The present disclosure relates to a radio frequency front-end module having a current protection function and also relates to an electronic device including the radio frequency front-end module, and belongs to the technical field of radio frequency integrated circuits.
With the continuous development of the integrated circuit technology, modern electronic devices have increasingly high requirements for radio frequency front-end modules, and particularly, there are more and more scenarios where operation is performed in harsh environments. For example, the temperature in the working environment may rise or fall to reach or exceed the required temperature range limit (typically, the temperature range is −25° C. to 85° C. or −40° C. to 110° C.). When a power apparatus works in the high-temperature or low-temperature environment, a safety working area of the power apparatus becomes smaller, and even when working current on the power apparatus exceeds its maximum current rating, irreversible damage or destruction to the power apparatus can occur. Thus, in order to ensure the normal operation of the power apparatus, it is necessary to implement appropriate protective measures to limit the excessive working current of the power apparatus in harsh environmental scenarios, thereby ensuring that the power apparatus always works within the safety working area.
As shown in
In the American patent application No. US2009256637A1, a high-frequency power amplifier is disclosed. A high-frequency power amplifier circuit in the fourth embodiment includes high-frequency power amplifier transistors, matching circuits, bias supply transistors, and passive elements. The passive elements are connected between a common power supply terminal and collectors of the bias supply transistors, and the bias supply transistors are connected to a first-stage transistor. The passive element is implemented by connecting a resistor and an inductor. In the high-frequency power amplifier circuit, the passive elements prevent reduction of electric power of the bias supply transistors, so as to improve linearity at high output.
The technical problem required to be solved by the present disclosure is to provide a radio frequency front-end module having a current protection function.
Another technical problem required to be solved by the present disclosure is to provide an electronic device including the radio frequency front-end module.
In order to achieve the above objectives, the present disclosure adopts following technical solutions:
According to a first aspect of an embodiment of the present disclosure, a radio frequency front-end module having a current protection function is provided, and includes an input matching module, a power amplifier, an output matching module, a power supply module and a protection unit, wherein
Preferably, the protection unit includes at least one current limiting resistor and one filter capacitor, wherein
Preferably, the protection unit further includes a trap circuit, and the trap circuit is connected with the filter capacitor in parallel.
Preferably, the power amplifier includes at least one stage of power amplification unit. The power amplification unit includes a bias circuit and a power amplification circuit. The protection unit is at least connected with the bias circuit of the at least one stage of power amplification unit.
Preferably, the bias circuit includes a first transistor, a second transistor, a third transistor, a first bias resistor and a first filter capacitor; the power amplification circuit includes a fourth transistor, a first ballast resistor and a first inductor; and the protection unit includes a first current limiting resistor and a second filter capacitor, wherein
Preferably, when the bias circuit, the power amplification circuit and the protection unit satisfy following formulas, the bias circuit and the power amplification circuit enter a current limiting protection working state:
V
1C
<V
1b
−V
th_bc
V
1C
=VDD−V
R
V
R
=I
1
*R
V1c denotes a collector voltage of the first transistor, V1b denotes a base voltage of the first transistor, Vth_bc denotes a threshold voltage between the base and the collector of the first transistor, VR denotes a voltage drop on the first current limiting resistor, I1 denotes a collector current of the first transistor, R denotes a resistance value of the first current limiting resistor, and VDD denotes a voltage of a second power supply.
Preferably, a thermistor with a temperature coefficient is adopted as the current limiting resistor of the protection unit; for a power amplifier likely to burn out at a low temperature, a thermistor with a negative temperature coefficient is adopted as the current limiting resistor; and for a power amplifier likely to burn out at a high temperature, a thermistor with a positive temperature coefficient is adopted as the current limiting resistor.
Preferably, the protection unit includes a plurality of different-size filter capacitors with capacitance values ranging from pF to uF, so as to filter radio frequency signals and envelope signals different in frequency and realize broadband filtering.
Preferably, a stabilized voltage supply with a temperature coefficient is adopted as a power supply connected with the first current limiting resistor in the protection unit; for the power amplifier likely to burn out at the low temperature, a stabilized voltage supply with a positive temperature coefficient is adopted as the power supply; and for the power amplifier likely to burn out at the high temperature, a stabilized voltage supply with a negative temperature coefficient is adopted as the power supply.
Preferably, the trap circuit is additionally arranged in the protection unit and formed by connecting one inductor and one capacitor in series, and the trap circuit and the second filter capacitor are connected in parallel. An inductor end of the trap circuit is connected with node ends of the first current limiting resistor and the second filter capacitor, and a capacitor end is connected with the ground potential end.
