CN115001524A

CN115001524A - WIFI radio frequency system based on LC discrete component

Info

Publication number: CN115001524A
Application number: CN202210918219.4A
Authority: CN
Inventors: 陈飞; 陈政; 王周锋
Original assignee: Shenzhen Comnect Technology Co ltd
Current assignee: Shenzhen Comnect Technology Co ltd
Priority date: 2022-08-01
Filing date: 2022-08-01
Publication date: 2022-09-02

Abstract

A WIFI radio frequency system based on LC discrete components relates to the technical field of communication and comprises an amplifying circuit connecting end unit, a merging unit and a WIFI chip connecting end unit; the merging unit comprises a first merging module and a second merging module, the first merging module comprises a first capacitor and a first inductor, and the second merging module comprises a second capacitor and a second inductor; the first path of merging module is used for transmitting a first path of signals of the differential signals, the second path of merging module is used for simultaneously transmitting a second path of signals of the differential signals, when the amplifying circuit outputs the single-ended signals to the WIFI chip, the merging unit enables the single-ended signals to be decomposed into the differential signals, and when the WIFI chip outputs the differential signals to the amplifying circuit, the merging unit enables the differential signals to be merged into the single-ended signals. The LC separating device not only reduces the cost of components, but also reduces the use space of the circuit board, has good immunity to external EMI and crosstalk of nearby signals, and can obtain higher signal amplitude.

Description

WIFI radio frequency system based on LC discrete component

Technical Field

The application relates to the technical field of communication, in particular to a WIFI radio frequency system based on LC discrete components.

Background

The signal transmitted by the WIFI chip is a differential signal, and the differential signal is processed by an amplifying circuit of power and then transmitted to an antenna terminal. In this process, the signals processed by the power amplifier circuit are single-ended signals, so that the differential signals with a phase difference of 180 degrees need to be combined into single-ended signals with the same phase before being input into the power amplifier circuit.

In the prior art, a balun is mainly used for merging differential signals, but the balun occupies more circuit board positions in the application process, the cost of the balun is high, and the amplitude loss of signals is large.

Disclosure of Invention

Object of the application

In view of this, an object of the present application is to provide a WIFI radio frequency system based on an LC discrete component, which is used to solve the technical problems in the prior art that a balun occupies a large number of circuit board positions in an application process, the balun is high in cost, and amplitude loss of a signal is large.

(II) technical scheme

The application discloses a WIFI radio frequency system based on LC discrete components, which comprises an amplifying circuit connecting end unit, a merging unit and a WIFI chip connecting end unit, wherein the amplifying circuit connecting end unit is used for connecting an amplifying circuit and the merging unit, and the WIFI chip connecting end unit is used for connecting the merging unit and a WIFI chip; the merging unit comprises a first merging module and a second merging module, the first merging module comprises a first capacitor and a first inductor, and the second merging module comprises a second capacitor and a second inductor; the first path merging module is used for transmitting a first path of signals of differential signals, the second path merging module is used for simultaneously transmitting a second path of signals of the differential signals, when the amplifying circuit outputs a single-ended signal to the WIFI chip, the merging unit enables the single-ended signal to be decomposed into differential signals, and when the WIFI chip outputs the differential signals to the amplifying circuit, the merging unit enables the differential signals to be merged into the single-ended signal.

In a possible implementation mode, the first capacitor is connected in series with a first inductor, and one end of the first inductor is grounded; the second capacitor is connected in series with the second inductor, one end of the second capacitor is grounded, a first node is arranged between the first capacitor and the first inductor and used for transmitting a first path of signals, a second node is arranged between the second capacitor and the second inductor and used for transmitting a second path of signals.

In a possible implementation manner, the WIFI chip connection end unit includes a third capacitor, and two ends of the third capacitor are respectively connected to a circuit in the WIFI chip connection end unit, where the circuit transmits the first path of signal and the second path of signal, so as to form a loop ground wire.

In a possible implementation manner, the WIFI chip connection terminal unit further includes a first band-pass filtering module and a second band-pass filtering module, where the first band-pass filtering module transmits the first path of signal, and the second band-pass filtering module is configured to transmit the second path of signal.

