A radio frequency front-end circuit

Abstract

The present application relates to the technical field of communication, in particular to a kind of radio frequency front-end circuit, comprising: filter, radio frequency front-end module, antenna module and signal processing module;Radio frequency front-end module is equipped with multiple filters and first single-pole multi-throw switch;Wherein, the first filter in multiple filters is configured to process the first main set signal including B75 frequency band;Second filter is configured to process the first main set MIMO signal including B3 frequency band;Third filter is configured to process the second main set MIMO signal including B66 frequency band;The output of first single-pole multi-throw switch is connected with the input of filter;The output of filter is connected with the input of signal processing module;The input of first single-pole multi-throw switch is connected with the output of antenna module, so that the carrier aggregation of B1+B3+B32.This in addition, using separate DIFEM to process signal, can reduce the number of external devices, and save circuit board space.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and in particular to a radio frequency front-end circuit. Background Technology

[0002] Please refer to Figure 1 In existing 5G RF solutions, MHB MIMO (mid-to-high frequency multiple input / output) designs typically employ a discrete device architecture. This involves a MIMO antenna paired with a 2200 / 2300 frequency divider combiner, an SPxT (single-pole multiple-throw switch), and MHB (mid-to-high frequency) discrete filtering components (where HB corresponds to the B7 / B41 / B40 bands, and MB corresponds to the 1+3+66 or 25+66 dual SAW bands). However, overseas markets, such as Europe, have higher requirements for communication performance, demanding support for 1+3+32 / 7+32 carrier aggregation (CA), ENDC, and N28_N75 New Radio (NR) carrier aggregation. The MB band of a conventional main antenna, when compatible with both B32 (downlink frequency 1432-1496MHz) and B75 (downlink frequency 1432-1516.9MHz), suffers from degraded antenna performance. Therefore, some brands choose to deploy the B32 / B75 bands on the MIMO antenna. Meanwhile, mid-to-low-end mobile phones need to support hundreds of CA (carrier aggregation) and ENDC (radio access network-new radio dual connectivity) combinations to meet the needs of overseas operators. In order to control R&D and production costs, a common PCB (printed board) design is often adopted, which increases the area occupied by radio frequency devices. The user's demand for large batteries (such as 7000mA and above) further compresses the motherboard space. In addition, existing MIMO DIFEM devices on the market have inherent defects. They are not compatible with the B75 / B32 frequency band (B75 frequency range includes B32), and their AUX (auxiliary) port does not support dual-opening function with internal devices. The above problems together constitute the main technical bottleneck in the current 5G mobile phone radio frequency MHB MIMO design field. Utility Model Content

[0003] The purpose of this invention is to provide a radio frequency front-end circuit that improves frequency band compatibility and simplifies system architecture.

[0004] This utility model provides a radio frequency front-end circuit, including: a filter, a radio frequency front-end module, an antenna module, and a signal processing module; The radio frequency front-end module is equipped with multiple filters and a first single-pole multi-throw switch; Among the plurality of filters, a first filter is configured to process a first master signal including the B75 band; a second filter is configured to process a first master MIMO signal including the B3 band; and a third filter is configured to process a second master MIMO signal including the B66 band. The output terminal of the first single-pole multi-throw switch is connected to the input terminal of the filter; The output of the filter is connected to the input of the signal processing module; The input terminal of the first single-pole multi-throw switch is connected to the output terminal of the antenna module.

[0005] Furthermore, the fifth filter among the plurality of filters is configured to process a third master MIMO signal including the B41 band; the sixth filter is configured to process a fourth master MIMO signal including the B7 band; and the seventh filter is configured to process a fourth master MIMO signal including the B40 band.

[0006] Furthermore, it also includes a second single-pole multi-throw switch and a third single-pole multi-throw switch; The input terminal of the second single-pole multi-throw switch is connected to the output terminal of the second filter, and the output terminal of the second single-pole multi-throw switch is connected to the input terminal of the signal processing module. The input terminal of the third single-pole multi-throw switch is connected to the output terminal of the third filter, and the output terminal of the third single-pole multi-throw switch is connected to the input terminal of the signal processing module.

[0007] Furthermore, the signal processing module includes: a low-noise amplifier module and a radio frequency transceiver; The input terminal of the low-noise amplifier module is connected to the output terminal of the filter, or to the second single-pole multi-throw switch and the third single-pole multi-throw switch; The output of the low-noise amplifier module is connected to the input of the radio frequency transceiver.

[0008] Furthermore, the second single-pole multi-throw switch and the third single-pole multi-throw switch are single-pole double-throw switches.

