CN204836094U - Power amplification circuit and radio frequency circuit - Google Patents

Abstract

The utility model discloses a power amplification circuit and radio frequency circuit, this power amplification circuit includes: first coupler, a power amplifier, the 2nd power amplifier, second coupler, a gating switch and the 2nd gating switch, wherein, the first output of first coupler is connected with a power amplifier's input, and a power amplifier's the output and the first input end of second coupler are connected, the second output of first coupler is connected with the 2nd power amplifier's input through a gating switch, and the 2nd power amplifier's output is connected with the second input of second coupler through the 2nd gating switch, a power amplifier and the 2nd power amplifier's control end all is connected with a logic power. The utility model discloses an adopt the balanced amplifier principle, it is parallelly connected in order to realize enlargeing signal power with two power amplifier to through adopting a plurality of gating switch, select different power amplifier as required, realize multiple mode.

Description

A power amplifier circuit and radio frequency circuit

technical field

The utility model relates to the field of mobile communication, in particular to a power amplifier circuit and a radio frequency circuit.

Background technique

In the Long Term Evolution system (LTE, Long Term Evolution) and Long Term Evolution technology upgrade system (LTE-A, Long Term Evolution Advanced) system, the demand for high-power uplink terminals and uplink continuous carrier aggregation has caused the current commercial terminal power amplifiers to fail to meet the maximum transmit power requirements of the protocol.

At present, the maximum output of commercial terminal power amplifiers that support LTE20MHz bandwidth is 28dBm. Since the RF front-end insertion loss (switch + filter + RF wiring loss) is generally 4dBm, the maximum emission reaching the antenna feed point is 24dBm. However, for the uplink continuous carrier aggregation radio frequency front-end circuit, the current power amplifier circuit cannot meet the requirement of the adjacent channel leakage ratio (ACLR) of the LTE radio frequency index equal to or greater than 40MHz bandwidth. Existing power amplifier manufacturers use software to control the bias voltage of the power amplifier to support the amplifying circuit of LTE with a bandwidth equal to or greater than 40MHz in in-band continuous carrier aggregation. The power is backed off by 1~2dB, which makes the emission radio frequency indicator margin insufficient.

For high-power uplink terminals, the maximum transmit power at the antenna feed point is required to be 27dBm. In the prior art, the terminal power amplifier module (driver stage) + LDMOS power transistor (amplifier stage) cascaded method is generally used to realize this. For example: LDMOS power transistor, but this solution has high cost, low efficiency, and high power consumption, and the power supply voltage (>=5V) of the LDMOS power transistor does not match the terminal power supply voltage (3.8V).

Utility model content

In order to solve the above technical problems, the utility model provides a power amplifying circuit and a radio frequency circuit, which solves the problem of insufficient radio frequency index margin in the prior art, and the mismatch between the power supply voltage of the LDMOS power transistor and the terminal power supply voltage.

According to one aspect of the present invention, a power amplifying circuit is provided, including: a first coupler, a first power amplifier, a second power amplifier, a second coupler, a first gating switch, and a second gating switch; in,

The first output end of the first coupler is connected with the input end of the first power amplifier, and the output end of the first power amplifier is connected with the first input end of the second coupler; The input terminal of the amplified signal;

The second output end of the first coupler is connected to the input end of the second power amplifier through the first gating switch, and the output end of the second power amplifier is connected to the second input end of the second coupler through the second gating switch; Wherein, the second coupler also includes an output terminal for outputting the amplified signal;

Wherein, the control terminal of the first power amplifier and the control terminal of the second power amplifier are both connected to a logic power supply.

Optionally, a third selection switch is provided between the control terminal of the second power amplifier and the logic power supply.

Optionally, the first gating switch, the second gating switch and the third gating switch are all single-pole double-throw switches.

Optionally, the second output end of the first coupler is connected to the input end of the first gating switch, the first output end of the first gating switch is connected to the input end of the second power amplifier, and the first gating switch The second output end is connected to one end of the first matching resistor, and the other end of the first matching resistor is connected to the ground.

Optionally, the output end of the second power amplifier is connected to the first input end of the second gating switch, the second input end of the second gating switch is connected to one end of the second matching resistor, and the other end of the second matching resistor connected to the ground terminal, and the output terminal of the second gating switch is connected to the second input terminal of the second coupler.

Optionally, the first input end of the third gating switch is connected to the logic power supply, the second input end of the third gating switch is connected to the ground end, and the output end of the third gating switch is connected to the control end of the second power amplifier. connect.

