Carrier aggregation circuit

Abstract

The utility model provides a carrier aggregation circuit, which comprises a first amplification filter circuit, a second amplification filter circuit, an antenna switch and a matching circuit, the output end of the antenna switch is used for aggregating and outputting a first radio frequency signal and a second radio frequency signal, the first amplifying and filtering circuit and the second amplifying and filtering circuit are used for amplifying and filtering the first radio frequency signal and the second radio frequency signal respectively, and the frequency band where the first radio frequency signal is located is lower than the frequency band where the second radio frequency signal is located. The matching circuit is used for suppressing signal leakage of the second radio frequency signal to a signal path where the first radio frequency signal is located when the second radio frequency signal and the first radio frequency signal are aggregated at the antenna switch. Compared with the prior art, the signal power attenuation in the carrier aggregation process can be effectively reduced by adding the matching circuit, so that the communication speed and quality are improved.

Description

Technical Field

[0001] The utility model is applicable to the field of communication technology, and in particular relates to a carrier aggregation circuit. Background Art

[0002] Carrier aggregation (CA) technology is primarily used to improve data transmission rates and spectrum efficiency in mobile communication systems. This technology combines multiple frequency bands or carriers to form a wider frequency band, thereby increasing data transmission rates. The advantages of carrier aggregation include: 1. It improves the data transmission rate of mobile communication systems, allowing users to enjoy faster download speeds and smoother video playback. 2. By combining multiple frequency bands or carriers, the system can provide a wider total bandwidth, thereby increasing spectrum efficiency, which is particularly important in situations where spectrum resources are limited. 3. It increases the capacity of mobile communication networks, allowing more users to connect simultaneously and enjoy high-speed data services. 4. It offers excellent compatibility and flexibility, adapting to different combinations of frequency bands and carriers to meet the needs of different regions and operators. Based on these advantages, carrier aggregation technology is widely used in next-generation mobile communication systems such as LTE (Long Term Evolution) and 5G. It plays an important role in scenarios such as high-speed mobile communications, enhancing indoor coverage, alleviating congestion in hotspots, improving coverage in rural and remote areas, and providing wireless broadband access. With the continuous development and popularization of 5G networks, carrier aggregation technology will play a more important role in the future mobile communications field, bringing better network experience to users.

[0003] In the existing carrier aggregation circuit, the RF signal is amplified by the amplifier circuit, filtered by the filter, and then output through the antenna switch. The circuit structure is as follows: Figure 1 As shown in the figure, MBPA and HBPA represent mid-band amplifiers and high-band amplifiers, respectively; MB FILTER and HB FILTER represent mid-band filters and high-band filters, respectively; ASM represents the antenna switch; and MHBANT represents the output port of the antenna switch. During carrier aggregation, MB (mid-band) and HB (high-band) signals are typically transmitted simultaneously, combined within the antenna switch, and output from the antenna switch's output port. During this process, the MB signal leaks through the antenna switch onto the HB path. Similarly, the HB signal leaks into the MB path, resulting in signal energy loss and reduced communication quality. Existing solutions to this problem include: 1. Filter selection requires consideration of its suppression of the carrier aggregation band, but most filters are not designed with carrier aggregation in mind. 2. Adding a high-resistance circuit to the filter's output increases insertion loss, provides insufficient suppression of the carrier aggregation band, and results in a complex structure and space occupancy.

[0004] Therefore, a new carrier aggregation circuit is urgently needed to solve the above technical problems. Utility Model Content

[0005] The utility model provides a carrier aggregation circuit, which aims to reduce signal power attenuation of radio frequency signals during the carrier aggregation process.

