Frequency conversion circuit, antenna system and electronic equipment

Abstract

The invention provides a frequency conversion circuit, an antenna system and electronic equipment, and belongs to the technical field of communication. The frequency conversion circuit is provided with an input end, a first output end and a second output end. The frequency conversion circuit comprises a frequency selection sub-circuit, a combining sub-circuit and a frequency mixing sub-circuit; wherein the frequency selection sub-circuit is configured to sort radio frequency signals input by an input end into a first frequency band signal, a second frequency band signal, a third frequency band signal and a local oscillation signal according to frequency; the frequency of the third frequency band signal is between the frequency of the first frequency band signal and the frequency of the second frequency band signal; the combining sub-circuit is configured to combine the first frequency band signal and the second frequency band signal and output a first radio frequency signal through a first output end, and the first radio frequency signal at least comprises a radio frequency signal of a specific frequency band; and the frequency mixing sub-circuit is configured to perform frequency mixing on the third frequency band signal and the local oscillator signal and output a second radio frequency signal through a second output end, and the second radio frequency signal is a radio frequency signal of a specific frequency band.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and specifically relates to a frequency conversion circuit, an antenna system and an electronic device. Background Art

[0002] In the existing indoor distribution system, in order to achieve high-speed and high-reliability wireless communication, the fifth generation mobile communication technology (5G) is increasingly widely used. However, in the distribution system of 5G signals, due to the large amount of user data, multiple-input multiple-output (MIMO) antennas are often required to achieve this. The existing indoor distribution systems are basically upgraded from 4G indoor distribution systems and cannot support the use of 5G MIMO antennas. The equipment and construction costs required for comprehensive transformation are extremely large, and a more efficient and reliable signal transmission solution is needed to solve these problems. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art and provides a frequency conversion circuit, an antenna system and an electronic device.

[0004] In a first aspect, an embodiment of the present disclosure provides a frequency conversion circuit having an input terminal, a first output terminal, and a second output terminal; the frequency conversion circuit includes a frequency selection subcircuit, a combining subcircuit, and a mixing subcircuit; wherein,

[0005] The frequency selection subcircuit is configured to select the radio frequency signal input from the input end into a first frequency band signal, a second frequency band signal, a third frequency band signal and a local oscillator signal according to the frequency; the frequency of the third frequency band signal is between the frequencies of the first frequency band signal and the second frequency band signal;

[0006] The combining sub-circuit is configured to combine the first frequency band signal and the second frequency band signal, and output a first radio frequency signal through the first output end, wherein the first radio frequency signal at least includes a radio frequency signal of a specific frequency band;

[0007] The mixing sub-circuit is configured to mix the third frequency band signal with the local oscillator signal, and output a second radio frequency signal through the second output terminal, where the second radio frequency signal is a radio frequency signal of a specific frequency band.

[0008] Among them, the radio frequency signal in the specific frequency band is a 5G radio frequency signal.

[0009] Wherein, the frequency selection subcircuit includes a first duplexer, a second duplexer, a matching circuit and a first dielectric filter;

[0010] The first duplexer has a first RF channel and a second RF channel, the first RF channel is configured to output the first frequency band signal, the third frequency band signal and the initial local oscillator signal among the RF signals inputted from the input end, and the second RF channel is configured to output the second frequency band signal among the RF signals inputted from the input end;

[0011] The second duplexer has a third RF channel and a fourth RF channel, the third RF channel and the fourth RF channel are both connected to the first RF channel, the third RF channel is configured to output a first frequency band signal, and the fourth RF channel is configured to output a third frequency band signal;

[0012] The matching circuit is configured to perform impedance matching on the first dielectric filter and the second duplexer;

[0013] The first dielectric filter is configured to filter the initial local oscillator signal and output the local oscillator signal.

