of the twelfth capacitor C12 is grounded.

[0054] Optionally, the antenna switching circuit 100 further includes a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15 and a second TVS diode D2. The first end of the thirteenth capacitor C13 is connected to the first end ANT of the RF switch chip U1, the second end of the thirteenth capacitor C13 is connected to the bandpass filter module 50, the first end of the fourteenth capacitor C14 is connected to the third end RF2 of the RF switch chip U1, the second end of the fourteenth capacitor C14 is connected to the built-in antenna, the first end of the fifteenth capacitor C15 is connected to the power supply end CDD of the RF switch chip U1, the second end of the fifteenth capacitor C15 is grounded, the first end of the second TVS diode D2 is connected to the built-in antenna and is connected to the second end of the first resistor R1 through a suspended contact when the narrowband board is in place, and the second end of the second TVS diode D2 is grounded.

[0055] See also Figure 5 , Figure 5 It is a structural diagram of an embodiment of a communication device provided in the present application. The communication device 1000 includes an external antenna, an internal antenna, a broadband control module 200 and an antenna switching circuit 100. The antenna switching circuit 100 is connected to the external antenna, the internal antenna and the broadband control module 200. The antenna switching circuit 100 is the antenna switching circuit 100 as described above and will not be repeated here.

[0056] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An antenna switching circuit, characterized in that: The antenna switching circuit comprises: A switching module, wherein a first end of the switching module is connected to the broadband control module, a second end of the switching module is connected to the external antenna, and a third end of the switching module is connected to the internal antenna; The in-place detection module is connected to the control end of the switching module, and is configured to detect the presence of the narrowband board, and control the switching module to conduct the signal path between the broadband control module and the external antenna, or the signal path between the broadband control module and the internal antenna according to the presence of the narrowband board.

2. The antenna switching circuit according to claim 1, characterized in that: The presence detection module is configured to conduct the signal path between the broadband control module and the external antenna when it is detected that the narrowband board is in place, and conduct the signal path between the broadband control module and the internal antenna when it is detected that the narrowband board is not in place.

3. The antenna switching circuit according to claim 1 or 2, characterized in that: The in-situ detection module comprises: a first resistor, wherein a first end of the first resistor is connected to a control end of the switching module, and a second end of the first resistor is connected to a suspended contact, wherein the suspended contact is configured to be grounded when the narrowband board is in place, or to be suspended when the narrowband board is not in place; A second resistor, wherein a first end of the second resistor is connected to the control end of the switching module, and a second end of the second resistor is configured to input a high level signal.

4. The antenna switching circuit according to claim 3, characterized in that: The first resistor is a zero-ohm resistor.

5. The antenna switching circuit according to claim 3, characterized in that: The second end of the second resistor is connected to the broadband control module, and the broadband control module is configured to output the high level signal.

6. The antenna switching circuit according to claim 1, characterized in that: The antenna switching circuit further includes a high-pass filtering module, an input end of the high-pass filtering module is connected to the external antenna, and an output end of the high-pass filtering module is connected to the second end of the switching module.

7. The antenna switching circuit according to claim 1, characterized in that: The antenna switching circuit also includes a low-pass filtering module, the input end of the low-pass filtering module is connected to the external antenna, the output end of the low-pass filtering module is connected to the narrowband port, and when the narrowband board is in place, the output end of the low-pass filtering module is connected to the narrowband board through the narrowband port.

8. The antenna switching circuit according to claim 1, characterized in that: The antenna switching circuit further includes a bandpass filtering module, an input end of the bandpass filtering module is connected to the first end of the switching module, and an output end of the bandpass filtering module is connected to the broadband control module.

9. The antenna switching circuit according to claim 1, characterized in that: The switching module is a radio frequency switch chip.

10. A communication device, characterized in that: The communication device comprises: External antenna; Built-in antenna; Broadband control module; An antenna switching circuit is connected to the external antenna, the internal antenna and the broadband control module, and the antenna switching circuit is the antenna switching circuit as described in any one of claims 1-9.

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