[0006] The utility model provides a carrier aggregation circuit, comprising a first amplifying and filtering circuit, a second amplifying and filtering circuit, an antenna switch, and a matching circuit;

[0007] The input end of the first amplifying and filtering circuit is used to receive a first radio frequency signal in a first frequency band, the output end of the first amplifying and filtering circuit is connected to the input end of the matching circuit, and the output end of the matching circuit is connected to the first input end of the antenna switch; the input end of the second amplifying and filtering circuit is used to receive a second radio frequency signal in a second frequency band, and the output end of the second amplifying and filtering circuit is connected to the second input end of the antenna switch;

[0008] The output end of the antenna switch is used to aggregate the first RF signal and the second RF signal and output them. The first amplification and filtering circuit and the second amplification and filtering circuit are used to amplify and filter the first RF signal and the second RF signal, respectively. The frequency band of the first RF signal is lower than the frequency band of the second RF signal. The matching circuit is used to suppress signal leakage of the second RF signal to the signal path of the first RF signal when the second RF signal and the first RF signal are aggregated at the antenna switch.

[0009] Preferably, the matching circuit includes a first capacitor and a first inductor, the first end of the first capacitor serves as the input end of the matching circuit, the second end of the first capacitor serves as the output end of the matching circuit, the first end of the first inductor is connected to the second end of the first capacitor, and the second end of the first inductor is grounded.

[0010] Preferably, the matching circuit further includes a second capacitor, and the first capacitor is connected to the first input terminal of the antenna switch after being connected in series with the second capacitor.

[0011] Preferably, the first amplifying and filtering circuit includes a first amplifier and a first filter, the input end of the first amplifier serves as the input end of the first amplifying and filtering circuit, the output end of the first amplifier is connected to the input end of the first filter, and the output end of the first filter serves as the output end of the first amplifying and filtering circuit.

[0012] Preferably, the second amplifying and filtering circuit includes a second amplifier and a second filter, the input end of the second amplifier serves as the input end of the second amplifying and filtering circuit, the output end of the second amplifier is connected to the input end of the second filter, and the output end of the second filter serves as the output end of the second amplifying and filtering circuit.

[0013] Compared to the prior art, the present invention utilizes a first amplifying and filtering circuit, a second amplifying and filtering circuit, an antenna switch, and a matching circuit. The output of the antenna switch is used to aggregate the first and second RF signals for output. The first and second amplifying and filtering circuits are used to amplify and filter the first and second RF signals, respectively. The frequency band of the first RF signal is lower than the frequency band of the second RF signal. The matching circuit is used to suppress leakage of the second RF signal into the signal path of the first RF signal when the second RF signal and the first RF signal are aggregated via the antenna switch. By adding the matching circuit, the present invention effectively reduces signal power attenuation during carrier aggregation, thereby improving communication speed and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described in detail below with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made with reference to the following drawings.

[0015] Figure 1 It is a structural diagram of a carrier aggregation circuit in the prior art;

[0016] Figure 2 Schematic diagram of an S-parameter curve of a mid-frequency band circuit of a carrier aggregation circuit in the prior art;

[0017] Figure 3 Schematic diagram of an S-parameter curve of a high-frequency band circuit of a carrier aggregation circuit in the prior art;

[0018] Figure 4 is a Smith chart of a carrier aggregation circuit in the prior art at an antenna switch input terminal;

[0019] Figure 5 This is a structural diagram of a carrier aggregation circuit provided by an embodiment of the present utility model;

[0020] Figure 6 1 is a schematic diagram of an S-parameter curve of a first amplification and matching circuit of a carrier aggregation circuit provided by an embodiment of the present utility model;

[0021] Figure 7 1 is a schematic diagram of an S-parameter curve of a second amplification and matching circuit of a carrier aggregation circuit provided by an embodiment of the present utility model;

[0022] Figure 8 It is a Smith chart of the antenna switch input end of the carrier aggregation circuit provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Please refer to Figure 4 The present invention provides a carrier aggregation circuit 100 , including a first amplifying and filtering circuit 1 , a second amplifying and filtering circuit 2 , a matching circuit 3 and an antenna switch 4 .

