Capacitance adjusting circuit and transmitting device
By designing a capacitive adjustment circuit that includes multiple switches and capacitors, the problem of high cost and harmony of the existing technology in the existing technology, and the incomplete combination of electricity values and increase the range Reduced costs and improved the flexibility of frequency regulation of the launch device.
Patent Information
- Application Number
- CN202323435709.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-15
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2033-12-15
AI Technical Summary
In the prior art, capacitance and inductor tuning devices that are mostly used to convert a single frequency band signal into a different frequency band signal are costly and inflexible, making it difficult to meet the performance requirements of antenna devices in different application scenarios.
Design a capacitance adjustment circuit, including a first switch, a second switch and a plurality of first capacitors. By controlling the status of the switches and the connection mode of the capacitors, various combinations of capacitance values are realized and the capacitance adjustment range is increased. The capacitance adjustment circuit is connected to the signal source and the antenna, and performs frequency modulation processing on the signal by adjusting the capacitance value.
The cost of the capacitor adjustment device is reduced, the frequency modulation flexibility of the transmitter is improved, the capacitance value can be adjusted according to different application scenarios, to meet the needs of different frequency bands, and the performance of the transmitter is improved.
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Figure CN222395656U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of communication technology, and in particular to a capacitance adjustment circuit and a transmitting device. Background Art
[0002] In today's wireless communication era, with the continuous development of radio frequency integrated circuits and electronic information industries, the integration of wireless communication terminals is becoming increasingly higher, and the standards of communication technology are becoming more diverse.
[0003] At present, single-frequency-band transmitting devices are gradually unable to meet daily needs. In order to meet the performance requirements of antenna devices in different application scenarios, related technologies often use sealed tuning devices with a large number of capacitors and inductors to convert single-frequency-band signals into signals of different frequency bands and send them through antennas. However, the tuning cost is high and the tuning is not flexible. Utility Model Content
[0004] The present application provides a capacitance adjustment circuit and a transmitting device, which are used to reduce the cost of the capacitance adjustment device and reduce the frequency modulation cost of the transmitting device.
[0005] In a first aspect, an embodiment of the present application provides a capacitance adjustment circuit, which can be applied to a transmitting device and frequency modulates a signal output by a signal source in the transmitting device, thereby meeting the requirements of the transmitting device in different application scenarios. The capacitance adjustment circuit includes: a first switch, a second switch, and a plurality of first capacitors.
[0006] The first switch includes an input terminal and multiple output terminals, and is used to control the input terminal of the first switch to be connected to one or more output terminals according to a received first control signal; the second switch includes multiple input terminals and an output terminal, and the second switch is used to control the output terminal of the second switch to be connected to one or more input terminals according to a received second control signal; each output terminal of the first switch corresponds to each input terminal of the second switch one by one, and each output terminal of the first switch is connected to the corresponding input terminal of the second switch through a first capacitor.
[0007] In one possible design, the first switch and the second switch are single-pole four-throw switches.
[0008] In a possible design, each output terminal of the first switch is connected to a first capacitor with a different capacitance value. With the above design, when a single output terminal of the first switch is turned on, the capacitance adjustment circuit can present four different capacitance values, thereby increasing the capacitance adjustment range of the capacitance adjustment circuit.
[0009] In one possible design, the capacitance adjustment circuit further includes a second capacitor connected between the input end of the first switch and the output end of the second switch. With the above design, when the output ends of the first switches are all turned off, the capacitance adjustment circuit still has capacitance output.
[0010] In a second aspect, an embodiment of the present application provides a transmitting device, which includes: a signal source, an antenna, and a capacitance adjustment circuit provided in the first aspect of the present application and any possible design thereof, wherein the capacitance adjustment circuit is connected between the signal source and the antenna.
[0011] In a possible design, the transmitting device also includes a first inductor connected between the signal source and the capacitance adjustment circuit.
[0012] In one possible design, the transmitting device also includes a second inductor connected between the capacitance adjustment circuit and the antenna.
[0013] In one possible design, the transmitting device also includes a capacitive sensor and a controller.