Preferably, the protection unit further includes an inductor constituting an RLC combined circuit together with the current limiting resistor and the filter capacitor, to further filter the radio frequency signals and the envelope signals.
Preferably, the RLC combined circuit includes an eleventh inductor, the current limiting resistor, an eleventh capacitor and a twelfth capacitor.
One end of the current limiting resistor is connected with the collector of the first transistor in the bias circuit, and is also connected with the eleventh capacitor; the other end of the current limiting resistor is connected with the eleventh inductor and is also connected with the twelfth capacitor; the other end of the eleventh inductor is connected with the second power supply end; and the other end of the eleventh capacitor and the other end of the twelfth capacitor are respectively connected with the ground potential end.
Preferably, a control switch is further included and connected to two ends of the protection unit in parallel, so as to realize turn-on or turn off of the protection unit; and a control signal end of the control switch is connected with the first power supply end or an output end of a power detection circuit.
According to a second aspect of the embodiment of the present disclosure, an electronic device is provided, and includes the above radio frequency front-end module having a current protection function.
Compared with the prior art, the radio frequency front-end module having a current protection function provided by the embodiment of the present disclosure can have the functions of over-current protection, over-voltage protection and overpower protection on the power amplifier through additional arrangement of the protection unit, such that working reliability and safety of the radio frequency front-end module in harsh environments are greatly improved. Meanwhile, the protection unit realizes the threshold voltage only by utilizing voltage drop changes of the current limiting resistor without causing additional circuit power consumption or occupying a large circuit area, and thus, the radio frequency front-end module having a current protection function provided by the present disclosure has the beneficial effects of being ingenious and reasonable in structural design, low in design cost, high in reliability, excellent in circuit perform, etc., and is applicable to various structures of radio frequency front-end modules.
The technical content of the present disclosure is specifically described in detail in combination with drawings and specific embodiments as below.
As shown in
The input matching module 1 is used for realizing impedance matching between the power amplifier 2 and the radio frequency signal input end PA IN. The power amplifier 2 is used for amplifying power of input radio frequency signals, and includes at least one stage of power amplification unit, and the power amplification unit includes a bias circuit and a power amplification circuit. The output matching module 3 is used for realizing power matching between the power amplifier 2 and the radio frequency signal output end PA OUT. The power supply module 4 provides bias current and voltage required for working of the power amplifier 2. The protection unit 5 provides current protection for the power amplifier 2 and is connected with the bias circuit of the at least one stage of power amplification unit. The protection unit 5 includes at least one current limiting resistor and one filter capacitor.
A power supply VCC provides power voltage and current for a power amplifier, and a power supply VDD provides power voltage and current for the bias circuit and the power supply module 4 in the power amplifier. Usually, the power supply VCC and the power supply VDD are both powered by an external power supply module.
In a first embodiment of the present disclosure, specific circuits of the power amplifier 2, the power supply module 4 and the protection unit 5 are shown in
In the first embodiment of the present disclosure, a circuit structure of any one of the three stages of power amplification units and a protection unit is shown in
The working principle of the radio frequency front-end module having a current protection function in the above first embodiment is as follows:
As shown in
I
2
≈β*I
1 (1)
V
R
=I
1
*R (2)
V
1C
=VDD−V
R (3)
V
1c
>V
1b
−V
th_bc (4)
V1C denotes a collector voltage of the first transistor HBT1, V1b denotes a base voltage of the first transistor HBT1, Vth_bc denotes a threshold voltage between the base and the collector of the first transistor HBT1, VR denotes a voltage drop on the first current limiting resistor R, I1 denotes a collector current of the first transistor HBT1, I2 denotes a collector current of the fourth transistor HBT4, R denotes a resistance value of the first current limiting resistor R, β denotes an amplification coefficient of the fourth transistor HBT4, and VDD denotes a voltage value of the power supply VDD. At the time, the bias circuit and the power amplification circuit do not enter a current limiting protection state, and the formula 4 shows a starting work condition of the first transistor HBT1.
