CN213846663U

CN213846663U - Radio frequency circuit and electronic equipment

Info

Publication number: CN213846663U
Application number: CN202022891889.0U
Authority: CN
Inventors: 易伟; 韦仁杰
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-07-30
Anticipated expiration: 2030-12-03

Abstract

The application discloses radio frequency circuit and electronic equipment belongs to the technical field of communication. The radio frequency circuit includes: the radio frequency transceiver, the first DPDT switch, the second DPDT switch, the SPDT switch, the first coupler and the second coupler; the radio frequency transceiver comprises a first receiving port, a second receiving port and a power detection port; the first receiving port is connected to the antenna through a first port of the first DPDT switch, and the second receiving port is connected to the antenna through a second port of the second DPDT switch; the radio frequency circuit is switched between a first working state and a second working state through the SPDT switch; under the condition that the radio frequency circuit is in a first working state, the power detection port is communicated with the first receiving port; and under the condition that the radio frequency circuit is in a second working state, the power detection port is conducted with the second receiving port. The radio frequency circuit is simplified and the system cost is reduced by multiplexing the double-pole double-throw switch in the existing radio frequency circuit.

Description

Radio frequency circuit and electronic equipment

Technical Field

The application belongs to the technical field of communication, and particularly relates to a radio frequency circuit and electronic equipment.

Background

In a mobile communication system, technologies for increasing Uplink rate include UL CA (Uplink Carrier aggregation) and UL SU-MIMO (Uplink Single User MIMO), and are mainly used for changing the problem of Uplink resource limitation and increasing Uplink throughput of a User. Since operators need to comprehensively consider terminal cost, implementation difficulty, and channel quality requirements, UL CA is considered more suitable for commercial deployment.

Currently, the problem of radio frequency power measurement is always a hot topic of concern in the industry. However, in the prior art, in the power detection in the uplink dual-transmission scenario such as UL CA, in order to meet the requirement of link budget on isolation, a plurality of switches need to be added, which often increases the system cost.

SUMMERY OF THE UTILITY MODEL

An object of the embodiments of the present application is to provide a radio frequency circuit and an electronic device, which can solve the problem of high cost of power detection of the radio frequency circuit in the prior art.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides a radio frequency circuit, including:

a radio frequency transceiver including a first receive port, a second receive port, a first transmit port, a second transmit port, and a power detection port;

a first DPDT switch, the first receive port connected to an antenna through a first port of the first DPDT switch, the first transmit port connected to an antenna through a second port of the first DPDT switch; a third port of the first DPDT switch is connected with a first antenna, and a fourth port is connected with a second antenna;

a second DPDT switch, wherein the second receiving port is connected to an antenna through a second port of the second DPDT switch, and the second transmitting port is connected to the antenna through a first port of the second DPDT switch; a third port of the second DPDT switch is connected with a third antenna, and a fourth port of the second DPDT switch is connected with a fourth antenna;

the SPDT switch comprises a movable end, a first immovable end and a second immovable end; the movable end is connected with the power detection port;

a first port of the first coupler is connected to the first stationary terminal, a second port of the first coupler is connected to the first receiving port, and a third port of the first coupler is connected to the first port of the first DPDT switch;

a first port of the second coupler is connected to the second stationary terminal, a second port of the second coupler is connected to the second receiving port, and a third port of the second coupler is connected to the second port of the second DPDT switch;

the radio frequency circuit is switched between a first working state and a second working state through the SPDT switch; wherein, under the condition that the radio frequency circuit is in the first working state, the power detection port is conducted with the first receiving port; and under the condition that the radio frequency circuit is in the second working state, the power detection port is conducted with the second receiving port.

In a second aspect, embodiments of the present application provide an electronic device including the radio frequency circuit as described above.

In the embodiment of the application, the existing radio frequency circuit is optimized, the coupler is placed on the radio frequency receiving link, and the double-pole double-throw switch in the existing radio frequency circuit is multiplexed, so that the isolation degree required in power detection is met, the loss of the coupler on the radio frequency transmitting link can be reduced, the radio frequency current is reduced under the same power scene, and the standby time length is further prolonged; the FBRX circuit is simplified, thereby reducing the cost of system implementation.

