CN221929805U - A circuit to eliminate high frequency self-excitation of low noise amplifier - Google Patents

Abstract

The utility model relates to the technical field of integrated circuits, in particular to a circuit for eliminating high-frequency self-excitation of a low-noise amplifier, which comprises an input module and an output module, wherein the input module and the output module are used for controlling the input and the output of radio-frequency current; the filter module is arranged at the output end of the input module and the input end of the output module and is used for removing oscillation components in the high-frequency self-oscillation signal and transmitting signals in a required frequency range; the amplifier module is arranged between the filter modules, and is used for amplifying an input signal of the input module, providing a signal amplifying function and transmitting the input signal to the output module; and a feedback control module disposed between the filter module and the amplifier module. The utility model has the advantages of eliminating the phenomenon that the amplifier has self excitation in a high frequency band, removing the interference of high-frequency radio frequency signals, reducing the noise level of the system, improving the accuracy and reliability of the signals and enabling the low-noise amplifying chip to work stably.

Description

A circuit to eliminate high frequency self-excitation of low noise amplifier

Technical Field

The utility model relates to the technical field of integrated circuits, in particular to a circuit for eliminating high-frequency self-excitation of a low-noise amplifier.

Background Art

In the global communication ecosystem, satellite communication is an important part of 5G-Advanced and 6G. Since the release of Huawei Mate60 Pro equipped with satellite calling function, satellite communication has been widely seen by Chinese people. Satellite communication has also become a hot topic in China and even the world. Ground equipment is an indispensable part of satellite communication, receiving antenna is an important part of satellite communication ground equipment, and low-noise amplifier circuit is a key component of receiving antenna.

In the process of receiving antenna design, self-excitation is an inevitable problem, which will greatly affect the performance indicators of the antenna. There are three main situations of self-excitation: low-frequency coupling caused by power lines; high-frequency coupling caused by signal lines; and common-mode coupling caused by poor grounding. Therefore, the utility model provides a circuit to eliminate high-frequency self-excitation of low-noise amplifiers to solve the above problems.

Utility Model Content

In view of the above existing technical problems, the present utility model is proposed.

The utility model aims to provide a circuit for eliminating high-frequency self-excitation of a low-noise amplifier, and aims to solve the self-excitation problem in the low-noise amplifier circuit.

In order to solve the above technical problems, the utility model provides the following technical solutions: a circuit for eliminating high-frequency self-excitation of a low-noise amplifier, comprising an input module and an output module, for input and output control of radio frequency current;

A filter module, arranged at the output end of the input module and the input end of the output module, for removing the oscillation component in the high-frequency self-excited oscillation signal and transmitting the signal within the required frequency range;

an amplifier module, disposed between the filter modules, for amplifying the input signal of the input module, providing a signal amplification function, and transmitting the input signal to the output module; and,

The feedback control module is arranged between the filter module and the amplifier module, and is used to control and adjust the feedback path to eliminate high-frequency self-excited oscillation.

As a preferred solution of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the filter module includes parallel coupled microstrip line filters, which are respectively arranged at the output end of the input module and the input end of the output module.

As a preferred solution for the circuit of eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the amplifier module includes a low-noise amplifier chip, both ends of the low-noise amplifier chip are respectively connected to the parallel coupled microstrip line filter, and the GND pin of the low-noise amplifier chip is grounded.

As a preferred solution for the circuit of eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the feedback control module includes a first decoupling capacitor, a second decoupling capacitor, a first capacitor, a second capacitor, a first resistor, a second resistor, a first magnetic bead and a second magnetic bead.

As a preferred solution of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the first resistor is connected to the input end of the low-noise amplifier chip, and the first magnetic bead is connected in series with the first resistor.

As a preferred solution of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the second resistor is connected to the output end of the low-noise amplifier chip, and the second magnetic bead is connected in series with the second resistor.

As a preferred solution of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, the first resistor and the second resistor have the same resistance value, which is 2Ω.

As a preferred solution for the circuit of the utility model to eliminate high-frequency self-excitation of a low-noise amplifier, one end of the first decoupling capacitor and the first capacitor are respectively connected in parallel with the first resistor, and the other ends of the first decoupling capacitor and the first capacitor are connected in series and grounded to the GND pin.

