阅读说明：本技术 网络匹配调谐保护电路以及包括其的射频功率放大器 (Network matching tuning protection circuit and radio frequency power amplifier comprising same ) 是由 张毕禅 王显泰 龙海波 王虹 雷华奎 李孟 钱永学 孟浩 黄鑫 于 2021-09-06 设计创作，主要内容包括：本发明提供了一种用于射频功率放大器的网络匹配调谐保护电路,包括：N个串联的正向二极管和N个串联的反向二极管,所述N个串联的正向二极管和所述N个串联的反向二极管并联连接,其中,所述网络匹配调谐保护电路被配置为其一端与所述射频功率放大器的匹配网络的信号传输线连接,并且所述网络匹配调谐保护电路的另一端与接地节点连接,其中,N是大于等于1的自然数。(The invention provides a network matching tuning protection circuit for a radio frequency power amplifier, which comprises: the power amplifier comprises N forward diodes and N backward diodes which are connected in series, wherein the N forward diodes and the N backward diodes which are connected in series are connected in parallel, the network matching tuning protection circuit is configured to be connected with a signal transmission line of a matching network of the radio frequency power amplifier at one end, the other end of the network matching tuning protection circuit is connected with a ground node, and N is a natural number which is greater than or equal to 1.)

1. A network matched tuned protection circuit for a radio frequency power amplifier, comprising:

n series-connected forward diodes and N series-connected backward diodes, the N series-connected forward diodes and the N series-connected backward diodes being connected in parallel,

wherein the network matching tuning protection circuit is configured such that one end thereof is connected to a signal transmission line of a matching network of the radio frequency power amplifier and the other end thereof is connected to a ground node,

wherein N is a natural number of 1 or more.

2. The network matched tuned protection circuit of claim 1, wherein the value of N is determined according to a defined power of the radio frequency power amplifier and a forward conduction voltage of a forward diode.

3. The network matched tuning protection circuit of claim 1, wherein the matching network comprises at least one of an input matching network, an inter-stage matching network, and an output matching network of a radio frequency power amplifier.

4. The network matching tuning protection circuit of claim 1, wherein the matching network comprises an internal matching network A and an internal matching network B,

wherein the network matching tuning protection circuit is configured to be connected to an output of the internal matching network A and an input of the internal matching network B.

5. The network matched tuned protection circuit of claim 4, wherein the internal matching network A comprises a high-pass CL network, and wherein the internal matching network B comprises a low-pass LC network.

6. The network matched tuned protection circuit of claim 4, wherein the internal matching network A comprises a low-pass CL network, and wherein the internal matching network B comprises a high-pass LC network.

7. The network matched tuned protection circuit of claim 4, wherein the internal matching network A comprises a high pass CL network, and

wherein the internal matching network B includes a series structure of a capacitor and an inductor, one end of the internal matching network B is connected to an output terminal of the matching network, and the other end thereof is connected to a ground node.

8. The network matched tuned protection circuit of claim 4, wherein the internal matching network A comprises a low pass CL network, and

wherein the internal matching network B includes a series structure of a capacitor and an inductor, one end of the internal matching network B is connected to an output terminal of the matching network, and the other end thereof is connected to a ground node.

9. The network matched tuned protection circuit of claim 4, wherein the defined power required by the radio frequency power amplifier is adjusted by the impedance of the internal matching network A and internal matching network B.

10. A radio frequency power amplifier including a network matched tuned protection circuit according to any of claims 1-9, comprising:

an input matching network configured to receive a radio frequency signal and provide the signal to the driver stage circuit;

a driver stage circuit including a driver stage bias circuit, a driver stage amplifier circuit;

an inter-stage matching network configured between the driver stage circuit and a power stage circuit;

a power stage circuit comprising a power stage bias circuit, a power stage amplifier circuit;

an output matching network configured to output an amplified radio frequency signal; and

a network matching tuned protection circuit configured to be connected between a signal transmission line of at least one of the input matching network, the interstage matching network, or the output matching network and a ground node.

Technical Field

The present invention relates to radio frequency power amplifiers, and in particular, to radio frequency power amplifiers including network matching based tuning protection circuits.

Background

A Power Amplifier (PA) chip is an important element in a mobile phone intelligent terminal, and its main function is to load a data signal to a specific carrier frequency point, and then amplify the signal to a certain Power, so as to meet the receiving requirement of a remote base station and maintain the stability of data transmission.

With the development of 3G, 4G and 5G communications, the demand for data transmission rate is higher and higher. To meet the requirement of ever-increasing transmission rate, the radio frequency power amplifier of the mobile phone terminal needs to initiate new challenges in the aspects of new frequency band, high linearity, high transmission power and the like. Especially, the power of the rf power amplifier is gradually increased, and it is important to add a protection circuit in the transmission link.

