Amplification device

Abstract

The amplifying device includes an amplifying circuit and a protection circuit. The amplifying circuit has an input terminal for receiving a radio frequency signal, and an output terminal for outputting an amplified radio frequency signal. The amplifying circuit includes a transistor. The transistor has a first terminal, a second terminal, and a control terminal. The first terminal of the transistor outputs the amplified radio frequency signal, and the control terminal of the transistor is coupled to the input terminal of the amplifying circuit. The first terminal of the protection circuit is coupled to the input terminal or the output terminal of the amplifying circuit. The protection circuit includes a switching unit and a clamping unit. The switching unit is controlled by a first control signal to be turned on or off. The clamping unit is coupled to the switching unit. When the switching unit is turned on, the clamping unit clamps the voltage of the first terminal of the protection circuit within a predetermined range.

Description

[0001] This application is a divisional application of application number 201811568858.2, invention name is amplification device, and application date is December 21, 2018. Technical Field

[0002] The present invention relates to an amplifier device, and more particularly to an amplifier device capable of maintaining linear performance in a bypass mode. Background Art

[0003] In mobile electronic devices, the communication module often transmits and receives radio frequency signals using the same antenna. For example, the transmitter and receiver of the communication module may be coupled to the same antenna. When the communication module receives a radio frequency signal through the antenna, it activates the low-noise amplifier in the receiver to amplify the signal and analyze the information contained therein. When the communication module transmits a radio frequency signal through the antenna, it activates the power amplifier in the transmitter to amplify the signal and output it through the antenna.

[0004] Generally speaking, the receiving-side low-noise amplifier (LNA) has a weak ability to withstand high-power signals. Therefore, when a communication module receives an RF signal through an antenna, if the system mistakenly activates the transmitter or couples the transmitter's energy, the stronger RF signal generated by the transmitter will also be input into the LNA, causing the LNA to malfunction or even damage it.

[0005] To protect low-noise amplifiers (LNAs), conventional clamping circuits are often added to the amplifier's input to prevent excessive RF signal swings from the transmitter, which could damage the amplifier. However, this also alters the matching impedance within the receiver, resulting in suboptimal signal amplification linearity. Summary of the Invention

[0006] An embodiment of the present invention provides an amplifier device, which includes an amplifier circuit and a protection circuit.

[0007] The amplifier circuit amplifies the radio frequency signal and has an input and an output. The input of the amplifier circuit receives the radio frequency signal, and the output of the amplifier circuit outputs the amplified radio frequency signal. The amplifier circuit includes a transistor having a first terminal, a second terminal, and a control terminal. The first terminal of the transistor outputs the amplified radio frequency signal, and the control terminal of the transistor is coupled to the input of the amplifier circuit.

[0008] The protection circuit has a first terminal and a second terminal. The first terminal of the protection circuit is coupled to the input terminal of the amplifier circuit or the output terminal of the amplifier circuit. The protection circuit includes a switch unit and a clamp unit. The switch unit is turned on or off by a control signal. The clamp unit is coupled to the switch unit and, when the switch unit is turned on, clamps the voltage at the first terminal of the protection circuit within a predetermined range. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. 1 is a schematic diagram of an amplifying device according to an embodiment of the present invention.

[0010] Figure 2 Schematic diagram of an amplifying device according to a second embodiment of the present invention.

[0011] Figure 3 Schematic diagram of an amplifying device according to embodiment 3 of the present invention.

[0012] Figure 4 Schematic diagram of an amplifying device according to a fourth embodiment of the present invention.