In a possible implementation, the first band-pass filtering module includes a first band-pass capacitor and a first band-pass inductor; the second band-pass filtering module comprises a second band-pass capacitor and a second band-pass inductor.

In one possible embodiment, the amplifying circuit connection terminal unit comprises a filter module.

In one possible implementation, the filtering module includes a pi-type LC filter circuit and a first-order LC filter circuit.

In one possible implementation, the first-order LC filter circuit includes a first LC filter inductor and a first LC filter capacitor, wherein one end of the first LC filter capacitor is grounded.

In one possible implementation, the pi-type LC filter circuit includes a first filter capacitor, a first filter inductor, and a second filter capacitor, and the first filter capacitor and the second filter capacitor are grounded.

In one possible embodiment, the amplifying circuit connection terminal unit further includes a dc blocking capacitor.

(III) advantageous effects

The phases of two paths of signals of the differential signals are changed through the inductors and the capacitors on the two circuits of the merging unit, when the differential signals are converted into single-ended signals, the two paths of signals of the differential signals processed by the inductors and the capacitors on the two circuits of the merging unit are changed into the same phase from the original phase difference of 180 degrees, and therefore the differential signals are merged to obtain the single-ended signals; on the contrary, when the single-ended signal is converted into the differential signal, the single-ended signal processed by the inductors and the capacitors on the two circuits of the merging unit is decomposed into two signals, and the two signals are 180 degrees in phase, so that the differential signal is obtained by decomposing the single-ended signal. The LC separating device is used for merging the differential signals and acquiring the differential signals, so that the cost of components is reduced, the product has price competitive advantage, the use space of a circuit board is reduced, good immunity to external EMI and crosstalk of nearby signals is achieved, and the signal amplitude is higher than that obtained by using a balun balancer.

Additional advantages, objects, and features of the application will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the application. The objectives and other advantages of the present application may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining and illustrating the present application and should not be construed as limiting the scope of the present application.

FIG. 1 is a block diagram of the system of the present application;

FIG. 2 is a diagram of a connection terminal unit of the amplifying circuit of the present application;

FIG. 3 is a block diagram of a merging unit according to the present application;

fig. 4 is a structural diagram of a connection end unit of the WIFI chip of the present application;

wherein: 1. an amplifying circuit connection terminal unit; 2. a merging unit; 3. a WIFI chip connection end unit; 11. a first-order LC filter circuit; 12. a pi-type LC filter circuit; 13. a blocking capacitor; 111. a first LC filter capacitor; 112. a first LC filter inductor; 121. a first filter capacitor; 122. a second filter capacitor; 123. a first filter inductor; 21. a first capacitor; 22. a first inductor; 23. a second capacitor; 24. a second inductor; 25. a first node; 26. a second node; 31. a first band pass filtering module; 32. a second band-pass filtering module; 33. a third capacitor; 34. a first decoupling capacitor; 35. a second decoupling capacitor; 311. a first band-pass capacitor; 312. a first band pass inductor; 321. a second band-pass inductor; 322. a second bandpass capacitor.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the above description of the present application, it should be noted that the terms "one side", "the other side" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which the product of the application is usually placed in when used, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

As shown in fig. 1 to 4, this embodiment provides a WIFI radio frequency system based on LC discrete components, which includes an amplifying circuit connection end unit 1, a combining unit 2, and a WIFI chip connection end unit 3, where the amplifying circuit connection end unit 1 is used to connect an amplifying circuit and the combining unit 2, and the WIFI chip connection end unit 3 is used to connect the combining unit 2 and a WIFI chip; the merging unit 2 includes a first merging module and a second merging module, the first merging module includes a first capacitor 21 and a first inductor 22, and the second merging module includes a second capacitor 23 and a second inductor 24; the first path of combining module is used for transmitting a first path of signal of the differential signal, and the second path of combining module is used for simultaneously transmitting a second path of signal of the differential signal, wherein the first path of signal and the second path of signal form the differential signal, and the phase difference between the first path of signal and the second path of signal is 180 degrees. When the amplifying circuit outputs a single-ended signal to the WIFI chip, the merging unit decomposes the single-ended signal into differential signals, and when the WIFI chip outputs differential signals to the amplifying circuit, the merging unit merges the differential signals into the single-ended signal, namely the merging unit merges the first path of signal and the second path of signal of the differential signals into the single-ended signal in the same phase.

