CN220139556U - Radio frequency receiving and transmitting circuit and radio frequency front-end circuit - Google Patents

Abstract

The utility model provides a radio frequency receiving and transmitting circuit and a radio frequency front-end circuit, which relate to the technical field of radio frequency communication, wherein the radio frequency receiving and transmitting circuit comprises an impedance matching unit and a radio frequency receiving and transmitting switch unit, a first end of the impedance matching unit is connected with a radio frequency transmitting port, a second end of the impedance matching unit is connected with an antenna, the radio frequency receiving and transmitting switch unit is arranged between a grounding element in the impedance matching unit and the ground, and the radio frequency receiving switch unit is also connected with a radio frequency receiving port; the radio frequency receiving and transmitting switch unit comprises a first switch module, wherein a first end of the first switch module is connected with the grounding element, and a second end of the first switch module is grounded. The utility model can reduce the number of the switching tubes, reduce the chip area, save the cost, obviously reduce the loss of the transmitting branch, improve the output power and the efficiency of the amplifier, and on the basis, improve the isolation of the transmitting state, and reduce the dependency of the switching tubes, thereby reducing the risk of the switching tubes.

Description

Radio frequency receiving and transmitting circuit and radio frequency front-end circuit

Technical Field

The utility model relates to the technical field of radio frequency communication, in particular to a radio frequency transceiver circuit and a radio frequency front-end circuit.

Background

At present, a traditional single-pole double-throw switch or a scheme for carrying out TR switching by a circulator is generally adopted by a TR circuit, and in the application process, the single-pole double-throw switch has the problems of switch compression, guan Naiya current resistance, large insertion loss and the like for a power amplifier, so that the power output capacity and the working efficiency of the power amplifier are affected, and a large chip size may be required.

The circulator is small in insertion loss, high in price, incapable of being integrated, large in occupied position in the assembly and difficult to meet the technical requirement of miniaturization of the assembly.

In the prior art, the efficiency of the TR architecture circuit in the transmitting circuit is generally low, the risk of the reliability of a switching tube exists, and the size of a chip or a component is large, so that the integration is difficult.

Therefore, a TR architecture circuit is lacking, which can reduce the size area of a chip and improve the output power and efficiency on the basis of considering the receiving and transmitting performances.

Disclosure of Invention

The utility model aims to provide a radio frequency receiving and transmitting circuit and a radio frequency front-end circuit, which construct an adaptive transmitting output matching framework by reducing the number of switching tubes, so that the reliability of the switching tubes can be reduced, the size area of a chip can be reduced, the loss on a transmitting branch can be reduced, and the isolation on a receiving and transmitting link can be optimized on the basis of considering the receiving and transmitting performances.

In a first aspect, a radio frequency transceiver circuit includes an impedance matching unit and a radio frequency transceiver switch unit, where a first end of the impedance matching unit is connected to a radio frequency transmitting port, a second end of the impedance matching unit is connected to an antenna, the radio frequency transceiver switch unit is disposed between a grounding element in the impedance matching unit and ground, and the radio frequency transceiver switch unit is further connected to a radio frequency receiving port;

the radio frequency receiving and transmitting switch unit comprises a first switch module, wherein a first end of the first switch module is connected with the grounding element, and a second end of the first switch module is grounded;

when the radio frequency transceiver circuit is in a transmitting state, the first switch module is conducted;

when the radio frequency receiving and transmitting circuit is in a receiving state, the first switch module is turned off.

Preferably, the ground element is the ground element nearest to the second end of the impedance matching unit.

Preferably, the first switch module includes: a first switching tube, a second inductive element;

wherein the first end of the first switch tube is connected with the grounding element; the second inductive element is connected with the first switching tube in parallel through the first end and the second end of the first switching tube, and the parallel resonance frequency of the parasitic capacitance between the first switching tube and the second inductive element is the center frequency of the received signal.