[0013]

Explanation of symbols

[0014] 100, 200, 300, 400 amplification devices

[0015] 110, 310, 410 amplifier circuits

[0016] 120, 220, 320, 420 protection circuits

[0017] 130 Bypass circuit

[0018] 140 Resistor Capacitor Filter 112, 114, 426 Passive components

[0019] M1 to M4, 122A, 132 transistors

[0020] C1, C2, C3, C4, C5 capacitors

[0021] 122, 222, 322, 422 switch units

[0022] 124, 224, 126, 324, 424 clamp units

[0023] D1, D2 diodes

[0024] SIG RF1 , SIG RF2 RF signal

[0025] SIG ctrl1 , SIG ctrl2 , SIG ctrl3 , SIGctrl4 control signal DETAILED DESCRIPTION

[0026] Figure 1 FIG. 1 is a schematic diagram of an amplifier device 100 according to an embodiment of the present invention. The amplifier device 100 includes an amplifier circuit 110 and a protection circuit 120. The amplifier circuit 110 can receive a radio frequency signal SIG. RF1 Amplification, and the protection circuit 120 can protect the amplifying circuit 110 to reduce damage caused by high-intensity radio frequency signals.

[0027] The amplifier circuit 110 has an input terminal IN and an output terminal OUT. The input terminal IN of the amplifier circuit 110 can receive a radio frequency signal SIG. RF1 , and the output terminal OUT of the amplifier circuit 110 can output the amplified radio frequency signal SIG RF2 .exist Figure 1 In the embodiment, the amplifier circuit 110 may include a transistor M1 having a first terminal, a second terminal and a control terminal. The first terminal of the transistor M1 may output the amplified RF signal SIG. RF2 , and the control terminal of the transistor M1 can be coupled to the input terminal IN of the amplifier circuit 110 .

[0028] The protection circuit 120 has a first terminal and a second terminal. The first terminal of the protection circuit 120 can be coupled to the input terminal IN of the amplifier circuit 110, and the second terminal of the protection circuit 120 can receive the first reference voltage V1. The protection circuit 120 can include a switch unit 122 and a clamp unit 124. The switch unit 122 is controlled by the control signal SIG. ctrl1 The clamping unit 124 is coupled to the switch unit 122. In some embodiments of the present invention, when the switch unit 122 is turned on, the clamping unit 124 can clamp the voltage at the first terminal of the protection circuit 120 within a predetermined range. In other words, when the input terminal of the amplifier circuit 110 receives a radio frequency signal with a relatively high intensity, i.e., a large voltage swing, the switch unit 122 can be turned on, and the clamping unit 124 can clamp the voltage of the input signal within a predetermined range that the amplifier circuit 110 can withstand, thereby reducing or preventing damage to the amplifier circuit 110.

[0029] In addition, Figure 1 In the embodiment, the amplifier device 100 may further include a bypass circuit 130. The bypass circuit 130 may be coupled to the input terminal IN and the output terminal OUT of the amplifier circuit 110. When the amplifier device 100 performs the bypass mode, the bypass circuit 130 may provide a bypass path between the input terminal IN and the output terminal OUT of the amplifier circuit 110. For example, if the RF signal SIG received by the amplifier device 100 is RF1The intensity of the signal is not strong enough and needs to be amplified by the amplifier circuit 110. At this time, the amplifier device 100 can execute the amplification mode to receive the radio frequency signal SIG. RF1 And output the amplified RF signal SIG RF2 and cuts off the bypass circuit 130 to prevent the radio frequency signal SIG RF1 From the input terminal IN to the output terminal OUT through the bypass circuit 130; if the radio frequency signal SIG received by the amplifier 100 RF1 The intensity of the signal is large enough and does not need to be amplified by the amplifier circuit 110. At this time, the amplifier device 100 can execute the bypass mode and turn on the bypass circuit 130 to pass the radio frequency signal SIG through the bypass circuit 130. RF1 The power is directly transmitted from the input terminal IN to the output terminal OUT, thereby reducing the power loss of the amplifier circuit 110 .

[0030] exist Figure 1 In the embodiment, the bypass circuit 130 may include a plurality of transistors 132, and the plurality of transistors 132 may be connected in series between the input terminal IN and the output terminal OUT of the amplifier circuit 110. In this way, it is possible to avoid a situation where a single transistor is mistakenly turned on due to a large input signal swing when the amplifier mode is executed, thereby preventing the bypass mode from being mistakenly activated.

