CN118249761A

CN118249761A - Push-pull power amplifying circuit

Info

Publication number: CN118249761A
Application number: CN202211666170.4A
Authority: CN
Inventors: 曹原; 刘子林; 倪建兴
Original assignee: Radrock Shenzhen Technology Co Ltd
Current assignee: Radrock Shenzhen Technology Co Ltd
Priority date: 2022-12-23
Filing date: 2022-12-23
Publication date: 2024-06-25

Abstract

The invention discloses a push-pull power amplifying circuit. The push-pull power amplifying circuit comprises a first differential pair and a balun; the balun comprises a first winding and a second winding which are mutually coupled; the first winding includes a first coil segment and a second coil segment; a first end of the first coil segment and a first end of the second coil segment are connected to a first end of the first differential pair; a second end of the first coil segment and a second end of the second coil segment are connected to a second end of the first differential pair; the second winding is disposed between the first coil section and the second coil section, a first end of the second winding is connected to a signal transmission end, and a second end of the second winding is connected to a ground end. The first coil section and the second coil section of the first winding are arranged between the first end and the second end of the first differential pair in parallel, so that the output impedance at the two ends of the first differential pair is larger, and the output power of the first differential pair is smaller, so that the requirements of working efficiency, working bandwidth and linearity are met.

Description

Push-pull power amplifying circuit

Technical Field

The invention relates to the technical field of radio frequency communication, in particular to a push-pull power amplifying circuit.

Background

The rapid development of mobile communication services places higher demands on low-power consumption and high-efficiency device designs. The radio frequency power amplifier is the module with the largest energy consumption in the wireless transmitting terminal, so that the efficiency of the radio frequency power amplifier directly determines the energy consumption level of the whole wireless transmitting terminal, and how to improve the working efficiency of the radio frequency power amplifier becomes a hot spot in the field of radio frequency technology research.

Push-pull power amplification circuits are widely used because of their high output power and operating efficiency, and existing push-pull power amplification circuits generally include a differential circuit for implementing differential amplification processing and a balun for implementing signal synthesis and impedance conversion. However, the existing push-pull power amplifying circuit cannot meet the output power requirement in a specific frequency band (for example, wiFi frequency band) and has high cost, so that the applicability of the push-pull power amplifying circuit is greatly limited.

Disclosure of Invention

The embodiment of the invention provides a push-pull power amplifying circuit, which aims to solve the problem that the existing push-pull power amplifying circuit cannot be suitable for the output power requirement under a specific frequency band (such as a WiFi frequency band).

The embodiment of the invention provides a push-pull power amplifying circuit, which comprises a first differential pair and a balun;

the balun comprises a first winding and a second winding which are mutually coupled;

The first winding includes a first coil segment and a second coil segment; a first end of the first coil segment and a first end of the second coil segment are connected to a first end of the first differential pair; a second end of the first coil segment and a second end of the second coil segment are connected to a second end of the first differential pair;

the second winding is disposed between the first coil section and the second coil section, a first end of the second winding is connected to a signal transmission end, and a second end of the second winding is connected to a ground end.

Preferably, the turns ratio of the first winding and the second winding is between [0.9:1,1:1 ].

Preferably, the working frequency band of the push-pull power amplifying circuit is between [5.1GHz and 5.9GHz ].

Preferably, the impedance difference between the balanced and unbalanced ends of the balun is configured to be between 0 ohm, 5 ohm.

Preferably, the impedance of the first and second balanced ends of the balun is configured to be between [8 ohm, 12 ohm ].

Preferably, the first winding and the second winding are disposed on a first metal layer;

The first end of the first coil section and the first end of the second coil section are connected to the first end of the first differential pair through a first connection line provided on the first metal layer; the second end of the first coil section and the second end of the second coil section are connected to the second end of the first differential pair through a second connecting wire disposed on the first metal layer;

the second winding comprises a third coil section and a fourth coil section, the first end of the third coil section is connected to the signal transmission end, the second end of the third coil section is connected with the first end of the fourth coil section through a first jumper wire arranged on the second metal layer, and the second end of the fourth coil section is connected to the grounding end.

The first end of the first coil section and the second end of the second coil section are connected to the first end of the first differential pair through a second jumper provided on a second metal layer, and the second end of the first coil section and the second end of the second coil section are connected to the second end of the first differential pair through a third jumper provided on the second metal layer;

The second winding is a single coil, a first end of the single coil is connected to the signal transmission end, and a second end of the single coil is connected to the ground end.

Preferably, the push-pull power amplifying circuit further comprises an impedance matching circuit disposed on an unbalanced end of the balun.

Preferably, the impedance matching circuit comprises a first matching inductance, a second matching inductance and a first capacitance;

The first matching inductor and the second matching inductor are connected in series and coupled to the unbalanced end of the balun;

A first end of the first capacitor is coupled between the first matching inductance and the second matching inductance, and a second end of the first capacitor is grounded.