According to another aspect of the present invention, there is also provided a radio frequency circuit, including the power amplifying circuit as described above, and the radio frequency circuit also includes: a first gating switch, a second gating switch for controlling the power amplifying circuit A baseband chip, a radio frequency chip, a filter circuit, a switch circuit and an antenna of the switch and the third gating switch; wherein,

The baseband chip, the radio frequency chip, the power amplifier circuit, the filter circuit, the switch circuit and the antenna are electrically connected in sequence.

The beneficial effects of the embodiment of the utility model are: adopting the principle of balanced amplification, the input signal is divided into two paths through the first coupler, and the signals of the two paths reach the first power amplifier or the second power amplifier respectively for amplification processing. The two channels of amplified signals arrive at the second coupler and are synthesized into one channel for output, which ensures that the signals are amplified to a sufficient multiple and solves the problem of insufficient radio frequency index margin in the prior art. In addition, a plurality of gating switches are provided on the path where the second power amplifier is located, and when the first power amplifier meets the amplifying power requirement, the second power amplifier is turned off to reduce power consumption. The aforementioned power amplifier circuit does not use LDMOS power transistors, and also avoids the problem of a mismatch between the power supply voltage of the LDMOS power transistor and the terminal power supply voltage.

Description of drawings

Fig. 1 represents the circuit principle diagram of the power amplifying circuit of the present utility model;

Fig. 2 shows the circuit principle diagram of the radio frequency circuit of the present invention.

In the figure: D ₁ , the first coupler, A ₁ , the first power amplifier, A ₂ , the second power amplifier, D ₂ , the second coupler, S ₁ , the first gating switch, S ₂ , the second Strobe switch, S ₃ , third strobe switch, V _CC , logic power supply, V _SS , ground terminal, R ₁ , first matching resistor, R ₂ , second matching resistor;

D ₁₀₁ , the first output end of the first coupler, D ₁₀₂ , the second output end of the first coupler, D ₁₀₃ , the input end of the first coupler;

D ₂₀₁ , the first input end of the second coupler, D ₂₀₂ , the second input end of the second coupler, D ₂₀₃ , the output end of the second coupler;

A ₁₀₁ , the input terminal of the first power amplifier, A ₁₀₂ , the output terminal of the first power amplifier; A ₁₀₃ , the control terminal of the first power amplifier;

A ₂₀₁ , the input terminal of the second power amplifier, A ₂₀₂ , the output terminal of the second power amplifier; A ₂₀₃ , the control terminal of the second power amplifier.

Detailed ways

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

As shown in Figure 1, the embodiment of the present utility model provides a power amplifier circuit, which specifically includes: a first coupler D ₁ , a first power amplifier A ₁ , a second power amplifier A ₂ , and a second coupler D ₂ , the first gating switch S ₁ and the second gating switch S ₂ . in,

The first output terminal D ₁₀₁ of the first coupler is connected to the input terminal A ₁₀₁ of the first power amplifier, and the output terminal A ₁₀₂ of the first power amplifier is connected to the first input terminal D ₂₀₁ of the second coupler; wherein, the first The coupler D ₁ also includes an input terminal D ₁₀₃ for inputting a signal to be amplified.

The second output terminal _D102 of the first coupler is connected to the input terminal _A201 of the second power amplifier through the _first gate switch S1, and the output terminal _A202 of the second power amplifier is connected to the second power amplifier through the _second gate switch S2. The second input terminal D ₂₀₂ of the two couplers is connected; wherein, the second coupler D ₂ further includes an output terminal D ₂₀₃ for outputting an amplified signal.

Wherein, the signal to be amplified is input from the input terminal D ₁₀₃ of the first coupler, and is equally divided into two channels, wherein one signal is transmitted to the input terminal A ₁₀₁ of the first power amplifier through the first output terminal D ₁₀₁ of the first coupler , after being amplified, it is transmitted to the first input terminal D ₂₀₁ of the second coupler through the output terminal A ₁₀₂ of the first power amplifier; the other signal is transmitted to the first selection terminal through the second output terminal D ₁₀₂ of the first When the switch S ₁ is turned on, when the first strobe switch S ₁ is connected to the input terminal A ₂₀₁ of the second power amplifier, the signal is transmitted to the input terminal A ₂₀₁ of the second power amplifier, and after being amplified, it passes through the second The output terminal A ₂₀₂ of the power amplifier is transmitted to the second gate switch S ₂ , and when the second gate switch S ₂ is gate-connected to the second input terminal D ₂₀₂ of the second coupler, the amplified signal is transmitted to the second gate switch S 2 . The second input terminal D ₂₀₂ of the second coupler combines the signal input at the first input terminal D ₂₀₁ of the second coupler with the signal input at the second input terminal D ₂₀₂ of the second coupler, and passes through the second The output terminal D203 of the second coupler is output.