[0014] Wherein, the frequency selection subcircuit includes a first duplexer and a dielectric triplexer;

[0015] The first duplexer has a first RF channel and a second RF channel, the first RF channel is configured to output the first frequency band signal, the third frequency band signal and the local oscillator signal among the RF signals inputted from the input end, and the second RF channel is configured to output the second frequency band signal among the RF signals inputted from the input end;

[0016] The dielectric triplexer has a fifth RF channel, a sixth RF channel and a seventh RF channel. The fifth RF channel, the sixth RF channel and the seventh RF channel are all connected to the first RF channel and are respectively configured to output the first frequency band signal, the third frequency band signal output and the local oscillator signal.

[0017] Among them, the frequency selection subcircuit includes a dielectric quadplexer, and the dielectric quadplexer has an eighth RF channel, a ninth RF channel, a tenth RF channel and an eleventh RF channel; the eighth RF channel, the ninth RF channel, the tenth RF channel and the eleventh RF channel are respectively configured to select the frequency of the RF signal input by the input end, and output the first frequency band signal, the second frequency band signal, the third frequency band signal output and the local oscillator signal.

[0018] Wherein, the mixing subcircuit includes an IQ mixer, a first matching balun, a second matching balun, a third matching balun and a second dielectric filter;

[0019] The first matching balun is configured to perform impedance matching between the third frequency band signal and the two signals required by the IQ mixer;

[0020] The second matching balun is configured to perform impedance matching between the local oscillator signal and two signals required by the IQ mixer;

[0021] The third matching balun is configured to perform impedance matching between the two signals output by the IQ mixer and the second dielectric filter;

[0022] The second dielectric filter is configured to filter the initial second radio frequency signal output by the third matching balun, and output the second radio frequency signal through the second output terminal.

[0023] Wherein, the mixing subcircuit includes a non-IQ mixer and a second dielectric filter;

[0024] The non-IQ mixer is configured to mix the intermediate frequency signal and the local oscillator signal to output an initial second radio frequency signal;

[0025] The second dielectric filter is configured to filter the initial second radio frequency signal and output the second radio frequency signal through the second output terminal.

[0026] Wherein, the combining sub-circuit includes a duplexer.

[0027] Wherein, the duplexer comprises a LTCC duplexer.

[0028] In a second aspect, an embodiment of the present disclosure provides an antenna system, which includes any of the frequency conversion circuits described above.

[0029] The antenna system further includes a first antenna unit and a second antenna unit, the first antenna unit is configured to transmit the first radio frequency signal, and the second antenna unit is configured to transmit the second radio frequency signal.

[0030] The first antenna unit includes any one of a directional antenna, an omnidirectional antenna, a horizontal plane antenna, a MIMO antenna, and a gain antenna.

[0031] The second antenna unit includes any one of a directional antenna, an omnidirectional antenna, a horizontal plane antenna, a MIMO antenna, and a gain antenna.

[0032] Wherein, the antenna system includes a distributed antenna system.

[0033] In a third aspect, an embodiment of the present disclosure provides an electronic device, comprising any of the antenna systems described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 4 is a circuit diagram of a frequency conversion circuit according to an embodiment of the present disclosure.

[0035] Figure 2 This is a circuit diagram of a first example of a frequency selection subcircuit in the frequency conversion circuit of an embodiment of the present disclosure.

[0036] Figure 3 This is a circuit diagram of a second example of a frequency selection subcircuit in the frequency conversion circuit of an embodiment of the present disclosure.

[0037] Figure 4 This is a circuit diagram of a third example of a frequency selection subcircuit in the frequency conversion circuit of an embodiment of the present disclosure.

[0038] Figure 5 This is a circuit diagram of a first example of a frequency mixing sub-circuit in the frequency conversion circuit of an embodiment of the present disclosure.

