WO2022033392A1

WO2022033392A1 - Attenuator circuit and radio frequency front-end architecture

Info

Publication number: WO2022033392A1
Application number: PCT/CN2021/111067
Authority: WO
Inventors: 宋楠; 倪建兴; 胡自洁; 倪楠; 曹原; 奉靖皓
Original assignee: 锐石创芯（深圳）科技有限公司
Priority date: 2020-08-13
Filing date: 2021-08-06
Publication date: 2022-02-17
Also published as: CN111953311B; CN111953311A

Abstract

Provided is an attenuator circuit, comprising: an input node; an output node; a first common attenuation module (10), configured to attenuate a signal, a first end of the first common attenuation module (10) being connected to the input node or the output node, and a second end of the first common attenuation module (10) being connected to a gating attenuation module (20); and the gating attenuation module (20), comprising a selectable bypass branch and at least one attenuation branch, the gating attenuation module (20) being connected to the first common attenuation module (10) in series. The parasitic capacitance of the attenuator circuit is effectively reduced, and the problem of poor attenuation performance caused by overlarge parasitic capacitance is solved.

Description

An attenuator circuit and radio frequency front-end architecture

This application is based on the Chinese Invention Application No. 2020108129730 filed on August 13, 2020, entitled "An Attenuator Circuit and Radio Frequency Front-End Architecture", and claims its priority.

technical field

The present application relates to the field of radio frequency technology, and in particular, to an attenuator circuit and a radio frequency front-end architecture.

Background technique

In the electronic application of radio frequency (Radio Frequency, RF for short), radio frequency front-end technology is widely used in remote sensing equipment, wireless communication equipment, radar equipment, portable ultrasonic equipment and other equipment. Among them, an attenuator circuit is included in some radio frequency front-end architectures, and the attenuator circuit is used to attenuate the signal.

FIG. 1 shows an attenuator circuit applied in a radio frequency front-end architecture in the prior art, and the attenuator circuit includes a bypass path and an attenuation path. The branch paths that do not pass through the attenuator, such as path 1 in Figure 1, are bypass paths; the branch paths that need to pass through the attenuator, such as paths 2, 3, and 4 in Figure 1, are attenuation paths.

However, in the process of attenuating the signal in the existing attenuator circuit, when the input signal passes through any one path, excessive parasitic capacitance will be generated on other paths, which will lead to the attenuation of the attenuator circuit due to the excessive parasitic capacitance. Performance is not ideal.

Application content

The present application provides an attenuator circuit and a radio frequency front-end structure to solve the problem of poor attenuation performance caused by excessive parasitic capacitance in the prior art.

The present application is implemented in this way, an attenuator circuit, comprising:

input node;

output node;

a first common attenuation module, the first common attenuation module is configured to attenuate signals, the first end of the first common attenuation module is connected to the input node or the output node, the first common attenuation module The second end of is connected with the gate attenuation module;

The gated attenuation module includes an optional bypass branch and at least one attenuation branch, and the gated attenuation module is connected in series with the first common attenuation module.

Optionally, the first common attenuation module includes a first common switch and a first common attenuator connected in series, a first end of the first common switch is connected to the input node or the output node, and the first common switch is connected to the input node or the output node. The second end of a common switch is connected to the first common attenuator.

Optionally, it also includes a second common attenuation module, the second common attenuation module includes a second common switch and a second common attenuator connected in series, and the first end of the second common switch is connected to the output node or the input node, the second end of the second common switch is connected to the second common attenuator;

The gated attenuation module is connected in series with the second common attenuation module.

Optionally, a bypass switch is further included, a first end of the bypass switch is connected to the input node, and a second end of the bypass switch is connected to the output node.

Optionally, the bypass branch in the gated attenuation module includes a bypass unit;

Each of the attenuation branches includes an attenuation unit and a bypass unit, and the second end of the attenuation unit is connected to the first end of the bypass unit;

When the gated attenuation module includes an attenuation branch, the common contact between the first end of the attenuation unit in the attenuation branch and the first end of the bypass unit in the bypass branch is used as the The first end of the gated attenuation module, the common contact between the second end of the bypass unit in the attenuation branch and the second end of the bypass unit in the bypass branch is used as the gate the second end of the attenuation module;

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2, and the first end of the attenuation unit in the first attenuation branch is connected to the bypass unit in the bypass branch. The common junction between the first ends is used as the first end of the gated attenuation module, starting from the second attenuation branch, the first end of the attenuation unit in each attenuation branch is connected to the previous attenuation branch. the connection point between the attenuation unit and the bypass unit; the common junction between the second ends of the bypass units of the N attenuation branches and the second ends of the bypass units in the bypass branch is used as the selection pass through the second end of the attenuation module.

Optionally, both the bypass unit of the bypass branch and the bypass unit of the attenuation branch include a switch.

Optionally, the attenuation unit of each attenuation branch includes a branch switch and a branch attenuator connected in series;

The first end of the branch switch serves as the first end of the attenuation unit, the second end of the branch switch is connected to the first end of the branch attenuator, and the second end of the branch attenuator is connected to the first end of the branch attenuator. The terminal is used as the second terminal of the attenuation unit.