[0014] The capacitance sensor is used to detect the capacitance between the capacitance sensor and the antenna, and output the capacitance to the controller; the controller is used to generate the first control signal and the second control signal according to the capacitance, and output the first control signal to the first switch, and output the second control signal to the second switch. With the above design, the application scenario of the transmitting device and the requirements for the antenna working frequency band in the application scenario can be determined by detecting the distance between the capacitance sensor and the antenna, and a control signal can be generated according to the above requirements, so that the capacitance adjustment circuit outputs a capacitance value that meets the above frequency band requirements.
[0015] In a possible design, the controller is specifically used to: determine the first switch state and the second switch state corresponding to the capacitance according to a pre-stored correspondence table between capacitance and switch state; and generate a first control signal corresponding to the first switch and a second control signal corresponding to the second switch according to the first switch state and the second switch state corresponding to the capacitance.
[0016] In addition, the technical effects brought about by the second aspect and any possible design thereof can refer to the technical effects brought about by the different designs in the first aspect of the embodiment of the present application, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] 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 paying creative labor.
[0018] Figure 1 A schematic diagram of a capacitance adjustment circuit provided in an embodiment of the present application Figure 1 ;
[0019] Figure 2 A schematic diagram of a capacitance adjustment circuit provided in an embodiment of the present application Figure 2 ;
[0020] Figure 3 A schematic diagram of the structure of a single-pole four-throw switch provided in an embodiment of the present application;
[0021] Figure 4 A schematic diagram of a capacitance adjustment circuit provided in an embodiment of the present application Figure 3 ;
[0022] Figure 5 A schematic diagram of a transmitting device provided in an embodiment of the present application Figure 1 ;
[0023] Figure 6 A schematic diagram of a transmitting device provided in an embodiment of the present application Figure 2 ;
[0024] Figure 7 A pin diagram of a capacitive sensor provided in an embodiment of the present application;
[0025] Figure 8 A schematic diagram of the structure of a capacitive sensor provided in an embodiment of the present application. DETAILED DESCRIPTION
[0026] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.
[0027] The terms used in the implementation methods of this application are only used to explain the specific embodiments of this application, and are not intended to limit this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0028] Below, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.
[0029] (1) The terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.
[0030] (2) The term "plurality" in the embodiments of the present application refers to two or more than two, and other quantifiers are similar.
[0031] (3) The term “and / or” in the embodiments of the present application describes the association relationship between associated objects, indicating that three types of relationships may exist. For example, A and / or B may represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B may be singular or plural.
[0032] (4) The “connection” in the embodiments of the present application can be understood as an electrical connection or a communication connection. The electrical connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, A and B are connected, which can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components. For example, A and B are connected, or A and C are directly connected, C and B are directly connected, and A and B are connected through C. The communication connection between two electrical components is a wireless connection between the two electrical components, that is, the two electrical components are electromagnetically connected.
[0033] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in combination with the accompanying drawings and specific implementation methods of the specification. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.
[0034] The present application provides a capacitance adjustment circuit, which can be applied to a transmitting device and connected to an inductor in the transmitting device. The capacitance adjustment circuit can output a plurality of different capacitance values, and the capacitance value and the inductor form a frequency modulation circuit to modulate a single frequency band signal output by a signal source, thereby outputting a signal that meets the requirements.
[0035] like Figure 1 As shown in FIG. 1 , a schematic diagram of a capacitor adjustment circuit is shown. Figure 1As shown, the capacitance adjustment circuit includes a first switch, a second switch and a plurality of first capacitors. The first switch includes an input terminal and a plurality of output terminals, and is used to control the input terminal of the first switch to be connected to one or more output terminals according to a received first control signal. The second switch includes a plurality of input terminals and an output terminal, and the second switch is used to control the output terminal of the second switch to be connected to one or more input terminals according to a received second control signal. Each output terminal of the first switch corresponds to each input terminal of the second switch one by one, and each output terminal of the first switch is connected to the corresponding input terminal of the second switch through a first capacitor.