In practical application environments, a transmission link generally includes a plurality of stages of power amplifiers, and the power of each stage is adjusted according to practical situations. If the protection circuit is added inside the chip, it cannot be flexibly adjusted. Therefore, according to the actual interstage transmission power, the protection circuit is added into the matching node, and the method is more flexible, practical and feasible.

Disclosure of Invention

The invention provides a network matching tuning protection circuit added in a radio frequency power amplifier, which realizes a power value required to be limited through impedance tuning of a matching structure, thereby achieving the protection function of the whole structure of a transmitting link.

One aspect of the present invention provides a network matching tuning protection circuit for a radio frequency power amplifier, including: the power amplifier comprises N forward diodes and N backward diodes which are connected in series, wherein the N forward diodes and the N backward diodes which are connected in series are connected in parallel, the network matching tuning protection circuit is configured to be connected with a signal transmission line of a matching network of the radio frequency power amplifier at one end, the other end of the network matching tuning protection circuit is connected with a ground node, and N is a natural number which is greater than or equal to 1.

One aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the value of N is determined according to a defined power of the radio frequency power amplifier and a forward conduction voltage of a forward diode.

An aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the matching network comprises at least one of an input matching network, an inter-stage matching network and an output matching network of the radio frequency power amplifier.

An aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the matching network comprises an internal matching network a and an internal matching network B, wherein the network matching tuning protection circuit is configured to be connected to an output of the internal matching network a and an input of the internal matching network B.

An aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the internal matching network a comprises a high-pass CL network, and wherein the internal matching network B comprises a low-pass LC network.

An aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the internal matching network a comprises a low-pass CL network, and wherein the internal matching network B comprises a high-pass LC network.

One aspect of the present invention provides a network matching tuning protection circuit for a radio frequency power amplifier, wherein the internal matching network a comprises a high-pass CL network, and wherein the internal matching network B comprises a series arrangement of a capacitor and an inductor, one end of the internal matching network B is connected to an output end of the matching network, and the other end thereof is connected to a ground node.

An aspect of the present invention provides a network matching tuning protection circuit for a radio frequency power amplifier, wherein the internal matching network a comprises a low pass CL network, and wherein the internal matching network B comprises a series arrangement of a capacitor and an inductor, one end of the internal matching network B is connected to an output end of the matching network, and the other end thereof is connected to a ground node.

One aspect of the present invention proposes a network matching tuning protection circuit for a radio frequency power amplifier, wherein the limited power required by the radio frequency power amplifier is adjusted by the impedance of the internal matching network a and the internal matching network B.

One aspect of the present invention provides a radio frequency power amplifier including a network matching tuning protection circuit, including: an input matching network configured to receive a radio frequency signal and provide the signal to the driver stage circuit; a driver stage circuit including a driver stage bias circuit, a driver stage amplifier circuit; an inter-stage matching network configured between the driver stage circuit and a power stage circuit; a power stage circuit comprising a power stage bias circuit, a power stage amplifier circuit; an output matching network configured to output an amplified radio frequency signal; and a network matching tuning protection circuit configured to be connected between a signal transmission line of at least one of the input matching network, the inter-stage matching network, or the output matching network and a ground node.

Drawings

Fig. 1 is a schematic diagram illustrating a radio frequency power amplifier including a network matching tuning protection circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention;

FIG. 3 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention;

fig. 4 is a circuit diagram illustrating a radio frequency power amplifier including a network matching tuning protection circuit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating an operating voltage swing of a network matched tuned protection circuit according to an embodiment of the present invention;

FIG. 6 is an impedance schematic illustrating a network matching tuned protection circuit according to an embodiment of the invention;

FIG. 7 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention; and

fig. 8 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention.

Detailed Description

Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms "couple," "connect," and derivatives thereof refer to any direct or indirect communication or connection between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with … …" and derivatives thereof means including, included within … …, interconnected, contained within … …, connected or connected with … …, coupled or coupled with … …, in communication with … …, mated, interwoven, juxtaposed, proximate, bound or bound with … …, having an attribute, having a relationship or having a relationship with … …, and the like. The term "controller" refers to any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware, or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of, when used with a list of items, means that a different combination of one or more of the listed items can be used and only one item in the list may be required. For example, "at least one of A, B, C" includes any one of the following combinations: A. b, C, A and B, A and C, B and C, A and B and C.

Definitions for other specific words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

In this patent document, the application combination of modules and the division levels of sub-modules are only used for illustration, and the application combination of modules and the division levels of sub-modules may have different manners without departing from the scope of the present disclosure.