[0009] Furthermore, it also includes: radio frequency coaxial connectors and radio frequency antennas; The input terminal of the low-noise amplifier module is connected to the radio frequency antenna via the radio frequency coaxial connector.

[0010] Furthermore, the radio frequency front-end module includes a MIPI interface, which is connected to external control commands.

[0011] Compared with the prior art, the present invention has at least the following technical effects: This invention achieves effective processing of signals from different frequency bands by integrating multiple filters with a single-pole multi-throw (DPMW) switch within a radio frequency front-end module (DIFEM). The DPMW switch can select different filter paths as needed, thus supporting the processing of multiple frequency bands and signal types. The filters are specifically configured to process signals in specific frequency bands, such as B1, B3, and B32, enabling carrier aggregation of B1+B3+B32. Furthermore, using a separate DIFEM for signal processing reduces the number of external components, lowers system complexity, and saves board space. Attached Figure Description

[0012] Figure 1 This is a simplified schematic diagram of the structure of a radio frequency front-end circuit in the background art; Figure 2 This is a simplified schematic diagram of the structure of a radio frequency front-end circuit according to Embodiment 1 of this utility model; Figure 3 This is a simplified structural diagram of a radio frequency front-end module according to Embodiment 1 of this utility model; Figure 4 This is a simplified schematic diagram of another structure of a radio frequency front-end module in Embodiment 1 of this utility model; Figure 5 This is a partially enlarged view of a radio frequency front-end circuit according to Embodiment 1 of this utility model. Detailed Implementation

[0013] The following description, in conjunction with schematic diagrams, illustrates a radio frequency front-end circuit of the present invention, which represents a preferred embodiment of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the scope of the invention.

[0014] The present invention will be described more specifically by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0015] Example 1 Please refer to Figure 1 and Figure 2 This embodiment discloses a radio frequency front-end circuit, including: a filter, a radio frequency front-end module 1, an antenna module, and a signal processing module; The radio frequency front-end module 1 is equipped with multiple filters and a first single-pole multi-throw switch 7; Among the plurality of filters, a first filter is configured to process a first master signal including the B75 band; a second filter is configured to process a first master MIMO signal including the B3 band; and a third filter is configured to process a second master MIMO signal including the B66 band. The output terminal of the first single-pole multi-throw switch 7 is connected to the input terminal of the filter; The output of the filter is connected to the input of the signal processing module; The input terminal of the first single-pole multi-throw switch 7 is connected to the output terminal of the antenna module.

[0016] In this embodiment, the RF front-end circuit integrates multiple filters with a first single-pole multi-throw switch within the RF front-end module 1 (DIFEM), achieving effective processing of signals across different frequency bands. The first single-pole multi-throw switch can select different filter paths as needed, thus supporting the processing of multiple frequency bands and signal types. The filters are specifically configured to process signals in specific frequency bands, such as B1, B3, and B32, enabling carrier aggregation of B1+B3+B32. Furthermore, using a separate DIFEM for signal processing reduces the number of external components, lowers system complexity, and saves board space.

[0017] Please refer to Figures 3-4 In one specific example, the first filter is a B75 RX filter, the second filter is a B3 RX filter or a B25 RX filter, and the third filter is a B66 RX filter. Of course, those skilled in the art can also choose to add filters of other different frequency bands according to the actual situation, for example... Figure 3 The filter shown is for the B25+B70 frequency band.

[0018] In another specific example, the second filter and the third filter share the same output port in the first single-pole multi-throw switch 7.

[0019] Understandably, since the B75 RX filter can handle a signal frequency range of (1432-1516.9MHz), covering the B32 band (1452-1496MHz), the first filter can be used simultaneously for receiving B32 band RF signals. Similarly, the B66 RX filter can handle a signal frequency range of 2110MHz–2200MHz, which completely covers the B1 band's receiving frequency range (2110–2170MHz), therefore, the B66 RX filter can also be used for receiving B1 band RF signals.

[0020] Furthermore, in this embodiment, a specific internal dual-opening debugging scheme is adopted in order to achieve multi-band concurrent operation and optimize signal performance.

[0021] Specifically, the dual-band debugging scheme includes: when it is necessary to simultaneously receive signals from the B75 (or its compatible B32) band and another band, a specific control word is sent to the first single-pole multi-throw switch 7 via control logic. Based on its bit position, the path connected to the B75 RX SAW filter and the other target path are precisely activated simultaneously. This "bit-by-bit dual-band" control method aims to optimize the isolation and insertion loss when the two paths are working simultaneously, ensuring that each receiving link obtains a high-quality RF signal in complex scenarios such as carrier aggregation or dual connectivity.