Each of the attenuation branches includes an attenuation unit and a bypass unit, wherein the second end of the attenuation unit is connected to the first end of the bypass unit of the attenuation branch;

The common junction between the first end of the attenuation unit of the attenuation branch and the first end of the bypass unit of the bypass branch is used as the first end of the gated attenuation module. The common junction between the second end of the bypass unit and the second end of the bypass unit of the bypass branch is used as the second end of the gating attenuation module.

Optionally, both the bypass unit of the bypass branch and the attenuation unit of the attenuation branch include a switch.

Optionally, the attenuation unit includes a branch switch and a branch attenuator connected in series;

When the gated attenuation module includes an attenuation branch, the attenuation branch includes a first attenuation unit and a bypass unit, and the second end of the first attenuation unit is connected to the first end of the bypass unit ; the common junction between the first end of the first attenuation unit and the first end of the bypass unit in the bypass branch is used as the first end of the gated attenuation module, and the attenuation branch in the The common junction between the second end of the bypass unit and the second end of the bypass unit in the bypass branch is used as the second end of the gated attenuation module;

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2, and the nth attenuation branch includes a first attenuation unit, a bypass unit, and a second attenuation unit, where n= 1, 2, 3..., N-1, the second end of the first attenuation unit is connected to the first end of the bypass unit, and the second end of the bypass unit is connected to the second attenuation unit The first end of the first attenuation branch is connected; the common joint between the first end of the first attenuation unit in the first attenuation branch and the first end of the bypass unit in the bypass branch is used as the gated attenuation module The first end of the first attenuation branch, the common joint between the second end of the second attenuation unit in the first attenuation branch and the second end of the bypass unit in the bypass branch is used as the gate of the gated attenuation module. The second end; starting from the second attenuation branch, the first end of the first attenuation unit in each attenuation branch is connected to the connection point of the first attenuation unit and the bypass unit of the previous attenuation branch, each the second end of the second attenuation unit in the attenuation branch is connected to the connection point of the bypass unit of the previous attenuation branch and the second attenuation unit;

The Nth attenuation branch includes a first attenuation unit and a bypass unit, the second end of the first attenuation unit is connected to the first end of the bypass unit; the first attenuation of the Nth attenuation branch The first end of the unit is connected to the connection point of the first attenuation unit of the previous attenuation branch and the bypass unit, and the second end of the bypass unit of the Nth attenuation branch is connected to the bypass unit of the previous attenuation branch. The connection point between the channel unit and the second attenuation unit.

Optionally, the first attenuation unit includes a first branch switch and a first branch attenuator connected in series, wherein the first end of the first branch switch serves as the first end of the first attenuation unit , the second end of the first branch switch is connected to the first end of the first branch attenuator, and the second end of the first branch attenuator serves as the second end of the first attenuation unit ;

The second attenuation unit includes a second branch attenuator and a second branch switch connected in series, wherein the first end of the second branch attenuator serves as the first end of the second attenuation unit, the The second end of the second branch attenuator is connected to the first end of the second branch switch, and the second end of the second branch switch serves as the second end of the second attenuation unit.

A radio frequency front-end architecture includes a low noise amplifier and the above attenuator circuit, wherein the attenuator circuit is connected in series before the low noise amplifier and/or after the amplification stage.

The attenuator circuit provided by the present application includes an input node; an output node; a first common attenuation module, the first common attenuation module is configured to attenuate signals, and a first end of the first common attenuation The input node or the output node, the second end of the first common attenuation module is connected to the gated attenuation module; the gated attenuation module includes an optional bypass branch and at least one attenuation branch. The pass attenuation module is connected in series with the first common attenuation module. By connecting a common attenuation module in series, the connection relationship between the original attenuation branches is changed, thereby effectively reducing the parasitic capacitance generated on other paths when the input signal passes through any path, thereby reducing the generation of the attenuator circuit. The parasitic capacitance is beneficial to optimize the attenuation performance of the attenuator circuit.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present application. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic diagram of an existing attenuator circuit;

2 is a schematic diagram of an attenuator circuit provided by an embodiment of the present application;

3 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application;

4 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application;

5 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application;

6 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application;

7 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application;

FIG. 8 is a schematic diagram of an attenuator circuit provided by another embodiment of the present application

9 is a schematic diagram of a T-type attenuator provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a π-type attenuator provided by an embodiment of the present application.

detailed description

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further 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 application, but not to limit the present application.

The present application provides an attenuator circuit, comprising an input node; an output node; a first common attenuation module and a gated attenuation module connected in series with each other, wherein a first end of the first common attenuation module is connected to the input node or all The output node, the first common attenuation module is configured to attenuate the signal, and the gated attenuation module includes an optional bypass branch and at least one attenuation branch. By connecting a common attenuation module in series, the connection relationship between the original attenuation branches is changed, thereby effectively reducing the parasitic capacitance generated on other paths when the input signal passes through any path, thereby reducing the generation of the attenuator circuit. The parasitic capacitance is beneficial to optimize the attenuation performance of the attenuator circuit. Optionally, a first common attenuator is included in the first common attenuator, the first end of the first common attenuator is connected to the input node or the output node, and the second end of the first common attenuator is connected to the selector. connected through the attenuation module.