Drawings

Fig. 1 is a schematic diagram of a radio frequency circuit according to an embodiment of the present application.

Detailed Description

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, but not all, embodiments of the present 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.

The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

In the CE rule certification test, indicators such as EIRP (Effective Isotropic Radiated Power) or SAR (Specific Absorption Rate) are related to the Power level and the stability of Power, and indicators such as radio frequency Power consumption or OTA (Over the Air) are also strongly related to the Power level and the stability of Power. Therefore, in the radio frequency index parameters, the absolute value of the power and the stability of the power belong to very important index parameters, and the detection of the power is always a concern in the industry.

In the power detection of the rf circuit shown in fig. 1, in order to avoid inaccurate power detection in a dual TX (Transmit) state, the power of one rf transmission link (e.g., the second rf transmission link TX2) does not affect the calculation of the coupling power of the other rf transmission link (e.g., the first rf transmission link TX1), and the isolation needs to be over 40dB to meet the link budget requirement. Here, it should be noted that the isolation, i.e., the attenuation between the input end and the output end of the circuit, i.e., the ratio of the power of the local oscillator or the signal leaked to other ports to the original power, is expressed in dB.

It is understood that isolation is a measure of the effectiveness of the switch cutoff. The technology of the current radio frequency switch determines the index of the switch, and the isolation degree is reduced along with the increase of the radio frequency. Taking the RF1630 device from sony corporation as an example, the indices are shown in the following table:

as can be seen from the above table, a typical value for the switching isolation is 26dB for frequencies in the range of 3001MHz to 4500MHz and 22dB for frequencies in the range of 4501MHz to 6000 MHz. In practical project application, the minimum value of the isolation degree under a limit environment needs to be considered, so the value of the practical isolation degree can be lower than the typical value, and the minimum value of the isolation degree is only 15 dB.

In the prior art, in order to meet the requirement of a power test link on isolation in an uplink dual transmission scenario such as UL CA, that is, to ensure that the power of the second radio frequency transmission link TX2 does not affect the judgment of the coupling power of the first radio frequency transmission link TX1 and ensure that the power of the first radio frequency transmission link TX1 does not affect the judgment of the coupling power of the second radio frequency transmission link TX2, a plurality of switches need to be added in a radio frequency circuit to increase the isolation, thereby increasing the system cost.

In order to solve the above problems, the radio frequency circuit provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings through specific embodiments and application scenarios thereof.

It should be noted that, in an actual terminal design, a radio frequency architecture (i.e., a radio frequency circuit) of a multi-system, multi-band, multi-antenna is involved, and the structure is relatively complex. In order to reduce the complexity of the description of the Radio frequency circuit, in the embodiment of the present application, only a NR (New Radio, New air interface) n78 frequency Band of one standard and one frequency Band (Band) is taken as an example for description.

As shown in fig. 1, an embodiment of the present application provides a radio frequency circuit, including:

a radio frequency transceiver 1, the radio frequency transceiver 1 including a first receiving port 101, a second receiving port 102, a first transmitting port, a second transmitting port and a power detecting port 103;

a first double-pole double-throw (DPDT) switch 4, a first receiving port 101 is connected to the antenna through a first port of the first DPDT switch 4, and a first transmitting port is connected to the antenna through a second port of the first DPDT switch 4; the third port of the first DPDT switch 4 is connected to the first antenna ANT1, and the fourth port is connected to the second antenna ANT 2;

a second DPDT switch 5, wherein the second receiving port 102 is connected to the antenna through a second port of the second DPDT switch 5, and the second transmitting port is connected to the antenna through a first port of the second DPDT switch 5; the third port of the second DPDT switch 5 is connected to a third antenna ANT3, and the fourth port is connected to a fourth antenna ANT 4.

Here, the first DPDT switch 4 and the second DPDT switch 5 are double-pole double-throw four-port devices, and the inside thereof is designed to have a symmetrical structure. The first DPDT switch 4 and the second DPDT switch 5 can realize the connection switching between the antennas of the rf transmission link and the rf reception link.