As a preferred solution of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model, one end of the second decoupling capacitor and the second capacitor are respectively connected in parallel with the second resistor, and the other ends of the second decoupling capacitor and the second capacitor are respectively grounded to GND pins.

As a preferred solution for the circuit of eliminating high-frequency self-excitation of the low-noise amplifier of the utility model, the secondary power supply capacitors of the drain and gate of the first capacitor and the second capacitor are both 1uF, and the access line of the input end of the low-noise amplifier chip is a gate high-resistance line.

The beneficial effects of the circuit for eliminating high-frequency self-excitation of a low-noise amplifier of the utility model are as follows: the circuit provided by the utility model can eliminate the phenomenon of self-excitation of the amplifier in the high-frequency band, can reduce the noise level of the system, and improve the accuracy and reliability of the signal; the parallel coupled microstrip line filter can effectively filter out high-frequency interference signals and prevent them from entering the low-noise amplifier chip, thereby reducing the noise level and interference of the system; the low-noise amplifier chip has the characteristics of low noise and high gain, can eliminate the phenomenon of common-mode coupling self-excitation caused by poor grounding, can enhance the input signal and suppress the introduction of noise, and improve the signal-to-noise ratio of the system; the feedback control module can control the gain and stability of the amplifier, can well suppress the phenomenon of low-frequency coupling self-excitation caused by the power line, and the decoupling capacitor can remove the interference of high-frequency radio frequency signals, so that the low-noise amplifier chip can work stably.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

FIG. 1 is a schematic diagram of the overall structure of a circuit for eliminating high-frequency self-excitation of a low-noise amplifier in the present invention.

FIG. 2 is a circuit diagram of a circuit for eliminating high-frequency self-excitation of a low-noise amplifier in the present invention.

FIG3 is a test diagram of antenna performance of a circuit for eliminating high-frequency self-excitation of a low-noise amplifier in the present invention.

DETAILED DESCRIPTION

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

Example 1

1 and 2 , which are the first embodiment of the utility model, a circuit for eliminating high-frequency self-excitation of a low-noise amplifier is provided, including an input module 100 and an output module 200, a filter module 300, an amplifier module 400 and a feedback control module 500. The input module 100 and the output module 200 are used for input and output control of radio frequency current.

Furthermore, the filter module 300 is arranged at the output end of the input module 100 and the input end of the output module 200, and is used to remove the oscillation component in the high-frequency self-excited oscillation signal and transmit the signal within the required frequency range. Preferably, the filter module 300 includes a parallel coupled microstrip line filter Z. Two parallel coupled microstrip line filters Z are arranged, which are respectively connected to the output end of the input module 100 and the input end of the output module 200. One can isolate the DC signal, and the other can filter out some clutter.

Furthermore, the amplifier module 400 is used to amplify the input signal of the input module 100, provide a signal amplification function, and transmit the input signal to the output module 200; specifically, the amplifier module 400 includes a low-noise amplifier chip U1, both ends of the low-noise amplifier chip U1 are respectively connected to the parallel coupled microstrip line filter Z, and the GND pin of the low-noise amplifier chip U1 is grounded. Preferably, the model of the low-noise amplifier chip U1 is CKRF7520CK34, and the chip is characterized by low noise and high gain. When drawing the printed circuit board PCB package, the pin grounding area of the chip ports 1 and 3 is as large as possible to ensure that the chip is fully grounded, which can eliminate the common-mode coupling self-excitation phenomenon caused by poor grounding.

Furthermore, the feedback control module 500 is disposed between the filter module 300 and the amplifier module 400, and is used to control and adjust the feedback path to eliminate high-frequency self-oscillation.