[0031] In addition, when executing the bypass mode, in the case of impedance mismatch, if the RF signal SIG RF1 Input to the protection circuit 120 may cause the gain linear range of the amplifier device 100 to be reduced. To reduce this problem, the amplifier device 100 can turn off the switch unit 122 when executing the bypass mode, and when the RF signal SIG needs to be amplified by the amplifier circuit 110 RF1 , that is, when the amplifier device 100 performs the amplification mode, the switch unit 122 is turned on. In this way, the linear performance of the amplifier device 100 can be maintained in the bypass mode, and the RF signal SIG can also be amplified by the amplifier circuit 110. RF1 When the protection circuit 120 is used to protect the amplifier circuit 110 .

[0032] exist Figure 1 In the embodiment, the clamping unit 124 has a first end and a second end, and the first end of the clamping unit 124 can be coupled to the first end of the protection circuit 120. The switch unit 122 has a first end, a second end, and a control end, and the first end of the switch unit 122 can be coupled to the second end of the clamping unit 124, and the second end of the switch unit 122 can be coupled to the second end of the protection circuit 120. The switch unit 122 can receive a first reference voltage V1, such as a common voltage or a ground voltage, and the control end of the switch unit 122 can receive a control signal SIG. ctrl1 .

[0033] In addition, Figure 1 In the embodiment, the switch unit 122 may include a plurality of transistors 122A connected in series to reduce the situation where the switch unit 122 is mistakenly turned on. However, in some embodiments of the present invention, the switch unit 122 may also include only a single transistor 122A. Furthermore, since the transistors 122A in the switch unit 122 do not need to operate in high current applications, the size of each transistor 122A may be smaller than the size of the transistor M1 to reduce the area required for the switch unit 122. Figure 1 In the embodiment of the present invention, each transistor 122A in the switch unit 122 may be a metal-oxide-semiconductor field-effect transistor (MOSFET), but the present invention is not limited thereto. In other embodiments of the present invention, the transistors in the switch unit 122 may also be bipolar junction transistors (BJT).

[0034] Furthermore, the clamping unit 124 may include at least one diode D1 and at least one diode D2. Diode D1 is coupled between the first and second terminals of the clamping unit 124 with the same first bias (for example, but not limited to forward bias). Diode D2 is coupled between the first and second terminals of the clamping unit 124 with the same second bias (for example, but not limited to reverse bias). Diodes D1 and D2 are connected in parallel with different biases. Thus, when the input signal swing is positive and excessive, diode D1, operating in the first bias, is turned on and diverts the input signal, thereby reducing the possibility of the amplifier circuit 110 being damaged by the input signal. Conversely, when the input signal swing is negative and excessive, diode D2, operating in the second bias, is turned on and diverts the input signal, thereby reducing the possibility of the amplifier circuit 110 being damaged by the input signal.

[0035] In some embodiments of the present invention, depending on the characteristics of the input signal, the clamping unit 124 may include only one of the diodes D1 operating in the first bias mode or the diodes D2 operating in the second bias mode. Furthermore, in some embodiments of the present invention, the number of diodes D1 and D2 may be the same or different.

[0036] exist Figure 1In order to protect the transistors in the bypass circuit 130 in bypass mode, the protection circuit 120 may further include a clamping unit 126, which may be connected in parallel with the switch unit 122. Thus, when the switch unit 122 is turned off in bypass mode, the clamping units 124 and 126 can jointly clamp the voltage of the input signal within a wider range, thereby protecting the bypass circuit 130 while also preventing distortion of the desired input RF signal. Furthermore, in other embodiments of the present invention, the protection circuit 120 may replace the clamping unit 126 with an impedance unit. The impedance unit may be, for example, but not limited to, a resistor and may be connected in parallel with the switch unit 122 to protect the bypass circuit 130. Furthermore, in other embodiments of the present invention, the protection circuit 120 may omit the clamping unit 126 or the impedance unit depending on actual operating conditions.