FIG. 2 is a schematic diagram of an attenuator circuit according to an embodiment of the present application. The attenuator circuit can be applied in RF front-end circuits, such as variable gain amplifiers, low noise amplifiers and power amplifiers, etc., connected in series before the amplifiers (variable gain amplifiers, low noise amplifiers or power amplifiers) and/or amplifiers Later. As shown in Figure 2, the attenuator circuit includes an input node and an output node;

A first common attenuation module 10, the first common attenuation module 10 is configured to attenuate signals, a first end of the first common attenuation module 10 is connected to the input node or the output node, the first The second end of the common attenuation module 10 is connected to the gated attenuation module 20;

The gated attenuation module 20 includes an optional bypass branch and at least one attenuation branch, and the gated attenuation module 20 is connected in series with the first common attenuation module 10 .

In this embodiment, the first common attenuation module 10 and the gated attenuation module 20 are connected in series between the input node and the output node of the attenuator circuit. Wherein, when the parasitic capacitance needs to be improved at the input node, the first end of the first common switch 11 is connected to the input node. The first common attenuation module 10 is used to attenuate the input signal once. The gated attenuation module 20 includes a user-selectable bypass branch and at least one attenuation branch. Each attenuation branch corresponds to an attenuation value, which is used to perform secondary attenuation on the output signal of the first common attenuation module 10 according to the corresponding attenuation value, thereby extending various attenuation degrees of the input signal.

As another preferred example of the present application, when the parasitic capacitance needs to be improved at the output node, the first end of the first common switch 11 is connected to the output node. The gated attenuation module 20 includes a user-selectable bypass branch and at least one attenuation branch. Each of the attenuation branches corresponds to an attenuation value, which is used to attenuate the input signal once according to the corresponding attenuation value; the first common attenuation module 10 is used to perform secondary attenuation on the output signal of the gated attenuation module 20 Attenuation, thereby extending various degrees of attenuation to the input signal.

Further, as shown in FIG. 3 , the first common attenuation module 10 includes a first common switch 11 and a first common attenuator 12 connected in series, and a first end of the first common switch 11 is connected to the input node Or at the output node, the second end of the first common switch 11 is connected to the first common attenuator 12 .

When the parasitic capacitance needs to be improved at the input node, the first end of the first common switch 11 is connected to the input node, and the second end of the first common switch 11 is connected to the first end of the first common attenuator 12 The second end of the first common attenuator 12 is connected to the first end of the gated attenuation module 20, and the second end of the gated attenuation module 20 is connected to the output node. The first common attenuation module 10 is used to attenuate the input signal once, and the attenuation degree of the signal is performed according to the attenuation value set in the first common attenuator 12 . The gated attenuation module 20 includes a user-selectable bypass branch and at least one attenuation branch. Each attenuation branch corresponds to an attenuation value, which is used to perform secondary attenuation on the output signal of the first common attenuation module 10 according to the corresponding attenuation value, thereby extending various attenuation degrees of the input signal.

As another preferred example of the present application, when the parasitic capacitance needs to be improved at the output node, the first end of the first common switch 11 is connected to the output node, and the second end of the first common switch 11 is connected to the output node. The first end of the first common attenuator 12 is connected, the second end of the first common attenuator 12 is connected to the first end of the gated attenuation module 20 , and the second end of the gated attenuation module 20 is connected the input node. The gated attenuation module 20 includes a user-selectable bypass branch and at least one attenuation branch. Each of the attenuation branches corresponds to an attenuation value, which is used to attenuate the input signal once according to the corresponding attenuation value; the first common attenuation module 10 is used to perform secondary attenuation on the output signal of the gated attenuation module 20 Attenuation, the attenuation degree of the signal is performed according to the attenuation value set in the first common attenuator 12, thereby extending various different attenuation degrees to the input signal.

In this embodiment, since the attenuation path between the first common attenuation module 10 and the gated attenuation module 20 is in a series relationship, when the first common attenuation module 10 is gated with any branch in the gated attenuation module 20, When it is used to attenuate the input signal, based on the calculation method of the series-parallel connection of capacitors, the parasitic capacitances generated on other paths in the attenuator circuit will be smaller than that of the prior art by directly connecting the parasitic capacitances on each of the other paths in parallel. The obtained value can effectively reduce the parasitic capacitance generated in the process of attenuating the input signal, thereby reducing the parasitic capacitance generated by the attenuator circuit, which is conducive to optimizing the attenuation performance of the attenuator circuit.

As another preferred example of the present application, as shown in FIG. 4 , on the basis of the embodiment in FIG. 3 , the attenuator circuit further includes a second common attenuation module 30 , and the second common attenuation module The second common switch 31 and the second common attenuator 32, the first end of the second common switch 31 is connected to the output node or the input node, and the second end of the second common switch 31 is connected to the first end of the second common switch 31. Two common attenuators 32 are connected; the gate attenuator module 20 is connected in series with the second common attenuator module 30 .

Here, when the parasitic capacitance needs to be improved at the input node and at the output node at the same time, a second common attenuation module 30 can be added on the basis of the embodiment in FIG. 3 . The second common attenuation module 30 corresponds to the first common attenuation module 10, and when the first common attenuation module 10 is used to connect an input node, the second common attenuation module 30 is used to connect an output node. That is, the first end of the first common switch 11 is connected to the input node, and the first end of the second common switch 31 is connected to the output node. The first common attenuation module 10 is used to attenuate the input signal once, and the attenuation degree of the signal is performed according to the attenuation value set in the first common attenuator 12 . The gated attenuation module 20 is configured to perform secondary attenuation on the output signal of the first common attenuation module 10 according to the attenuation value corresponding to the branch selected by the user. The second common attenuation module 30 is used to attenuate the output signal of the gated attenuation module 20 three times.

