Millimeter wave amplifier output open circuit protection circuit

Abstract

The invention relates to the technical field of radio frequency communication, in particular to a millimeter wave amplifier output open circuit protection circuit. A first protection unit, a second protection unit and an adjusting unit; by utilizing the original diode protection circuit, when the load voltage output by the millimeter wave amplifier is too high, the Vload voltage reduces the bias voltage, so that the gain of the millimeter wave amplifier is correspondingly reduced, the derating of the millimeter wave amplifier is realized, the millimeter wave amplifier is protected, and the derating threshold can be actually adjusted according to the set adjusting unit. And the ns-level millimeter wave amplifier protection is realized.

Description

Technical Field

[0001] This invention relates to the field of radio frequency communication technology, and more specifically, to a millimeter-wave amplifier output open-circuit protection circuit. Background Technology

[0002] Traditional amplifier protection circuits use a series diode at the amplifier output port as a protection circuit, such as... Figure 1 As shown, in traditional diode protection circuits, the time-domain waveform of the amplifier output port voltage still increases significantly when the amplifier is open-circuited, resulting in limited protection capability. Excessive open-circuit voltage can burn out the millimeter-wave amplifier. Current technologies have limited protection capabilities and often only meet specific needs for amplifier protection, frequently leading to amplifier damage from open circuits. Summary of the Invention

[0003] This invention addresses the problem that existing amplifier protection circuits have limited protection capabilities for millimeter-wave amplifiers, leading to frequent open-circuit damage. It proposes an open-circuit protection circuit for millimeter-wave amplifier outputs. Based on the existing diode protection circuit, when the output load voltage of the millimeter-wave amplifier is too high, the Vload voltage will pull down the bias voltage, thereby reducing the gain of the millimeter-wave amplifier and derating it to protect it. Furthermore, the derating threshold can be adjusted by a set adjustment unit, achieving nanosecond-level millimeter-wave amplifier protection.

[0004] The specific implementation details of this invention are as follows: A millimeter-wave amplifier output open-circuit protection circuit is connected to a diode protection circuit at the output of the millimeter-wave amplifier; it includes a first protection unit, a second protection unit, and an adjustment unit; One end of the adjustment unit is connected to the diode protection circuit, and the other end is connected to the first protection unit; One end of the first protection unit is input with a first bias voltage, and the other end is connected to the adjustment unit; The second protection unit receives a second bias voltage at one end and is connected to the adjustment unit at the other end. The first protection unit is used to generate a positive protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the forward direction. The second protection unit is used to generate a negative protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the negative direction. The adjustment unit is used to adjust the output power threshold of the millimeter-wave amplifier.

[0005] To better realize the present invention, the first protection unit further includes a transistor Q4; The base of the transistor Q4 is connected to the second adjustment unit and is connected to the diode protection circuit through the adjustment unit. The collector of the transistor Q4 is input with a first bias voltage, and the emitter of the transistor Q4 is connected to the ground terminal through the adjustment unit.

[0006] To better realize the present invention, the second protection unit further includes a transistor Q5; The base of transistor Q5 is connected to the base of transistor Q4, the collector of transistor Q5 is input with a second bias voltage, and the emitter of transistor Q5 is connected to ground through an adjustment unit.

[0007] To better realize the present invention, the adjustment unit further includes a first adjustment unit, a second adjustment unit, and a third adjustment unit; One end of the first adjustment unit is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the second adjustment unit is connected to the emitter of transistor Q4, and the other end is connected to ground. One end of the second adjustment unit is connected to the emitter of transistor Q5, and the other end is connected to ground.

[0008] To better realize the present invention, the first adjustment unit further includes resistor R1, resistor R2, and... One end of the resistor R2 is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the resistor R1 is connected between the resistor R2 and the base of the transistor Q4, and the other end is connected to ground.

[0009] To better realize the present invention, the second adjustment unit further includes a resistor R3; One end of the resistor R3 is connected to the emitter of the transistor Q4, and the other end is connected to ground.

[0010] To better realize the present invention, the second adjustment unit further includes a resistor R4; One end of the resistor R4 is connected to the emitter of the transistor Q5, and the other end is connected to ground.