[0037] exist Figure 1 In the embodiment, the amplifier circuit 110 may further include transistors M2, M3, and M4, passive components 112 and 114, capacitors C1, C2, C3, C4, and C5, and a resistor-capacitor filter (RC filter) 140. The transistor M2 has a first terminal, a second terminal, and a control terminal. The first terminal of the transistor M2 may be coupled to the second terminal of the transistor M1, and the control terminal of the transistor M2 may receive a control signal SIG. ctrl2 The passive element 112 has a first terminal and a second terminal. The first terminal of the passive element 112 can be coupled to the second terminal of the transistor M2, and the second terminal of the passive element 112 can receive the first reference voltage V1. The transistor M3 has a first terminal, a second terminal and a control terminal. The second terminal of the transistor M3 can be coupled to the first terminal of the transistor M1, and the control terminal of the transistor M3 can receive the control signal SIG. ctrl3 In some embodiments of the present invention, the transistors M2 and M3 can reduce the cross-voltage borne by the transistor M1, thereby protecting the transistor M1 and further improving the amplification gain.

[0038] The passive component 114 has a first terminal and a second terminal. The first terminal of the passive component 114 can receive a second reference voltage V2, and the second terminal of the passive component 114 can be coupled to the first terminal of the transistor M3. In some embodiments of the present invention, the first reference voltage V1 can be, for example, but not limited to, a reference voltage in the system, and the second reference voltage V2 can be, for example, but not limited to, an operating voltage in the system. The second reference voltage V2 can be greater than the first reference voltage V1. In addition, in some embodiments of the present invention, the passive components 112 and 114 can be, for example, but not limited to, inductors, and can choke high-frequency noise in the bias voltage.

[0039] The capacitor C1 has a first terminal and a second terminal. The first terminal of the capacitor C1 can be coupled to the second terminal of the passive component 114 and can be used for impedance matching of the amplifier circuit. The transistor M4 has a first terminal, a second terminal and a control terminal. The first terminal of the transistor M4 is coupled to the second terminal of the capacitor C1. The second terminal of the transistor M4 can be coupled to the output terminal OUT of the amplifier circuit 110. The control terminal of the transistor M4 can receive the control signal SIG. ctrl4 When the amplifying device 100 performs the amplifying mode, the control signal SIG ctrl4 The transistor M4 is turned on. When the amplifier 100 performs the bypass mode, the control signal SIG ctrl4 The transistor M4 will be turned off.

[0040] Capacitor C2 can be coupled to the output terminal OUT, mainly used to block DC signals. Capacitor C3 can be coupled to the input terminal IN, and capacitor C3 can provide matching impedance so that the input terminal IN can receive the RF signal SIG. RF1 , and can also block DC signals. Capacitors C4 and C5 can be coupled to both ends of the bypass circuit 130. Capacitors C4 and C5 can provide matching impedance to facilitate the bypass circuit 130 to receive the RF signal SIG. RF1 , and it can also block DC signals.

[0041] The resistor-capacitor filter 140 can be coupled to the control terminal of the transistor M3 and can convert the control signal SIG ctrl3 The noise in the transistor M3 is filtered out to make the operation of the transistor M3 more stable.

[0042] Since the protection circuit 120 in the amplifying device 100 can amplify the radio frequency signal SIG through the amplifying circuit 110 RF1 When the protection circuit 120 is in bypass mode, the internal switch unit 122 is turned on and rectified through the clamp unit 124, thereby effectively protecting the transistors in the amplifier circuit 110. In addition, the protection circuit 120 can also turn off the internal switch unit 122 in the bypass mode, thereby reducing the RF signal SIG. RF1 The current flows into the impedance mismatch protection circuit 120, so that the amplifier device 100 can maintain better linear performance. Figure 1 In the embodiment, the clamping unit 124 in the protection circuit 120 may be coupled to a first terminal of the protection circuit 120 , and the switch unit 122 may be coupled to a second terminal of the protection circuit 120 , but the present invention is not limited thereto.