[0039] Figure 6 This is a circuit diagram of a second example of a frequency mixing sub-circuit in the frequency conversion circuit of an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] Before introducing the frequency conversion circuit, antenna system and electronic device in the embodiments of the present disclosure, it should be noted that the first frequency band signal, the second frequency band signal and the third frequency band signal mentioned in the embodiments of the present disclosure, wherein the maximum frequency of the first frequency band signal is less than the minimum frequency of the third frequency band signal, and the maximum frequency of the third frequency band signal is less than the minimum frequency of the second frequency band signal, for the sake of convenience of description, the first frequency band signal is referred to as a low-frequency signal, the second frequency band signal is referred to as a high-frequency signal, and the third frequency band signal is referred to as an intermediate-frequency signal. For the frequency conversion circuit in the embodiments of the present disclosure, the bandwidth expansion of the 5G radio frequency signal is achieved, that is, the radio frequency signal in a specific frequency band is an example of a 5G radio frequency signal. However, it should be understood that for specific application scenarios, the bandwidth expansion of signals in other frequency bands can be achieved by selecting specific devices in the frequency conversion circuit, such as the selection of filters.

[0043] First, Figure 1 is a circuit diagram of a frequency conversion circuit according to an embodiment of the present disclosure; Figure 1 As shown, an embodiment of the present disclosure provides a frequency conversion circuit, which has an input terminal Input, a first output terminal Output1 and a second output terminal Output2; the frequency conversion circuit specifically includes a frequency selection subcircuit 11, a combining subcircuit 12 and a mixing subcircuit 13. Among them, the frequency selection subcircuit 11 is configured to select the radio frequency signal input by the input terminal Input into a high-frequency signal, a low-frequency signal, an intermediate frequency signal and a local oscillator signal according to the frequency. The combining subcircuit 12 is configured to combine the low-frequency signal and the high-frequency signal, and output the first radio frequency signal through the first output terminal Output1, and the first radio frequency signal includes at least a 5G radio frequency signal. The mixing subcircuit 13 is configured to mix the intermediate frequency signal and the local oscillator signal, and output the second radio frequency signal through the second output terminal Output2, and the second radio frequency signal is a 5G radio frequency signal.

[0044] It should be noted that the first RF signal outputted by the combiner subcircuit 12 through the first output terminal Output1 in the embodiment of the present disclosure is composed of the high-frequency signal and the low-frequency signal written by the input terminal Input, that is, the first RF signal includes the high-frequency signal and the low-frequency signal. It can be understood that the first RF signal includes RF signals of multiple frequency bands, and the 5G RF signal is one of the RF signals of multiple frequency bands.

[0045] In the embodiment of the present disclosure, the frequency selection circuit is composed of only a frequency selection sub-circuit 11, a combining sub-circuit 12 and a mixing sub-circuit 13. The circuit has a simple structure and can realize low-loss branching of signals for different purposes, thereby reducing the power loss of the entire circuit. Moreover, the frequency selection circuit can realize bandwidth expansion of 5G radio frequency signals, thereby improving the transmission rate and reliability of the signal.

[0046] Below, the exemplary implementable structures of the frequency selection subcircuit 11, the mixing subcircuit 13 and the combining subcircuit 12 in the embodiment of the present disclosure are described respectively. Before introducing these three parts of the structure, it should be noted that the RF signal input by the input terminal Input of the frequency conversion circuit includes two parts. The first part is the traditional communication signal frequency band (low-frequency signal and high-frequency signal), such as 900MHz, 1800MHz, 2GHz, 2.3GHz and 2.6GHz signals; the second part is the intermediate frequency signal IF and the local oscillator signal LO used for frequency conversion to generate a 2.6GHz signal, and the frequency bands of the IF signal and the LO signal fall within the idle frequency bands of 900MHz and 1800MHz. Among them, the 2.6GHz signal is a 5G RF signal. Correspondingly, the frequency band of the first RF signal output by the first output terminal Output1 includes 900MHz, 1800MHz, 2GHz, 2.3GHz and 2.6GHz signals; the second RF signal output by the second output terminal Output2 is another 2.6GHz frequency band signal for bandwidth expansion generated by IF and LO frequency conversion. The frequency selection subcircuit 11 is used to divide the traditional communication frequency band 900MHz, 1800MHz, 2GHz, 2.3GHz and 2.6GHz signals and the IF signal and LO signal used for mixing. The 900MHz, 1800MHz, 2GHz, 2.3GHz and 2.6GHz signals are directly transmitted by the antenna to the coverage scene, and the IF signal and the LO signal are transmitted to the coverage scene via the multiplexed antenna after mixing. The mixing subcircuit 13 is mainly used to realize the frequency conversion of the IF signal to the 2.6GHz signal, with the smallest possible frequency conversion loss and the best possible linearity, to meet the requirements of system communication. The combining subcircuit 12 is used to combine the low-frequency signal (900MHz) and the high-frequency signal (1800MHz, 2GHz, 2.3GHz and 2.6GHz signals) in the non-mixing signal into one channel, and output it through the first output terminal Output1. In addition, since the principle of the multiplexing operation of the frequency selection subcircuit 11 is to divide different signals according to frequency bands through high-pass filters and low-pass filters, the IF signal and the LO signal must be separated from the original signal, and the 900MHz signal and the 1800MHz, 2GHz, 2.3GHz and 2.6GHz signals must be divided into two paths. At this time, the combining subcircuit 12 combines the signals so that the antenna unit can transmit and cover the radio frequency signal.