Compared with the prior art, the first capacitor 21 and the first inductor 22 form one path of the merging unit LC discrete differential circuit, and the second capacitor 23 and the second inductor 24 form the other path of the merging unit LC discrete differential circuit; when the differential signals are changed into single-ended signals, the phases of the signals are changed through inductors and capacitors on two paths of a merging unit, wherein the first capacitor 21 and the first inductor 22 form one path of a merging unit LC discrete differential circuit to lead the phase of the signals on the path to lag 90 degrees, and the second capacitor 23 and the second inductor 24 form the other path of the merging unit LC discrete differential circuit to lead the phase of the signals on the path to lead 90 degrees, so that the phases of the first path of signals and the second path of signals are changed into the same phase from 180 degrees, and the single-ended signals are obtained; on the contrary, when the single-ended signal is changed into the differential signal, the phases of the signals are also changed through two paths of the merging unit, so that the single-ended signal is changed into the differential signal with the phase difference of 180 degrees. The LC separating device is used for combining the differential signals and acquiring the differential signals, so that the cost of components is reduced, the product has price competitive advantage, the use space of a circuit board is reduced, good immunity to external EMI and crosstalk of nearby signals is achieved, and the signal amplitude is higher than that obtained by using a balun balancer.

In this embodiment, the first capacitor 21 is connected in series with the first inductor 22, and one end of the first inductor 22 is grounded; the second capacitor 23 and the second inductor 24 are connected in series, one end of the second capacitor 23 is grounded, a first node 25 is arranged between the first capacitor 21 and the first inductor 22, the first node 25 is used for transmitting a first path of signal, a second node 26 is arranged between the second capacitor 23 and the second inductor 24, and the second node 26 is used for transmitting a second path of signal. In this embodiment, the first capacitor 21 has a value of 1.2pF/0201, the first inductor 22 has a value of 2.7nH/0201, the second capacitor 23 has a value of 1.2pF/0201, and the second inductor 24 has a value of 2.7 nH/0201.

In this embodiment, the WIFI chip connection end unit 3 includes a third capacitor 33, two ends of the third capacitor 33 are respectively connected to the circuits for transmitting the first path of signal and the second path of signal in the WIFI chip connection end unit, and the circuits are grounded to form a loop ground wire, so that a circulation loop of the signals is reduced, and differential mode interference between differential signals is removed. In this embodiment, the value of the third capacitor 33 is 1.5F/0201. The WIFI chip connection end unit 3 further includes a first band-pass filtering module 31 and a second band-pass filtering module 32, where the first band-pass filtering module 31 transmits a first path of signal, and the second band-pass filtering module 32 is configured to transmit a second path of signal; the first band-pass filtering module 31 comprises a first band-pass capacitor 311 and a first band-pass inductor 312; the second band-pass filtering module 32 includes a second band-pass capacitor 322 and a second band-pass inductor 321. The WIFI chip connection terminal unit 3 further includes a first decoupling capacitor 34 and a second decoupling capacitor 35, where the first decoupling capacitor 34 and the second decoupling capacitor 35 remove noise signals in a first path of signals and a second path of signals in differential signals of the WIFI chip, respectively, and match impedances in the first path of signals and the second path of signals in the differential signals of the WIFI chip. In this embodiment, the value of the first band-pass capacitor 311 is 0.1uF/6.3V/0201, and the value of the first band-pass inductor 312 is 10 nH/0201; the value of the second band-pass capacitor 322 is 0.1uF/6.3V/0201 and the value of the second band-pass inductor 321 is 10 nH/0201; the first decoupling capacitor 34 has a value of 1.2pF/0201 and the second decoupling capacitor 35 has a value of 1.2 pF/0201.