Specifically, the feedback control module 500 includes a first decoupling capacitor C1, a second decoupling capacitor C3, a first capacitor C2, a second capacitor C4, a first resistor R1, a second resistor R2, a first magnetic bead L1 and a second magnetic bead L2, the first resistor R1 is connected to the input end of the low-noise amplifier chip U1, the first resistor R1 is connected between the low-noise amplifier chip U1 and the parallel coupled microstrip line filter Z, the first magnetic bead L1 is connected in series with the first resistor R1, one end of the first decoupling capacitor C1 and the first capacitor C2 are respectively connected in parallel with the first resistor R1, and the first decoupling capacitor C1 is close to the low-noise amplifier chip. The first decoupling capacitor C1 is connected to the input end of the low-noise amplifier chip U1, and the other end of the first capacitor C2 is connected in series and the GND pin is grounded; the second resistor R2 is connected to the output end of the low-noise amplifier chip U1, and the second resistor R2 is connected between the low-noise amplifier chip U1 and the parallel coupled microstrip line filter Z, the second magnetic bead L2 is connected in series with the second resistor R2, one end of the second decoupling capacitor C3 and the second capacitor C4 are respectively connected in parallel with the second resistor R2, the second decoupling capacitor C3 is connected close to the output end of the low-noise amplifier chip U1, and the other ends of the second decoupling capacitor C3 and the second capacitor C4 are respectively grounded to the GND pins.

Preferably, the first resistor R1 and the second resistor R2 have the same resistance value, both of which are 2Ω, which can reduce the power ripple. When the resistance value here is too large, the RF signal output by the circuit will have low-frequency clutter signals; the drain and gate secondary power supply capacitors of the first capacitor C2 and the second capacitor C4 are both 1uF, which can well filter out the power ripple and improve the stability of the low-noise amplifier chip. In summary, the above-mentioned low-frequency coupling self-excitation phenomenon caused by the power line can be well suppressed.

Preferably, the first decoupling capacitor C1 is 100 pF, and the second decoupling capacitor C3 is 0.5 pF, which can remove the interference of high-frequency radio frequency signals and make the low-noise amplifier chip work stably.

Preferably, the access line of the input end of the low-noise amplifier chip U1 is a gate high-resistance line, and the high-resistance line is designed to be 1.5 mm to improve the RF and feed isolation; the magnetic bead model of the first magnetic bead L1 and the second magnetic bead L2 is FBMH1608HM601, which is used for high-frequency signal isolation.

The working principle of this embodiment is as follows: input RF current, the external RF signal enters the circuit through the input module 100, and passes through the parallel coupled microstrip line filter Z to isolate the DC signal to ensure that it does not propagate to the subsequent circuit, and filter out the interference signal, and then flows through the resistors and capacitors and other components of the feedback control module 500 to filter out the power ripple, remove the interference and isolation of the high-frequency RF signal, and improve the stability of the low-noise amplifier chip; then enters the input end of the low-noise amplifier chip U1, that is, port 4, which can improve the RF and feed isolation. The low-noise amplifier chip U1 receives and amplifies the RF signal processed by the filter, and again passes through the isolation and interference of the resistors and capacitors and other components of the feedback control module 500. The amplified and filtered RF signal is output through the output module 200 for use by the required subsequent circuits.

In summary, high-frequency interference signals are filtered out by parallel coupled microstrip line filters, amplified by low-noise amplifier chips, and output through the coordination of capacitors and resistors. This can effectively eliminate the self-excitation phenomenon of the low-noise amplifier in the high-frequency band and ensure the accuracy and reliability of the signal.

The circuit provided by the utility model can eliminate the self-excitation phenomenon of the amplifier in the high frequency band, can reduce the noise level of the system, and improve the accuracy and reliability of the signal. The parallel coupled microstrip line filter Z can effectively filter out the high-frequency interference signal so that it will not enter the low-noise amplifier chip, thereby reducing the noise level and interference of the system; the low-noise amplifier chip has the characteristics of low noise and high gain, can eliminate the common-mode coupling self-excitation phenomenon caused by poor grounding, can enhance the input signal and suppress the introduction of noise, and improve the signal-to-noise ratio of the system; the feedback control module 500 can control the gain and stability of the amplifier, can well suppress the low-frequency coupling self-excitation phenomenon caused by the power line, and the decoupling capacitor can remove the interference of the high-frequency radio frequency signal, so that the low-noise amplifier chip can work stably. By eliminating the high-frequency self-excitation phenomenon, the performance of the amplifier can be improved and the stability and reliability of the output signal can be guaranteed.

