A radio frequency circuit and a mobile terminal

Abstract

The application discloses a kind of radio frequency circuit and mobile terminal, radio frequency circuit includes first antenna, radio frequency chip, baseband chip, antenna tuner and radio frequency switch;Baseband chip includes first control port and second control port, first control port is connected with radio frequency switch by first control line, and second control port is connected with antenna tuner and radio frequency switch by second control line respectively;Wherein, baseband chip is used to output first control signal to radio frequency switch and antenna tuner by first control port, and output second control signal to radio frequency switch and antenna tuner by second control port;Radio frequency switch is used to switch on different radio frequency channels of radio frequency chip according to first control signal and second control signal;Antenna tuner is used to adjust impedance according to first control signal and second control signal.The application can effectively simplify the wiring of PCB by multiplexing control line to control antenna tuner and radio frequency switch simultaneously.

Description

Technical Field

[0001] This invention relates to the field of mobile communication technology, and in particular to a radio frequency circuit and a mobile terminal. Background Technology

[0002] The RF front-end contains many switching devices, each requiring control lines for operational status control. Due to the large number of devices—for example, diversity switches used in mobile terminals require three control lines, while antenna tuning switches require two—and the control lines for each switch are independent, mobile terminals require numerous control lines, complicating PCB layout.

[0003] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0004] The purpose of this invention is to provide a radio frequency circuit and a mobile terminal that can effectively reduce the wiring of control lines by reusing control lines, thereby simplifying the wiring of PCB boards.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This application provides a radio frequency circuit, including a first antenna, a radio frequency chip, a baseband chip, an antenna tuner, and a radio frequency switch; the baseband chip includes a first control port and a second control port, the first control port is connected to the radio frequency switch and the antenna tuner respectively through a first control line, the second control port is connected to the antenna tuner and the radio frequency switch respectively through a second control line, the radio frequency switch is also connected to the radio frequency chip and the first antenna respectively, and the first antenna is also connected to the antenna tuner;

[0007] The baseband chip is used to output a first control signal to the RF switch and the antenna tuner through the first control port, and to output a second control signal to the RF switch and the antenna tuner through the second control port; the RF switch is used to connect different RF channels of the first antenna and the RF chip according to the first control signal and the second control signal, and to switch the frequency band of the first RF signal transmitted and received by the first antenna; the antenna tuner is used to adjust the impedance according to the first control signal and the second control signal.

[0008] In some embodiments of the radio frequency circuit, the baseband chip further includes a third control port, which is connected to the radio frequency switch via a third control line; the baseband chip is also used to output a third control signal to the radio frequency switch via the third control port; the radio frequency switch is also used to connect the first antenna and the radio frequency chip according to the first control signal, the second control signal and the third control signal, so that the first antenna transmits and receives the second radio frequency signal.

[0009] In some embodiments of the radio frequency circuit, the radio frequency switch includes a common port, a first switching port, a second switching port, a third switching port, and a fourth switching port; the common port is connected to a first antenna, and the first switching port, the second switching port, the third switching port, and the fourth switching port are all connected to the radio frequency chip.

[0010] In some embodiments of the radio frequency circuit, the radio frequency switch further includes a fifth switching port, a sixth switching port, a seventh switching port, and an eighth switching port, all of which are connected to the radio frequency chip.

[0011] In some embodiments of the radio frequency circuit, the radio frequency chip includes a first radio frequency port, a second radio frequency port, a third radio frequency port and a fourth radio frequency port, wherein the first radio frequency port is connected to a first switching port, the second radio frequency port is connected to a second switching port, the third radio frequency port is connected to a third switching port, and the fourth switching port is connected to a fourth switching port.

[0012] In some embodiments of the radio frequency circuit, the radio frequency chip further includes a fifth radio frequency port, a sixth radio frequency port, a seventh radio frequency port, and an eighth radio frequency port; the fifth radio frequency port is connected to a fifth switching port, the sixth radio frequency port is connected to a sixth switching port, and the seventh radio frequency port is connected to an eighth switching port.

[0013] In some embodiments of the radio frequency circuit, the first control port, the second control port, and the third control port are all GPIO ports.