[0047] First, the frequency selection subcircuit 11 of the embodiment of the present disclosure is introduced.

[0048] First example: Figure 2 FIG. 1 is a circuit diagram of a first example of a frequency selection subcircuit 11 in the frequency conversion circuit of an embodiment of the present disclosure; Figure 2As shown, the frequency selection subcircuit 11 in this example is composed of two duplexers, a matching circuit 13 and a dielectric filter. For the convenience of description and to distinguish from other examples, the two duplexers are respectively referred to as the first duplexer 111 and the second duplexer 112, and the dielectric filter is referred to as the first dielectric filter 14.

[0049] The first duplexer 111 has a first RF channel 111a and a second RF channel 111b. The first RF channel 111a is configured to output a relatively low frequency portion of the RF signal inputted by the input terminal Input, that is, to output a low frequency signal, an intermediate frequency signal, and a local oscillator signal (900MHz, IF signal, and LO signal). The second RF channel 111b is configured to output a relatively high frequency portion of the RF signal inputted by the input terminal Input, that is, to output a high frequency signal (1800MHz, 2GHz, 2.3GHz, and 2.6GHz signal). The second duplexer 112 has a third RF channel 112a and a fourth RF channel 112b, both of which are connected to the first RF channel 111a, the third RF channel 112a is configured to output a low frequency signal (900MHz), and the fourth RF channel 112b is configured to output an intermediate frequency signal (IF signal). The matching circuit 13 is configured to perform impedance matching on the first dielectric filter 14 and the second duplexer 112. The first dielectric filter 14 is configured to filter the initial local oscillation signal and output a local oscillation signal (LO signal).

[0050] It should be noted that the reason why the first RF channel 111a, the second RF channel 111b, the third RF channel 112a and the fourth RF channel 112b can output RF signals of a specific frequency band is because corresponding filters, such as low-pass filters, high-pass filters, etc., are configured in the first RF channel 111a, the second RF channel 111b, the third RF channel 112a and the fourth RF channel 112b.

[0051] In this example, the LO signal is filtered by the first dielectric filter 14 because the frequency of the LO signal is close to the low-frequency signal (900 MHz) and the IF signal. Therefore, the first dielectric filter 14 is used for filtering to achieve greater out-of-band suppression, thereby ensuring that the insertion loss of other RF channels is not deteriorated.

[0052] In some examples, the first duplexer 111 and the second duplexer 112 include, but are not limited to, Low Temperature Co-fired Ceramic (LTCC) duplexers.

[0053] In some examples, the first dielectric filter 14 in this embodiment includes, but is not limited to, a LTCC filter.

[0054] In some examples, the matching circuit 13 may be composed of components such as capacitors and inductors that are electrically connected.

[0055] Second example: Figure 3 is a circuit diagram of a second example of the frequency selection subcircuit 11 in the frequency conversion circuit of the embodiment of the present disclosure; Figure 3 As shown, the frequency selection subcircuit 11 in this example includes a duplexer and a dielectric triplexer 115. Since the function of the duplexer is the same as that of the first duplexer 111 in the first example, the duplexer is also referred to as the first duplexer 111.