Preferably, the first differential pair includes a first amplifying transistor and a second amplifying transistor;

The push-pull power amplifying circuit further comprises a first matching capacitor and a second matching capacitor;

A first end of the first matching capacitor is connected with the first amplifying transistor, and a second end of the first matching capacitor is connected with the first end of the first coil section and the first end of the second coil section;

The first end of the second matching capacitor is connected with the second amplifying transistor, and the second end of the second matching capacitor is connected with the second end of the first coil section and the second end of the second coil section

Preferably, the push-pull power amplifying circuit further includes a common mode rejection circuit, a first end of the common mode rejection circuit is connected to the first amplifying transistor, a second end of the common mode rejection circuit is connected to the second amplifying transistor, and a third end of the common mode rejection circuit is grounded.

Preferably, the common mode rejection circuit includes a first inductor, a second inductor and a second capacitor, wherein a first end of the first inductor is connected with the first amplifying transistor, a second end of the first inductor is connected with a first end of the second inductor, a second end of the second inductor is connected with the second amplifying transistor, and a connection node between the first inductor and the second inductor is grounded through the second capacitor.

Preferably, a connection node between the first inductor and the second inductor is connected to a power supply terminal.

Preferably, the push-pull power amplifying circuit further comprises a first resonant circuit and a second resonant circuit;

one end of the first resonant circuit is connected with a connecting node between the first amplifying transistor and the first matching capacitor, and the other end of the first resonant circuit is grounded;

One end of the second resonant circuit is connected with a connecting node between the second amplifying transistor and the second matching capacitor, and the other end of the second resonant circuit is grounded.

Preferably, the first resonant circuit comprises a first resonant inductor and a first resonant capacitor which are connected in series, one end of the first resonant inductor is connected with a connecting node between the first amplifying transistor and the first matching capacitor, and one end of the first resonant capacitor is grounded;

The second resonant circuit comprises a second resonant inductor and a second resonant capacitor which are connected in series, one end of the second resonant inductor is connected with a connecting node between the second amplifying transistor and the second matching capacitor, and one end of the second resonant capacitor is grounded.

According to the push-pull power amplifying circuit, the first winding comprises the first coil section and the second coil section which are designed in a sectional mode, and the second winding is arranged between the first coil section and the second coil section, so that the coupling effect between the first winding and the second winding can be guaranteed; the first coil section and the second coil section are arranged between the first end and the second end of the first differential pair in parallel so as to conveniently adjust the turn ratio between the first winding and the second winding. And because the first winding adopts the first coil section and the second coil section of sectional type design for the second winding can set up between first coil section and second coil section, makes first winding and second winding can set up on two-layer base plate, compares in traditional structural design who sets up at four-layer base plate, can save the cost.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments of the present invention will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a push-pull power amplifier circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing another structure of a push-pull power amplifier circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a balun according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a push-pull power amplifying circuit according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the present invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for the same elements throughout for clarity.

It will be understood that when an element or layer is referred to as being "on" …, "" adjacent to "…," "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected to or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on" …, "" directly adjacent to "…," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially relative terms, such as "under …," "under …," "below," "under …," "over …," "above," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "below …" and "under …" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In the following description, for the purpose of providing a thorough understanding of the present invention, detailed structures and steps are presented in order to illustrate the technical solution presented by the present invention. Preferred embodiments of the present invention are described in detail below, however, the present invention may have other embodiments in addition to these detailed descriptions.

The embodiment of the invention provides a push-pull power amplifying circuit, which is shown in fig. 1 and 2, and comprises a first differential pair 1 and a balun 2; balun 2 includes a first winding 21 and a second winding 22 coupled to each other; the first winding 21 comprises a first coil section 211 and a second coil section 212; the first end of the first coil section 211 and the first end of the second coil section 212 are connected to the first end of the first differential pair 1; a second end of the first coil section 211 and a second end of the second coil section 212 are connected to a second end of the first differential pair 1; the second winding 22 is disposed between the first coil section 211 and the second coil section 212, a first end of the second winding 22 is connected to a signal transmission end, and a second end of the second winding 22 is connected to a ground end.

The first differential pair 1 is a semiconductor device which is formed by packaging two transistors with consistent performance into a whole in a push-pull power amplifying circuit. Balun 2 is a device used in a push-pull power amplification circuit to effect signal conversion between a balanced terminal and an unbalanced terminal.

The first winding 21 and the second winding 22 are two windings of balun 2, respectively, one of the two windings is a primary winding, and the other is a secondary winding. I.e. when the first winding 21 is the primary winding of balun 2, the second winding 22 is the secondary winding of balun 2; accordingly, when the second winding 22 is the primary winding of balun 2, the first winding 21 is the secondary winding of balun 2.