In this embodiment, the amplifying circuit connection end unit 1 includes a filtering module, which is used for 50 ohm impedance matching and filtering ripple noise on the RF link; the filtering module comprises a pi-type LC filtering circuit 12 and a first-order LC filtering circuit 11; the first-order LC filter circuit 11 comprises a first LC filter inductor 112 and a first LC filter capacitor 111, wherein one end of the first LC filter capacitor 112 is grounded; the pi-type LC filter circuit 12 includes a first filter capacitor 121, a first filter inductor 123, and a second filter capacitor 122, where the first filter capacitor 121 and the second filter capacitor 122 are grounded. In this embodiment, the value of the first LC filter inductor 112 is 2.4nH/0201, and the value of the first LC filter capacitor 111 is 0.3 pF/0201; the first filter capacitor 121 has a value of 0.3pF/0201, the first filter inductor 123 has a value of 2.4nH/0201, and the second filter capacitor 122 has a value of 0.3 pF/0201.

In this embodiment, the connection end unit 1 of the amplifying circuit further includes a dc blocking capacitor 13 for isolating a dc current, and a value of the dc blocking capacitor 13 is 22 pF/0201.

Finally, the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting, although the present application is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application, and all the technical solutions of the present application should be covered by the claims of the present application.

Claims

1. A WIFI radio frequency system based on LC discrete components is characterized by comprising an amplifying circuit connecting end unit, a merging unit and a WIFI chip connecting end unit, wherein the amplifying circuit connecting end unit is used for connecting an amplifying circuit and the merging unit, and the WIFI chip connecting end unit is used for connecting the merging unit and a WIFI chip; the merging unit comprises a first merging module and a second merging module, the first merging module comprises a first capacitor and a first inductor, and the second merging module comprises a second capacitor and a second inductor; the first path merging module is used for transmitting a first path of signals of differential signals, the second path merging module is used for simultaneously transmitting a second path of signals of the differential signals, when the amplifying circuit outputs a single-ended signal to the WIFI chip, the merging unit enables the single-ended signal to be decomposed into differential signals, and when the WIFI chip outputs the differential signals to the amplifying circuit, the merging unit enables the differential signals to be merged into the single-ended signal.

2. The WIFI radio frequency system based on the LC discrete components as claimed in claim 1, wherein the first capacitor is connected in series with a first inductor, and one end of the first inductor is grounded; the second capacitor is connected in series with the second inductor, one end of the second capacitor is grounded, a first node is arranged between the first capacitor and the first inductor and used for transmitting a first path of signals, and a second node is arranged between the second capacitor and the second inductor and used for transmitting a second path of signals.

3. The WIFI radio frequency system based on the LC discrete component of claim 1, wherein the WIFI chip connection end unit comprises a third capacitor, and two ends of the third capacitor are respectively connected with circuits for transmitting the first path of signal and the second path of signal in the WIFI chip connection end unit to form a loop ground wire.

4. The WIFI radio frequency system based on the LC discrete component according to claim 3, wherein the WIFI chip connection terminal unit further comprises a first band-pass filtering module and a second band-pass filtering module, the first band-pass filtering module is used for transmitting a first signal, and the second band-pass filtering module is used for transmitting a second signal.

5. The WIFI radio frequency system based on the LC discrete component of claim 4, wherein the first band-pass filtering module comprises a first band-pass capacitor and a first band-pass inductor; the second band-pass filtering module comprises a second band-pass capacitor and a second band-pass inductor.

6. The LC discrete component-based WIFI radio frequency system of claim 1, wherein the amplifying circuit connection terminal unit comprises a filtering module.

7. The WIFI radio frequency system based on the LC discrete components is characterized in that the filtering module comprises a pi-type LC filtering circuit and a first-order LC filtering circuit.

8. The WIFI radio frequency system based on the LC discrete components is characterized in that the first-order LC filter circuit comprises a first LC filter inductor and a first LC filter capacitor, wherein one end of the first LC filter capacitor is grounded.

9. The WIFI radio frequency system based on the LC discrete components as claimed in claim 8, wherein the pi-type LC filter circuit comprises a first filter capacitor, a first filter inductor and a second filter capacitor, and the first filter capacitor and the second filter capacitor are grounded.

10. The LC discrete component-based WIFI radio frequency system of claim 9, wherein the amplifying circuit connection end unit further comprises a dc blocking capacitor.