[0043] Figure 2Schematic diagram of an amplifier device 200 according to a second embodiment of the present invention. Amplifier device 200 has a similar structure to amplifier device 100 and operates according to similar principles. The difference between the two is that the protection circuit 220 of amplifier device 200 includes a switch unit 222 and a clamp unit 224, but does not include a clamp unit or an impedance unit connected in parallel with the switch unit 222. The first terminal of the switch unit 222 is coupled to the first terminal of the protection circuit 220, and the control terminal of the switch unit 222 can receive a control signal SIG. ctrl1 A first terminal of the clamping unit 224 is coupled to the second terminal of the switch unit 222 , and a second terminal of the clamping unit 224 is coupled to the second terminal of the protection circuit 220 . The second terminal of the protection circuit 220 can receive the first system voltage V1 .

[0044] In addition, Figure 1 In the embodiment, the second end of the protection circuit 120 can receive the first system voltage V1, but the present invention is not limited thereto. Figure 3 FIG3 is a schematic diagram of an amplifier device 300 according to a third embodiment of the present invention. Amplifier device 300 and amplifier device 100 have similar structures and operate according to similar principles. The difference between the two is that in the protection circuit 320 of amplifier device 300, a clamp unit 324 and a switch unit 322 can be coupled between the first and second terminals of the protection circuit 320, and the second terminal of the switch unit 322 is coupled to the second terminal of the protection circuit 320 and the first terminal of transistor M2. In other words, the switch unit 322 in the protection circuit 320 can be connected in series with the transistor M2 in the amplifier circuit 310 to reduce the possibility of the switch unit 322 in the protection circuit 320 being mis-turned on. This reduces the number of transistors in the switch unit 322, thereby reducing the area of ​​the amplifier device 300.

[0045] Figure 4 FIG4 is a schematic diagram of an amplifier device 400 according to a fourth embodiment of the present invention. Amplifier device 400 and amplifier device 300 have similar structures and operate according to similar principles. The difference between the two is that the switch unit 422 in the protection circuit 420 of amplifier device 400 can replace the transistor M2 in amplifier circuit 310 of amplifier device 300, and the second terminal of the clamp unit 424 can be coupled to the second terminal of transistor M1. In this case, the size of transistor 422A in switch unit 422 can be larger than that of transistor M1 to limit the current in amplifier circuit 410.

[0046] That is to say, in Figure 4In an embodiment, the amplifier circuit 410 can share the transistor 422A in the switch unit 422 with the protection circuit 420, and the transistor M2 originally in the amplifier circuit 310 can be omitted. In this case, the protection circuit 420 may further include a passive element 426. The passive element 426 has a first end and a second end. The first end of the passive element 426 can be coupled to the second end of the switch unit 422, and the second end of the passive element 426 can be coupled to the second end of the protection circuit 420 and can receive the first reference voltage V1. In this way, since the switch unit 422 in the protection circuit 420 can share the same transistor with the amplifier circuit 410, the number of transistors in the amplifier device 400 can be further reduced, thereby reducing the area of ​​the amplifier device 400.

[0047] exist Figures 1 to 4 In some embodiments, the first terminals of the protection circuits 120 to 420 are respectively coupled to the input terminals of the amplifier circuits 110 to 410 to protect the amplifier circuits 110 to 410. In some embodiments, the amplifier devices 100, 200, 300, 400 may be coupled to other amplifier devices to form a multi-stage amplifier device to convert the radio frequency signal SIG RF1 In this case, the first end of the protection circuit 120, 220, 320, 420 can also be coupled to the output end of the amplifying circuit 110, 310, 410, so as to protect the next stage amplifying device.

[0048] In summary, the amplifier device provided by the embodiments of the present invention can reduce the likelihood of damage to the amplifier circuit from high-intensity RF signals through a protection circuit. Furthermore, because the protection circuit may include a switch unit and a clamp unit, when the amplifier device is in bypass mode, the switch unit can be turned off to maintain or improve the linear performance of the amplifier device.

[0049] The above descriptions are merely preferred embodiments of the present invention. Any equivalent changes and modifications made within the scope of the claims of the present invention shall fall within the scope of the present invention.