In the normal operation mode of the rf power amplifier, the maximum power value that can be borne by the power stage (driver stage) is greatly related to the supply voltage/bias circuit/modulation signal. The protection circuit inside a general power stage (driving stage) chip has a relatively fixed protection value for excess power. When the supply voltage, the bias circuit, etc. are adjusted, the internal protection circuit cannot function.

When the power calibration is performed on the transmitting link of the chip, or the load impedance mismatch is severe, the protection circuit inside the chip does not work, and the chip is burnt. Therefore, it is very important to add a protection circuit between the matching networks.

Fig. 1 is a schematic diagram illustrating a radio frequency power amplifier including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 1, a two-stage power amplifier is taken as an example. The radio frequency input signal enters an input matching network, and the maximum power entering the drive stage amplifier is limited by matching the tuning protection circuit D1 through the input network; when a radio frequency signal enters the interstage matching network, the maximum power entering the power stage amplifier is limited through the interstage matching network tuning protection circuit D2; when the radio frequency signal enters the output network matching network, the maximum power output to the load is limited through the output matching network tuning protection circuit D3, and therefore power protection of the whole transmission link is achieved. It will be appreciated by those skilled in the art that although a two-stage rf power amplifier is shown in fig. 1, the principles of the present invention are equally applicable to a multi-stage power amplifier, with protection circuits added to the matching networks before and after the amplifier circuit to limit the maximum amount of power that can be passed through each matching network.

If the driver-level amplifier can withstand a maximum power of 20dBm, the driver-level amplifier may be damaged when the power is too high, resulting in failure of the entire transmit chain. The network matching tuning protection circuit according to the embodiment of the invention limits the power value of the RF1 signal passing through the input matching network, and the excess power can be discharged through the protection circuit, thereby protecting the drive stage amplifier.

According to the embodiment of the invention, the protection circuit is added in the front-end matching network of the radio frequency power amplifier circuit, the power value of the signal which can pass is limited, and the power value can be adjusted in the matching network, so that the phenomenon that the driving stage or the power stage of the circuit is burnt by excessive power conduction is avoided.

It will be appreciated by those skilled in the art that the principles of the present invention may be applied to other stages in a radio frequency power amplifier, such as a power stage amplifier, to provide protection to the circuit.

Fig. 2 is a schematic diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 2, an input network matching tuned protection circuit is taken as an example. An input matching network including a protection circuit includes: an internal matching network A, a protection circuit and an internal matching network B. Referring to fig. 2, the protection circuit is located between an internal matching network a and an internal matching network B. It will be appreciated by those skilled in the art that the protection circuit according to embodiments of the present invention may also be located before the internal matching network a or after the internal matching network B without departing from the scope of the present invention.

Fig. 3 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 3, the input matching network including the protection circuit is mainly composed of three parts (an internal matching network a, a protection circuit, and an internal matching network B). Referring to fig. 3, a radio frequency RF signal is input from RF-in and output from RF-out, wherein a line from RF-in to RF-out is a signal transmission line. The protection circuit is located between the internal matching network a and the internal matching network B. It will be appreciated by those skilled in the art that the protection circuit according to embodiments of the present invention may also be located before the internal matching network a or after the internal matching network B without departing from the scope of the present invention.

The internal matching network A is a high-pass CL network consisting of a series capacitor and a parallel inductor. The internal matching network B is a low-pass LC network consisting of a series inductor and a parallel capacitor. The locations of the internal matching network a and the internal matching network B may be interchanged. The internal matching network a may be composed of a plurality of identical structures and the internal matching network B may also be composed of a plurality of identical structures without departing from the scope of the present invention.

The protection circuit is composed of a parallel structure of N forward diodes (D11-D1N) and N reverse diodes (D21-D2N). The protection circuit is configured to be cascaded with an internal matching network a and an internal matching network B. According to an embodiment of the present invention, the protection circuit is configured to be connected between a signal transmission line and a ground node of the matching network. Referring to fig. 3, one end of the protection circuit is connected to the signal output terminal of the internal matching network a and the signal input terminal of the internal matching network B, and the other end of the protection circuit is grounded. It will be understood by those skilled in the art that the above examples are merely illustrative of the present invention and that various changes and modifications may be made to the above structure such that one end of the protection circuit is connected to a signal transmission line from RF-in to RF-out and the other end thereof is connected to a ground node.

Fig. 4 is a circuit diagram illustrating a radio frequency power amplifier including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 4, the network matching tuned protection circuit is configured in the matching network before the driver stage, and those skilled in the art will appreciate that the network matching tuned protection circuit may also be configured in the inter-stage matching network and the output matching network without departing from the scope of the present invention.

When the RF signal RF1 is of low power, there is no damage to the driver stage or power stage, and the protection circuit is not effective. When the power of the RF signal RF1 is large and close to the required limit, the protection circuit is turned on.