When the current I2 of the fourth transistor HBT4 is increased through an external circuit, the first transistor HBT1 is required to provide larger output current I1 according to the formula 1. At the time, due to the increased current I1, according to the formula 2 and the formula 3, voltage drop VR of the first current limiting resistor R is increased, a collector voltage Vic of the first transistor HBT1 is reduced, and when Vic is reduced to V1C<V1b-Vth_bc, the current I1 is sharply reduced, and accordingly, the current I2 is reduced, thereby realizing an over-current protection function of the circuit. In other words, when V1C<V1b-Vth_bc, the bias circuit and the power amplification circuit enter a current-limiting protection working state. Usually, in the GaAs HBT technology, Vth_bc is 1.2 V, V1b is 2.4 V, and thus, when V1C<1.2V, the bias circuit and the power amplification circuit enter the current-limiting protection working state.
The voltage drop VR on the first current limiting resistor R in the protection unit serves as a threshold voltage to limit a maximum current of the power amplification circuit, thereby realizing a current protection function. In addition, the second filter capacitor C plays a filtering role, which is in a low-resistance state at radio frequency and envelope signal frequency, such that the voltage drop VR on the first current limiting resistor R cannot change along with changes of radio frequency signals and envelope signals, thereby ensuring that the first transistor HBT1 is in a stable working state.
As shown in
According to the technical solution provided by the first embodiment, there may be different variation examples for the circuit structure of the power amplifier, a power supply module and the protection unit in
In addition, in the technical solution shown in
It needs to be explained that according to actual requirements of the power amplification circuit, the protection unit may include but not limited to one filter capacitor, which may alternatively include a plurality of different-size capacitors with capacitance values ranging from pF to uF, so as to filter radio frequency signals different in frequency and realize the effect of broadband filtering.
In a second embodiment of the present disclosure, for the situation of power apparatus damage or destruction due to great rise or fall of the working environment temperature, the power amplifier 2, the power supply module 4 and the protection unit 5 in the radio frequency front-end module may adopt two following technical solutions to solve the problem about over-current protection.
As shown in
assuming that the circuit is the power amplification circuit likely to burn out at the low temperature, and the thermistor with the negative temperature coefficient is selected as the first current limiting resistor R, when the temperature is reduced, the resistance value of the first current limiting resistor R is increased, at the time, according to the formula 1, the formula 2 and the formula 3, the voltage drop VR of the first current limiting resistor R is increased, the collector voltage V1C of the first thermistor HBT1 is reduced, and when V1C is reduced to V1C<V1b-Vth_bc, the current I1 is sharply reduced, and the current I2 is reduced as well, thereby realizing the over-current protection function on the power amplification circuit likely to burn out at the low temperature. Compared with the first current limiting resistor being a common resistor, the thermistor with the negative temperature coefficient is adopted as the first current limiting resistor, protection start time can be shortened, and the protection function is further enhanced.
Assuming that the circuit is the power amplification circuit likely to burn out at the high temperature, and the thermistor with the positive temperature coefficient is selected as the first current limiting resistor R, when the temperature is increased, the resistance value of the first current limiting resistor R is increased, at the time, according to the formula 1, the formula 2 and the formula 3, the voltage drop VR of the first current limiting resistor R is increased, the collector voltage Vic of the first thermistor HBT1 is reduced, and when Vic is reduced to V1c<V1b-Vth_bc, the current I1 is sharply reduced, and the current I2 is reduced as well, thereby realizing the over-current protection function on the power amplification circuit likely to burn out at the high temperature. Compared with the first current limiting resistor being the common resistor, the thermistor with the positive temperature coefficient is adopted as the first current limiting resistor, protection start time can be shortened, and the protection function is further enhanced.
As shown in
assuming that the circuit is the power amplification circuit likely to burn out at the low temperature, and the stabilized voltage supply with the positive temperature coefficient is selected as the bias power supply Vreg4, when the temperature is reduced, voltage output of the bias power supply Vreg4 is reduced, at the time, according to the formula 1 and the formula 3 (at the time, Vreg4 replaces VDD in the formulas), the collector voltage Vic of the first transistor HBT1 is reduced, and when Vic is reduced to V1C<V1b-Vth_bc, the current I1 is sharply reduced, and the current I2 is reduced as well, thereby realizing the over-current protection function on the power amplification circuit likely to burn out at the low temperature. Compared with a constant power supply VDD, the stabilized voltage supply with the positive temperature coefficient is selected as the bias power supply Vreg4, protection start time can be shortened, and the protection function is further enhanced.