Wherein the first winding 21 comprises a first coil section 211 and a second coil section 212 of a segmented design, the first end of the first coil section 211 and the first end of the second coil section 212 being connected to the first end of the first differential pair 1, the second end of the first coil section 211 and the second end of the second coil section 212 being connected to the second end of the first differential pair 1, that is to say, the first coil section 211 and the second coil section 212 being arranged in parallel between the first end and the second end of the first differential pair 1. Since the first winding 21 includes the first coil section 211 and the second coil section 212 of the sectional design, the first coil section 211 and the second coil section 212 are disposed in parallel between the first end and the second end of the first differential pair 1, so that the first winding 21 may receive the first differential pair 1 and output a set of differential signals, or so that the first winding 21 may output a set of differential signals to the first differential pair 1, where the first winding 21 is a balanced end of the balun 2.

For example, the first differential pair 1 includes a first amplifying transistor M1 and a second amplifying transistor M2, the first winding 21 includes a first coil section 211 and a second coil section 212, a first end of the first coil section 211 and a first end of the second coil section 212 are connected to the first amplifying transistor M1, and a second end of the second coil section 212 are connected to the second amplifying transistor M2, so that the first coil section 211 and the second coil section 212 of the sectional design are disposed in parallel at both ends of the first differential pair 1.

Wherein the second winding 22 is arranged between the first coil section 211 and the second coil section 212, so that the second winding 22 is mutually coupled with the first coil section 211 and the second coil section 212, and the coupling effect between the two windings of the balun 2 can be ensured. The first end of the second winding 22 is connected to the signal transmission end, and the second end of the second winding 22 is connected to the ground end, so that the first end of the second winding 22 can receive a single-ended signal or output a single-ended signal, and the second winding 22 is an unbalanced end of the balun 2.

The output power of the first differential pair 1 is associated with the output impedance of the two ends of the first differential pair 1, that is, the larger the output impedance of the two ends of the first differential pair 1 is, the smaller the output power of the first differential pair 1 is, and conversely, the smaller the output impedance of the two ends of the first differential pair 1 is, the larger the output power of the first differential pair 1 is. When the first differential pair 1 operates in a specific operating frequency band, for example: when the first differential pair 1 processes radio frequency signals in a specific working frequency band (for example, a WIFI frequency band), larger output power is not needed, and working efficiency, working bandwidth and linearity can be guaranteed.

As an example, the push-pull power amplifying circuit includes a first differential pair 1 and a balun 2, the balun 2 includes a first winding 21 and a second winding 22, the first winding 21 includes a first coil section 211 and a second coil section 212 which are designed in a segmented manner, and the second winding 22 is disposed between the first coil section 211 and the second coil section 212, so that a coupling effect between the first winding 21 and the second winding 22 can be ensured; the first coil section 211 and the second coil section 212 are arranged in parallel between the first end and the second end of the first differential pair 1, so that the turns ratio between the first winding 21 and the second winding 22 can be conveniently adjusted, the balun 2 is hardly involved in impedance conversion of the push-pull power amplifying circuit or has smaller impedance conversion, the output impedance of the two ends of the first differential pair 1 is larger, and the output power of the first differential pair 1 is smaller, so that the working efficiency, the working bandwidth and the linearity under smaller output power can be met. And because the first winding 21 comprises the first coil section 211 and the second coil section 212 which are designed in a sectional mode, and the second winding 22 is arranged between the first coil section 211 and the second coil section 212, the first winding 21 and the second winding 22 can be arranged on two layers of substrates, and compared with the traditional structural design arranged on four layers of substrates, the cost can be saved.

In one embodiment, the turns ratio of the first winding 21 and the second winding 22 is between [0.9:1,1:1 ].

As an example, since the output impedance of balun 2 is equal to the input impedance of balun 2 multiplied by the square of the turns ratio, the greater the turns ratio of first winding 21 and second winding 22, the greater the degree of impedance conversion of balun 2, and conversely, the smaller the turns ratio of first winding 21 and second winding 22, the lesser the degree of impedance conversion of balun 2. In this example, the first coil section 211 and the second coil section 212 are disposed in parallel between two ends of the first differential pair 1, so that the turns ratio of the first winding 21 to the second winding 22 is between [0.9:1,1:1], and at this time, the balun 2 is hardly involved in the impedance conversion of the differential amplification process of the first differential pair 1 or is involved in the impedance conversion of the differential amplification process of the first differential pair 1, which is less, so that the output impedance of two ends of the first differential pair 1 is larger under the condition of ensuring the working efficiency, the working bandwidth and the linearity of the first differential pair 1, thereby meeting the requirement of the first differential pair 1 for smaller output power. For example, the turns ratio between the first winding 21 and the second winding 22 is 1: when 1, balun 2 does not participate in impedance conversion in the differential amplification process of first differential pair 1. The turns ratio between the first winding 21 and the second winding 22 is 0.9: when 1, balun 2 participates in impedance conversion of the first differential pair 1, but the impedance conversion is smaller, at this time, the output impedance of the first amplifying transistor M1 and the second amplifying transistor M2 in the first differential pair 1 is larger, and correspondingly, the output power of the first differential pair 1 is smaller, so as to satisfy the working efficiency, the working bandwidth and the linearity under the smaller output power. It will be appreciated that if the first coil section 211 and the second coil section 212 are arranged in series 5 between the two ends of the first differential pair 1, corresponding to two turns of the first winding, then the first winding 21