Preferably, the first switch module further includes a first capacitor, the second end of the first switch tube is connected in series with the first capacitor and grounded, wherein a series resonance frequency of the microstrip effect between the first capacitor and the first switch tube is a center frequency of a transmission signal.

Preferably, the first end of the first switch tube is grounded through an inductor or a microstrip line.

Preferably, the radio frequency transceiver switch unit further comprises a second switch module, wherein a first end of the second switch module is connected with the first end of the first switch module and the grounding element respectively, and a second end of the second switch module is connected with a radio frequency receiving port;

when the radio frequency transceiver circuit is in a transmitting state, the second switch module is turned off;

when the radio frequency receiving and transmitting circuit is in a receiving state, the second switch module is conducted.

Preferably, the second switch module includes: a second switching tube and a third inductive element;

the first end of the second switch tube is respectively connected with the first end of the third inductive element and the first end of the first switch module; and the second end of the second switching tube is respectively connected with the second end of the third inductive element and the radio frequency receiving port, wherein the parallel resonance frequency of the parasitic capacitance between the second switching tube and the third inductive element is the center frequency of the transmitted signal.

Preferably, the second end of the second switch tube is grounded through an inductor or a microstrip line.

Preferably, the impedance matching unit includes:

the first inductive element, the fourth inductive element, the fifth inductive element, the sixth inductive element, the seventh inductive element, the eighth inductive element, the second grounding capacitor and the third capacitor;

the fourth inductive element is connected with the seventh inductive element, the eighth inductive element, the third capacitor, the first end of the first inductive element and the antenna in sequence, and the second end of the first inductive element is connected with the radio frequency receiving and transmitting switch unit; the first end of the fifth inductive element is connected with a power supply, the second end of the fifth inductive element and the first end of the sixth inductive element are connected with the connection point of the fourth inductive element and the seventh inductive element, and the second end of the sixth inductive element is connected with a second grounding capacitor. A second aspect of a radio frequency front-end circuit, including an amplifier transistor and the radio frequency transceiver circuit of any one of the first aspects, wherein a third terminal of the impedance matching unit is connected to a power supply;

when the radio frequency receiving and transmitting circuit is in a receiving state, the power supply provides zero potential for the drain voltage of the amplifier transistor.

The radio frequency transceiver circuit and the radio frequency front-end circuit provided by the utility model have the beneficial effects that: the radio frequency receiving and transmitting circuit comprises an impedance matching unit and a radio frequency receiving and transmitting switch unit, wherein a first end of the impedance matching unit is connected with a radio frequency transmitting port, a second end of the impedance matching unit is connected with an antenna, the radio frequency receiving and transmitting switch unit is arranged between a grounding element in the impedance matching unit and the ground, and the radio frequency receiving and transmitting switch unit is also connected with a radio frequency receiving port; the radio frequency receiving and transmitting switch unit comprises a first switch module, wherein a first end of the first switch module is connected with the grounding element, and a second end of the first switch module is grounded; when the radio frequency transceiver circuit is in a transmitting state, the first switch module is conducted; when the radio frequency receiving and transmitting circuit is in a receiving state, the first switch module is turned off; by reducing the number of the switching tubes, an adaptive TR switching circuit is constructed, the chip area is reduced to a great extent, the cost is saved, the loss of a transmitting branch is obviously reduced, the output power and the efficiency of an amplifier are improved, the isolation of a transmitting state is improved on the basis, the dependence of the switching tubes is reduced, and the risk of the switching tubes is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a system structure of a radio frequency transceiver circuit according to an embodiment of the present utility model;

FIG. 2 is a prior art transceiver architecture for an external circulator;

FIG. 3 is a schematic diagram of a prior art transceiver structure with a switch tube having a composite parallel structure;

fig. 4 is a transceiver architecture with a serial-parallel structure of a switching tube in the prior art;

fig. 5 is a schematic structural diagram of a first switch module according to an embodiment of the utility model;

fig. 6 is a second schematic diagram of a system structure of a radio frequency transceiver circuit according to an embodiment of the present utility model;

fig. 7 is a schematic structural diagram of a second switch module according to an embodiment of the utility model;