[0036] Specifically, the first switch and the second switch can be single-pole multiple-throw, and each input end of the first switch is connected to the corresponding input end of the second switch through a first capacitor, which can control the number of output ends of the first switch that are turned on and the number of input ends of the second switch that are turned on, and select a capacitor in series or select multiple first capacitors connected in parallel, so that the capacitor adjustment circuit presents different capacitance values. In this way, when the capacitor adjustment circuit is applied to a transmitting device, the capacitor adjustment circuit can be controlled to adjust to the corresponding capacitance value according to the frequency band of the wireless signal that the transmitting device needs to send, so that the signal output to the antenna can meet the needs of the application scenario and improve the performance of the transmitting device.
[0037] To facilitate understanding of the capacitor adjustment circuit provided in the embodiment of the present application, the working process of the capacitor adjustment circuit is described below by taking the example that the first switch and the second switch are both single-pole four-throw switches.
[0038] like Figure 2 , which is a structural schematic diagram of a capacitor adjustment circuit when the first switch and the second switch are single-pole four-throw switches, see Figure 2 As shown, the input terminal vin of the first switch can be connected to the inductor L1 and the signal source required for frequency modulation respectively, the first output terminal RF1 of the first switch can be connected to the corresponding input terminal of the second switch through a capacitor C1, the second output terminal RF2 of the first switch can be connected to the corresponding input terminal of the second switch through a capacitor C2, the third output terminal RF3 of the first switch can be connected to the corresponding input terminal of the second switch through a capacitor C3, the fourth output terminal RF4 of the first switch can be connected to the corresponding input terminal of the second switch through a capacitor C4, and the output terminal Vout of the second switch can be connected to an inductor L2 and the antenna respectively.
[0039] Among them, inductor L1 and inductor L2 are both adjustable inductors. Inductor L1 and inductor L2 can use discrete devices or inductor chips. The model and parameters of the inductor device can be selected according to the application scenario of the transmitting device, and this application does not make too many restrictions here.
[0040] In practical applications, the first switch and the second switch are single-pole four-throw switches, and the switches can be implemented using integrated chips. Figure 3 The diagram shown is a schematic diagram of a single-pole four-throw switch. Figure 3 As shown in FIG. 1 , the single-pole four-throw switch includes not only an input terminal ANT and four output terminals, namely RF1, RF2, RF3 and RF4, but also the five ports are the pins for transmitting signals of the single-pole four-throw switch. In addition to the above pins, the single-pole four-throw switch also includes V1~V3 control pins and power supply VDD pin. Among them, the V1~V3 control pins of the single-pole four-throw switch can receive control signals and control the internal conduction state according to the level amplitude of the received control signal.
[0041] The corresponding relationship between the control signals received by the V1-V3 control pins of the single-pole four-throw switch and the conduction state of the single-pole four-throw switch can be seen in Table 1.
[0042] Table 1
[0043] V1 V2 V3 Output port that is turned on 0 0 1 All Access 0 1 1 RF1 and RF2 1 0 1 RF3 and RF4 0 0 0 RF1 0 1 0 RF2 1 0 0 RF3 1 1 0 RF4 1 1 1 Fully disconnected
[0044] As shown in Table 1, the level amplitude of the control signal received by the control pins V1 to V3 in the first switch can be set to control the conduction of the output terminal corresponding to the first switch and the number of the output terminals that are controlled to be conducted. When multiple output terminals are conducted, the capacitors connected to the multiple output terminals are connected in parallel. Therefore, a corresponding control signal can be provided to the capacitor adjustment circuit according to the frequency band requirements of the transmitting device to make the capacitor adjustment circuit output a capacitance value that meets the requirements. The capacitor adjustment circuit and the two inductors form a frequency modulation device to perform frequency modulation on the signal output by the signal source, and finally transmit the frequency modulated signal through the antenna.
[0045] In practical applications, the capacitor connected to each input end of the first switch can be a capacitor with different capacitance values to increase the capacitance adjustment range of the capacitance adjustment circuit. In addition, the present application can make the single-pole four-throw present 8 output states by setting a suitable control signal, and the capacitance adjustment circuit can output different capacitance values for each output state. Compared with the existing general control method of only turning on one output port at a time, the capacitance adjustment range of the capacitance adjustment circuit can be increased without increasing the device cost, thereby meeting the frequency band requirements of the transmitting device.
