Improved matching circuit of receiving module

Abstract

The utility model discloses an improved matching circuit of a receiving module, and relates to the technical field of matching circuits of receiving modules. The antenna comprises a radio frequency switch with an antenna and a plurality of groups of matching branches connected with the radio frequency switch, wherein each matching branch comprises a matching network combination, a filter, a fourth matching network and a radio frequency low-noise amplifier which are connected in sequence; the matching network combination comprises a first matching network, a second matching network and a third matching network; a first radio frequency switch is arranged between the second matching network and the radio frequency switch; and two sides of the third matching network are respectively provided with a second radio frequency switch and a third radio frequency switch. According to the utility model, the area and the cost of the switch are saved, and a corresponding control logic part is also omitted; the performance of the single-carrier receiving module in the working mode can be optimal, and the impedance optimal matching in the CA working mode can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of receiving module matching circuits, and particularly relates to an improved matching circuit of a receiving module. Background Art

[0002] The RF front end of the communication system requires impedance matching to ensure effective reception and transmission of the system. In the wireless communication system of the Industrial Internet, the country has strict requirements on the transmission power, such as not exceeding +20dBm. If a good match cannot be achieved, it will affect the communication distance of the system.

[0003] like Figure 1 As shown, in the RF matching circuit, the traditional way is that each receiving module has a fixed matching structure, which needs to take into account the performance in the single carrier mode and the CA mode. The two working modes share a matching structure, which cannot achieve the optimal matching of performance. In order to solve the above problems, such as the adjustable matching circuit of a diversity RF front-end module disclosed by announcement number CN217216550U, it is described that the number of RF switches and matching circuits is the same, and each RF switch is connected to a matching circuit; but in fact, in this circuit, two switches are actually required to control both sides of a series capacitor, but in the remaining parallel circuit, one switch controls the matching of an inductor, and the area and cost corresponding to the switch are relatively high; another example is the adjustable matching circuit of a diversity RF front-end module disclosed by CN217216550U, the most complex matching structure that can be realized is parallel inductance + series capacitor + parallel inductance, and the structure is limited. In fact, it only uses the characteristics of the switch to match the form of permutation and combination of inductance and capacitance. Therefore, in response to the above problems, an improved matching circuit of a receiving module of the present technical solution is proposed. Utility Model Content

[0004] The utility model provides an improved matching circuit of a receiving module, which adds a radio frequency switch to the original matching circuit to adjust the matching value of the matching circuit, so as to improve the matching performance in the case of carrier aggregation CA; and the added matching switch is in a series form, a parallel form, or a series + parallel form; relative to the existing schemes in the background technology, the inductance matching in the present technical scheme only achieves two matching effects by the on and off states of an inductor, instead of the two switches in their patents, and the control switch part is always one less than theirs, saving the area and cost of the switch, and also saving the corresponding control logic part; and the matching structure of the present technical scheme is not limited to this circuit, and can be various forms such as parallel capacitors / inductors+series inductors+parallel capacitors / inductors, and the structure is not limited, which can meet the performance of the single-carrier receiving module in the working mode to achieve the best; after the additional introduction of the matching switch, on the basis of the single-carrier mode matching, by controlling the radio frequency path switch, the value or structure of the matching network can be changed to achieve the optimal impedance matching in the CA working mode; in summary, the problems in the background technology are solved.

[0005] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0006] The utility model discloses an improved matching circuit of a receiving module, comprising a radio frequency switch with an antenna, and a plurality of matching branches connected to the radio frequency switch, wherein the matching branches comprise a matching network combination, a filter, a fourth matching network, and a radio frequency low noise amplifier connected in sequence;

[0007] The matching network combination includes a first matching network connected between the filter and the radio frequency switch, a second matching network connected to the radio frequency switch and grounded, and a third matching network connected to both sides of the first matching network;

[0008] A first radio frequency switch is provided between the second matching network and the radio frequency switch; a second radio frequency switch and a third radio frequency switch are provided on both sides of the third matching network respectively;

[0009] The second matching network uses capacitors, and the first matching network and the third matching network use inductors; or the second matching network uses inductors, and the first matching network and the third matching network use capacitors.