Specifically, here, the DPDT switch is provided with four ports, which respectively connect the rf transmitting link and the rf receiving link of the rf transceiver 1 to different antennas. For example, in an embodiment of the present application, as shown in fig. 1, the first port and the third port of the first DPDT switch 4 connect the first rf receive link RX1 with the first antenna ANT 1; the second and fourth ports of the first DPDT switch 4 connect the first radio frequency transmit chain TX1 with the second antenna ANT2 or the third radio frequency receive chain RX3 with the second antenna ANT 2. It can be seen that the first DPDT switch 4 can function to switch the antenna.

The SPDT switch 201 comprises a movable end, a first fixed end and a second fixed end; the moving end is connected with the power detection port 103;

a first coupler 301, wherein a first port of the first coupler 301 is connected to a first stationary terminal, a second port is connected to the first receiving port 101, and a third port is connected to a first port of the first DPDT switch 4;

a second coupler 302, wherein a first port of the second coupler 302 is connected to the second stationary terminal, a second port is connected to the second receiving port 102, and a third port is connected to the second port of the second DPDT switch 5.

Here, it should be noted that the coupler is a radio frequency device that extracts a small portion of a signal from a main channel of a wireless signal. The loss of the coupler on the radio frequency transmitting link is reduced by placing the coupler on the radio frequency receiving link; the loss of a radio frequency transmission link is reduced to a certain extent, so that the radio frequency current is reduced under the same power scene, and the standby time is prolonged; under the condition of the same radio frequency current, the power of the system is improved, and the radio frequency emission performance under a weak field is improved.

The radio frequency circuit is switched between a first working state and a second working state through the SPDT switch 201; under the condition that the radio frequency circuit is in a first working state, the power detection port 103 is conducted with the first receiving port 101; under the condition that the radio frequency circuit is in the second working state, the power detection port 103 is conducted with the second receiving port 102.

Here, with the SPDT switch 201, switching of the radio frequency circuit between different operating states can be achieved. For example, when the SPDT switch 201 is in the state shown in fig. 1, the power detection port 103 may be conducted to the first receiving port 101 through the first coupler 301, so as to implement power detection of the first radio frequency transmission link TX 1.

It should be noted that early Power Detection is HDET (High Power Detection), and the dynamic range coverage is limited. In order to implement the power test of the uplink dual-transmission radio frequency circuit in the scenarios such as UL CA, the adopted power test is an FBRX (FeedBack Receiver) circuit, which has a demodulation function on a FeedBack link, thereby expanding the dynamic coverage of power test. For the power detection in the calibration state, the isolation of the DPDT switch is a fixed value, and the dynamic range of the FBRX circuit can also be covered, so that the calibration requirement can be met.

Optionally, the FBRX circuit comprises: a first FBRX circuit 2 and a second FBRX circuit 3. The first FBRX circuit 2 includes an SPDT switch 201, and the second FBRX circuit 3 includes a first coupler 301 and a second coupler 302. The first FBRX circuit 2 connects the power detection link with the power detection port 103 of the radio frequency transceiver, and is used for switching the detection link when performing power detection in a multi-channel UL CA and other scenarios under a dual TX condition. And the power detection of each path adopts a time division mode. The second FBRX circuit 3 comprises a power coupler for each rf transmit chain for sampling and monitoring the signals of the rf transceiver 1.

In the embodiment of the present application, the SPDT switch 201 in the first FBRX circuit 2 switches between different operating states of the radio frequency circuit, so that the power detection port 103 is conducted with the first receiving port 101 or the second receiving port 102, thereby implementing a power test of the radio frequency circuit. When the radio frequency circuit is used for power test, the second FBRX circuit 3 is connected into a radio frequency receiving link, and the requirement of the radio frequency power measuring link on the isolation is met by utilizing the isolation of the first DPDT switch 4 and the second DPDT switch 5, so that the system implementation cost is reduced.

Optionally, the method further comprises:

the power amplifier comprises a first power amplifier, a first filter, a second power amplifier and a second filter;

a first port of the first power amplifier is connected to the first receiving port 101, a second port of the first power amplifier is connected to a first port of the first filter, and a second port of the first filter is connected to a second port of the first coupler 301;

the first port of the second power amplifier is connected to the second receiving port 102, the second port is connected to the first port of the second filter, and the second port of the second filter is connected to the second port of the second coupler 302.