[0046] It should be understood that if the capacitance adjustment circuit is required to output different capacitance values, each output terminal that is turned on in the eight states needs to be turned on at the corresponding input terminal in the second switch to form a closed path and transmit the signal to the back-end device.
[0047] In one example, in order to reduce the control difficulty of the capacitor adjustment circuit, the ports RF1, RF2, RF3 and RF4 pins in the second switch are respectively connected to the RF1, RF2, RF3 and RF4 pins in the first switch through a capacitor. At this time, the first switch and the second switch can receive control signals with the same amplitude, or the control pins of the first switch and the second switch are connected and receive the same control signal.
[0048] In actual application, since the above-mentioned 8 output terminals of the first switch are turned on in the state where all the output terminals are turned off, in order to realize that the capacitance adjustment circuit has a capacitance value, refer to Figure 4 As shown, the capacitance adjustment circuit may further include a second capacitor C, and the second capacitor C is connected between the input end of the first switch and the output end of the second switch.
[0049] Taking the case where the first switch and the second switch receive control signals of the same amplitude as an example, Figure 4 In the capacitance adjustment circuit shown, the relationship between the control signal and the total capacitance of the capacitance adjustment circuit can be seen in Table 2.
[0050] Table 2
[0051] V1 V2 V3 V4 V5 V6 Total Capacitance 0 0 0 0 0 0 C+C1 0 1 0 0 1 0 C+C2 1 1 0 1 0 0 C+C3 1 0 0 1 0 0 C+C4 0 1 1 0 1 1 C+C1+C2 1 0 1 1 0 1 C+C3+C4 1 1 1 1 1 1 C 0 0 1 0 0 1 C+C1+C2+C3+C4
[0052] As shown in Table 2, the capacitance adjustment circuit can output 8 different capacitance values. According to the signal output by the signal source and the application scenario of the transmitting device, a suitable control signal can be configured to perform frequency modulation processing on the signal output by the signal source, so that the working frequency band of the antenna meets the requirements and the transmission performance of the transmitting device is improved.
[0053] It should be noted that when only some ports of the first switch and the second switch are turned on, parasitic capacitance Coff may exist between the ports that are not turned on. Therefore, the output capacitance of the capacitance adjustment circuit is the sum of the total capacitance corresponding to the current port conduction state and the parasitic capacitance Coff.
[0054] It should be noted that the structures of the first switch and the second switch mentioned above are only examples. In actual applications, the first switch and the second switch can also be other types of switches. For example, the first switch and the second switch can use single-pole five-throw switches, so that the capacitor adjustment circuit can have more capacitor output values. The specific switch type can be set according to the frequency band requirements of the transmitting device, and this application does not impose too many restrictions here.
[0055] Based on the same concept, the present application also provides a transmitting device, see Figure 5As shown, the transmitting device may include the aforementioned capacitance adjustment circuit, a signal source and an antenna. The capacitance adjustment circuit is connected between the signal source and the antenna, and is used to perform frequency modulation on the signal output by the signal source, and output the frequency modulated signal to the antenna.
[0056] In a possible implementation, the transmitting device further includes a first inductor L1 connected between the signal source and the capacitance adjustment circuit, wherein the first inductor L1 and the capacitance adjustment circuit are combined to perform frequency modulation processing on the signal output by the signal source.
[0057] In a possible implementation, the transmitting device further includes a second inductor L2 connected between the capacitance adjustment circuit and the antenna, wherein the second inductor L2 and the capacitance adjustment circuit are combined to perform frequency modulation processing on the signal output by the signal source.
[0058] In actual use, the first inductor L1 and the second inductor L2 may be adjustable capacitor devices, which may be implemented by discrete capacitor devices or integrated chips, and the present application does not make too many restrictions here.