And the turns ratio of the second winding 22 is 2:1, balun 2 participates in the impedance conversion of first differential pair 1 and the impedance conversion is bigger, can lead to the output impedance of first differential pair 1 less, its output power is bigger, can't satisfy less output power's demand, consequently, adopt the first winding 1 of sectional type parallel design to compare in the first winding 1 of series design, can more satisfy less output power's demand.

0 In one embodiment, the push-pull power amplifier circuit operates in a frequency range between 5.1GHz and 5.9 GHz.

As an example, the operation frequency band of the push-pull power amplifying circuit is between [5.1ghz,5.9ghz ], wherein the [5.1ghz,5.9ghz ] is mainly the WiFi frequency band, that is, the push-pull power amplifying circuit is mainly applied to the WiFi frequency band. Generally, when the first differential pair 1 operates in the WiFi frequency band, the first differential pair

When a differential pair 1 processes the radio frequency signal in the WiFi frequency band, no larger output power is generally required, and at this time, a first coil section 211 and a second coil section 212 of the first winding 21 are arranged in parallel in the first

The second winding 22 is arranged between the first coil section 211 and the second coil section 212 at two ends of the differential pair 1, and the turns ratio of the first winding 21 and the second winding 22 is adjusted so that the balun 2 does not perform impedance conversion or performs smaller impedance conversion, and the output impedance at two ends of the first differential pair 1 is larger

The output power of the first differential pair 1 is smaller, so that the requirement of smaller output power of 0 in the WiFi frequency band can be met, and the working efficiency, the working bandwidth and the linearity can be ensured.

In one embodiment, the impedance difference between the balanced and unbalanced ends of balun 2 is configured to be between 0 ohms, 5 ohms.

As an example, since the first coil section 211 and the second coil section 212 of the first winding 21 are disposed in parallel at both ends of the first differential pair 1, that is, the first winding 21 is connected to both ends of the first differential pair 1, the first winding 21 receives the differential signal output from the first differential pair 1 or outputs the differential signal to the first differential pair 1, and at this time, the first winding 21 is the balanced end of the balun 2. Accordingly, since one end of the second winding 22 is connected to the signal transmission terminal and the other end is connected to the ground terminal, the second winding 22 can receive the single-ended signal output from the signal transmission terminal or output the single-ended signal to the signal transmission terminal, and the second winding 22 is an unbalanced terminal of the balun 2.

In this example, the impedance difference between the balanced end and the unbalanced end of the balun 2 is configured to be between [0 ohm, 5 ohm ], that is, the impedance difference between the first winding 21 and the second winding 22 of the balun 2 is configured to be between [0 ohm, 5 ohm ], which means that in the differential amplification process of the first differential pair 1, the balun 2 does not perform impedance conversion (for example, the impedance difference between the two is 0 ohm) or performs smaller impedance conversion (for example, the impedance difference between the two is less than or equal to 5 ohm), at this time, the output impedance of the two ends of the first differential pair 1 is larger, so that the output power of the first differential pair 1 is smaller, thereby not only meeting the requirement of smaller output power in the WiFi frequency band, but also guaranteeing the working efficiency, the working bandwidth and the linearity.

In an embodiment, the impedance of the first and second balanced terminals of balun 2 is configured to be between [8 ohm, 12 ohm ].

As an example, since the first coil section 211 and the second coil section 212 of the first winding 21 are disposed in parallel at both ends of the first differential pair 1, that is, the first winding 21 is connected to both ends of the first differential pair 1, so that the first winding 21 receives the differential signal output from the first differential pair 1 or outputs the differential signal to the first differential pair 1, at this time, the first winding 21 is a balanced end of the balun 2, an end of the first winding 21 connected to the first end of the first differential pair 1 is a first balanced end thereof, and an end of the first winding 21 connected to the second end of the first differential pair 1 is a second balanced end thereof.