When the first common attenuation module 10 is used to connect an output node, the second common attenuation module 30 is used to connect an input node. That is, the first end of the first common switch 11 is connected to the output node, and the first end of the second common switch 31 is connected to the input node. The second common attenuation module 30 is used to attenuate the input signal once, and the attenuation degree of the signal is performed according to the attenuation value set in the second common attenuator 32 . The gate attenuation module 20 is configured to perform secondary attenuation on the output signal of the second common attenuation module 30 according to the attenuation value corresponding to the branch selected by the user. The first common attenuation module 10 is used to attenuate the output signal of the gated attenuation module 20 three times.

In this embodiment, since the attenuation path between the first common attenuation module 10 and the gated attenuation module 20 is in a series relationship, when a branch of the first common attenuation module 10 and the gated attenuation module 20 is used for input When the signal is attenuated, from the perspective of the input node, the parasitic capacitance generated on other attenuation paths in the attenuator circuit will be smaller than the value obtained by directly connecting the parasitic capacitance on each other path in parallel in the prior art; , since the attenuation path between the second common attenuation module 30 and the gated attenuation module 20 is in a series relationship, when a branch in the second common attenuation module 30 and the gated attenuation module 20 is used to attenuate the input signal, From the output node, the parasitic capacitances generated on other attenuation paths in the attenuator circuit at this time will be smaller than the value obtained by directly connecting the parasitic capacitances on each of the other paths in parallel in the prior art. The attenuator circuit provided by the embodiment of the present application effectively reduces the parasitic capacitance generated in the process of attenuating the input signal, thereby reducing the parasitic capacitance generated by the attenuator circuit, which is conducive to optimizing the attenuation of the attenuator circuit performance.

Optionally, as a preferred example of the present application, the attenuator circuit may further include a bypass path, and the bypass path includes a bypass switch 40 . The first end of the bypass switch 40 is connected to the input node, and the second end is connected to the output node, as shown in FIG. 5 . Here, the bypass switch 40 acts as a selection switch of the bypass path. If the input signal does not need to be attenuated, by closing the bypass switch 40 on the bypass path, the input signal directly passes through the bypass path and is output.

It should be understood that, FIG. 5 is provided on the basis of the example of FIG. 3 , and in other embodiments, the bypass switch 40 may also be applied to the example of FIG. 4 , which is not limited here.

Specifically, a preferred example of the present application is proposed on the basis of the embodiments of FIG. 2 to FIG. 5 , the bypass branch in the gated attenuation module includes a bypass unit;

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2; the first end of the attenuation unit in the first attenuation branch and the bypass unit in the bypass branch The common junction between the first ends is used as the first end of the gated attenuation module, starting from the second attenuation branch, the first end of the attenuation unit in each attenuation branch is connected to the previous attenuation branch. the connection point between the attenuation unit and the bypass unit; the common junction between the second ends of the bypass units of the N attenuation branches and the second ends of the bypass units in the bypass branch is used as the selection pass through the second end of the attenuation module.

Optionally, the bypass unit of the bypass branch includes a switch for gating the bypass branch. The bypass unit of the attenuation branch includes a switch for gating the attenuation branch.

The attenuation unit of each attenuation branch includes a branch switch and a branch attenuator connected in series; wherein the first end of the branch switch serves as the first end of the attenuation unit, and the first end of the branch switch is used as the first end of the attenuation unit. The two ends are connected to the first end of the branch attenuator, and the second end of the branch attenuator serves as the second end of the attenuation unit.

For ease of understanding, the following description is given by taking the gated attenuation module including one bypass branch and two attenuation branches as an example, and the two attenuation branches are respectively denoted as the first attenuation branch and the second attenuation branch . As shown in FIG. 6 , the gate attenuation module 20 includes a first switch 21, a second switch 22, a first branch attenuator 23, a third switch 24, a fourth switch 25, a second branch attenuator 26, the fifth switch 27;

The common contact between the first end of the first switch 21 and the first end of the second switch 22 is used as the first end of the gate attenuation module 20;

The second end of the second switch 22 is connected to the first end of the first branch attenuator 23;

The common contact between the second end of the first branch attenuator 23 and the first end of the third switch 24 is connected to the first end of the fourth switch 25;

The second end of the fourth switch 25 is connected to the first end of the second branch attenuator 26;

The second end of the second branch attenuator 26 is connected to the first end of the fifth switch 27;

The common contact between the second end of the first switch 21 , the second end of the third switch 24 , and the second end of the fifth switch 27 is used as the output end of the gate attenuation module 20 .