FIG. 8 is a third schematic diagram of a system structure of a radio frequency transceiver circuit according to an embodiment of the present utility model;

FIG. 9 is a schematic diagram of an impedance matching unit according to an embodiment of the present utility model;

fig. 10 is a schematic structural diagram of a radio frequency front-end circuit according to an embodiment of the present utility model;

fig. 11 is a schematic diagram of a system structure of a radio frequency transceiver circuit according to an embodiment of the present utility model.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be understood that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like indicate orientations or positional relationships based on those shown in the drawings, or those conventionally put in place when the inventive product is used, or those conventionally understood by those skilled in the art, merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Examples

In the prior art, for the traditional TR switching mode, the transmission path loss is obviously increased by a circulator, a pure parallel switch or a serial-parallel switch connected with a transmitting branch, and the size is larger and the insertion loss is larger because of a complex structure such as a traditional switching structure of an external circulator; for the traditional switching architecture of a pure parallel switch or a serial-parallel switch, different voltage-resistant or current-resistant requirements need to be considered, the current-resistant capability is selected from the aspect of the total grid width of the tube core, the voltage-resistant capability is considered from the aspect of the number of grid stacks, and for the traditional switching architecture, the voltage-resistant requirement or the current-resistant requirement is high.

Referring to fig. 1, the present embodiment provides a radio frequency transceiver circuit, which specifically includes:

in a first aspect, a radio frequency transceiver circuit includes an impedance matching unit and a radio frequency transceiver switch unit, wherein a first end of the impedance matching unit is connected to a radio frequency transmitting port TX, a second end of the impedance matching unit is connected to an antenna ANT, the radio frequency transceiver switch unit is disposed between a grounding element in the impedance matching unit and ground, and the radio frequency transceiver switch unit is further connected to a radio frequency receiving port RX; the radio frequency receiving and transmitting switch unit comprises a first switch module Q1, wherein a first end of the first switch module Q1 is connected with the grounding element, and a second end of the first switch module is grounded; when the radio frequency transceiver circuit is in a transmitting state, the first switch Q1 module is conducted; when the radio frequency transceiver circuit is in a receiving state, the first switch Q1 module is turned off.

Further, the grounding element may be an inductive element or other grounding element, as shown in fig. 9, in this embodiment, a first inductive element L1 may be used, where the first inductive element L1 is the grounding element closest to the second end of the impedance matching unit, that is, the grounding element closest to the antenna ANT in the impedance matching unit, and according to this arrangement, the performance of the radio frequency transceiver circuit may be maximized, the loss of the transmitting branch may be significantly reduced, and further the output power and efficiency of the amplifier may be improved, where the first inductive element L1 may be an inductance or a microstrip line.

Referring to fig. 2, 3 and 4, conventional transceiver structures in the prior art are shown in fig. 2, which is a transceiver structure of an external circulator; fig. 3 is a transceiver architecture with switching tubes in a composite parallel structure, including four switching tubes: q2, Q3, Q4, and Q5; wherein, during transmitting operation, Q2 and Q3 are off, Q4 and Q5 are conducted to ground, and the receiving state is reverse; fig. 4 is a transceiver architecture with a serial-parallel structure of switching transistors, and also includes four switching transistors Q2", Q3", Q4", and Q5". The transceiver structure of fig. 2, which is an external circulator, has a larger chip size and a larger insertion loss than the switch tube structure, i.e., the structures of fig. 3 and 4 and fig. 1 according to the embodiment of the present utility model. The transceiver architecture shown in fig. 3 and 4 is a more common manner in the prior art, and the transceiver architecture shown in fig. 2 is more practical for high-frequency or high-power circuits; whereas the transceiver architecture shown in fig. 3 is more practical for low frequency or low power circuits. However, the transceiver architecture shown in fig. 2, 3 and 4 can significantly increase the loss of the transmission path.