In addition, when the _first strobe switch S1 is not strobe-connected to the input terminal A ₂₀₁ of the second power amplifier, and the _second strobe switch S2 is not strobe-connected to the second input terminal D ₂₀₂ of the second coupler , the _second power amplifier A2 does not work to reduce the overall power consumption.

Wherein, since both the first power amplifier and the second power amplifier are active devices, in order to ensure their normal operation, the control terminal A ₁₀₃ of the first power amplifier and the control terminal A ₂₀₃ of the second power amplifier are all connected to a logic power supply V _CC connected.

Among them, the function of the _first coupler D1 and the _second coupler D2 is to divide one signal into two channels or combine the two signals into one channel, so the _first coupler D1 and the _second coupler D2 can be 3dB coupler is used.

By adopting the principle of balanced amplification, the signal can be guaranteed to be amplified to a sufficient multiple, which solves the problem of insufficient margin for transmitting radio frequency indicators in the prior art. In addition, a plurality of gating switches are provided on the path where the second power amplifier is located, and when the first power amplifier meets the amplifying power requirement, the second power amplifier is turned off to reduce power consumption. The aforementioned power amplifier circuit does not use LDMOS power transistors, and also avoids the problem of a mismatch between the power supply voltage of the LDMOS power transistor and the terminal power supply voltage.

Optionally, when the _second power amplifier A2 is not working, in order to avoid device damage due to no-load, a third gating switch S is provided between the control terminal A ₂₀₃ of the second power amplifier and the logic power supply V _{CC 3} , if and only when the _second power amplifier A2 is working, the _third select switch S3 selects the path between the control terminal A ₂₀₃ of the second power amplifier and the logic power supply V _CC .

Optionally, the first strobe switch S ₁ , the second strobe switch S ₂ and the third strobe switch S ₃ are all switches capable of selecting paths, either physical switches or logical switches, in order to ensure that the first coupler The port matching problem of D ₁ and the second coupler D ₂ , and the problem of no-load of the second power amplifier A ₂ , the first gating switch S ₁ , the second gating switch S ₂ and the third gating switch S ₃ are all A single pole double throw switch.

Specifically, in order to ensure port matching of the _first coupler D1, the second output terminal _D102 of the first coupler is connected to the input terminal of the _first gating switch S1, and the _first output of the first gating switch S1 terminal is connected to the input terminal A ₂₀₁ of the second power amplifier, the second output terminal of the _first strobe switch S1 is connected to _one end of the _first matching resistor R1, and the other end of the first matching resistor R1 is connected to the ground terminal V _SS connect. When the first strobe switch S1 strobes the path between the second output terminal D ₁₀₂ of the first coupler and the input terminal A ₂₀₁ of the second power amplifier, the second power amplifier A ₂₀₁ works, when the first strobe switch When S ₁ selects the path between the second output terminal D ₁₀₂ of the first coupler and the first matching resistor R ₁ , the second power amplifier A ₂₀₁ does not work, and the second output terminal D ₁₀₂ of the first coupler realizes impedance Matching, generally, the resistance of the _first matching resistor R1 is 50 ohms.

Similarly, in order to ensure port matching of the _second coupler D2. The output terminal A ₁₀₂ of the second power amplifier is connected to the first input terminal of the _second gating switch S2, the _second input terminal of the second gating switch S2 is connected to one end of the _second matching resistor R2, and the second matching The other end of the resistor R ₂ is connected to the ground terminal V _SS , and the output end of the second select switch S ₂ is connected to the second input end D ₂₀₂ of the second coupler.

In order to avoid the no-load problem of the _second power amplifier A2, the first input terminal of the _third strobe switch S3 is connected to the logic power supply _VCC , and the second input terminal of the _third strobe switch S3 is connected to the ground terminal _VSS , the output terminal of the _third gating switch S3 is connected to the control terminal _A203 of the second power amplifier.

According to another aspect of the embodiment of the present utility model, there is also provided a radio frequency circuit, as shown in FIG. 2 , including the power amplifying circuit as described above, and the radio frequency circuit further includes: used to control the The baseband chip, radio frequency chip, filter circuit, switch circuit and antenna of the first gate switch, the second gate switch and the third gate switch; wherein, the baseband chip, radio frequency chip, power amplifier circuit, filter circuit, switch circuit and The antennas are in turn electrically connected.