[0011] The present invention has the following beneficial effects: This invention utilizes the existing diode protection circuit. When the output load voltage of the millimeter-wave amplifier is too high, the Vload voltage will pull down the bias voltage, thereby reducing the gain of the millimeter-wave amplifier accordingly. This derating of the millimeter-wave amplifier protects it. Furthermore, the derating threshold can be adjusted according to the set adjustment unit, achieving nanosecond-level millimeter-wave amplifier protection. Attached Figure Description

[0012] Figure 1 It is a traditional protection amplifier circuit.

[0013] Figure 2 This is a waveform diagram of the load voltage when the amplifier is connected to a load.

[0014] Figure 3 This is the voltage waveform of Vdown when the amplifier is connected to a load.

[0015] Figure 4 The voltage waveform of Load when the amplifier is open-circuited.

[0016] Figure 5 This is the voltage waveform of Vdown when the amplifier is connected to a load.

[0017] Figure 6 The schematic diagram of the millimeter-wave amplifier output open-circuit protection circuit provided by the present invention. Detailed Implementation

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments, and therefore should not be regarded as a limitation on the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1:

[0020] This embodiment proposes an open-circuit protection circuit for the output of a millimeter-wave amplifier, which is connected to a diode protection circuit at the output of the millimeter-wave amplifier; it includes a first protection unit, a second protection unit, and an adjustment unit; One end of the adjustment unit is connected to the diode protection circuit, and the other end is connected to the first protection unit; One end of the first protection unit is input with a first bias voltage, and the other end is connected to the adjustment unit; The second protection unit receives a second bias voltage at one end and is connected to the adjustment unit at the other end. The first protection unit is used to generate a positive protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the forward direction. The second protection unit is used to generate a negative protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the negative direction. The adjustment unit is used to adjust the output power threshold of the millimeter-wave amplifier.

[0021] Working principle: This embodiment improves upon the original millimeter-wave amplifier diode protection circuit to achieve a highly reliable millimeter-wave amplifier protection scheme. Utilizing the original diode protection circuit, when the output load voltage of the millimeter-wave amplifier is too high, the Vload voltage will pull down the bias voltage, thereby reducing the gain of the millimeter-wave amplifier accordingly. This derating of the millimeter-wave amplifier protects it, and the derating threshold can be adjusted according to the set adjustment unit, achieving nanosecond-level millimeter-wave amplifier protection.

[0022] The millimeter-wave amplifier output open-circuit protection circuit proposed in this embodiment is connected to one of the diodes in the millimeter-wave amplifier diode protection circuit, depending on the protection power threshold, or directly connected between the last grounded diode and the second-to-last diode in the millimeter-wave amplifier diode protection circuit. Example 2:

[0023] This embodiment is based on the above embodiment 1, such as... Figure 5 As shown, the structure of the first protection unit and the second protection unit is described with reference to a specific embodiment.

[0024] The first protection unit includes transistor Q4; The base of the transistor Q4 is connected to the second adjustment unit and is connected to the diode protection circuit through the adjustment unit. The collector of the transistor Q4 is input with a first bias voltage, and the emitter of the transistor Q4 is connected to the ground terminal through the adjustment unit.

[0025] The second protection unit includes transistor Q5; The base of transistor Q5 is connected to the base of transistor Q4, the collector of transistor Q5 is input with a second bias voltage, and the emitter of transistor Q5 is connected to ground through an adjustment unit.

[0026] Working principle: When the millimeter-wave amplifier output is open, the output voltage will rise abnormally (or DC offset will occur), and this voltage will be transmitted to the base of Q4 and Q5 through R2.

[0027] If the output is a positive voltage: Q4 is forward biased at the BE junction and Q4 is turned on. Its collector current is pulled down through R3, triggering subsequent protection logic (such as shutting down the output stage).

[0028] If the output is a negative voltage: the BE junction of Q5 is forward biased (the emitter potential is higher than the base), Q5 is turned on, and its collector current is pulled down through R4, which also triggers the protection.

[0029] When the millimeter-wave amplifier output is open, by Figure 4 As can be seen, when the Vload voltage increases, transistors Q4 and Q5 turn on, pulling down the bias voltages of transistors Q1 and Q2 in the millimeter-wave amplifier. This reduces the overall gain of the millimeter-wave amplifier, thereby reducing the output power and bringing the millimeter-wave amplifier to a safe operating state. This structure can achieve nanosecond-level protection for millimeter-wave amplifiers.