Compared with the radio frequency receiving and transmitting circuit provided by the embodiment of the utility model, the radio frequency receiving and transmitting circuit only comprises one switching tube Q1, the quantity of the switching tubes is greatly reduced based on the radio frequency receiving and transmitting circuit, and the receiving and transmitting framework is arranged on a bypass, namely between a grounding element of an impedance matching unit and the ground, so that a main parallel tube or a serial tube does not exist in a transmitting link, and when the transmitting branch works, only the current-resisting capacity of the switching tube in the first matching module is considered, so that the transmitting power and efficiency are greatly improved, and the power consumption of the transmitting branch is reduced.

And only one switching tube Q1 is adopted in the file of the utility model, so that the number of tube cores of the traditional single-pole double-throw switch is reduced, and particularly compared with a transceiving framework of a serial-parallel structure shown in fig. 3, the microstrip line with one quarter wavelength is reduced, the number of chips is reduced to a great extent, the cost is saved, and the size of a component is reduced.

As shown in fig. 5, the first switch module includes: a first switching tube Q1 and a second inductive element L2;

wherein, the first end of the first switch tube Q1 is connected with the grounding element; the second inductive element L2 is connected in parallel with the first switching tube Q1 through the first end and the second end of the first switching tube Q1, and the parallel resonance frequency of the parasitic capacitance between the first switching tube Q2 and the second inductive element L2 is the center frequency of the received signal.

The drain and source electrodes of the first switch Q1 are all shorted by using an inductance or microstrip line, as shown in fig. 5, that is, the drain and source electrodes of the switch tube are shorted by the second inductive element L2, so that the drain and source voltage Vds of the switch tube in conducting operation can be kept at an equipotential, that is, the drain and source electrodes are a zero-state operating point, and meanwhile, the inductance value of the second inductive element L2 is adjusted, so that the parallel resonance between the second inductive element L2 and the drain and source parasitic capacitance of the switch tube meets the center frequency of the received signal; thereby improving the closing impedance of the switching tube when the switching tube is in a closing state; in the reception state, the switching tube Q1 is turned off and has a high switching tube off impedance Roff, so that the reception loss in the reception state can be reduced.

Further, the first switch module further includes a first capacitor C1, and the second end of the first switch tube Q1 is connected in series with the first capacitor C1 and grounded, where a series resonance frequency of the microstrip effect between the first capacitor C1 and the first switch tube Q1 is a center frequency of the transmission signal.

The first capacitor C1 is connected in series to ground, in the transmitting state, the first switching tube Q2 is turned on, and the drain-source of the first switching tube Q2 is mainly a series microstrip effect of the on-resistance Ron of the switching tube, so that the series resonance of the microstrip effect between the first capacitor C1 and the drain-source of the first switching tube Q1 is at the center frequency of the transmitting signal by adjusting the resistance of the first capacitor C1, thereby reducing the in-band and grounding resistance of the switching tube, and improving the isolation effect in the transmitting state.

Further, the first end of the first switching tube Q1 is grounded through an inductor or a microstrip line.

Through the arrangement, drain-source ground potential can be provided for the switch tube in the radio frequency transceiver switch unit.

In another possible embodiment, as shown in fig. 6, the radio frequency transceiver switch unit further includes a second switch module, a first end of the second switch module is connected to the first end of the first switch module and the grounding element, and a second end of the second switch module is connected to the radio frequency receiving port;

when the radio frequency transceiver circuit is in an emission state, the second switch module is turned off;

when the radio frequency transceiver circuit is in a receiving state, the second switch module is conducted.

Further, as shown in fig. 7, the second switch module includes: a second switching tube Q2 and a third inductive element L3;

the first end of the second switching tube Q2 is respectively connected with the first end of the third inductive element L3 and the first end of the first switching module; the second end of the second switching tube Q2 is connected to the second end of the third inductive element L3 and the radio frequency receiving port, respectively, where the parallel resonance frequency of the parasitic capacitance between the second switching tube Q2 and the third inductive element L3 is the center frequency of the transmitted signal.