In this example, the impedance of the first balance end and the second balance end of the balun 2 is configured to be between [8 ohm, 12 ohm ], that is, the impedance of the first end and the impedance of the second end of the first differential pair 1 are configured to be between [8 ohm, 12 ohm ], which means that the output impedance of the two ends of the first differential pair 1 reaches a larger standard, so that the output power of the first differential pair 1 is smaller, thereby not only meeting the requirement of smaller output power in the WiFi frequency band, but also guaranteeing the working efficiency, the working bandwidth and the linearity.

In one embodiment, as shown in fig. 1 and 3, the first winding 21 and the second winding 22 are disposed on the first metal layer; the first end of the first coil section 211 and the first end of the second coil section 212 are connected to the first end of the first differential pair 1 through a first connection line 213 provided on the first metal layer; the second end of the first coil section 211 and the second end of the second coil section 212 are connected to the second end of the first differential pair 1 by a second connection line 214 provided on the first metal layer; the second winding 22 includes a third coil section 221 and a fourth coil section 222, a first end of the third coil section 221 is connected to a signal transmission end, a second end of the third coil section 221 is connected to a first end of the fourth coil section 222 through a first jumper 224 provided on the second metal layer, and a second end of the fourth coil section 222 is connected to a ground end.

As an example, the first winding 21 and the second winding 22 of balun 2 are both provided on a first metal layer. The first winding 21 includes a first coil section 211 and a second coil section 212 of a sectional design, the first coil section 211 and the second coil section 212 being disposed in parallel between the first end and the second end of the first differential pair 1, in which the first end of the first coil section 211 and the first end of the second coil section 212 are connected to the first end of the first differential pair 1 through a first connection line 213 disposed on the first metal layer, and the second end of the second coil section 212 are connected to the second end of the first differential pair 1 through a second connection line 214 disposed on the first metal layer. That is, the first coil section 211, the second coil section 212, the first connection line 213 connecting the first end of the first coil section 211 and the first end of the second coil section 212, and the second connection line 214 connecting the second end of the first coil section 211 and the second end of the second coil section 212 are all disposed on the first metal layer.

The second winding 22 includes a third coil segment 221 and a fourth coil segment 222 that are arranged in a segmented manner, the third coil segment 221 and the fourth coil segment 222 are arranged in series between the signal transmission end and the ground end, specifically, a first end of the third coil segment 221 is connected to the signal transmission end, a second end of the third coil segment 221 is connected to a first end of the fourth coil segment 222 through a first jumper 224 that is arranged on the second metal layer, and a second end of the fourth coil segment 222 is connected to the ground end. That is, the third coil section 221 and the fourth coil section 222 are disposed on the first metal layer, and the first jumper 224 connecting the second end of the third coil section 221 and the first end of the fourth coil section 222 is disposed on the second metal layer to avoid the first jumper 224 from contacting the first connection line 213 and the second connection line 214.

In this example, the first coil section 211 and the second coil section 212 in the first winding 21 are disposed on the first metal layer, and are connected to both ends of the first differential pair 1 through a first connection line 213 and a second connection line 214, respectively, disposed on the first metal layer; and the third coil section 221 and the fourth coil section 222 in the second winding 22 are also disposed on the first metal layer, and are serially disposed between the signal transmission end and the ground end through the first jumper 224 disposed on the second metal layer, so as to avoid the connection of the first jumper 224 with the first connection line 213 and the second connection line 214, thereby ensuring the basic function of the balun 2, and realizing the layout of the balun 2 by adopting two metal layers, so that the area and the cost can be saved.

In one embodiment, as shown in fig. 2, the first winding 21 and the second winding 22 are disposed on a first metal layer; the first end of the first coil section 211 and the second end of the second coil section 212 are connected to the first end of the first differential pair 1 by a second jumper 215 provided on the second metal layer, and the second end of the first coil section 211 and the second end of the second coil section 212 are connected to the second end of the first differential pair 1 by a third jumper 216 provided on the second metal layer; the second winding 22 is a single coil 223, a first end of the single coil 223 is connected to the signal transmission terminal, and a second end of the single coil 223 is connected to the ground terminal.

As an example, the first winding 21 and the second winding 22 of balun 2 are both provided on a first metal layer. The first winding 21 includes a first coil section 211 and a second coil section 212 of a segmented design, the first coil section 211 and the second coil section 212 being disposed in parallel between the first end and the second end of the first differential pair 1, in which the first end of the first coil section 211 and the first end of the second coil section 212 are connected to the first end of the first differential pair 1 by a second jumper 215 disposed on the second metal layer, and the second end of the second coil section 212 are connected to the second end of the first differential pair 1 by a third jumper 216 disposed on the second metal layer. That is, the first coil section 211 and the second coil section 212 are disposed on the first metal layer, the second jumper 215 connecting the first end of the first coil section 211 and the first end of the second coil section 212, and the third jumper 216 connecting the second end of the first coil section 211 and the second end of the second coil section 212 are disposed on the second metal layer.