[0010] Furthermore, a direct grounding line is provided between the radio frequency switch and the first matching network, and a fifth matching network is provided in between, and the fifth matching network is of the same type as the second matching network.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] (1) Based on the existing matching circuit, the utility model adds a radio frequency switch to adjust the matching value of the matching circuit to improve the matching performance in the case of carrier aggregation CA; the added matching switch can be in series, in parallel, or in a combination of series and parallel. Compared with the prior art, the inductor matching of this solution only achieves two matching effects by switching one inductor on and off, saving the area and cost of the switch and also eliminating the corresponding control logic part;

[0013] (2) Furthermore, the matching structure may be in various forms such as parallel capacitor / inductor+series inductor+parallel capacitor / inductor, and the structure is not limited, and can meet the requirements of achieving optimal performance in the working mode of the single carrier receiving module;

[0014] (3) After the additional matching switch is introduced, the optimal impedance matching in the CA working mode can be achieved by controlling the RF path switch and changing the value or structure of the matching network on the basis of single-carrier mode matching.

[0015] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 The circuit structure diagram of the existing traditional matching method;

[0018] Figure 2 This is a new 2CA matching method diagram based on two sets of matching network combinations in the utility model;

[0019] Figure 3 The utility model is a new 3CA and Multi-CA matching method based on three matching network combinations;

[0020] Figure 4 This is a diagram showing the control matching method using parallel capacitors and series inductors as an example;

[0021] Figure 5 This is a diagram of the control matching method using parallel inductance and series capacitance as an example. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In the description of the present invention, it should be understood that the terms "both sides", "middle", "connected in sequence", "grounded" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0024] like Figure 1 As shown, in the RF matching circuit, the traditional method is that each receiving module has a fixed matching structure, which needs to take into account the performance in the single carrier mode and the CA mode. The two working modes share a matching structure, which cannot achieve the optimal performance match. Based on this, an improved matching circuit of a receiving module of the present technical solution is proposed.

[0025] The specific solution is: FEM is a receiving circuit composed of multiple receiving modules, including switches, filters, LNA (LDiFEM) and their matching components, and optimizes the matching structure and matching values ​​to achieve the best performance in the working mode of the single-carrier receiving module. In the working mode of carrier aggregation technology (CA), due to the multiple switches being opened, another path is added, causing the performance of each path to deteriorate due to the change in impedance. The method of controlling the matching structure and matching values ​​by introducing RF path switches (not limited to series, parallel, etc.) can achieve the common optimal matching in the single-carrier mode and the CA mode.

[0026] See also Figure 2-3 As shown, an improved matching circuit of a receiving module of the utility model includes a radio frequency switch ANT_SW with an antenna ANT, and a plurality of matching branches connected to the radio frequency switch ANT_SW, wherein the matching branches include a matching network combination, a filter, a fourth matching network, and a radio frequency low noise amplifier connected in sequence;

[0027] The matching network combination includes a first matching network connected between the filter and the radio frequency switch ANT_SW, a second matching network connected to the radio frequency switch ANT_SW and grounded, and a third matching network connected to both sides of the first matching network;

[0028] A first radio frequency switch RF_SW1 is provided between the second matching network and the radio frequency switch ANT_SW; a second radio frequency switch RF_SW2 and a third radio frequency switch RF_SW3 are provided on both sides of the third matching network respectively;

[0029] in, Figure 2 The figure is a new 2CA matching method diagram; the matching branches in the figure are specifically two groups, which are output by RF1 and RF2 respectively; the first matching network in the corresponding two groups is specifically matching network 1 and matching network 5, the second matching network is specifically matching network 3 and matching network 7; the third matching network is specifically matching network 4 and matching network 8; the fourth matching network is matching network 2 and matching network 6 in the two groups;

[0030] in, Figure 3 The new 3CA and Multi+CA matching method diagram is proposed; relative to Figure 2 The difference is that there is an additional set of matching branches output by RF3;

[0031] Among them, the second matching network uses capacitors, and the first matching network and the third matching network use inductors; or the second matching network uses inductors, and the first matching network and the third matching network use capacitors; the application patent proposed in this technical solution is for inductors / capacitors and other components, without limitation; the aforementioned switch specifically uses a combination of multiple 1p1t or nPnT.

[0032] A direct grounding line is provided between the radio frequency switch ANT_SW and the first matching network, and a fifth matching network is provided in between. The fifth matching network is of the same type as the second matching network.