[0025] The input end of the first amplifying and filtering circuit 1 is used to receive a first radio frequency signal of a first frequency band, the output end of the first amplifying and filtering circuit 1 is connected to the input end of the matching circuit 3, and the output end of the matching circuit 3 is connected to the first input end of the antenna switch 4; the input end of the second amplifying and filtering circuit 2 is used to receive a second radio frequency signal of a second frequency band, and the output end of the second amplifying and filtering circuit 2 is connected to the second input end of the antenna switch 4;

[0026] The output end of the antenna switch 4 is used to aggregate the first RF signal and the second RF signal and output them. The first amplification and filtering circuit 1 and the second amplification and filtering circuit 2 are used to amplify and filter the first RF signal and the second RF signal, respectively. The frequency band of the first RF signal is lower than the frequency band of the second RF signal. The matching circuit 3 is used to suppress the leakage of the second RF signal to the signal path of the first RF signal when the second RF signal and the first RF signal are aggregated at the antenna switch 4.

[0027] Specifically, the RF signal received by the first amplifying and filtering circuit 1 is in the mid-frequency band, while the RF signal received by the second amplifying and filtering circuit 2 is in the high-frequency band. The operating frequency band of the carrier aggregation circuit 100 is in the 2300-2496 MHz band. The impedance position of the combined frequency band of the first amplifying and filtering circuit 1 and the second amplifying and filtering circuit 2 is transformed from near the short-circuit point to near the open-circuit point through the matching circuit 3. When the first amplifying and filtering circuit 1 and the second amplifying and filtering circuit 2 operate simultaneously, the path of the first amplifying and filtering circuit 1 presents a high-impedance state to the signal of the second amplifying and filtering circuit 2, which greatly reduces signal leakage from the second amplifying and filtering circuit 2, thereby improving communication speed and quality. This circuit not only has low insertion loss (IL) but also has good suppression of the frequency band with which it is carrier-filtered.

[0028] In this embodiment, the matching circuit 3 includes a first capacitor C1 and a first inductor L1. The first end of the first capacitor C1 serves as the first end of the matching circuit 3, and the second end of the first capacitor C1 serves as the second end of the matching circuit 3. The first end of the first inductor L1 is connected to the second end of the first capacitor C1, and the second end of the first inductor L1 is grounded.

[0029] In this embodiment, the matching circuit 3 further includes a second capacitor C2 , and the first capacitor C1 is connected to the first input terminal of the antenna switch 4 after being serially connected to the second capacitor C2 .

[0030] In this embodiment, the first amplifying and filtering circuit 1 includes a first amplifier 11 and a first filter 12. The first end of the first amplifier 11 serves as the first end of the first amplifying and filtering circuit 1. The second end of the first amplifier 11 is connected to the first end of the first filter 12. The second end of the first filter 12 serves as the second end of the first amplifying and filtering circuit 1.

[0031] In this embodiment, the second amplifying and filtering circuit 2 includes a second amplifier 21 and a second filter 22. The first end of the second amplifier 2 serves as the first end of the second amplifying and filtering circuit 2. The second end of the second amplifier 21 is connected to the first end of the second filter 22. The second end of the second filter 22 serves as the second end of the second amplifying and filtering circuit 2.

[0032] Next, we will compare and illustrate the simulation results, taking the frequency band B1&3 as an example. In the existing technology, combined with Figure 1 As shown, the single-channel filter of the RF signal path of the B1&3 frequency band is simulated respectively, and the simulation results are shown in Figures 2 to 4 As shown in the figure, it can be seen that the filter has a small loss within the band, but it does not suppress the frequency band with which it is aggregated, especially 2.96GHz, which is close to the short-circuit area. Therefore, when it is aggregated with B41, the signal of B41 will pass through. Figure 1 The circuit is transmitted to the ground, resulting in the signal in the B41 band being unable to be transmitted normally.