[0014] In some embodiments of the radio frequency circuit, the first radio frequency signal is a low-frequency radio frequency signal, and the second radio frequency signal is a low-frequency radio frequency signal, a mid-frequency radio frequency signal, or a high-frequency radio frequency signal.

[0015] In some embodiments of the radio frequency circuit, the radio frequency circuit further includes a transmitting module and a second antenna, and the baseband chip further includes a fourth control port and a fifth control port. The fourth control port is connected to the transmitting module through a fourth control line, and the fifth port is connected to the transmitting module through a fifth control line.

[0016] The baseband chip is also used to output a fourth control signal to the transmitter module through the fourth control port and a fifth control signal to the transmitter module through the fifth control port; the transmitter module is used to connect the second antenna and the radio frequency chip according to the fourth and fifth control signals, so that the second antenna transmits a third radio frequency signal.

[0017] This application also provides a mobile terminal, including the radio frequency circuit described above.

[0018] Compared to existing technologies, this invention provides a radio frequency (RF) circuit and a mobile terminal. The RF circuit multiplexes the control lines of the RF switch to control the antenna tuner, enabling the antenna tuner to adjust its impedance accordingly when the RF switch switches the frequency band of the RF signal. This reduces the number of control lines in the antenna tuner and simplifies the PCB layout. Attached Figure Description

[0019] Figure 1 This is a first structural block diagram of the radio frequency circuit provided by the present invention.

[0020] Figure 2 This is a second structural block diagram of the radio frequency circuit provided by the present invention.

[0021] Figure 3 This is a third structural block diagram of the radio frequency circuit provided by the present invention.

[0022] Figure 4 This is a fourth structural block diagram of the radio frequency circuit provided by the present invention.

[0023] Figure 5 This is a fifth structural block diagram of the radio frequency circuit provided by the present invention. Detailed Implementation

[0024] The purpose of this invention is to provide a radio frequency circuit and a mobile terminal that can effectively reduce the wiring of control lines by reusing control lines, thereby simplifying the wiring of PCB boards.

[0025] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] Please see Figure 1 The present invention provides a radio frequency circuit, including a first antenna 11, a radio frequency chip 12, a baseband chip 13, an antenna tuner 14, and a radio frequency switch 15. The baseband chip 13 includes a first control port A and a second control port B. The first control port A is connected to the antenna tuner 14 and the radio frequency switch 15 respectively through a first control line 16. The second control port B is connected to the antenna tuner 14 and the radio frequency switch 15 respectively through a second control line 17. The radio frequency switch 15 is also connected to the radio frequency chip 12 and the first antenna 11 respectively. The first antenna 11 is also connected to the antenna tuner 14.

[0027] The baseband chip 13 is used to output a first control signal to the RF switch 15 and the antenna tuner 14 through the first control port A, and to output a second control signal to the RF switch 15 and the antenna tuner 14 through the second control port B; the RF switch 15 is used to switch different RF channels of the RF chip 12 according to the first control signal and the second control signal, thereby switching the frequency band of the first RF signal transmitted and received by the first antenna 11; the antenna tuner 14 is used to adjust the impedance according to the first control signal and the second control signal.

[0028] In this embodiment, the first antenna 11 is a diversity antenna, and the corresponding RF switch 15 is a diversity switch. The diversity switch switches according to the frequency band of the RF signal, and the antenna tuner 14 adjusts its impedance according to the frequency band of the RF signal, thereby achieving impedance matching of the first antenna 11. Therefore, in this embodiment, two control lines of the diversity switch are multiplexed to control the antenna tuner 14, thus reducing the control line wiring of the antenna tuner 14 and simplifying the PCB layout. Both the first control port A and the second control port B are GPIO ports. Meanwhile, each control line requires a control port on the baseband chip 13; reducing the number of control lines reduces the use of control ports, thus saving GPIO ports on the baseband chip 13.

