KR101531232B1 - Wideband doherty combiner - Google Patents

Abstract

The present invention relates to a broadband Doherty combiner, which comprises: a signal source for providing each input signal; each signal impedance line which is connected to the signal source and has respective characteristic impedance in accordance with each input signal; a first impedance conversion line for converting characteristic impedance, which is outputted from one signal impedance line of the signal impedance lines, to predetermined first impedance; a second impedance conversion line for converting characteristic impedance, which is outputted from the other signal impedance line of the signal impedance lines, to predetermined second impedance; a third impedance conversion line which matches the first impedance and the second impedance, which have been converted from the first impedance and the second impedance conversion lines, with an output load; a first impedance connection line to be connected to the first impedance conversion line; and a second impedance connection line to be connected to the second conversion line. The present invention is capable of enhancing an operating bandwidth and efficiency by improving coupling loss of input signals, reduction of second harmonic components, and the total coupling loss that occurs in a band other than a center frequency when output signals are combined through impedance lines to be connected from each impedance conversion line which is applied with an N number of output signals from a Doherty combiner.

Description

Broadband Doherty combiner {WIDEBAND DOHERTY COMBINER}

The present invention relates to a Doherty combiner, and more particularly to a Doherty combiner which reduces a combine loss of an input signal through another impedance line connected to each impedance conversion line where N output signals are combined in a Doherty combiner A high efficiency which improves the second band harmonic and improves the operation band and efficiency by improving the total coupling loss occurring in the band other than the center frequency when the output signal is combined, To a Doherty coupler having low loss wideband characteristics.

Recently, due to the spread of broadband communication technology and various broadband personal communication devices, a high output signal and a wide signal band have been used in the field of amplifiers and a higher efficiency has been demanded in fixed and portable communication devices. Therefore, various amplifiers Structure is proposed.

Meanwhile, various kinds of couplers including a Doherty coupler are used in order to group the input signals of a plurality of amplifiers into one signal. Among the couplers, the Doherty coupler receives the inputs of the main amplifier and the auxiliary amplifier, The advantage of improving the efficiency while maintaining the same output is widely used in the field of amplifier signal combining.

In the Doherty coupler as described above, the coupling loss due to coupling is 10 log (1 / N) in the case of the conventional Doherty coupler, and the coupling loss of each line is about -3.01 dB with respect to the center frequency. And the second harmonic is about -6dB.

However, the coupling loss in the conventional Doherty coupler has a problem of gradually increasing with reference to the center frequency in a band excluding the center frequency, and a large coupling loss has to be paid for using a wide band. In addition, in the case of the second harmonic, there is a problem that an additional circuit must be implemented in order to remove the harmonic component generated in the amplifier.

Korean Patent No. 10-1057736 discloses a combiner-circulator integrated communication device and a Doherty amplifier including the same.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a broadband Doherty combiner that reduces coupling loss of an input signal by connecting an impedance branch line to each impedance conversion line, The present invention aims to improve the total coupling loss occurring in a band other than the center frequency in combination of signals to improve the operating band.

The broadband-type heater combiner according to the embodiment of the present invention may improve efficiency by improving the coupling loss by removing the second harmonic component by connecting an impedance branch line to each impedance conversion line to which N output signals are coupled, .

In order to achieve the above object, a Doherty combiner according to the present invention includes: a signal source for providing respective input signals; Each signal impedance line connected to the signal source and having a respective characteristic impedance according to the respective input signal; A first impedance conversion line for converting a characteristic impedance output from a signal impedance line of each of the signal impedance lines to a predetermined first impedance; A second impedance conversion line for converting a characteristic impedance output from another signal impedance line of each of the signal impedance lines to a predetermined second impedance; A third impedance conversion line for matching the first impedance and the second impedance converted from the first impedance and the second impedance conversion line with the output load; A first impedance connection line connected to the first impedance conversion line; And a second impedance connection line connected to the second impedance conversion line.

The Doherty coupler according to the embodiment of the present invention is characterized in that the first impedance conversion line and the second impedance conversion line are coupled at one node and connected to the third impedance conversion line.

In the Doherty coupler according to the embodiment of the present invention, the third impedance conversion line is connected to the first impedance conversion line and the second impedance conversion line at one node, and the impedance generated from the node is output to the output And the impedance is matched.

The Doherty coupler according to another embodiment of the present invention is characterized in that the impedance of the first impedance connection line is larger than the impedance of the first impedance conversion line and the phase value is 10 or more.

The Doherty coupler according to another embodiment of the present invention is characterized in that the impedance of the first impedance connecting line has a value of the impedance of the first impedance converting line x 2.

The Doherty coupler according to another embodiment of the present invention is characterized in that the impedance of the second impedance connection line is larger than the impedance of the second impedance conversion line and the phase value is 10 or more.

The Doherty coupler according to another embodiment of the present invention is characterized in that the impedance of the second impedance connection line has a value of the impedance of the second impedance conversion line × 2.

In the Doherty coupler according to another embodiment of the present invention, the length of the first impedance conversion line changes according to the phase of the input signal, and the second impedance conversion line and the third impedance conversion line have phase values of 90 degrees or more Value.