Assuming that the circuit is the power amplification circuit likely to burn out at the high temperature, and the stabilized voltage supply with the negative temperature coefficient is selected as the bias power supply Vreg4, when the temperature is increased, voltage output of the bias power supply Vreg4 is reduced, at the time, according to the formula 1 and the formula 3 (at the time, Vreg4 replaces VDD in the formulas), the collector voltage Vic of the first transistor HBT1 is reduced, and when Vic is reduced to V1c<V1b-Vth_bc, the current I1 is sharply reduced, and the current I2 is reduced as well, thereby realizing the over-current protection function on the power amplification circuit likely to burn out at the high temperature. Compared with the constant power supply VDD, the stabilized voltage supply with the negative temperature coefficient is selected as the bias power supply Vreg4, protection start time can be shortened, and the protection function is further enhanced.
According to the technical solution provided by the second embodiment, there may also be different variation examples for the circuit structure of the power amplifier, the power supply module and the protection unit according to different requirements for the circuit performance. For example, the power amplifier is not limited to be formed by cascading three stages of power amplification units, which may alternatively be formed by cascading one, two, or even multiple stages of power amplification units together, so as to realize the technical solution provided by the present disclosure.
In addition, in the technical solution shown in
In a third embodiment of the present disclosure, as shown in
In the RLC combined circuit, the eleventh resistor R is the current limiting resistor, and the eleventh capacitor C2 and the twelfth capacitor C3 are both filter capacitors. It needs to be explained that the RLC combined circuit may alternatively be combined in other forms, but includes at least one current limiting resistor and one filter capacitor.
In addition, the RLC combined circuit may alternatively implement turn-on and turn-off of the protection unit through a control switch SW, and the control switch SW can be turned on at high power or high current or high voltage to limit current, such that the RLC combined circuit cannot affect working performance of the power amplifier under normal conditions.
As shown in
As shown in
The technical solution provided by the above third embodiment may alternatively be similarly applicable to the circuit structures of the first embodiment and the second embodiment according to specific circuit requirements, and one control switch SW is connected to the two ends of the protection unit in parallel to realize turn-on and turn-off of the protection unit, thereby achieving functions of optimizing a circuit protection function and working performance.
To verify the technical effects of the radio frequency front-end module provided by the embodiment of the present disclosure, the inventors perform input power and output current simulation tests on the technical solution of the present disclosure and the existing technical solution (without the protection unit). The test results are shown in
The radio frequency front-end module having a current protection function provided by the present disclosure may be applied to an electronic device to serve as an important part of a communication component. The electronic device described herein refers to a computer device that is used in a mobile environment and supports a plurality of communication standards including GSM, EDGE, TD_SCDMA, TDD_LTE, FDD_LTE, 5G, etc., and the electronic device may be a mobile phone, a notebook computer, a tablet, an on-board computer, etc. In addition, the technical solutions provided by the embodiments of the present disclosure are also applicable to other radio frequency integrated circuit application occasions, such as a communication base station, and intelligent connected vehicles.
As shown in
Through the detailed descriptions of the technical solution of the present disclosure according to the above embodiments, it can be seen that compared with the prior art, the radio frequency front-end module having a current protection function provided by the embodiment of the present disclosure can have the functions of over-current protection, over-voltage protection and overpower protection on the power amplifier through additional arrangement of the protection unit, such that working reliability and safety of the radio frequency front-end module in harsh environments are greatly improved. Meanwhile, the protection unit realizes the threshold voltage only by utilizing voltage drop changes of the current limiting resistor without causing additional circuit power consumption or occupying a large circuit area, and thus, the radio frequency front-end module having a current protection function provided by the present disclosure has the beneficial effects of being ingenious and reasonable in structural design, low in design cost, high in reliability, excellent in circuit perform, etc., and is applicable to various structures of radio frequency front-end modules.
It needs to be explained that the above multiple embodiments are only illustrative, and the technical solutions of the various embodiments may be combined and are all within the scope of the protection of the present disclosure.
In addition, the terms “first” and “second” are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features limited with “first” and “second” may explicitly or implicitly include one or more features. In the description of the present disclosure, “a plurality of” means two or more, unless otherwise explicitly and specifically defined.
The radio frequency front-end module having a current protection function, and the electronic device provided by the present disclosure are described in detail above. For those of ordinary skill in the art, any obvious modification made without departing from the essential contents of the present disclosure will constitute an infringement of the patent rights of the present disclosure, and the corresponding legal responsibilities should be borne.
Number | Date | Country | Kind |
---|---|---|---|
202210051858.5 | Jan 2022 | CN | national |
Number | Date | Country | |
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Parent | PCT/CN2023/072885 | Jan 2023 | WO |
Child | 18416841 | US |