[0029] In this embodiment, the antenna tuner 14 is mainly used for low-frequency band expansion and performance optimization. The first radio frequency signal in this embodiment is a low-frequency band radio frequency signal. Typically, each low frequency corresponds to one state of the antenna tuner 14. However, with diversity switching, each frequency band has one state, which can cover the switching requirements of the antenna tuner 14. Therefore, the first control line 16 and the second control line 17 of the diversity switch can be multiplexed to control the antenna tuner 14. When the diversity switch is switched, that is, when the low-frequency band is changed, the antenna tuner 14 also needs to switch states to perform corresponding impedance adjustment.

[0030] If the frequency bands of the low-frequency radio frequency signals in this embodiment are B8, B5, B20, and B28 respectively, the control signal of the first control line 16 is a high-level signal or a low-level signal, and the control signal of the second control line 17 is a high-level signal or a low-level signal. Let a high-level signal be 1 and a low-level signal be 0. Then, the correspondence between the control signals of the first control line 16 and the second control line 17 connected to the antenna tuner 14 and the corresponding frequency bands is shown in the following table:

[0031]

[0032] Furthermore, please refer to the following: Figure 2The baseband chip 13 also includes a third control port C, which is a GPIO port. The third control port C is connected to the RF switch 15 through the third control line 18. The baseband chip 13 is also used to output a third control signal to the RF switch 15 through the third control port C. The RF switch 15 is also used to connect the first antenna 11 and the RF chip 12 according to the first control signal, the second control signal and the third control signal, so that the first antenna 11 can transmit and receive the second RF signal.

[0033] In this embodiment, the second radio frequency signal is a low-frequency, mid-frequency, or high-frequency radio frequency signal. That is, when the first and second control signals control the diversity switch to switch to a low-frequency radio frequency signal, the antenna tuner 14 can also adjust its impedance accordingly. This means that when switching to a low-frequency radio frequency signal is required, only the control signals on the first control line 16 and the second control line 17 change; the control signal on the third control line remains unchanged. In other words, the multiplexed first control line 16 and second control line 17 in this embodiment are control lines used to control the switching of the low-frequency radio frequency signal.

[0034] In this embodiment, the first control signal includes a high-level signal and a low-level signal, the second control signal includes a high-level signal and a low-level signal, and the third control signal includes a high-level signal and a low-level signal. Wherein, 0 represents a low-level signal and 1 represents a high-level signal. The operating frequency bands of the first antenna 11 corresponding to the control signals on the three control lines can be shown in the table below:

[0035]

[0036] The design of the antenna tuner 14 and impedance matching is mainly aimed at performance enhancement between different low-frequency RF signals, and has little impact on the performance of mid-frequency and high-frequency RF signals. If the low-frequency RF signals in this embodiment are B8, B5, B20, and B28, then the control signals when switching between these frequency bands only change on the first control line 16 and the second control line 17, while the control signal on the third control line 18 remains unchanged. By using the first control line 16 and the second control line 17 as multiplexed control lines, the antenna tuner 14 will also perform corresponding impedance adjustment when switching between B8, B5, B20, and B28.

[0037] Therefore, when the mobile terminal operates in, for example, the B1 band, i.e., when the first antenna 11 transmits and receives the second radio frequency signal, the control signals of the diversity switch on the first control line 16 and the second control line 17 are the same as when operating in the B8 band. This means that the antenna tuner 14 will also switch to the antenna matching used when operating in the B8 band. Because the design of the antenna tuner 14 for adjusting impedance matching is mainly for performance extension between different low-frequency radio frequency signals, it has little impact on the performance of intermediate frequencies like B1. Therefore, even if the antenna tuner 14 switches to the impedance matching used for B8 according to the control signals on the first control line 16 and the second control line 17, it will not affect the antenna performance of B1. The same applies when the mobile terminal operates in the B3, B7, and B40 bands.

[0038] Further, please refer to Figure 3 The RF switch 15 includes a common port m, a first switching port a, a second switching port b, a third switching port c, and a fourth switching port d. The common port m is connected to the first antenna 11, and the first switching ports a, b, c, and d are all connected to the RF chip 12. Correspondingly, the RF chip 12 includes a first RF port a1, a second RF port b1, a third RF port c1, and a fourth RF port d1. The first RF port a1 is connected to the first switching port a, the second RF port b1 is connected to the second switching port b, the third RF port c1 is connected to the third switching port c, and the fourth RF port d1 is connected to the fourth switching port d. Specifically, the first switching port a and the common port m form a first RF channel; the second switching port b and the common port m form a second RF channel; the third switching port c and the common port m form a third RF channel; and the fourth switching port d and the common port m form a fourth RF channel.