[0033] In the present invention, a matching circuit 3 is added to the first amplifying and filtering circuit 1, and its structure is as follows: Figure 4 As shown, the carrier aggregation circuit 100 proposed in the present invention is simulated, and the simulation results are as follows: Figures 6 to 8 As shown. Figure 2 、 3 and Figure 6 、 7 By comparison, it can be found that after loading the matching circuit 3 of the present invention, the maximum in-band LOSS (i.e., insertion loss) deteriorates by only 0.42dB. Figure 4 and Figure 8 A comparison reveals that, after adding the matching circuit 3 of the present invention, the impedance position of the combined frequency band shifts from near the short-circuit point to near the open-circuit point. This means that when the MB IF and HB HF channels operate simultaneously, the MB IF path presents a high impedance to the HB HF signal. This significantly reduces HB HF signal leakage, thereby improving communication speed and quality.

[0034] It should be noted that the above description is based on the first RF signal in the mid-frequency band and the second RF signal in the high-frequency band. Of course, it is not limited to this. As long as the frequency band of the first RF signal is lower than the frequency band of the second RF signal, the principle is the same as that of the above embodiment and will not be repeated here.

[0035] Compared to the prior art, the present invention utilizes a first amplifying and filtering circuit, a second amplifying and filtering circuit, an antenna switch, and a matching circuit. The output of the antenna switch is used to aggregate the first and second RF signals for output. The first amplifying and filtering circuit is used to amplify and filter the first and second RF signals, respectively. The frequency band of the first RF signal is lower than the frequency band of the second RF signal. The matching circuit is used to suppress leakage of the second RF signal into the signal path of the first RF signal when the second RF signal and the first RF signal are aggregated via the antenna switch. By adding a matching circuit, the present invention effectively reduces signal power attenuation during carrier aggregation, thereby improving communication speed and quality.

[0036] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0037] The embodiments of the present invention are described above in conjunction with the accompanying drawings. What is disclosed is only a preferred embodiment of the present invention. However, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms and equivalent changes without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A carrier aggregation circuit, characterized in that: It includes a first amplifying and filtering circuit, a second amplifying and filtering circuit, an antenna switch and a matching circuit; The input end of the first amplifying and filtering circuit is used to receive a first radio frequency signal in a first frequency band, the output end of the first amplifying and filtering circuit is connected to the input end of the matching circuit, and the output end of the matching circuit is connected to the first input end of the antenna switch; the input end of the second amplifying and filtering circuit is used to receive a second radio frequency signal in a second frequency band, and the output end of the second amplifying and filtering circuit is connected to the second input end of the antenna switch; The output end of the antenna switch is used to aggregate the first RF signal and the second RF signal and output them. The first amplification and filtering circuit and the second amplification and filtering circuit are used to amplify and filter the first RF signal and the second RF signal, respectively. The frequency band of the first RF signal is lower than the frequency band of the second RF signal. The matching circuit is used to suppress signal leakage of the second RF signal to the signal path of the first RF signal when the second RF signal and the first RF signal are aggregated at the antenna switch.

2. The carrier aggregation circuit according to claim 1, wherein: The matching circuit includes a first capacitor and a first inductor, the first end of the first capacitor serves as the input end of the matching circuit, the second end of the first capacitor serves as the output end of the matching circuit, the first end of the first inductor is connected to the second end of the first capacitor, and the second end of the first inductor is grounded.

3. The carrier aggregation circuit according to claim 2, wherein: The matching circuit further includes a second capacitor, and the first capacitor is connected to the first input terminal of the antenna switch after being connected in series with the second capacitor.

4. The carrier aggregation circuit according to claim 1, wherein: The first amplifying and filtering circuit includes a first amplifier and a first filter. The input end of the first amplifier serves as the input end of the first amplifying and filtering circuit. The output end of the first amplifier is connected to the input end of the first filter. The output end of the first filter serves as the output end of the first amplifying and filtering circuit.

5. The carrier aggregation circuit according to claim 1, wherein: The second amplifying and filtering circuit includes a second amplifier and a second filter. The input end of the second amplifier serves as the input end of the second amplifying and filtering circuit. The output end of the second amplifier is connected to the input end of the second filter. The output end of the second filter serves as the output end of the second amplifying and filtering circuit.

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