The parallel resonant frequency of the parasitic capacitance between the second switching tube Q2 and the third inductive element L3 is the center frequency of the transmitted signal, and the working principle is equivalent to that of the first switching tube Q1 and the second inductive element L2; when the second switching tube Q2 is turned off, the parallel resonance between the inductance value of the third inductive element L3 with a suitable resistance and the drain-source parasitic capacitance CDS of the second switching tube Q2 is at the center frequency of the transmitted signal, so that the isolation degree can be improved by the second switching tube Q2 on the transmitting path.

Further, the second end of the second switching tube Q2 is grounded through an inductor or a microstrip line.

On the basis, the second end of the second switching tube Q2 is grounded through an inductor or a microstrip line, the receiving end of the radio frequency receiving and transmitting switching unit provides a ground potential, and on the basis, the ESD capacity of the low-noise input end can be increased.

In practical applications, the wireless communication system generally further includes a Limiter limit, a low noise amplifier LNA, as shown in fig. 8, where the second end of the second switching tube in the embodiment of the present utility model may be further connected to the Limiter limit, the low noise amplifier LNA, and a ground inductor L9; in another embodiment, the grounding inductor or the grounding microstrip line may be built into the input terminal of the limiter or the low noise amplifier, and the ESD capability of the low noise amplifier input terminal may be increased by providing the receiving terminal of the rf transceiver switch unit with the ground potential.

Further, as shown in fig. 9, the impedance matching unit includes: the first inductive element L1, the fourth inductive element L4, the fifth inductive element L5, the sixth inductive element L6, the seventh inductive element L7, the eighth inductive element L8, the second ground capacitor C2, the third capacitor C3;

the fourth inductive element L4 is sequentially connected with the seventh inductive element L7, the eighth inductive element L8, the third capacitor C3, one end of the first inductive element L1 and the antenna, and the second end of the first inductive element L1 is connected with the radio frequency transceiver switch unit; the first end of the fifth inductive element L5 is connected to the power supply VDD, the second end of the fifth inductive element L5 and the first end of the sixth inductive element L6 are both connected to the connection point of the fourth inductive element L4 and the seventh inductive element L7, and the second end of the sixth inductive element L6 is connected to the second ground capacitor C2.

Here, it should be noted that each inductive element in the impedance matching unit, for example, the fourth inductive element L4, the fifth inductive element L5, the sixth inductive element L6, the seventh inductive element L7, and the eighth inductive element L8 may use one of inductance or microstrip line, that is, the impedance matching unit may include: a second grounding capacitor C2, a third capacitor C3, a first inductive element or a first microstrip line, a fourth inductance or a fourth microstrip line, a fifth inductance or a fifth microstrip line, a sixth inductance or a sixth microstrip line, a seventh inductance or a seventh microstrip line, an eighth inductance or an eighth microstrip line; the inductive element can be selected from microstrip lines, the specific inductance and the number of the microstrip lines can be adjusted according to the actual impedance, and the embodiment of the utility model is not limited in particular.

According to fig. 9, the impedance matching unit further includes a fourth capacitor C4, and a first end of the fourth capacitor C4 is connected to a connection point between the seventh inductive element L7 and the eighth inductive element L8; the second terminal of the fourth capacitor C4 is grounded.

Further, the impedance matching unit includes a grounding element, the rf transceiver switch unit is disposed between the grounding element and the ground, the grounding element may be an inductive element or other grounding element, and is the grounding element closest to the second end of the impedance matching unit; in this embodiment, the first inductive element L1 may be adopted, and the point T in fig. 9 is a connection point between the ground element L1 and the impedance matching unit, and the rf transceiver switch unit is disposed between the ground element L1 and the ground, so that the performance of the rf transceiver circuit is maximized, the loss of the transmitting branch is obviously reduced, and the output power and efficiency of the amplifier are improved.