[0022] Furthermore, in this embodiment, the filter is a surface acoustic wave filter or a bulk acoustic wave filter.

[0023] Specifically, a surface acoustic wave (SAW) filter is a device that uses sound waves propagating on the surface of a piezoelectric substrate for filtering. Its working principle involves converting an electrical signal into a SAW wave using interdigital transducers, and then converting the SAW wave back into an electrical signal using another set of interdigital transducers, thus achieving filtering for a specific frequency band. A bulk acoustic wave (SAW) filter, on the other hand, utilizes the bulk acoustic wave resonance characteristics of piezoelectric materials for filtering. Its structure typically consists of upper and lower electrodes and a piezoelectric layer in the middle. Different frequency band filtering requirements are achieved by adjusting the electrode structure and the thickness of the piezoelectric layer. As a preferred embodiment, the SAW filter can use lithium tantalate or lithium niobate as the piezoelectric substrate material, and the bulk acoustic wave filter can use aluminum nitride or zinc oxide as the piezoelectric layer material.

[0024] Therefore, using surface acoustic wave (SAW) filters or bulk acoustic wave (BAW) filters can effectively solve the problems of large space occupation and high system complexity of traditional discrete filters in 5G MIMO RF front-ends. These two types of filters are characterized by small size and high integration, enabling multi-band signal filtering without increasing the area of ​​RF devices.

[0025] Furthermore, this application also proposes that a fifth filter among a plurality of filters is configured to process a third principal MIMO signal including the B41 band; a sixth filter is configured to process a fourth principal MIMO signal including the B7 band; and a seventh filter is configured to process a fourth principal MIMO signal including the B40 band.

[0026] Please refer to Figures 3-4 In one specific example, the fifth filter is a B41 RX filter, the sixth filter is a B7 RX filter, and the seventh filter is a B40 RX filter.

[0027] In another specific example, the fifth filter is a B41 RX filter, the sixth filter is a B7 RX filter, and the seventh filter is a B40 RX filter.

[0028] By adding dedicated filter configurations for the B41, B7, and B40 bands, the RF front-end circuitry can simultaneously support the processing of multiple master MIMO signals. Specifically, the addition of the B41 band filter solves the problem that traditional solutions cannot directly implement the M32+B32 carrier aggregation required by the European market; the configuration of the B7 and B40 band filters avoids the use of additional frequency dividers or triplers, reducing board space requirements. This solution, through optimized filter configuration, improves the support capability for multi-band MIMO signals while maintaining the integration of the RF front-end module 1.

[0029] Please refer to Figure 5 Furthermore, it also includes a second single-pole multi-throw switch S1 and a third single-pole multi-throw switch S2.

[0030] The input terminal of the second single-pole multi-throw switch S1 is connected to the output terminal of the second filter, and the output terminal of the second single-pole multi-throw switch S1 is connected to the input terminal of the signal processing module.

[0031] The input terminal of the third single-pole multi-throw switch S2 is connected to the output terminal of the third filter, and the output terminal of the third single-pole multi-throw switch S2 is connected to the input terminal of the signal processing module.

[0032] In a specific example, a single-pole multiple-throw (SPMD) switch can be implemented using semiconductor switches, microelectromechanical system (MEMS) switches, or relay switches, or it can be a GaAs FET switch with low insertion loss and high isolation. Furthermore, the switching speed of the SPMD switch needs to meet the requirements of radio frequency signal processing, typically less than 1 microsecond.

[0033] Specifically, this scheme achieves flexible routing control of MIMO signals in the B3 and B66 bands by adding two single-pole multi-throw (SPMD) switches. The second SPMD switch S1 handles the first primary MIMO signal in the B3 band, and the third SPMD switch S2 handles the second primary MIMO signal in the B66 band. This avoids mutual interference between multiple MIMO signals during transmission, improving signal transmission quality.

[0034] Furthermore, the signal processing module also includes a low-noise amplifier module 3 and an RF transceiver 2. The input terminal of the low-noise amplifier module 3 is connected to the output terminal of the filter, or to the second single-pole multi-throw switch S1 and the third single-pole multi-throw switch S2. The output terminal of the low-noise amplifier module 3 is connected to the input terminal of the RF transceiver 2.

[0035] The low-noise amplifier module 3 is used to amplify the received radio frequency signal with low noise. The low-noise amplifier module 3 may include multiple low-noise amplifier units, each of which processes signals in a specific frequency band. The radio frequency transceiver 2 is used to perform signal transmission and reception conversion and processing. The radio frequency transceiver 2 may be integrated into the baseband chip or exist as a standalone device.