The second winding 22 includes a single coil 223 integrally provided, a first end of the single coil 223 is connected to a signal transmission terminal, a second end of the single coil 223 is connected to a ground terminal, and the single coil 223 is disposed on the first metal layer.

In this example, the first coil section 211 and the second coil section 212 in the first winding 21 are disposed on the first metal layer, and are connected to both ends of the first differential pair 1 through the second jumper 215 and the third jumper 216 disposed on the second metal layer, respectively; and the single coil 223 in the second winding 22 is arranged on the first metal layer, two ends of the single coil 223 are respectively connected to the signal transmission end and the grounding end, the second jumper 215 and the third jumper 216 which are arranged on the second metal layer are used for connecting the first coil section 211 and the second coil section 212, and the first winding 21 is prevented from being contacted with the single coil 223, so that the basic function of the balun 2 is ensured, the layout of the balun 2 is realized by adopting two metal layers, and the area and the cost can be saved.

In an embodiment, as shown in fig. 4, the push-pull power amplifying circuit further comprises an impedance matching circuit 3 arranged on the unbalanced side of the balun 2.

The impedance matching circuit 3 is a circuit for realizing impedance matching.

As an example, the push-pull power amplifying circuit further includes an impedance matching circuit 3 disposed on the unbalanced end of the balun 2, so that the impedance matching circuit 3 is used to perform impedance matching on the radio frequency signal transmitted on the unbalanced end of the balun 2, so that the matched radio frequency signal meets the required impedance requirement, and the working efficiency, the working bandwidth and the linearity of the push-pull power amplifying circuit are ensured.

In one embodiment, as shown in fig. 4, the impedance matching circuit 3 includes a first matching inductance L31, a second matching inductance L32, and a first capacitance C31; the first matching inductor L31 and the second matching inductor L32 are connected in series and are coupled to the unbalanced end of the balun 2; a first end of the first capacitor C31 is coupled between the first matching inductance L31 and the second matching inductance L32, and a second end of the first capacitor C31 is grounded.

The first matching inductance L31 and the second matching inductance L32 are inductances for actual impedance matching. The first capacitor C31 is a capacitor for realizing impedance matching.

As an example, the impedance matching circuit 3 provided on the unbalanced terminal of the balun 2 includes a first matching inductance L31, a second matching inductance L32, and a first capacitance C31. The first matching inductance L31 and the second matching inductance L32 are coupled in series to the unbalanced terminal of the balun 2, i.e., the first matching inductance L31 and the second matching inductance L32 are disposed in series between the balun 2 and the signal transmission terminal. A first end of the first capacitor C31 is coupled between the first matching inductance L31 and the second matching inductance L32, and a second end of the first capacitor C31 is grounded. In this example, the first matching inductance L31, the second matching inductance L32 and the first capacitor C31 cooperate to form a T-type impedance network, and perform impedance matching on the radio frequency signal on the unbalanced end of the balun 2, so as to meet the impedance requirement of the circuit where the balun is located, and further improve the Q value of the impedance matching circuit 3. Furthermore, the impedance matching circuit 3 is provided on the unbalanced end of the balun 2, and also has a harmonic filtering function.

In one embodiment, as shown in fig. 4, the first differential pair 1 includes a first amplifying transistor M1 and a second amplifying transistor M2; the push-pull power amplification circuit further comprises a first matching capacitor C11 and a second matching capacitor C12; a first end of the first matching capacitor C11 is connected to the first amplifying transistor M1, and a second end of the first matching capacitor C11 is connected to the first end of the first coil section 211 and the first end of the second coil section 212; the first end of the second matching capacitor C12 is connected to the second amplifying transistor M2, and the second end of the second matching capacitor C12 is connected to the second end of the first coil section 211 and the second end of the second coil section 212.

The first matching capacitor C11 and the second matching capacitor C12 are capacitors for realizing impedance matching.

As an example, the first differential pair 1 includes a first amplifying transistor M1 and a second amplifying transistor M2, and the push-pull power amplifying circuit further includes a first matching capacitor C11 and a second matching capacitor C12. The first end of the first matching capacitor C11 is connected to the first amplifying transistor M1, the second end of the first matching capacitor C11 is connected to the first end of the first winding 21, that is, the second end of the first matching capacitor C11 is connected to the first end of the first coil section 211 and the first end of the second coil section 212, that is, the second end of the first matching capacitor C11, so that the signal output by the first amplifying transistor M1 is input to the first end of the first winding 21 after being impedance-matched by the first matching capacitor C11, and normal operation of the balun 21 is ensured. The first end of the second matching capacitor C12 is connected to the second amplifying transistor M2, and the second end of the second matching capacitor C12 is connected to the second end of the first winding 21, that is, the second end of the second matching capacitor C12 is connected to the second end of the first coil section 211 and the second end of the second coil section 212, so that the signal output by the second amplifying transistor M2 is input to the second end of the first winding 21 after being impedance-matched by the second matching capacitor C12, and normal operation of the balun 21 is ensured.