In this embodiment, the signal attenuation values of the first branch attenuator 23 and the second branch attenuator 26 may be the same or different, which are not limited here. The first switch 21 serves as a bypass unit of the bypass branch, and forms a first attenuation path with the first common attenuation module 10 and/or the second common attenuation module 30 . The second switch 22 and the first branch attenuator 23 serve as the attenuation unit of the first attenuation branch, the third switch 24 serves as the bypass unit of the first attenuation branch, and the first common attenuation module 10 and/or Or the second common attenuation module 30 constitutes a second attenuation path. The fourth switch 25 and the second branch attenuator 26 are used as the attenuation unit of the second attenuation branch, and the fifth switch 27 is used as the bypass unit of the second attenuation branch, combined with the attenuation unit of the first attenuation branch , forming a third attenuation path with the first common attenuation module 10 and/or the second common attenuation module 30 . Therefore, the corresponding attenuation path can be selected by closing the corresponding switch according to the attenuation degree of the signal.

Exemplarily, taking FIG. 6 as an example, it is assumed that the attenuator circuit includes a first common attenuator module 10 and a gated attenuator module 20, the attenuation value corresponding to the first common attenuator 12 is 2dB, the first branch attenuator The attenuation value corresponding to 23 is 3dB, and the attenuation value corresponding to the second branch attenuator 26 is 4dB. If the input signal needs to be attenuated by 2dB, the first common switch 11 and the first switch 21 on the bypass branch are closed, and the other switches are opened, and the input signal will pass through the first common attenuator 12 for 2dB attenuation. At this time, the parasitic capacitance generated by the attenuator circuit is: the parasitic capacitance corresponding to the fifth switch 27 is connected in series with the parasitic capacitance corresponding to the fourth switch 25, and then connected in parallel with the parasitic capacitance corresponding to the third switch 24, and then The value obtained by connecting the parasitic capacitance corresponding to the second switch 22 in series; it can be seen that the parasitic capacitance is smaller than the value obtained by directly connecting the parasitic capacitance on each other attenuation path in parallel in the prior art.

If the input signal needs to be attenuated by 5dB, the first common switch 11 , the second switch 22 , and the third switch 24 are closed, and the other switches are opened. The input signal will pass through the first common attenuator 12 for 2dB signal attenuation, and then pass through the first branch attenuator 23 for 3dB signal attenuation; at this time, the parasitic capacitance generated by the attenuator circuit includes two parts: one is the bypass branch. The parasitic capacitance corresponding to the first switch 31 on the road, and the second is the value obtained by connecting the parasitic capacitance corresponding to the fourth switch 25 on the third attenuation branch and the parasitic capacitance corresponding to the fifth switch 27 in series; it can be seen that the two Part of the parasitic capacitance is smaller than the value obtained by directly connecting the parasitic capacitances on each of the other attenuation paths in parallel in the prior art.

If the input signal needs to be attenuated by 9dB, the first common switch 11, the second switch 22, the fourth switch 25, and the fifth switch 27 are closed, and the other switches are opened, and the input signal will pass through the first The common attenuator 12 performs 2dB signal attenuation, then passes through the first branch attenuator 23 for 3dB signal attenuation, and finally passes through the second attenuator 26 for 4dB signal attenuation; at this time, the parasitic capacitance generated by the attenuator circuit includes two Parts: one is the parasitic capacitance corresponding to the first switch 21 on the bypass branch, and the other is the parasitic capacitance corresponding to the third switch 24 on the first attenuation branch; it can be seen that the parasitic capacitance of the two parts is smaller than the prior art. The value of the parasitic capacitance on each other attenuation path is directly connected in parallel.

It should be understood that, in this embodiment of the present application, a sixth switch may be further connected between the second branch attenuator 26 and the fifth switch 27 to construct the next attenuation branch. The number of specific branches is set according to actual needs, and there is no limit here.

It should be understood that the foregoing FIG. 6 is a schematic structural diagram of the gating attenuation module proposed on the basis of the example of FIG. 3 , and is not used to limit the embodiments of the present application. In some other embodiments, the above-mentioned gate attenuation module is also applicable to the example in FIG. 4 or FIG. 5 , which is not limited here.

Specifically, another preferred example of the present application is proposed on the basis of any of the embodiments in FIGS. 2 to 5 , wherein the bypass branch in the gated attenuation module includes a bypass unit;

Wherein, the first end of the branch switch in the attenuation unit is used as the first end of the attenuation unit, and the second end of the branch switch is connected to the first end of the branch attenuator, so The second end of the branch attenuator serves as the second end of the attenuation unit.

For ease of understanding, the following description is given by taking the gated attenuation module including one bypass branch and two attenuation branches as an example, and the two attenuation branches are respectively denoted as the first attenuation branch and the second attenuation branch . As shown in FIG. 7 , the gate attenuation module 20 includes a first switch 21, a second switch 22, a first branch attenuator 23, a third switch 24, a fourth switch 25, a second branch attenuator 26, Fifth switch 27 .

The common contact between the first end of the first switch 21 , the first end of the second switch 22 , and the first end of the fourth switch 25 is used as the first end of the gate attenuation module 20 ;

the second end of the first branch attenuator 23 is connected to the first end of the third switch 24;

Here, the attenuation values of the first branch attenuator 22 and the second branch attenuator 26 may be the same or different, which are not limited here. The first switch 21 serves as a bypass unit of the bypass branch, and forms a first attenuation path with the first common attenuation module 10 and/or the second common attenuation module 30 . The second switch 22 and the first branch attenuator 23 serve as the attenuation unit of the first attenuation branch, the third switch 24 serves as the bypass unit of the first attenuation branch, and the first common attenuation module 10 and/or Or the second common attenuation module 30 constitutes a second attenuation path. The fifth switch 25 and the second branch attenuator 26 serve as the attenuation unit of the second attenuation branch, the fifth switch 27 serves as the bypass unit of the second attenuation branch, and the first common attenuation module 10 and/or Or the second common attenuation module 30 constitutes a third attenuation path. The user can select the corresponding attenuation path by closing the switch according to the attenuation degree of the signal.