[0059] In one possible implementation, see Figure 6 As shown, the transmitting device also includes a capacitive sensor and a controller. The controller is connected to the capacitive sensor, the control pins V1 to V3 of the first switch, and the control pins V1 to V3 of the second switch, respectively, and is used to increase the first control signal for the control pins V1 to V3 of the first switch, and provide the second control signal for the control pins V1 to V3 of the second switch.
[0060] Specifically, the capacitive sensor is used to detect the capacitance between the antenna and output the detected capacitance to the controller; the controller is used to generate a first control signal and a second control signal according to the capacitance, and output the first control signal to the first switch, and output the second control signal to the second switch.
[0061] In one example, the capacitive sensor may be a Cap Sensor externally connected to the antenna, see Figure 7 As shown in the figure, the external pins of the capacitive sensor are shown, where the CS0 pin is connected to the antenna, the VDD pin is connected to the power supply, the GND pin is grounded, and the NIRQ pin outputs the capacitance value detected by the capacitive sensor. Figure 8 The figure shows the internal structure of the capacitive sensor. The value detected by the capacitive sensor is converted into a digital signal that can be directly processed by the analog front end and the digital processing output controller.
[0062] The controller can determine the application scenario of the transmitting device according to the capacitance detected by the capacitance sensor, and determine the first switch state and the second switch state corresponding to the capacitance according to a pre-stored correspondence table between the capacitance and the switch state; and generate a first control signal corresponding to the first switch and a second control signal corresponding to the second switch according to the first switch state and the second switch state corresponding to the capacitance.
[0063] In combination with the above description, the above-mentioned capacitance sensor can detect the capacitance between the antenna periodically or in real time. When the detected capacitance changes, it indicates that the application scenario of the transmitting device and the required frequency band have also changed. The controller can provide the first control signal to the first switch and the second control signal to the second switch according to the capacitance, thereby controlling the capacitance adjustment circuit to change the capacitance value of the frequency modulation device, thereby re-modulating the signal output by the signal source and outputting a signal that meets the current requirements.
[0064] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of protection of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.
Claims
1. A capacitance adjustment circuit, characterized in that: include: A first switch, a second switch, and a plurality of first capacitors; The first switch comprises an input terminal and a plurality of output terminals, and is used to control the input terminal of the first switch to be connected to one or more output terminals according to a received first control signal; The second switch comprises a plurality of input terminals and an output terminal, and the second switch is used to control the output terminal of the second switch to be connected to one or more input terminals according to a received second control signal; Each output end of the first switch corresponds to each input end of the second switch one by one, and each output end of the first switch is connected to the corresponding input end of the second switch through a first capacitor.
2. The circuit according to claim 1, characterized in that The first switch and the second switch are single-pole four-throw switches.
3. The circuit according to claim 1 or 2, characterized in that: The first capacitor connected to each output end of the first switch has a different capacitance.
4. The circuit according to claim 1 or 2, characterized in that: The capacitance adjustment circuit further includes a second capacitor connected between an input terminal of the first switch and an output terminal of the second switch.
5. A launching device, characterized in that: include: A signal source, an antenna and a capacitance adjustment circuit as claimed in any one of claims 1 to 4, wherein the capacitance adjustment circuit is connected between the signal source and the antenna.
6. The device according to claim 5, characterized in that The transmitting device also includes a first inductor connected between the signal source and the capacitance adjustment circuit.
7. The device according to claim 5 or 6, characterized in that The transmitting device also includes a second inductor connected between the capacitance adjustment circuit and the antenna.
8. The device according to claim 5 or 6, characterized in that The transmitting device also includes a capacitive sensor and a controller; The capacitive sensor is used to detect the capacitance between the sensor and the antenna, and output the capacitance to the controller; The controller is used to generate the first control signal and the second control signal according to the capacitance, and output the first control signal to the first switch, and output the second control signal to the second switch.
9. The device according to claim 8, characterized in that The controller is specifically used for: Determine the first switch state and the second switch state corresponding to the capacitance according to a pre-stored correspondence table between capacitance and switch state; A first control signal corresponding to the first switch and a second control signal corresponding to the second switch are generated according to the first switch state and the second switch state corresponding to the capacitance.