[0056] The first duplexer 111 has a first RF channel 111a and a second RF channel 111b. The first RF channel 111a is configured to output a relatively low frequency portion of the RF signal inputted by the input terminal Input, that is, to output a low frequency signal, an intermediate frequency signal, and a local oscillator signal (900MHz, IF signal, and LO signal). The second RF channel 111b is configured to output a relatively high frequency portion of the RF signal inputted by the input terminal Input, that is, to output a high frequency signal (1800MHz, 2GHz, 2.3GHz, and 2.6GHz signals). The dielectric triplexer 115 has a fifth RF channel 115a, a sixth RF channel 115b, and a seventh RF channel 115c. The fifth RF channel 115a, the sixth RF channel 115b, and the seventh RF channel 115c are all connected to the first RF channel 111a. The fifth RF channel 115a is configured to output a low frequency signal (900MHz); the sixth RF channel 115b is configured to output an IF signal; and the seventh RF channel 115c is configured to output an LO signal.

[0057] It should be noted that the reason why the first RF channel 111a, the second RF channel 111b, the fifth RF channel 115a, the sixth RF channel 115b and the seventh RF channel 115c can output RF signals of a specific frequency band is because corresponding filters, such as low-pass filters, high-pass filters, etc., are configured in the first RF channel 111a, the second RF channel 111b, the fifth RF channel 115a, the sixth RF channel 115b and the seventh RF channel 115c.

[0058] In this example, a dielectric triplexer 115 is used to divide the low-frequency signal (900MHz), IF signal and LO signal into three paths. Since the three frequency bands are closely spaced, an out-of-band suppression dielectric triplexer 115 is required to achieve this, which can greatly reduce the insertion loss of the IF signal, thereby reducing the frequency conversion loss of the entire system.

[0059] In some examples, the first duplexer 111 includes, but is not limited to, a LTCC duplexer.

[0060] The third example: Figure 4 FIG. 1 is a circuit diagram of a third example of the frequency selection subcircuit 11 in the frequency conversion circuit of the embodiment of the present disclosure; Figure 4 As shown, the frequency selection subcircuit 11 in this example includes a dielectric quadplexer 116, and the dielectric quadplexer 116 has an eighth RF channel 116a, a ninth RF channel 116b, a tenth RF channel 116c, and an eleventh RF channel 116d. Among them, the eighth RF channel 116a is configured to select the frequency of the RF signal input by the input terminal Input and output a low-frequency signal; the ninth RF channel 116b is configured to select the frequency of the RF signal input by the input terminal Input and output a high-frequency signal; the tenth RF channel 116c is configured to select the frequency of the RF signal input by the input terminal Input and output an IF signal; the eleventh RF channel 116d is configured to select the frequency of the RF signal input by the input terminal Input and output a LO signal.

[0061] In this example, the frequency selection subcircuit 11 uses a dielectric quadplexer 116, which is used to divide the RF signal input from the input terminal Input into four paths. In this case, the integration of the circuit can be further increased, the complexity of the circuit can be reduced, and it is easier to produce.

[0062] Next, the frequency mixing sub-circuit 13 of the embodiment of the present disclosure is introduced.

[0063] First example: Figure 5 FIG. 1 is a circuit diagram of a first example of a frequency mixing subcircuit 13 in the frequency conversion circuit of an embodiment of the present disclosure; Figure 5 As shown, the mixing subcircuit 13 in this example is composed of an IQ mixer 131, three matching baluns and a dielectric filter. For the convenience of description and to distinguish from other examples, the three matching baluns are respectively referred to as the first matching balun 132, the second matching balun 133 and the third matching balun 134, and the dielectric filter is referred to as the second dielectric filter 135.