[0039] In some embodiments, when the diversity switch is controlled by two control lines, the first control line 16 and the second control line 17, each control line has two control signals, a high-level signal and a low-level signal, which can achieve four states for switching, respectively controlling the switching of four radio frequency channels, namely the first radio frequency channel, the second radio frequency channel, the third radio frequency channel and the fourth radio frequency channel, so that the first antenna 11 can achieve the switching of radio frequency signals in four frequency bands.

[0040] In some embodiments, please refer to Figure 4The RF switch 15 also includes a fifth switching port e, a sixth switching port f, a seventh switching port g, and an eighth switching port h, all of which are connected to the RF chip 12. Correspondingly, the RF chip 12 also includes a fifth RF port e1, a sixth RF port f1, a seventh RF port g1, and an eighth RF port h1; the fifth RF port e1 is connected to the fifth switching port e, the sixth RF port f1 is connected to the sixth switching port f, and the seventh RF port g1 is connected to the eighth switching port h. Specifically, the fifth switching port e is connected to the common port m to form a fifth RF channel; the sixth switching port f is connected to the common port m to form a sixth RF channel; the seventh switching port g is connected to the common port m to form a seventh RF channel; and the eighth switching port h is connected to the common port m to form an eighth RF channel.

[0041] In this embodiment, the diversity switch requires three control lines for control. Each control line has a high-level signal and a low-level signal, which can switch the eight working states of the diversity switch, conduct eight switching ports, and realize the switching of eight radio frequency channels, so that the first antenna 11 can realize the switching of radio frequency signals of eight frequency bands.

[0042] Further, please refer to Figure 5 The radio frequency circuit also includes a transmitting module 19 and a second antenna 20. The baseband chip 13 also includes a fourth control port D and a fifth control port F. The fourth control port D is connected to the transmitting module 19 through a fourth control line 21, and the fifth port is connected to the transmitting module 19 through a fifth control line 22. The baseband chip 13 is also used to output a fourth control signal to the transmitting module 19 through the fourth control port D and to output a fifth control signal to the transmitting module 19 through the fifth control port F. The transmitting module 19 is used to connect the second antenna 20 and the radio frequency chip 12 according to the fourth control signal and the fifth control signal, so that the second antenna 20 transmits a third radio frequency signal.

[0043] This invention multiplexes the two control lines controlling the switching of low-frequency radio frequency signals on the diversity switch to control the antenna tuner 14, avoiding the need for a separate control line for the antenna tuner 14, saving two control lines and simplifying PCB layout. It also saves control ports on the baseband chip, reducing the number of chip ports required, thus saving costs for mobile terminals and improving product competitiveness. Furthermore, using separate control lines to control the antenna tuner 14 requires leading the control lines from the control port of the baseband chip 13 to the antenna tuner 14, typically requiring a long trace and placing space requirements on the PCB. By multiplexing the control lines of the diversity switch to control the antenna tuner 14, since both the diversity switch and the antenna tuner 14 are designed close to the antenna, their placement on the PCB is relatively short. This reduces the PCB space requirements and lowers the complexity of the PCB layout.

[0044] In this embodiment, the second antenna 20 is the main antenna, and the third radio frequency signal can be a mid-frequency radio frequency signal or a high-frequency radio frequency signal. The radio frequency chip 12 is connected to the transmitting module 19, which can transmit third radio frequency signals of different frequency bands.

[0045] Furthermore, the present invention also provides a mobile terminal, which includes the radio frequency circuit described above. Since the radio frequency circuit has been described in detail above, it will not be repeated here.