The embodiment of the utility model removes the influence of the direct access switch tube of the main transmission path on the receiving matching for adjusting the transmitting output matching, and comprises three aspects:

in the first aspect, the line widths of the seventh inductive element L7 and the eighth inductive element L8 may be adjusted so that, in the receiving state, a high radio frequency impedance is presented as viewed from the connection point T of the ground element L1 and the impedance matching unit to the connection point P of the fourth inductive element L4 and the seventh inductive element L7;

further, when the line widths of the seventh inductive element L7 and the eighth inductive element L8 are adjusted, the capacitance of the ground resistor C4 between the seventh inductive element L7 and the eighth inductive element L8 can be appropriately reduced; this ground resistance C4 can be removed when the line length is adjusted so that the impedance in the P-direction from T presents a high radio frequency impedance.

In the second aspect, adding the sixth inductive element L6 and the second grounding capacitor C2 can increase the Q value of the quality factor at the P point in the transmitting state, thereby reducing the transmitting loss.

In the third aspect, the line lengths of the fifth inductive element L5 and the sixth inductive element L6 may be adjusted under a preset threshold, that is, if the line length of the fifth inductive element L5 is increased, in order to maintain a good matching on the transmission link, the line length of the sixth inductive element L6 may be correspondingly reduced, and the overall radio frequency impedance from the connection point T of the ground element L1 and the impedance matching unit to the connection point P of the fourth inductive element L4 and the seventh inductive element L7 may be increased by the mutual adjustment under the preset threshold.

In a second aspect, as shown in fig. 10, the present embodiment further provides a radio frequency front-end circuit, including an amplifier transistor and the radio frequency transceiver circuit of any one of the first aspect, where a third terminal of the impedance matching unit is connected to a power supply; when the radio frequency receiving and transmitting circuit is in a receiving state, the power supply source provides zero potential for the drain voltage VDD of the amplifier transistor, and concretely, the power supply source comprises a first power supply source and a second power supply source, wherein the first power supply source provides drain voltage for the amplifier transistor; the second power supply provides a gate voltage for the amplifier transistor;

in this embodiment, in the receiving state, the first transistor Q1 is turned off, the first power supply provides zero potential for the drain voltage of the amplifier transistor, that is, vdd=0v, and the second power supply provides negative potential for the gate voltage VG of the amplifier transistor, and maintains the gate voltage VG of the amplifier transistor negative, where the entire structure is that the amplifier transistor is connected in series with the fourth inductive element, and then connected in parallel to the connection point P of the fourth inductive element L4 and the seventh inductive element L7, and grounded. If the timing circuit is provided, in the receiving state, the drain voltage VDD of the amplifier transistor will drop to 0V first, and the gate voltage VG of the amplifier transistor will rise to 0V again, and in the receiving state, the die of the amplifier transistor will be completely similar to the on-state switch ground, so that the quality factor Q value at the connection point P of the fourth inductive element L4 and the seventh inductive element L7 can be greatly improved, and the receiving loss can be greatly reduced.

Further, in combination with the conventional transceiver architecture shown in fig. 3 and fig. 4, if the switching timing is turned over in advance during the operation of the transmitting state, the switching tube Q2 and the switching tube Q3 in fig. 3, and the switching tube Q2 "in fig. 4, the switching tube Q3" has a voltage-withstanding or current-resisting risk, the current-resisting capability is selected from the aspect of the total gate width of the die, and the voltage-resisting capability can be considered from the aspect of the number of stacked grid bars; on the basis of reducing the number of the switching tubes and optimizing the setting positions of the switching architecture, the risk of the second switching tube Q2 and the third switching tube Q3 is far lower than that of the switching tube shown in the traditional architecture in the figures 3 and 4 even if the time sequence is overturned in advance; therefore, the switching tube in the radio frequency front-end circuit provided by the utility model has stronger risk capability of resisting time sequence error.

As shown in fig. 11, the present embodiment provides an exemplary rf front-end circuit, which includes all the technical features and all the technical effects of the rf transceiver circuit of the first aspect.