In an embodiment, as shown in fig. 4, the push-pull power amplifying circuit further includes a common mode rejection circuit 5, a first end of the common mode rejection circuit 5 is connected to the first amplifying transistor M1, a second end of the common mode rejection circuit 5 is connected to the second amplifying transistor M2, and a third end of the common mode rejection circuit 5 is grounded.

The common mode rejection circuit 5 is a circuit for achieving common mode rejection.

As an example, the push-pull power amplifying circuit further includes a common mode rejection circuit 5, a first end of the common mode rejection circuit 5 is connected to the first amplifying transistor M1, a second end of the common mode rejection circuit 5 is connected to the second amplifying transistor M2, and a third end of the common mode rejection circuit 5 is grounded for achieving common mode rejection.

In an embodiment, as shown in fig. 4, the common mode rejection circuit 5 includes a first inductor L51, a second inductor L52, and a second capacitor C51, a first end of the first inductor L51 is connected to the first amplifying transistor M1, a second end of the first inductor L51 is connected to a first end of the second inductor L52, a second end of the second inductor L52 is connected to the second amplifying transistor M2, and a connection node between the first inductor L51 and the second inductor L52 is grounded through the second capacitor C51.

As an example, the common mode rejection circuit 5 includes a first inductor L51, a second inductor L52, and a second capacitor C51, the first inductor L51 and the second inductor L52 are serially connected between the output terminal of the first amplifying transistor M1 and the output terminal of the second amplifying transistor M2, and a connection node between the first inductor L51 and the second inductor L52 is grounded through the second capacitor C51. In this example, the odd harmonic signal output by the first amplifying transistor M1 goes to ground through the first inductor L51 and the second capacitor C51, that is, the first inductor L51 and the second capacitor C51 cooperate to form a first suppression branch, so as to suppress the odd harmonic signal output by the first amplifying transistor M1. The odd harmonic signal output by the second amplifying transistor M2 goes to the ground through the second inductor L52 and the second capacitor C51, that is, the second inductor L52 and the second capacitor C51 cooperate to form a second suppression branch, so as to suppress the odd harmonic signal output by the second amplifying transistor M2. In this example, the first suppression branch and the second suppression branch share the second capacitor C51, which can reduce the number of components in the circuit, and is helpful for saving area and reducing cost.

In an embodiment, a connection node between the first inductor L51 and the second inductor L52 is connected to the power supply terminal VCC.

As an example, the connection node between the first inductor L51 and the second inductor L52 is connected to the power supply terminal VCC, so that the power supply terminal VCC feeds the first amplifying transistor M1 through the first inductor L51 and feeds the second amplifying transistor M2 through the second inductor L52. In this example, in the common mode rejection circuit 5, the connection node between the first inductor L51 and the second inductor L52 is connected to the power supply terminal VCC, so that the first inductor L51 and the second inductor L52 not only can cooperate with the second capacitor C51 to implement an odd wave rejection function, but also can be connected to the power supply terminal VCC to form a feeding function. Understandably, the sharing of the first inductor L51 and the second inductor L52 does not require additional new components, which is helpful for reducing the number of components in the circuit, saving area and reducing cost.

In an embodiment, as shown in fig. 4, the push-pull power amplifying circuit further includes a first resonant circuit 6 and a second resonant circuit 7; one end of the first resonant circuit 6 is connected with a connection node between the first amplifying transistor M1 and the first matching capacitor C11, and the other end of the first resonant circuit 6 is grounded; one end of the second resonant circuit 7 is connected to a connection node between the second amplifying transistor M2 and the second matching capacitor C12, and the other end of the second resonant circuit 7 is grounded.

As an example, the push-pull power amplifying circuit further comprises a first resonant circuit 6 and a second resonant circuit 7. One end of the first resonant circuit 6 is connected with a connection node between the first amplifying transistor M1 and the first matching capacitor C11, and the other end of the first resonant circuit 6 is grounded to adjust the harmonic frequency output by the first amplifying transistor M1, so as to achieve the purpose of suppressing harmonic signals. One end of the second resonant circuit 7 is connected with a connection node between the second amplifying transistor M2 and the second matching capacitor C12, and the other end of the second resonant circuit 7 is grounded to adjust the harmonic frequency of the second amplifying transistor M2, so as to achieve the purpose of suppressing harmonic signals.