Example 2

3 , which is a second embodiment of the present utility model, this embodiment provides a circuit for eliminating high-frequency self-excitation of a low-noise amplifier. In order to verify its beneficial effects, a scientific demonstration is carried out through simulation experiments.

This embodiment is effectively verified by ADS simulation software. First, a circuit schematic diagram for eliminating high-frequency self-excitation of a low-noise amplifier is established, and electromagnetic field parameters are added according to the preferred solution. Then, the transmission characteristics of the circuit are calculated through a mathematical model.

As shown in Figure 3, the first part of Figure 3 is the gain value when the high resistance line is 1.5mm, and the second part of Figure 3 is the noise coefficient. According to the data shown in the figure, the circuit provided by the utility model can effectively remove the interference of high-frequency radio frequency signals, make the low-noise amplifier chip work stably, suppress the low-frequency coupling self-excitation phenomenon caused by the power line, and eliminate the common-mode coupling self-excitation phenomenon caused by poor grounding.

Importantly, it should be noted that the construction and arrangement of the present application shown in a number of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values (e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete element may be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present utility model. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also an equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment may not be described (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention).

It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims (10)

1. A circuit for eliminating high-frequency self-excitation of a low-noise amplifier is characterized in that: comprising the steps of (a) a step of,

An input module (100) and an output module (200) for input and output control of radio frequency current;

the filter module (300) is arranged at the output end of the input module (100) and the input end of the output module (200) and is used for removing oscillation components in the high-frequency self-oscillation signal and transmitting signals in a required frequency range;

An amplifier module (400) disposed between the filter modules (300) for amplifying an input signal of the input module (100), providing a signal amplifying function, and transmitting the input signal to the output module (200); and

And the feedback control module (500) is arranged between the filter module (300) and the amplifier module (400) and is used for controlling and adjusting a feedback path and eliminating high-frequency self-oscillation.

2. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 1 wherein: the filter module (300) comprises a parallel coupling microstrip line filter (Z) which is respectively arranged at the output end of the input module (100) and the input end of the output module (200).

3. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 2 wherein: the amplifier module (400) comprises a low-noise amplifying chip (U1), wherein two ends of the low-noise amplifying chip (U1) are respectively connected with the parallel coupling microstrip line filter (Z), and a GND pin of the low-noise amplifying chip (U1) is grounded.

4. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 3, wherein: the feedback control module (500) comprises a first decoupling capacitor (C1), a second decoupling capacitor (C3), a first capacitor (C2), a second capacitor (C4), a first resistor (R1), a second resistor (R2), a first magnetic bead (L1) and a second magnetic bead (L2).

5. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 4 wherein: the first resistor (R1) is connected with the input end of the low-noise amplifying chip (U1), and the first magnetic beads (L1) are connected with the first resistor (R1) in series.

6. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 4 wherein: the second resistor (R2) is connected with the output end of the low-noise amplifying chip (U1), and the second magnetic beads (L2) are connected with the second resistor (R2) in series.

7. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 5 or 6 wherein: the first resistor (R1) and the second resistor (R2) have the same resistance value of 2 omega.

8. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 5 wherein: one ends of the first decoupling capacitor (C1) and the first capacitor (C2) are respectively connected with the first resistor (R1) in parallel, and the other ends of the first decoupling capacitor (C1) and the first capacitor (C2) are connected in series and a GND pin is grounded.

9. A circuit for canceling high frequency self-excitation of a low noise amplifier as defined in claim 6 wherein: one ends of the second decoupling capacitor (C3) and the second capacitor (C4) are respectively connected with the second resistor (R2) in parallel, and the other ends of the second decoupling capacitor (C3) and the second capacitor (C4) are respectively grounded through GND pins.

10. A circuit for canceling high frequency self-excitation of a low noise amplifier according to claim 8 or 9, wherein: the drain electrode of the first capacitor (C2) and the second capacitor (C4) and the second power supply capacitor of the grid electrode are 1uF, and the access line of the input end of the low-noise amplifying chip (U1) is a grid electrode high-resistance line.