Exemplarily, taking FIG. 7 as an example, it is assumed that the attenuator circuit includes a first common attenuation module 10 and a gated attenuation module 20, and it is assumed that the attenuation value corresponding to the first common attenuator 12 is 3dB, and the first branch attenuation The attenuation value corresponding to the attenuator 23 is 6dB, and the attenuation value corresponding to the second branch attenuator 26 is 12dB. If the input signal needs to be attenuated by 3dB, the first common switch 11 and the first switch 21 are closed, and the other switches are opened, and the input signal will be attenuated by 3dB through the first common attenuator 12; this The parasitic capacitance generated by the attenuator circuit is: the parasitic capacitance corresponding to the fourth switch 25 is connected in series with the parasitic capacitance corresponding to the fifth switch 27, the parasitic capacitance of the second switch 22 is connected in series with the parasitic capacitance of the third switch 24, and then The value obtained by connecting the two parts in series with the parasitic capacitance corresponding to the first switch 21 on the bypass branch in parallel; it can be seen that the parasitic capacitance will be smaller than that obtained by directly paralleling the parasitic capacitance on each of the other attenuation paths in the prior art value of .

If the input signal needs to be attenuated by 9dB, then the first common switch 11 , the second switch 22 , and the third switch 24 are closed, and the other switches are open, and the input signal will pass through the first common attenuator 12 for 3dB attenuation. The signal attenuated by the second branch circuit is attenuated by 6dB, and then the signal attenuated by the second branch attenuator 13; at this time, the parasitic capacitance generated by the attenuator circuit includes two parts: one is the parasitic capacitance corresponding to the first switch 21 of the bypass branch. , and the second is the value obtained by connecting the parasitic capacitance corresponding to the fourth switch 25 on the second attenuation branch with the parasitic capacitance corresponding to the fifth switch 27 in series; it can be seen that the parasitic capacitances of the two parts are smaller than those of the other components in the prior art. The value obtained by directly paralleling the parasitic capacitance on an attenuation path.

If the input signal needs to be attenuated by 15dB, the first common switch 12 , the fourth switch 25 and the fifth switch 27 are closed, and the other switches are opened, and the input signal will pass through the first common attenuator 22 for 3dB attenuation. The signal is attenuated and then attenuated by 12dB through the second branch attenuator 26; at this time, the parasitic capacitance generated by the attenuator circuit is: the parasitic capacitance corresponding to the second switch 22 and the third switch 24 on the first attenuation branch The value obtained by connecting the capacitor in series, and then connecting it in parallel with the first switch 21 on the bypass branch; it can be seen that the parasitic capacitance is smaller than that obtained by directly connecting the parasitic capacitance on each other attenuation path in parallel in the prior art value of .

It should be understood that the foregoing FIG. 7 is a schematic structural diagram of the gating attenuation module proposed on the basis of the example of FIG. 3 , and is not used to limit the embodiments of the present application. In some other embodiments, the above-mentioned gate attenuation module is also applicable to the example in FIG. 4 or FIG. 5 , which is not limited here.

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2; the nth (n=1, 2, 3..., N-1) attenuation branch includes the first attenuation unit, a bypass unit, and a second attenuation unit, the second end of the first attenuation unit is connected to the first end of the bypass unit, and the second end of the bypass unit is connected to the second attenuation unit The first end is connected; the common point between the first end of the first attenuation unit in the first attenuation branch and the first end of the bypass unit in the bypass branch is used as the gate of the gated attenuation module. The first end, the common joint between the second end of the second attenuation unit in the first attenuation branch and the second end of the bypass unit in the bypass branch is used as the first terminal of the gated attenuation module. Two ends; starting from the second attenuation branch, the first end of the first attenuation unit in each attenuation branch is connected to the connection point of the first attenuation unit and the bypass unit of the previous attenuation branch, and each attenuation the second end of the second attenuation unit in the branch is connected to the connection point of the bypass unit of the previous attenuation branch and the second attenuation unit;

The second attenuation unit includes a second branch attenuator and a second branch switch connected in series, wherein the first end of the second attenuator serves as the first end of the second branch attenuation unit, the The second end of the second branch attenuator is connected to the first end of the second branch switch, and the second end of the second branch switch serves as the second end of the second attenuation unit.

For ease of understanding, the following description is given by taking an example that the gated attenuation module includes one bypass branch and two attenuation branches, and the attenuation branches are respectively denoted as a first attenuation branch and a second attenuation branch. As shown in FIG. 8 , the gate attenuation module 20 includes a first switch 21, a second switch 22, a first branch attenuator 23, a third switch 24, a second branch attenuator 25, a fourth switch 26, the fifth switch 27, the third branch attenuator 28, the sixth switch 29;

The common contact between the second end of the first branch attenuator 23 and the first end of the third switch 24 is connected to the fifth switch 27;

The second end of the fifth switch 27 is connected to the first end of the third branch attenuator 28;

the second end of the third branch attenuator 28 is connected to the first end of the sixth switch 29;

The common contact between the second end of the sixth switch 29 and the second end of the third switch 24 is connected to the first end of the second branch attenuator 25;

the second end of the second branch attenuator 25 is connected to the first end of the fourth switch 26;

The common contact between the second end of the fourth switch 26 and the second end of the first switch 21 serves as the second end of the gate attenuation module 20 .