[0064] Among them, the IQ mixer 131 is a double-balanced IQ mixer 131, which is configured to receive a differential signal and output a differential signal. Therefore, the first matching balun 132 is configured to impedance match the IF signal and the two differential signals required by the IQ mixer 131; the second matching balun 133 is configured to impedance match the LO signal and the two signals required by the IQ mixer 131; the third matching balun 134 is configured to impedance match the two signals output by the IQ mixer 131 and the second dielectric filter 135. The second dielectric filter 135 is configured to filter the initial second RF signal output by the third matching balun 134, and output a 2.6GHz 5G RF signal through the second output terminal Output2.

[0065] In this example, a double-balanced IQ mixer 131 is used to convert the IF and LO signals to generate another 2.6 GHz signal. The double-balanced mixer can achieve the best combination of isolation, linearity and noise coefficient. The IQ mixer 131 can improve image suppression and ensure the nonlinear performance of the system. At the same time, the second dielectric filter 135 is used to filter the 2.6 GHz frequency band signal generated by the frequency conversion, filter out the out-of-band spurious signals generated by the mixing, and ensure the communication quality.

[0066] In some examples, the second dielectric filter 135 in this embodiment includes, but is not limited to, a LTCC filter.

[0067] Second example: Figure 6 is a circuit diagram of a second example of the frequency mixing sub-circuit 13 in the frequency conversion circuit of the embodiment of the present disclosure; Figure 6 As shown, the mixing subcircuit 13 in this example includes a non-IQ mixer 136 and a dielectric filter. The dielectric filter has the same function as the dielectric filter in the mixing subcircuit 13 in the first example, and is therefore also referred to as a second dielectric filter 135.

[0068] Among them, the non-IQ mixer 136 is configured to mix the intermediate frequency signal and the local oscillator signal to output an initial second RF signal; the second dielectric filter 135 is configured to filter the initial second RF signal and output a 2.6 GHz 5G RF signal through the second output terminal Output2.

[0069] In this example, a non-IQ mixer 136 is used, and the matching balun can be removed compared to the mixing sub-circuit 13 of the first example. Since the matching balun is prone to mismatching to varying degrees due to various reasons during actual wiring, which increases the loss, the non-IQ mixer 136 is used to replace the IQ mixer 131 to reduce the frequency conversion loss to a certain extent. At the same time, the second dielectric filter 135 is used to filter the 2.6 GHz frequency band signal generated by the frequency conversion, filter out the out-of-band spurious signals generated by the mixing, and ensure the communication quality.

[0070] In some examples, the second dielectric filter 135 in this embodiment includes, but is not limited to, a LTCC filter.

[0071] Finally, the combining sub-circuit 12 in the embodiment of the present disclosure is described. The combining sub-circuit 12 in the embodiment of the present disclosure uses a duplexer, which can be a LTCC duplexer. The duplexer is used to combine the signals in reverse, so that the antenna unit can transmit and cover the RF signal.

[0072] In a second aspect, an embodiment of the present disclosure provides an antenna system, the antenna system comprising any of the above frequency conversion circuits, and providing a signal source for the antenna system through the frequency conversion circuit. The antenna system in the embodiment of the present disclosure may specifically be a distributed antenna system (Distributed Antenna System, or DAS).

[0073] In some examples, the antenna system includes not only a signal source, but also a transmission medium and an antenna unit. The signal source is connected to the antenna unit via the transmission medium. In an embodiment of the present disclosure, the antenna unit may specifically include a first antenna unit and a second antenna unit, the first antenna unit being configured to transmit the first radio frequency signal, and the second antenna unit being configured to transmit the second radio frequency signal.

[0074] Furthermore, the transmission medium may be a coaxial cable, an optical cable, a LAN, or the like.

[0075] In some examples, the antenna system in the disclosed embodiments is a passive distributed antenna (Passive DAS): mainly used in small buildings and spaces. Only coaxial cables are used to transmit the RF signal of the base station or repeater to the antenna unit. The electronic components used include: splitters, combiners, attenuators, dummy loads, circulators, filters, and couplers.