In summary, according to the radio frequency transceiver circuit and the radio frequency front-end circuit provided by the utility model, the number of the switch tubes is reduced, and the adaptive transmission output matching architecture is constructed, so that the reliability of the switch tubes can be reduced, the size area of a chip can be reduced, the loss on a transmission branch can be reduced, and the isolation on a transceiver link can be optimized on the basis of considering the receiving and transmitting performances. The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. The radio frequency receiving and transmitting circuit comprises an impedance matching unit and a radio frequency receiving and transmitting switch unit, wherein a first end of the impedance matching unit is connected with a radio frequency transmitting port, and a second end of the impedance matching unit is connected with an antenna;

the radio frequency receiving and transmitting switch unit comprises a first switch module, wherein a first end of the first switch module is connected with the grounding element, and a second end of the first switch module is grounded;

when the radio frequency transceiver circuit is in a transmitting state, the first switch module is conducted;

when the radio frequency receiving and transmitting circuit is in a receiving state, the first switch module is turned off.

2. The radio frequency transceiver circuit of claim 1, wherein the ground element is the ground element nearest the second end of the impedance matching unit.

3. The radio frequency transceiver circuit of claim 1, wherein the first switch module comprises: a first switching tube, a second inductive element;

wherein the first end of the first switch tube is connected with the grounding element; the second inductive element is connected with the first switching tube in parallel through the first end and the second end of the first switching tube, and the parallel resonance frequency of the parasitic capacitance between the first switching tube and the second inductive element is the center frequency of the received signal.

4. The radio frequency transceiver circuit of claim 3, wherein the first switch module further comprises a first capacitor, the second end of the first switch tube is connected in series with the first capacitor and grounded, and wherein a series resonance frequency of the microstrip effect between the first capacitor and the first switch tube is a center frequency of the transmission signal.

5. A radio frequency transceiver circuit according to claim 3, wherein the first end of the first switching tube is grounded via an inductance or a microstrip line.

6. The radio frequency transceiver circuit of claim 1, wherein the radio frequency transceiver switch unit further comprises a second switch module, a first end of the second switch module being connected to the first end of the first switch module and the ground element, respectively, and a second end of the second switch module being connected to a radio frequency receiving port;

when the radio frequency transceiver circuit is in a transmitting state, the second switch module is turned off;

when the radio frequency receiving and transmitting circuit is in a receiving state, the second switch module is conducted.

7. The radio frequency transceiver circuit of claim 6, wherein the second switch module comprises: a second switching tube and a third inductive element;

the first end of the second switch tube is respectively connected with the first end of the third inductive element and the first end of the first switch module; and the second end of the second switching tube is respectively connected with the second end of the third inductive element and the radio frequency receiving port, wherein the parallel resonance frequency of the parasitic capacitance between the second switching tube and the third inductive element is the center frequency of the transmitted signal.

8. The radio frequency transceiver circuit of claim 7, wherein the second end of the second switching tube is grounded via an inductor or a microstrip line.

9. The radio frequency transceiver circuit of claim 1, wherein the impedance matching unit comprises: the first inductive element, the fourth inductive element, the fifth inductive element, the sixth inductive element, the seventh inductive element, the eighth inductive element, the second grounding capacitor and the third capacitor;

the fourth inductive element is connected with the seventh inductive element, the eighth inductive element, the third capacitor, the first end of the first inductive element and the antenna in sequence, and the second end of the first inductive element is connected with the radio frequency receiving and transmitting switch unit; the first end of the fifth inductive element is connected with a power supply, the second end of the fifth inductive element and the first end of the sixth inductive element are connected with the connection point of the fourth inductive element and the seventh inductive element, and the second end of the sixth inductive element is connected with a second grounding capacitor.

10. A radio frequency front-end circuit, characterized by comprising an amplifier transistor and the radio frequency transceiver circuit of any one of claims 1 to 9, a third terminal of the impedance matching unit being connected to a power supply;

when the radio frequency receiving and transmitting circuit is in a receiving state, the power supply provides zero potential for the drain voltage of the amplifier transistor.