[0036] Furthermore, in order to further improve the insertion loss of the circuit, this embodiment also provides a circuit debugging process, wherein the debugging objective is: on the current RF path, when the switch is in the single-on state, the frequency band S22 that needs to be double-on is matched to the open point through passive capacitors and inductors.

[0037] When the dual-band frequency is B32, the passive parameter S22 of B1+B3 needs to be adjusted to the corresponding open point when the B1+B3 switches are in the single-open state. The open position here refers to the position from the S22 port of the network analyzer to the first single-pole multi-throw switch 7, that is, the S22 position of the first single-pole multi-throw switch 7 in the OFF state.

[0038] The specific debugging steps are as follows: S1. First, a B75 RX SAW DIE (B75 surface acoustic wave receiver chip) is integrated on the internal substrate of the DIFEM. This DIE has excellent low in-band loss and high out-of-band rejection characteristics.

[0039] S2. Design a switching circuit that can simultaneously support the switching function of frequency bands B1+B3 and B32.

[0040] S3. When it is necessary to receive the B32 signal, set the B1+B3 switch to the single-on state and the B32 switch to the on state.

[0041] S4. In order to optimize the reception performance of B32 signal, when the B1+B3 switch is open, the S22 parameter of the B1+B3 frequency band at the B32 frequency point is adjusted to the open point through a precisely calculated capacitor and inductor matching network, thereby minimizing the interference to the B32 signal.

[0042] S5. Verify the S22 parameters using a network analyzer to ensure that the insertion loss in the B32 band is optimal.

[0043] In this embodiment, compared to traditional solutions, by integrating B75 (B32) support within the DIFEM, the cost of an external frequency divider combiner or Tri SAW can be eliminated, saving approximately 20-30 mm² of PCB area. 2This also reduces the number of connection points in the RF link, lowering the total insertion loss of the system by 0.3-0.5 dB and improving the system's receiving sensitivity. Furthermore, the internal dual-band debugging technology effectively solves the problem of inter-band interference, enabling the system to maintain good isolation when operating on multiple frequency bands simultaneously, meeting the stringent requirements of European operators for M+B32 CA / ENDC scenarios.

[0044] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A radio frequency front-end circuit, characterized in that, include: Filters, RF front-end modules, antenna modules, and signal processing modules; The radio frequency front-end module is equipped with multiple filters and a first single-pole multi-throw switch; Among the plurality of filters, a first filter is configured to process a first master signal including the B75 band; a second filter is configured to process a first master MIMO signal including the B3 band; and a third filter is configured to process a second master MIMO signal including the B66 band. The output terminal of the first single-pole multi-throw switch is connected to the input terminal of the filter; The output of the filter is connected to the input of the signal processing module; The input terminal of the first single-pole multi-throw switch is connected to the output terminal of the antenna module.

2. The radio frequency front-end circuit as described in claim 1, characterized in that, The filter is a surface acoustic wave filter or a bulk acoustic wave filter.

3. The radio frequency front-end circuit as described in claim 1, characterized in that, The fifth filter of the plurality of filters is configured to process a third master MIMO signal including the B41 band; the sixth filter is configured to process a fourth master MIMO signal including the B7 band; and the seventh filter is configured to process a fourth master MIMO signal including the B40 band.

4. The radio frequency front-end circuit as described in claim 1, characterized in that, It also includes a second single-pole multi-throw switch and a third single-pole multi-throw switch; The input terminal of the second single-pole multi-throw switch is connected to the output terminal of the second filter, and the output terminal of the second single-pole multi-throw switch is connected to the input terminal of the signal processing module. The input terminal of the third single-pole multi-throw switch is connected to the output terminal of the third filter, and the output terminal of the third single-pole multi-throw switch is connected to the input terminal of the signal processing module.

5. The radio frequency front-end circuit as described in claim 4, characterized in that, The signal processing module includes: a low-noise amplifier module and an RF transceiver; The input terminal of the low-noise amplifier module is connected to the output terminal of the filter, or to the second single-pole multi-throw switch and the third single-pole multi-throw switch; The output of the low-noise amplifier module is connected to the input of the radio frequency transceiver.

6. The radio frequency front-end circuit as described in claim 5, characterized in that, The second single-pole multi-throw switch and the third single-pole multi-throw switch are single-pole double-throw switches.

7. The radio frequency front-end circuit as described in claim 5, characterized in that, Also includes: RF coaxial connectors and RF antennas; The input terminal of the low-noise amplifier module is connected to the radio frequency antenna via the radio frequency coaxial connector.

8. The radio frequency front-end circuit as described in claim 1, characterized in that, The radio frequency front-end module includes a MIPI interface, which is connected to external control commands.

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