In this embodiment, the attenuation values of the first branch attenuator 23 , the second branch attenuator 25 , and the third branch attenuator 28 may be the same or different, which are not limited here. The first switch 21 serves as a bypass unit of the bypass branch, and forms a first attenuation path with the first common attenuation module 10 and/or the second common attenuation module 30 . The second switch 22 and the first branch attenuator 23 serve as the first attenuation unit of the first attenuation branch, the third switch 24 serves as the bypass unit of the first attenuation branch, and the second branch attenuates The switch 25 and the fourth switch 26 serve as the second attenuation unit of the first attenuation branch, and form a second attenuation path with the first common attenuation module 10 and/or the second common attenuation module 30 . The fifth switch 27 and the third branch attenuator 28 are used as the first attenuation unit of the second attenuation branch, and the sixth switch 29 is used as the bypass unit of the second attenuation branch, combined with the first attenuation branch The first attenuation unit and the second attenuation unit of the circuit and the first common attenuation module 10 and/or the second common attenuation module 30 form a third attenuation path. The user can select the corresponding attenuation path by closing the switch according to the attenuation degree of the signal.

It should be understood that the foregoing FIG. 8 is a schematic structural diagram of the gating attenuation module proposed on the basis of the example of FIG. 3 , and is not used to limit the embodiments of the present application. In some other embodiments, the above-mentioned gate attenuation module is also applicable to the example in FIG. 4 or FIG. 5 , which is not limited here.

Optionally, both the common attenuator and the branch attenuator are two-port networks composed of resistive elements, the impedance and the attenuation are constants independent of frequency, and the phase shift is equal to zero. Optionally, the common attenuators and branch attenuators include but are not limited to T-type attenuators or π-type attenuators.

Optionally, as shown in FIG. 9 , a schematic structural diagram of the T-type attenuator provided in this embodiment. In FIG. 7, the T-type attenuator includes a first resistor R11, a second resistor R12, and a third resistor R13, wherein one end of the first resistor R11, the second resistor R12, and the third resistor R13 are connected in common, so The other end of the first resistor R11 is used as an input end, and the other end of the third resistor R13 is used as an output end.

Optionally, as shown in FIG. 10 , a schematic structural diagram of the π-type attenuator provided in this embodiment. In FIG. 8 , the π-type attenuator includes a first resistor R21, a second resistor R22, and a third resistor R23, wherein the common junction of the first resistor R21 and the second resistor R22 is used as an input terminal, and the first resistor R21 and the second resistor R22 The common junction of the resistor R21 and the third resistor R23 is used as the output terminal.

To sum up, the attenuator circuit provided by the embodiment of the present application can effectively reduce the parasitic capacitance generated during the process of attenuating the input signal, thereby reducing the parasitic capacitance generated by the attenuator circuit, which is beneficial to optimizing the radio frequency The attenuation performance of the front-end architecture.

Embodiments of the present application further provide a radio frequency front-end architecture, where the radio frequency front-end architecture includes a low-noise amplifier and the above-mentioned attenuator circuit, where the attenuator circuit is connected in series before the low-noise amplifier and/or an amplifier stage Later. Since the parasitic capacitance of the attenuator circuit is small, the attenuation performance is improved compared to the prior art, so that the attenuation performance of the radio frequency front-end architecture is greatly optimized.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that: it is still possible to implement the above-mentioned implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the application, and should be included in the within the scope of protection of this application.

Claims

An attenuator circuit comprising:

input node;

output node;

a first common attenuation module, the first common attenuation module is configured to attenuate signals, the first end of the first common attenuation module is connected to the input node or the output node, the first common attenuation module The second end of is connected with the gate attenuation module;

The gated attenuation module includes an optional bypass branch and at least one attenuation branch, and the gated attenuation module is connected in series with the first common attenuation module.
The attenuator circuit of claim 1, wherein the first common attenuation module comprises a first common switch and a first common attenuator connected in series, and a first end of the first common switch is connected to the input node Or in the output node, the second end of the first common switch is connected to the first common attenuator.
The attenuator circuit of claim 2, further comprising a second common attenuation module, the second common attenuation module comprising a second common switch and a second common attenuator connected in series, the second common switch being The first end is connected to the output node or the input node, and the second end of the second common switch is connected to the second common attenuator;

The gated attenuation module is connected in series with the second common attenuation module.
The attenuator circuit of claim 2 or 3, further comprising a bypass switch, a first end of the bypass switch is connected to the input node, and a second end of the bypass switch is connected to the output node.
The attenuator circuit according to any one of claims 1-3, wherein the bypass branch in the gated attenuation module comprises a bypass unit;

Each of the attenuation branches includes an attenuation unit and a bypass unit, and the second end of the attenuation unit is connected to the first end of the bypass unit;