The protection circuit has two power limiting modes.

The first way is to determine the defined power by the number N of diodes in forward and reverse direction.

Fig. 5 is a schematic diagram illustrating an operating voltage swing of a network matched tuned protection circuit according to an embodiment of the present invention.

Referring to fig. 5, + Vdiode _ N represents a forward turn-on voltage after N diodes are connected in series, and-Vdiode _ N represents a reverse turn-on voltage after N diodes are connected in series. When the front and back matching networks C1, L1 and L2, C2 of the protection circuit are fixed, the power value to be limited is determined by the maximum forward conduction voltage and the minimum reverse conduction voltage in the protection circuit. At the moment, the power required to be limited is only related to the number N of the diodes, the power required to be limited can be increased by increasing N, and the power required to be limited can be reduced by reducing N. By adjusting the number of N, the power to be limited can be adjusted.

The second way is to limit the power RF1 by adjusting the matching networks C1, L1 and L2, C2 before and after the protection circuit.

Fig. 6 is an impedance diagram illustrating a network matching tuned protection circuit according to an embodiment of the invention.

Referring to FIG. 6, the input impedance Zin _ B of the internal matching network node B is represented by L2, C2 and the driver stage impedance Zin __{Drive stage}To determine; the input impedance Zin _ A of the internal matching network node A is represented by C1, L1, L2, C2 and the driver stage impedance Zin \u_{Drive stage}To jointly decide. By adjusting the values of C1, L1, L2 and C2And realizing impedance transformation on the protection circuit. The impedance value is inversely proportional to the power, so that the impedance is increased, and the power is reduced; reduce impedance and increase power. Therefore, the adjustment effect of limiting power is also realized through the impedance transformation on the internal matching A and the internal matching B, and the protection effect of the driving stage is realized.

Fig. 7 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 7, the matching network including the protection circuit is mainly composed of three parts (an internal matching network a, a protection circuit, and an internal matching network B). Referring to fig. 7, a radio frequency RF signal is input from RF-in and output from RF-out, wherein a line from RF-in to RF-out is a signal transmission line. The internal matching network A is a high-pass CL network consisting of a series capacitor and a parallel inductor. The internal matching network B is composed of a capacitor and an inductor series connection structure. The locations of the internal matching network a and the internal matching network B may be interchanged. The internal matching network a may be composed of a plurality of identical structures and the internal matching network B may also be composed of a plurality of identical structures, all without departing from the scope of the present invention.

The protection circuit is composed of a parallel structure of N forward diodes (D11-D1N) and N reverse diodes (D21-D2N). The protection circuit is configured to be cascaded with an internal matching network a and an internal matching network B. According to an embodiment of the present invention, the protection circuit is configured to be connected between a signal transmission line and a ground node of the matching network. Referring to fig. 7, one end of the protection circuit is connected to the signal output terminal of the internal matching network a and the signal input terminal of the internal matching network B, and the other end of the protection circuit is grounded.

The protection circuit is added into the matching network, so that the conduction power in the matching network is limited, and the protection effect on the radio frequency power amplifier is achieved.

Fig. 8 is a circuit diagram illustrating a matching network including a network matching tuning protection circuit according to an embodiment of the present invention.

Referring to fig. 8, the matching network including the protection circuit is mainly composed of three parts (an internal matching network a, a protection circuit, and an internal matching network B). Referring to fig. 8, a radio frequency RF signal is input from RF-in and output from RF-out, wherein a line from RF-in to RF-out is a signal transmission line. The internal matching network A is a low-pass LC network consisting of a series inductor and a parallel capacitor. The internal matching network B is composed of a capacitor and an inductor series connection structure. The locations of the internal matching network a and the internal matching network B may be interchanged. The internal matching network a may be composed of a plurality of identical structures and the internal matching network B may also be composed of a plurality of identical structures, all without departing from the scope of the present invention.

The protection circuit is composed of a parallel structure of both forward N diodes (D11-D1N) and reverse N diodes (D21-D2N), and is configured to be cascaded with an internal matching network A and an internal matching network B. According to an embodiment of the present invention, the protection circuit is configured to be connected between a signal transmission line and a ground node of the matching network. Referring to fig. 8, one end of the protection circuit is connected to the signal output terminal of the internal matching network a and the signal input terminal of the internal matching network B, and the other end of the protection circuit is grounded.

The protection circuit is added into the matching network, so that the conduction power in the matching network is limited, and the protection effect on the radio frequency power amplifier is achieved.

Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to embrace such alterations and modifications as fall within the scope of the appended claims.

None of the description in this specification should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope. The scope of patented subject matter is defined only by the claims.