[0046] In summary, this invention provides a radio frequency (RF) circuit and a mobile terminal. The RF circuit includes a first antenna, an RF chip, a baseband chip, an antenna tuner, and an RF switch. The baseband chip includes a first control port and a second control port. The first control port is connected to the antenna tuner and the RF switch via a first control line, and the second control port is connected to the antenna tuner and the RF switch via a second control line. The baseband chip outputs a first control signal to the RF switch and the antenna tuner via the first control port, and outputs a second control signal to the RF switch and the antenna tuner via the second control port. The RF switch switches between different RF channels of the RF chip based on the first and second control signals. The antenna tuner adjusts the impedance based on the first and second control signals. This invention, by multiplexing control lines to simultaneously control the antenna tuner and the RF switch, effectively reduces the number of control lines and simplifies PCB layout.

[0047] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A radio frequency circuit, characterized in that, The system includes a first antenna, a radio frequency (RF) chip, a baseband chip, an antenna tuner, and an RF switch. The baseband chip includes a first control port, a second control port, and a third control port. The first control port is connected to the RF switch and the antenna tuner via a first control line. The second control port is connected to the antenna tuner and the RF switch via a second control line. The third control port is connected to the RF switch via a third control line. The RF switch is also connected to the RF chip and the first antenna, and the first antenna is also connected to the antenna tuner. The baseband chip is configured to output a first control signal to the RF switch and the antenna tuner via the first control port, output a second control signal to the RF switch and the antenna tuner via the second control port, and output a third control signal to the RF switch via the third control port. The RF switch is configured to switch between different RF channels of the RF chip according to the first and second control signals, thereby switching the frequency band of the first RF signal transmitted and received by the first antenna. The antenna tuner is configured to adjust the impedance according to the first and second control signals. The RF switch is also configured to connect the first antenna and the RF chip according to the first, second, and third control signals, thereby enabling the first antenna to transmit and receive a second RF signal. The first RF signal is a low-frequency RF signal, and the second RF signal is a low-frequency RF signal, a mid-frequency RF signal, or a high-frequency RF signal. The radio frequency switch includes a common port, a first switching port, a second switching port, a third switching port, a fourth switching port, a fifth switching port, a sixth switching port, a seventh switching port, and an eighth switching port; the common port is connected to the first antenna; the first switching port, the second switching port, the third switching port, and the fourth switching port are all connected to the radio frequency chip; the fifth switching port, the sixth switching port, the seventh switching port, and the eighth switching port are all connected to the radio frequency chip. The radio frequency chip includes a first radio frequency port, a second radio frequency port, a third radio frequency port, a fourth radio frequency port, a fifth radio frequency port, a sixth radio frequency port, a seventh radio frequency port, and an eighth radio frequency port. The first radio frequency port is connected to the first switching port, the second radio frequency port is connected to the second switching port, the third radio frequency port is connected to the third switching port, the fourth switching port is connected to the fourth switching port, the fifth radio frequency port is connected to the fifth switching port, the sixth radio frequency port is connected to the sixth switching port, and the seventh radio frequency port is connected to the eighth switching port. The first switching port is connected to the common port to form a first radio frequency channel; the second switching port is connected to the common port to form a second radio frequency channel; the third switching port is connected to the common port to form a third radio frequency channel; the fourth switching port is connected to the common port to form a fourth radio frequency channel; the fifth switching port is connected to the common port to form a fifth radio frequency channel; the sixth switching port is connected to the common port to form a sixth radio frequency channel; the seventh switching port is connected to the common port to form a seventh radio frequency channel; and the eighth switching port is connected to the common port to form an eighth radio frequency channel.

2. The radio frequency circuit according to claim 1, characterized in that, The first control port, the second control port, and the third control port are all GPIO ports.

3. The radio frequency circuit according to claim 1 or 2, characterized in that, The radio frequency circuit further includes a transmitting module and a second antenna. The baseband chip further includes a fourth control port and a fifth control port. The fourth control port is connected to the transmitting module through a fourth control line, and the fifth control port is connected to the transmitting module through a fifth control line. The baseband chip is also used to output a fourth control signal to the transmitting module through the fourth control port, and to output a fifth control signal to the transmitting module through the fifth control port; The transmitting module is used to connect the second antenna and the radio frequency chip according to the fourth control signal and the fifth control signal, so that the second antenna transmits the third radio frequency signal.

4. A mobile terminal, characterized in that, Includes the radio frequency circuit as described in any one of claims 1-3.

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