[0033] like Figure 4 In the example, if the parallel capacitance required in the single-carrier working mode is relatively small and the value is C1, while the parallel capacitance required in the CA mode is relatively large and the value is C1+C2, then the RF switch RF_SW1 is set to be disconnected in the single-carrier mode, at which time the capacitance of the parallel capacitance is C1, and in the CA working mode, RF_SW1 is turned on, at which time the capacitance of the parallel capacitance is C1+C2, so as to achieve the best match; conversely, if the parallel capacitance required in the single-carrier working mode is relatively large and the value is C1+C2, while the parallel capacitance required in the CA mode is relatively small and the value is C1, then RF_SW1 is set to be turned on in the single-carrier mode, at which time the capacitance of the parallel capacitance is C1+C2, and in the CA working mode, RF_SW1 is disconnected, at which time the capacitance of the parallel capacitance is C1, so as to achieve the best match;

[0034] If the series inductance required in the single-carrier working mode is relatively small and its value is (L1*L2) / (L1+L2), while the series inductance required in the CA mode is relatively large and its value is L1, then set RF_SW2 and RF_SW3 to be turned on in the single-carrier mode and disconnected in the CA mode to achieve the best match; if the series inductance required in the single-carrier working mode is relatively large and its value is L1, while the series inductance required in the CA mode is relatively small and its value is (L1*L2) / (L1+L2), then set RF_SW2 and RF_SW3 to be disconnected in the single-carrier mode and turned on in the CA mode to achieve the best match;

[0035] like Figure 5 As shown in the figure, if the parallel inductance required in the single-carrier working mode is relatively small and the value is (L1*L2) / (L1+L2), and the parallel inductance required in the CA mode is relatively large and the value is L1, then RF_SW1 is set to be turned on in the single-carrier mode. At this time, the capacitance of the parallel capacitor is (L1*L2) / (L1+L2). In the CA working mode, RF_SW1 is disconnected. At this time, the inductance value of the parallel inductance is L1, so as to achieve the optimal matching; conversely, if the parallel inductance required in the single-carrier working mode is relatively large and the value is L1, and the parallel inductance required in the CA mode is relatively small and the value is (L1*L2) / (L1+L2), then RF_SW1 is set to be disconnected in the single-carrier mode. At this time, the inductance value of the parallel inductance is L1. In CA working mode, RF_SW1 is turned on, and the inductance of the parallel inductor is (L1*L2) / (L1+L2) to achieve the best match; if the series capacitance required in single-carrier working mode is small and the value is C1, while the series capacitance required in CA mode is large and the value is C1+C2, then the RF switches RF_SW2 and RF_SW3 are set to be disconnected in single-carrier mode and turned on in CA mode to achieve the best match; if the series capacitance required in single-carrier working mode is large and the value is C1+C2, while the series capacitance required in CA mode is small and the value is C1, then RF_SW2 and RF_SW3 are set to be turned on in single-carrier mode and disconnected in CA mode to achieve the best match.

[0036] This patent includes but is not limited to Figure 4 , Figure 5 The L-type matching includes a single component + a single switch, and also includes the occasions where multiple L-type and π-type matching network structures are superimposed or used in combination. This patent includes DiFEM, LDiFEM, and other occasions where modules requiring single carrier mode and multi-carrier mode are required.

[0037] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. An improved matching circuit of a receiving module, comprising a radio frequency switch with an antenna, and a plurality of matching branches connected to the radio frequency switch, wherein the matching branches comprise a matching network combination, a filter, a fourth matching network, and a radio frequency low noise amplifier connected in sequence, characterized in that: The matching network combination includes a first matching network connected between the filter and the radio frequency switch, a second matching network connected to the radio frequency switch and grounded, and a third matching network connected to both sides of the first matching network; A first radio frequency switch is arranged between the second matching network and the radio frequency switch; a second radio frequency switch and a third radio frequency switch are arranged on both sides of the third matching network respectively.

2. The improved matching circuit of a receiving module according to claim 1, characterized in that: The second matching network uses capacitors, and the first matching network and the third matching network use inductors.

3. The improved matching circuit of a receiving module according to claim 1, characterized in that: The second matching network uses inductors, and the first matching network and the third matching network use capacitors.

4. The improved matching circuit of a receiving module according to claim 1, characterized in that: A direct grounding line is provided between the radio frequency switch and the first matching network, and a fifth matching network is provided in between. The fifth matching network is of the same type as the second matching network.

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