Here, the first power amplifier and the second power amplifier may amplify the power of the radio frequency signal, and a specific type thereof may be selected according to an actual application, such as a linear power amplifier, a switching power amplifier, and the like, which is not limited herein.

The first filter and the second filter are used for filtering the radio frequency signal, such as suppressing unwanted noise in the radio frequency signal. The filter can be selected according to actual conditions, and the embodiment of the application is not limited.

In this embodiment, the isolation of the FBRX circuit is improved by multiplexing the ASDiv (Antenna switch switching) rf switches, i.e., the first DPDT switch 4 and the second DPDT switch 5 shown in fig. 1, so as to reduce the number of switches in the rf circuit in the prior art and save the system implementation cost.

For example, when performing power detection on the first rf transmit link TX1, it is only necessary to connect the SPDT switch 201 of the first FBRX circuit 2 to the first coupler 301. At this time, the isolation is the sum of the isolation of the SPDT switch 201 and the isolation of the first DPDT switch 4, and the requirement of the power detection link on the isolation can be met.

In addition, the embodiments and the drawings of the present application are described based on the scenario of uplink 2TX in the n78 frequency band, but it should be understood that the present application is not limited to the n78 frequency band, and may also be applied to other frequency bands and scenarios such as WiFi (bluetooth) or BT (bluetooth).

In summary, the radio frequency circuit of the present application is mainly optimized for the FBRX circuit in the UL CA scenario, and on the premise of ensuring that the requirement of system isolation is met, the number of switches of the FBRX circuit is reduced, and the FBRX circuit is simplified, thereby reducing the cost of system implementation; by placing the coupler on the receive chain, the loss of the coupler on the radio frequency transmit chain is reduced.

An embodiment of the present application further provides an electronic device, which is characterized by including the radio frequency circuit described above.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A radio frequency circuit, comprising:

a radio frequency transceiver (1), the radio frequency transceiver (1) comprising a first receiving port (101), a second receiving port (102), a first transmitting port, a second transmitting port and a power detecting port (103);

a first DPDT switch (4), the first receive port (101) being connected to an antenna through a first port of the first DPDT switch (4), the first transmit port being connected to an antenna through a second port of the first DPDT switch (4); a third port of the first DPDT switch (4) is connected with a first antenna, and a fourth port is connected with a second antenna;

a second DPDT switch (5), the second receive port (102) being connected to the antenna through a second port of the second DPDT switch (5), the second transmit port being connected to the antenna through a first port of the second DPDT switch (5); a third port of the second DPDT switch (5) is connected with a third antenna, and a fourth port is connected with a fourth antenna;

a Single Pole Double Throw (SPDT) switch (201), the SPDT switch (201) including a moving end, a first stationary end and a second stationary end; the movable end is connected with the power detection port (103);

a first coupler (301), wherein a first port of the first coupler (301) is connected to the first stationary terminal, a second port is connected to the first receiving port (101), and a third port is connected to a first port of the first DPDT switch (4);

a second coupler (302), wherein a first port of the second coupler (302) is connected to the second stationary terminal, a second port is connected to the second receiving port (102), and a third port is connected to a second port of the second DPDT switch (5);

wherein the radio frequency circuit is switched between a first operating state and a second operating state by the SPDT switch (201); wherein, when the radio frequency circuit is in the first working state, the power detection port (103) is conducted with the first receiving port (101); under the condition that the radio frequency circuit is in the second working state, the power detection port (103) is conducted with the second receiving port (102).

2. The radio frequency circuit of claim 1, further comprising:

wherein a first port of the first power amplifier is connected with the first receiving port (101), a second port is connected with a first port of the first filter, and a second port of the first filter is connected with a second port of the first coupler (301);

the first port of the second power amplifier is connected to the second receive port (102), the second port is connected to the first port of the second filter, and the second port of the second filter is connected to the second port of the second coupler (302).

3. An electronic device comprising a radio frequency circuit as claimed in any one of claims 1 to 2.