The baseband chip transmits the processed baseband signal to the RF chip to convert it into a radio frequency signal, and then transmits the radio frequency signal to the power amplifier circuit for amplification. The amplified radio frequency signal is filtered by the filter circuit, and then transmitted to the antenna through the switch circuit for emission. or,

The antenna transmits the received radio frequency signal to the filter circuit through the switch circuit for filtering, then transmits the filtered radio frequency signal to the power amplifier circuit for amplification processing, and transmits the amplified radio frequency signal to the radio frequency chip to convert it into a baseband signal. Then the processed baseband signal is transmitted to the baseband chip for processing.

Wherein, the baseband chip is also used to control the first gating switch, the second gating switch and the third gating switch in the power amplifier circuit, when the power of the radio frequency signal received by the antenna is greater than a certain value, the baseband chip controls the first gating switch A strobe switch, a second strobe switch and a third strobe switch strobe the path where the second power amplifier does not work, and when the power of the radio frequency signal received by the antenna is less than a certain value, the baseband chip controls the first strobe switch , the second gating switch and the third gating switch gating the working path of the second power amplifier. In this way, the working state of the power amplifier circuit can be automatically adjusted according to the current network environment, making the entire radio frequency circuit more flexible.

When the first strobe switch strobes the path of the first matching resistor, the second strobe switch strobes the path of the second matching resistor, and the third strobe switch strobes the path of the ground terminal, that is to say, the second power amplifier does not work state, when the output power of the power amplifier circuit device is less than a certain value, such as 21dBm (or can also be defined as other empirical values); The path of the second power amplifier and the path of the third gating switch gating logic power supply, that is to say when the second power amplifier is in the working state, when the output power of the power amplifier circuit device is greater than a certain value, such as 21dBm (or also can defined as other empirical values).

What has been described above is a preferred embodiment of the present utility model, and it should be pointed out that for those skilled in the art, some improvements and modifications can also be made without departing from the principles described in the present utility model. Within the protection scope of the present utility model.

Claims (7)

1. A power amplification circuit, comprising: the power amplifier comprises a first coupler, a first power amplifier, a second coupler, a first gating switch and a second gating switch; wherein,

a first output end of the first coupler is connected with an input end of the first power amplifier, and an output end of the first power amplifier is connected with a first input end of the second coupler; the first coupler further comprises an input end used for inputting a signal to be amplified;

a second output end of the first coupler is connected with an input end of the second power amplifier through a first gating switch, and an output end of the second power amplifier is connected with a second input end of the second coupler through a second gating switch; wherein the second coupler further comprises an output for outputting an amplified signal;

and the control end of the first power amplifier and the control end of the second power amplifier are both connected with a logic power supply.

2. The power amplifier circuit according to claim 1, wherein a third gating switch is provided between the control terminal of the second power amplifier and the logic power supply.

3. The power amplification circuit of claim 2, wherein the first gate switch, the second gate switch, and the third gate switch are single-pole double-throw switches.

4. The power amplifier circuit according to claim 3, wherein the second output terminal of the first coupler is connected to the input terminal of the first gating switch, the first output terminal of the first gating switch is connected to the input terminal of the second power amplifier, the second output terminal of the first gating switch is connected to one end of a first matching resistor, and the other end of the first matching resistor is connected to the ground terminal.

5. The power amplifier circuit according to claim 4, wherein an output terminal of the second power amplifier is connected to a first input terminal of the second gating switch, a second input terminal of the second gating switch is connected to one terminal of a second matching resistor, the other terminal of the second matching resistor is connected to a ground terminal, and an output terminal of the second gating switch is connected to a second input terminal of the second coupler.

6. The power amplifier circuit according to claim 5, wherein a first input terminal of the third gating switch is connected to the logic power supply, a second input terminal of the third gating switch is connected to a ground terminal, and an output terminal of the third gating switch is connected to the control terminal of the second power amplifier.

7. A radio frequency circuit comprising the power amplification circuit of any one of claims 1 to 6, the radio frequency circuit further comprising: the baseband chip, the radio frequency chip, the filter circuit, the switch circuit and the antenna are used for controlling the first gating switch, the second gating switch and the third gating switch in the power amplification circuit; wherein,

the baseband chip, the radio frequency chip, the power amplifying circuit, the filter circuit, the switch circuit and the antenna are electrically connected in sequence.