In an embodiment, as shown in fig. 4, the first resonant circuit 6 includes a first resonant inductor L61 and a first resonant capacitor C61 connected in series, one end of the first resonant inductor L61 is connected to a connection node between the first amplifying transistor M1 and the first matching capacitor C11, and one end of the first resonant capacitor C61 is grounded; the second resonant circuit 7 includes a second resonant inductor L71 and a second resonant capacitor C71 connected in series, one end of the second resonant inductor L71 is connected to a connection node between the second amplifying transistor M2 and the second matching capacitor C12, and one end of the second resonant capacitor C71 is grounded.

As an example, the first resonant circuit 6 includes a first resonant inductor L61 and a first resonant capacitor C61 connected in series, one end of the first resonant inductor L61 is connected to a connection node between the first amplifying transistor M1 and the first matching capacitor C11, one end of the first resonant capacitor C61 is grounded, and the harmonic frequency output by the first amplifying transistor M1 is adjusted by using the LC resonant circuit formed by the first resonant inductor L61 and the first resonant capacitor C61, so as to achieve the purpose of suppressing the harmonic signal. The second resonant circuit 7 includes a second resonant inductor L71 and a second resonant capacitor C71 connected in series, one end of the second resonant inductor L71 is connected to a connection node between the second amplifying transistor M2 and the second matching capacitor C12, and one end of the second resonant capacitor C71 is grounded, and the harmonic frequency of the second amplifying transistor M2 is adjusted by using the LC resonant circuit formed by the first resonant inductor L61 and the first resonant capacitor C61, so as to achieve the purpose of suppressing harmonic signals.

In this example, the first resonant inductor L61 and the first resonant capacitor C61 cooperate to form the first resonant circuit 6, the second resonant inductor L71 and the second resonant capacitor C71 cooperate to form the second resonant circuit 7, and the first resonant circuit 6 and the second resonant circuit 7 are configured to resonate at second order harmonics, so that the first differential pair 1 is a differential pair in a classF differential amplifying circuit, and the advantages of high linearity, low loss and high power added efficiency are achieved.

The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention 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 technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention.

Claims

1. A push-pull power amplifying circuit, comprising a first differential pair and a balun;

2. The push-pull power amplification circuit of claim 1, wherein a turns ratio of the first winding and the second winding is between [0.9:1,1:1 ].

3. The push-pull power amplification circuit of claim 1 wherein the push-pull power amplification circuit operates at a frequency band between [5.1ghz,5.9ghz ].

4. The push-pull power amplification circuit of claim 1, wherein an impedance difference between the balanced and unbalanced terminals of the balun is configured to be between [0 ohm, 5 ohm ].

5. The push-pull power amplification circuit of claim 1, wherein the impedance of the first and second balanced terminals of the balun is configured to be between [8 ohm, 12 ohm ].

6. The push-pull power amplification circuit of claim 1, wherein the first winding and the second winding are disposed on a first metal layer;

7. The push-pull power amplification circuit of claim 1, wherein the first winding and the second winding are disposed on a first metal layer;

8. The push-pull power amplification circuit of claim 7, further comprising an impedance matching circuit disposed on an unbalanced side of the balun.

9. The push-pull power amplification circuit of claim 8 wherein the impedance matching circuit comprises a first matching inductance, a second matching inductance, and a first capacitance;

10. The push-pull power amplification circuit of claim 8, wherein the first differential pair comprises a first amplifying transistor and a second amplifying transistor;

The first end of the second matching capacitor is connected with the second amplifying transistor, and the second end of the second matching capacitor is connected with the second end of the first coil section and the second end of the second coil section.

11. The push-pull power amplification circuit of claim 10, further comprising a common mode rejection circuit, a first terminal of the common mode rejection circuit coupled to the first amplification transistor, a second terminal of the common mode rejection circuit coupled to the second amplification transistor, and a third terminal of the common mode rejection circuit coupled to ground.

12. The push-pull power amplification circuit of claim 11, wherein the common mode rejection circuit comprises a first inductor, a second inductor, and a second capacitor, a first end of the first inductor being coupled to the first amplification transistor, a second end of the first inductor being coupled to the first end of the second inductor, a second end of the second inductor being coupled to the second amplification transistor, a connection node between the first inductor and the second inductor being coupled to ground through the second capacitor.

13. The push-pull power amplification circuit of claim 12, wherein a connection node between the first inductor and the second inductor is connected to a power supply terminal.

14. The push-pull power amplification circuit of claim 10, wherein the push-pull power amplification circuit further comprises a first resonant circuit and a second resonant circuit;

15. The push-pull power amplification circuit of claim 14, wherein the first resonant circuit comprises a first resonant inductor and a first resonant capacitor connected in series, one end of the first resonant inductor being connected to a connection node between the first amplifying transistor and the first matching capacitor, one end of the first resonant capacitor being grounded;