Claims

1. An amplifying device, characterized in that: Include: an amplifier circuit for amplifying a radio frequency signal, having an input terminal for receiving the radio frequency signal, and an output terminal for outputting the amplified radio frequency signal, the amplifying circuit includes a first transistor having a first terminal for outputting the amplified radio frequency signal, a second terminal, and a control terminal coupled to the input terminal of the amplifier circuit; and a protection circuit having a first terminal coupled to the input terminal of the amplifier circuit or the output terminal of the amplifier circuit, and a second terminal, the protection circuit comprising: a switch unit, configured to be turned on or off by a first control signal; and a first clamping unit, coupled to the switch unit, for clamping the voltage of the first end of the protection circuit within a predetermined range when the switch unit is turned on; When the amplifying device amplifies the radio frequency signal through the amplifying circuit, the switch unit is turned on; and When the amplifying device performs a bypass mode, the switching unit is turned off.

2. The amplifying device according to claim 1, characterized in that The device further includes a bypass circuit coupled to the input terminal and the output terminal of the amplifier circuit, for providing a bypass path between the input terminal and the output terminal of the amplifier circuit when the amplifier device performs the bypass mode.

3. The amplifying device according to claim 2, characterized in that The first end of the protection circuit is coupled to the input end of the amplifier circuit.

4. The amplifying device according to claim 3, characterized in that in: The switch unit has a first terminal coupled to the first terminal of the protection circuit, a second terminal, and a control terminal for receiving the first control signal; and The first clamping unit has a first end coupled to the second end of the switch unit, and a second end coupled to the second end of the protection circuit.

5. The amplifying device according to claim 3, characterized in that in: The first clamping unit has a first end coupled to the first end of the protection circuit, and a second end; and The switch unit has a first terminal coupled to the second terminal of the first clamp unit, a second terminal, and a control terminal for receiving the first control signal.

6. The amplifying device according to claim 5, characterized in that in: The second end of the first clamping unit is further coupled to the second end of the first transistor.

7. The amplifying device according to claim 6, characterized in that The protection circuit further includes a passive element having a first end coupled to the second end of the switch unit and a second end coupled to the second end of the protection circuit and configured to receive a first reference voltage.

8. The amplifying device according to claim 6, characterized in that in: The switch unit includes at least one transistor, and a size of the at least one transistor of the switch unit is larger than a size of the first transistor.

9. The amplifying device according to claim 5, characterized in that The amplifying circuit further comprises: a second transistor having a first terminal coupled to the second terminal of the first transistor, a second terminal, and a control terminal for receiving a second control signal; and A first passive element has a first terminal coupled to the second terminal of the second transistor and a second terminal for receiving a first reference voltage.

10. The amplifying device according to claim 9, characterized in that The second end of the switch unit is coupled to the second end of the protection circuit and the first end of the second transistor.

11. The amplifying device according to claim 9, characterized in that The second end of the switch unit is coupled to the second end of the protection circuit and is used to receive the first reference voltage.

12. The amplifying device according to claim 9, characterized in that in: The switch unit includes at least one transistor, and a size of the at least one transistor of the switch unit is smaller than a size of the first transistor.

13. The amplifying device according to claim 12, characterized in that Each transistor of the switch unit is a metal oxide semiconductor field effect transistor or a bipolar junction transistor.

14. The amplifying device according to claim 2, characterized in that The amplifier circuit further includes: a third transistor having a first terminal, a second terminal coupled to the first terminal of the first transistor, and a control terminal for receiving a third control signal; a second passive element having a first end for receiving a second reference voltage and a second end coupled to the first end of the third transistor; a capacitor having a first end coupled to the second end of the second passive element, and a second end; and a fourth transistor; having a first terminal coupled to the second terminal of the capacitor, a second terminal coupled to the output terminal of the amplifier circuit, and a control terminal for receiving a fourth control signal; When the amplifying device performs the bypass mode, the fourth transistor is turned off.

15. The amplifying device according to claim 1, characterized in that The protection circuit further includes a second clamping unit connected in parallel with the switch unit.

16. The amplifying device according to claim 1, characterized in that The protection circuit further includes an impedance unit connected in parallel with the switch unit.

17. The amplifying device according to claim 1, characterized in that The first clamping unit includes at least one first diode, and the at least one first diode is coupled between a first end of the first clamping unit and a second end of the first clamping unit in a same first bias manner.

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