[0076] In some examples, the antenna system may be a transceiver antenna, that is, it can realize both the transmission and reception of electromagnetic wave signals. Of course, the antenna system is not limited to the above structure, but also includes a transceiver unit, a radio frequency transceiver, a signal amplifier, a power amplifier, and a filter unit. The antenna in the communication device can be used as a transmitting antenna or a receiving antenna. Among them, the transceiver unit may include a baseband and a receiving end, and the baseband provides a signal of at least one frequency band, such as a 2G signal, a 3G signal, a 4G signal, a 5G signal, etc., and sends a signal of at least one frequency band to the radio frequency transceiver. After the antenna in the communication system receives the signal, it can be processed by the filter unit, the power amplifier, the signal amplifier, and the radio frequency transceiver and then transmitted to the receiving end in the transceiver unit. The receiving end may be, for example, a smart gateway.

[0077] Furthermore, the RF transceiver is connected to the transceiver unit, and is used to modulate the signal sent by the transceiver unit, or to demodulate the signal received by the antenna and transmit it to the transceiver unit. Specifically, the RF transceiver may include a transmitting circuit, a receiving circuit, a modulation circuit, and a demodulation circuit. After the transmitting circuit receives various types of signals provided by the baseband, the modulation circuit can modulate the various types of signals provided by the baseband and then send them to the antenna. The antenna receives the signal and transmits it to the receiving circuit of the RF transceiver. The receiving circuit transmits the signal to the demodulation circuit, and the demodulation circuit demodulates the signal and transmits it to the receiving end.

[0078] Furthermore, the RF transceiver is connected to a signal amplifier and a power amplifier, and the signal amplifier and the power amplifier are connected to a filter unit, and the filter unit is connected to at least one antenna. In the process of sending signals in the communication system, the signal amplifier is used to improve the signal-to-noise ratio of the signal output by the RF transceiver and then transmit it to the filter unit; the power amplifier is used to amplify the power of the signal output by the RF transceiver and then transmit it to the filter unit; the filter unit may specifically include a duplexer and a filter circuit, and the filter unit combines the signals output by the signal amplifier and the power amplifier and filters out the clutter before transmitting them to the antenna, and the antenna radiates the signal. In the process of receiving signals in the communication system, the antenna receives the signal and transmits it to the filter unit, and the filter unit filters out the clutter from the signal received by the antenna and then transmits it to the signal amplifier and the power amplifier, and the signal amplifier amplifies the signal received by the antenna to increase the signal-to-noise ratio; the power amplifier amplifies the power of the signal received by the antenna. The signal received by the antenna is processed by the power amplifier and the signal amplifier and then transmitted to the RF transceiver, and the RF transceiver then transmits it to the transceiver unit.

[0079] In some examples, the signal amplifier may include various types of signal amplifiers, such as a low noise amplifier, which is not limited herein.

[0080] In some examples, the antenna system provided by the embodiments of the present disclosure further includes a power management unit, which is connected to a power amplifier to provide the power amplifier with a voltage for amplifying a signal.

[0081] In a third aspect, an embodiment of the present disclosure provides an electronic device, which includes the above-mentioned antenna system.

[0082] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A frequency conversion circuit, which has an input terminal, a first output terminal and a second output terminal; the frequency conversion circuit includes a frequency selection subcircuit, a combining subcircuit and a mixing subcircuit; wherein, The frequency selection subcircuit is configured to select the radio frequency signal input from the input end into a first frequency band signal, a second frequency band signal, a third frequency band signal and a local oscillator signal according to the frequency; the frequency of the third frequency band signal is between the frequencies of the first frequency band signal and the second frequency band signal; The combining sub-circuit is configured to combine the first frequency band signal and the second frequency band signal, and output a first radio frequency signal through the first output end, wherein the first radio frequency signal at least includes a radio frequency signal of a specific frequency band; The mixing sub-circuit is configured to mix the third frequency band signal with the local oscillator signal, and output a second radio frequency signal through the second output terminal, where the second radio frequency signal is a radio frequency signal of a specific frequency band.

2. The frequency conversion circuit according to claim 1, wherein: The radio frequency signal in the specific frequency band is a 5G radio frequency signal.