[0030] The other parts of this embodiment are the same as those in Embodiment 1 above, so they will not be described again. Example 3:

[0031] This embodiment describes the structure of the adjustment unit based on any one of the above embodiments 1-2, using a specific embodiment.

[0032] The adjustment unit includes a first adjustment unit, a second adjustment unit, and a third adjustment unit; One end of the first adjustment unit is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the second adjustment unit is connected to the emitter of transistor Q4, and the other end is connected to ground. One end of the second adjustment unit is connected to the emitter of transistor Q5, and the other end is connected to ground.

[0033] The first adjustment unit includes resistor R1, resistor R2, One end of the resistor R2 is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the resistor R1 is connected between the resistor R2 and the base of the transistor Q4, and the other end is connected to ground.

[0034] The second adjustment unit includes a resistor R3; One end of the resistor R3 is connected to the emitter of the transistor Q4, and the other end is connected to ground.

[0035] The second adjustment unit includes a resistor R4; One end of the resistor R4 is connected to the emitter of the transistor Q5, and the other end is connected to ground.

[0036] Working principle: In this embodiment, the power threshold to be protected is adjusted by adjusting the resistance ratio of resistors R1, R2, R3, and R4.

[0037] The other parts of this embodiment are the same as any one of the above embodiments 1-2, so they will not be described again.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A millimeter-wave amplifier output open-circuit protection circuit, connected to a diode protection circuit at the output terminal of the millimeter-wave amplifier; characterized in that, It includes a first protection unit, a second protection unit, and an adjustment unit; One end of the adjustment unit is connected to the diode protection circuit, and the other end is connected to the first protection unit; One end of the first protection unit is input with a first bias voltage, and the other end is connected to the adjustment unit; The second protection unit receives a second bias voltage at one end and is connected to the adjustment unit at the other end. The first protection unit is used to generate a positive protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the forward direction. The second protection unit is used to generate a negative protection trigger signal and shut down the millimeter-wave amplifier output stage when the millimeter-wave amplifier is open in the negative direction. The adjustment unit is used to adjust the output power threshold of the millimeter-wave amplifier.

2. The millimeter-wave amplifier output open-circuit protection circuit according to claim 1, characterized in that, The first protection unit includes transistor Q4; The base of the transistor Q4 is connected to the second adjustment unit and is connected to the diode protection circuit through the adjustment unit. The collector of the transistor Q4 is input with a first bias voltage, and the emitter of the transistor Q4 is connected to the ground terminal through the adjustment unit.

3. The millimeter-wave amplifier output open-circuit protection circuit according to claim 2, characterized in that, The second protection unit includes transistor Q5; The base of transistor Q5 is connected to the base of transistor Q4, the collector of transistor Q5 is input with a second bias voltage, and the emitter of transistor Q5 is connected to ground through an adjustment unit.

4. The millimeter-wave amplifier output open-circuit protection circuit according to claim 3, characterized in that, The adjustment unit includes a first adjustment unit, a second adjustment unit, and a third adjustment unit; One end of the first adjustment unit is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the second adjustment unit is connected to the emitter of transistor Q4, and the other end is connected to ground. One end of the second adjustment unit is connected to the emitter of transistor Q5, and the other end is connected to ground.

5. The millimeter-wave amplifier output open-circuit protection circuit according to claim 4, characterized in that, The first adjustment unit includes resistor R1, resistor R2, One end of the resistor R2 is connected to the diode protection circuit, and the other end is connected to the base of the transistor Q4; One end of the resistor R1 is connected between the resistor R2 and the base of the transistor Q4, and the other end is connected to ground.

6. The millimeter-wave amplifier output open-circuit protection circuit according to claim 4, characterized in that, The second adjustment unit includes a resistor R3; One end of the resistor R3 is connected to the emitter of the transistor Q4, and the other end is connected to ground.

7. The millimeter-wave amplifier output open-circuit protection circuit according to claim 4, characterized in that, The second adjustment unit includes a resistor R4; One end of the resistor R4 is connected to the emitter of the transistor Q5, and the other end is connected to ground.

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