CN219893295U

CN219893295U - Miller effect removing circuit

Info

Publication number: CN219893295U
Application number: CN202321503435.9U
Authority: CN
Inventors: 周小平
Original assignee: Zhuhai Baolan Science And Technology Co ltd
Current assignee: Zhuhai Baolan Science And Technology Co ltd
Priority date: 2023-06-14
Filing date: 2023-06-14
Publication date: 2023-10-24
Anticipated expiration: 2033-06-14

Abstract

The utility model relates to a Miller effect removing circuit which comprises a common base triode, wherein one side of the common base triode is provided with a common emitter circuit, and one side of the common emitter circuit and one side of the common base triode are provided with base direct current bias. Parasitic distributed capacitance Cbc is arranged between the collector electrode and the base electrode of the triode; parasitic distributed capacitance Cbe is arranged between the base electrode and the emitter electrode; these form a low-pass filter with the base resistor, and the low-pass filtering with Cbe cannot be avoided without any influence, and the amplification factor and Q2 are not related, provided that Q1 is in the amplification region. The amplification factor of the common emitter amplifying circuit formed by the Q1 is not influenced as long as the conduction of the Q2 is ensured. R3 and R4 provide base voltages required for conducting Q2, and C3 ensures that the base of Q2 is grounded in an alternating current manner. The introduction of Q2 allows the collector of Q1 to be AC grounded, so the "Miller effect" is absent, and the circuit is low in cost, good in effect with small changes, and only small increases in cost.

Description

Miller effect removing circuit

Technical Field

The utility model relates to the technical field of a Miller effect removing circuit used for preventing distortion of a high-frequency circuit, in particular to application in the high-frequency circuit.

Background

The transistors Cbc and Cbe exist, which form a low-pass filter with the base resistor R1/R2. The low-pass filter formed by the capacitor Cbe is unavoidable and can be understood. The low-pass filter formed by Cbc multiplies the low-pass effect by the connection of the common-emitter amplifier circuit. The voltage across Cbc is (1+a) Vi, a is the amplification factor, and Vi is the input voltage. The actual effect that can be seen as Cbe is (1+a) times amplified, which is the miller effect.

The miller effect makes the common emitter amplification circuit narrowest in bandwidth, worst in frequency characteristic, and incapable of amplifying high-frequency signals. Many electrical appliances at present need good frequency characteristics and bandwidths, and the conventional electrical appliances are narrow-band circuits and cannot amplify high-frequency signals, so those skilled in the art propose a circuit for removing the miller effect.

Disclosure of Invention

In view of the foregoing problems in the prior art, it is a primary object of the present utility model to provide a miller effect removing circuit.

The technical scheme of the utility model is as follows: the utility model provides a remove miller effect circuit, includes and shares base triode, the one side electric connection of sharing base triode has a common emitter circuit, the one side electric connection of sharing base triode has base DC bias, one side electric connection that base DC bias kept away from sharing the emitter circuit has base ground AC capacitor, one side electric connection that base ground AC capacitor kept away from base DC bias has equivalent load.

As a preferred embodiment, one side of the common emitter circuit is provided with a ground line.

As a preferred embodiment, one side of the common base triode is provided with a voltage interface.

As a preferred embodiment, the common base triode, the common emitter circuit, the base dc bias, the base grounded ac capacitor and the equivalent load are electrically conductive through copper wires.

Compared with the prior art, the utility model has the advantages and positive effects that:

in the utility model, cbc is arranged between the collector electrode and the base electrode of the triode; cbe is arranged between the base electrode and the emitter electrode; these form a low-pass filter with the base resistor, and the low-pass filtering with Cbe cannot be avoided without any influence, and the amplification factor and Q2 are not related, provided that Q1 is in the amplification region. The amplification factor of the common emitter amplifying circuit formed by the Q1 is not influenced as long as the conduction of the Q2 is ensured. R3 and R4 provide base voltages required for conducting Q2, and C3 ensures that the base of Q2 is grounded in an alternating current manner. The introduction of Q2 allows the collector of Q1 to be AC grounded, so that the "Miller effect" is absent; the circuit has low cost, brings good effect with small change, and has little increase in cost.

Drawings

Fig. 1 is a schematic circuit structure of the present utility model.

Legend description: 1. a common base triode; 2. a common emitter circuit; 3. a base DC bias; 4. a base electrode is grounded and is used for an alternating current capacitor; 5. equivalent load.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The utility model will be further described with reference to the drawings and the specific embodiments

Example 1

As shown in fig. 1, the present utility model provides a technical solution: the common-base transistor comprises a common-base transistor 1, wherein one side of the common-base transistor 1 is electrically connected with a common-emitter circuit 2, one sides of the common-emitter circuit 2 and the common-base transistor 1 are electrically connected with a base direct-current bias 3, one side of the base direct-current bias 3, which is far away from the common-emitter circuit 2, is electrically connected with a base grounding alternating-current capacitor 4, and one side of the base grounding alternating-current capacitor 4, which is far away from the base direct-current bias 3, is electrically connected with an equivalent load 5; a grounding wire is arranged on one side of the common emitter circuit 2; one side of the common base triode 1 is provided with a voltage interface; the common base triode 1, the common emitter circuit 2, the base direct current bias 3, the base grounding alternating current capacitor 4 and the equivalent load 5 are conducted through copper wires.

Working principle:

as shown in fig. 1, cbc is arranged between the collector and the base of the triode; cbe is arranged between the base electrode and the emitter electrode; they form a low-pass filter with the base resistor, and the low-pass filtering with Cbe cannot be avoided. The low-pass filter formed by Cbc can multiply the low-pass effect due to the connection of the common-emission amplifying circuit, so that the bandwidth of the common-emission amplifying circuit is the narrowest, the frequency characteristic is the worst, and the high-frequency signal cannot be amplified; the magnification is independent of Q2, provided that Q1 is in the amplification region. The amplification factor of the common emitter amplifying circuit formed by the Q1 is not influenced as long as the conduction of the Q2 is ensured. R3 and R4 provide base voltages required for conducting Q2, and C3 ensures that the base of Q2 is grounded in an alternating current manner. The introduction of Q2 allows the collector of Q1 to be ac grounded, so the "miller effect" is not present, and the use of this circuit is low in cost, with small changes, good results, and only a small increase in cost.

Finally, it should be noted that: the embodiments described above are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced with equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims

1. A de-miller effect circuit comprising a common base transistor (1), characterized in that: the common-base triode comprises a common-base triode body and is characterized in that one side of the common-base triode body (1) is electrically connected with a common-emitter circuit (2), one side of the common-emitter circuit (2) and one side of the common-base triode body (1) are electrically connected with a base direct-current bias (3), one side of the base direct-current bias (3) away from the common-emitter circuit (2) is electrically connected with a base grounding alternating-current capacitor (4), and one side of the base grounding alternating-current capacitor (4) away from the base direct-current bias (3) is electrically connected with an equivalent load (5).

2. The de-miller effect circuit of claim 1, wherein: and one side of the common emitter circuit (2) is provided with a grounding wire.

3. The de-miller effect circuit of claim 1, wherein: one side of the common base triode (1) is provided with a voltage interface.

4. The de-miller effect circuit of claim 1, wherein: the common base triode (1), the common emitter circuit (2), the base direct current bias (3), the base grounding alternating current capacitor (4) and the equivalent load (5) form a circuit whole.