3. The frequency conversion circuit according to claim 1, wherein: The frequency selection subcircuit includes a first duplexer, a second duplexer, a matching circuit and a first dielectric filter; The first duplexer has a first RF channel and a second RF channel, the first RF channel is configured to output the first frequency band signal, the third frequency band signal and the initial local oscillator signal among the RF signals inputted from the input end, and the second RF channel is configured to output the second frequency band signal among the RF signals inputted from the input end; The second duplexer has a third RF channel and a fourth RF channel, the third RF channel and the fourth RF channel are both connected to the first RF channel, the third RF channel is configured to output a first frequency band signal, and the fourth RF channel is configured to output a third frequency band signal; The matching circuit is configured to perform impedance matching on the first dielectric filter and the second duplexer; The first dielectric filter is configured to filter the initial local oscillator signal and output the local oscillator signal.

4. The frequency conversion circuit according to claim 1, wherein: The frequency selection subcircuit includes a first duplexer and a dielectric triplexer; The first duplexer has a first RF channel and a second RF channel, the first RF channel is configured to output the first frequency band signal, the third frequency band signal and the local oscillator signal among the RF signals inputted from the input end, and the second RF channel is configured to output the second frequency band signal among the RF signals inputted from the input end; The dielectric triplexer has a fifth RF channel, a sixth RF channel and a seventh RF channel. The fifth RF channel, the sixth RF channel and the seventh RF channel are all connected to the first RF channel and are respectively configured to output the first frequency band signal, the third frequency band signal output and the local oscillator signal.

5. The frequency conversion circuit according to claim 1, wherein: The frequency selection subcircuit includes a dielectric quadplexer, and the dielectric quadplexer has an eighth radio frequency channel, a ninth radio frequency channel, a tenth radio frequency channel, and an eleventh radio frequency channel; The eighth RF channel, the ninth RF channel, the tenth RF channel and the eleventh RF channel are respectively configured to perform frequency selection on the RF signal input by the input end, and output the first frequency band signal, the second frequency band signal, the third frequency band signal output and the local oscillator signal.

6. The frequency conversion circuit according to claim 1, wherein: The mixing subcircuit includes an IQ mixer, a first matching balun, a second matching balun, a third matching balun and a second dielectric filter; The first matching balun is configured to perform impedance matching between the third frequency band signal and the two signals required by the IQ mixer; The second matching balun is configured to perform impedance matching between the local oscillator signal and two signals required by the IQ mixer; The third matching balun is configured to perform impedance matching between the two signals output by the IQ mixer and the second dielectric filter; The second dielectric filter is configured to filter the initial second radio frequency signal output by the third matching balun, and output the second radio frequency signal through the second output terminal.

7. The frequency conversion circuit according to claim 1, wherein: The mixing subcircuit includes a non-IQ mixer and a second dielectric filter; The non-IQ mixer is configured to mix the intermediate frequency signal and the local oscillator signal to output an initial second radio frequency signal; The second dielectric filter is configured to filter the initial second radio frequency signal and output the second radio frequency signal through the second output terminal.

8. The frequency conversion circuit according to any one of claims 1 to 7, wherein: The combining subcircuit includes a duplexer.

9. The frequency conversion circuit according to any one of claims 8, wherein: The duplexer includes a LTCC duplexer.

10. An antenna system, comprising the frequency conversion circuit according to any one of claims 1 to 9.

11. The antenna system according to claim 10, wherein: The system further includes a first antenna unit and a second antenna unit, wherein the first antenna unit is configured to transmit the first radio frequency signal, and the second antenna unit is configured to transmit the second radio frequency signal.

12. The antenna system according to claim 11, wherein: The first antenna unit includes any one of a directional antenna, an omnidirectional antenna, a horizontal plane antenna, a MIMO antenna, and a gain antenna.

13. The antenna system according to claim 11, wherein: The second antenna unit includes a directional antenna, an omnidirectional antenna, a horizontal plane antenna, a MIMO antenna, and a gain antenna.

14. The antenna system according to any one of claims 10 to 13, wherein: The antenna system comprises a distributed antenna system.

15. An electronic device comprising the antenna system according to any one of claims 10 to 14.

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