When the gated attenuation module includes an attenuation branch, the common contact between the first end of the attenuation unit in the attenuation branch and the first end of the bypass unit in the bypass branch is used as the The first end of the gated attenuation module, the common contact between the second end of the bypass unit in the attenuation branch and the second end of the bypass unit in the bypass branch is used as the gate the second end of the attenuation module;

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2, and the first end of the attenuation unit in the first attenuation branch is connected to the bypass unit in the bypass branch. The common junction between the first ends is used as the first end of the gated attenuation module, starting from the second attenuation branch, the first end of the attenuation unit in each attenuation branch is connected to the previous attenuation branch. the connection point between the attenuation unit and the bypass unit; the common junction between the second ends of the bypass units of the N attenuation branches and the second ends of the bypass units in the bypass branch is used as the selection pass through the second end of the attenuation module.
6. The attenuator circuit of claim 5, wherein the bypass unit of the bypass branch and the bypass unit of the attenuation branch each include a switch.
The attenuator circuit of claim 5, wherein the attenuation unit of each attenuation branch comprises a branch switch and a branch attenuator connected in series;

The first end of the branch switch serves as the first end of the attenuation unit, the second end of the branch switch is connected to the first end of the branch attenuator, and the second end of the branch attenuator is connected to the first end of the branch attenuator. The terminal is used as the second terminal of the attenuation unit.
The attenuator circuit according to any one of claims 1-3, wherein the bypass branch in the gated attenuation module comprises a bypass unit;

Each of the attenuation branches includes an attenuation unit and a bypass unit, wherein the second end of the attenuation unit is connected to the first end of the bypass unit of the attenuation branch;

The common junction between the first end of the attenuation unit of the attenuation branch and the first end of the bypass unit of the bypass branch is used as the first end of the gated attenuation module. The common junction between the second end of the bypass unit and the second end of the bypass unit of the bypass branch is used as the second end of the gating attenuation module.
9. The attenuator circuit of claim 8, wherein the bypass unit of the bypass branch and the attenuation unit of the attenuator branch each include a switch.
The attenuator circuit of claim 8, wherein the attenuating unit comprises a branch switch and a branch attenuator connected in series;

The first end of the branch switch serves as the first end of the attenuation unit, the second end of the branch switch is connected to the first end of the branch attenuator, and the second end of the branch attenuator is connected to the first end of the branch attenuator. The terminal is used as the second terminal of the attenuation unit.
The attenuator circuit according to any one of claims 1-3, wherein the bypass branch in the gated attenuation module comprises a bypass unit;

When the gated attenuation module includes an attenuation branch, the attenuation branch includes a first attenuation unit and a bypass unit, and the second end of the first attenuation unit is connected to the first end of the bypass unit ; the common junction between the first end of the first attenuation unit and the first end of the bypass unit in the bypass branch is used as the first end of the gated attenuation module, and the attenuation branch in the The common junction between the second end of the bypass unit and the second end of the bypass unit in the bypass branch is used as the second end of the gated attenuation module;

When the gated attenuation module includes N attenuation branches, N is a positive integer greater than or equal to 2, and the nth attenuation branch includes a first attenuation unit, a bypass unit, and a second attenuation unit, where n= 1, 2, 3..., N-1), the second end of the first attenuation unit is connected to the first end of the bypass unit, and the second end of the bypass unit is connected to the second attenuation unit The first end of the unit is connected; the common contact between the first end of the first attenuation unit in the first attenuation branch and the first end of the bypass unit in the bypass branch is used as the gate attenuation The first end of the module, the common contact between the second end of the second attenuation unit in the first attenuation branch and the second end of the bypass unit in the bypass branch is used as the gated attenuation module From the second attenuation branch, the first end of the first attenuation unit in each attenuation branch is connected to the connection point of the first attenuation unit and the bypass unit of the previous attenuation branch, and each attenuation The second end of the second attenuation unit in one attenuation branch is connected to the connection point of the bypass unit of the previous attenuation branch and the second attenuation unit;

The Nth attenuation branch includes a first attenuation unit and a bypass unit, the second end of the first attenuation unit is connected to the first end of the bypass unit; the first attenuation of the Nth attenuation branch The first end of the unit is connected to the connection point of the first attenuation unit of the previous attenuation branch and the bypass unit, and the second end of the bypass unit of the Nth attenuation branch is connected to the bypass unit of the previous attenuation branch. The connection point between the channel unit and the second attenuation unit.
12. The attenuator circuit of claim 11, wherein the bypass unit of the bypass branch and the bypass unit of the attenuation branch each include a switch.
The attenuator circuit of claim 11, wherein the first attenuating unit comprises a first branch switch and a first branch attenuator connected in series, wherein the first end of the first branch switch serves as the The first end of the first attenuation unit, the second end of the first branch switch is connected to the first end of the first branch attenuator, and the second end of the first branch attenuator is used as the the second end of the first attenuation unit;

The second attenuation unit includes a second branch attenuator and a second branch switch connected in series, wherein the first end of the second branch attenuator serves as the first end of the second attenuation unit, the The second end of the second branch attenuator is connected to the first end of the second branch switch, and the second end of the second branch switch serves as the second end of the second attenuation unit.
A radio frequency front-end architecture, comprising a low noise amplifier and an attenuator circuit according to any one of claims 1 to 13, wherein the attenuator circuit is connected in series before the low noise amplifier and/or after the amplification stage.