The Doherty combiner according to another embodiment of the present invention is characterized in that the input signal is two or more, and the impedance line is two or more, and corresponds to the input signal.

A Doherty combiner according to another embodiment of the present invention includes: a first signal source for providing a first input signal; A second signal source for providing a second input signal; A third signal source for providing a third input signal; A first signal impedance line coupled to the first signal source and having a first characteristic impedance in accordance with the first input signal; A second signal impedance line coupled to the second signal source and having a second characteristic impedance in accordance with the second input signal; A third signal impedance line coupled to the third signal source and having a third characteristic impedance in accordance with the third input signal; A first impedance conversion line for converting the first characteristic impedance into a predetermined first impedance; A second impedance conversion line for converting the second characteristic impedance and the third characteristic impedance coupled through the node to a predetermined second impedance; A third impedance conversion line for matching the first impedance and the second impedance to an output load; A first impedance connection line connected to the first impedance conversion line; And a second impedance connection line connected to the second impedance conversion line.

The broadband Doherty combiner according to the present invention reduces the coupling loss of the input signal by connecting the impedance branch line to each of the impedance conversion lines to which the N output signals are coupled, Thereby improving the total coupling loss and improving the operating band.

The broadband Doherty combiner according to the embodiment of the present invention provides an effect of improving the coupling loss by improving the coupling loss by removing the second harmonic component by connecting the impedance branch lines to the respective impedance conversion lines to which the N output signals are coupled do.

1 is a detailed circuit diagram of a high-efficiency low-loss broadband Doherty combiner according to an embodiment of the present invention.
2 is an exemplary diagram of a T-Network;
3 is an exemplary graph of a Doherty combiner with three input signal sources according to an embodiment of the present invention.
Fig. 4 is a characteristic graph of a Doherty coupler according to the prior art with three input signal sources; Fig.
5 is a detailed circuit diagram of a high-efficiency low-loss broadband Doherty combiner according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the custom. Therefore, the definition should be based on the contents throughout this specification.

1 is a detailed circuit diagram of a high-efficiency low-loss broadband Doherty combiner according to an embodiment of the present invention.

1, the Doherty coupler 100 of the present invention includes signal sources (R ₁ , R _{N -1} , R _N ) and signal impedance lines 101, 102, 103 having characteristic impedances of signals and Z a first impedance conversion line 104, a third impedance conversion line 106, first impedance conversion lines having a second impedance of the impedance transformation lines (105), Z _g has an impedance of Z _f has an impedance of _e A first impedance connection line 107 having an impedance of connected Z _h , a second impedance connection line 108 having an impedance of Z _i connected to the second impedance conversion line, and an output load 301 having an impedance of Z ₀ .

Hereinafter, the operation of each component of the Doherty combiner 100 shown in FIG. 1 will be described in detail.

First, there may be three signal sources, as shown in FIG. 1, and may provide respective input signals for each signal source. On the other hand, the number of signal sources is not limited to the number, and signal impedance lines according to input signals generated from a plurality of signal sources can be coupled through nodes.

A first signal source (R ₁ ) providing a first input signal when there are three sources, a second signal source (R _{N -1} ) providing a second input signal, and a third signal source (R _N ).

And a signal impedance line connected to each signal source. The signal impedance line is connected to the first signal source and has a first signal impedance line 101 having _a first characteristic impedance Z _a in accordance with the first input signal, A second signal impedance line 102 having a second characteristic impedance Z _b according to a second input signal and a second signal impedance line 102 having a third characteristic impedance Z _c in accordance with a third input signal, And a third signal impedance line (103).

The signal impedance lines 101, 102, and 103 of the signal sources R ₁ , R _{N -1} , and R _N and the output load 301 may have the same impedance. The other signal sources R _{N -1} and R _N except for the signal source R ₁ are coupled through the node A 201 through the impedance lines 102 and 103 of the respective signal sources, The signal is coupled to the signal at the node B 202 via the second impedance conversion line 105 and output to the output load 301 via the third impedance conversion line 106.

In the Doherty coupler 100 of the present invention as described above, the first and second impedance conversion lines 104 and 105 having the impedance of Z _{e and} the impedance of Z _f are used to convert the input signal sources R ₁ , R _{N -1} , R _N ), and a third impedance conversion line 106 having an impedance of Z _g is connected between the first impedance conversion line 104 and the second impedance conversion line 105, Of the load impedance. The thus generated load impedance is matched with the output impedance of the output load 301.

The first impedance connection line 107 and the second impedance connection line 108 are connected to each other through a first impedance conversion line 104 and a second impedance conversion line 105 via a third impedance conversion line 106 It serves to reduce coupling loss when combined. A node C 203 connected to the first impedance connection line from the first impedance conversion line and a node D 204 connected to the second impedance connection line from the second impedance.

The specific values of the impedance of the first impedance connecting line 107 and the second impedance connecting line 108 can be determined as shown in Equation (1) below.

A typical T-network is configured in the format shown in FIG.

If not distribute the signals input to P ₀ to P _1, if all nagandago assumed to be P _2, the impedance Z ₁ is Z as compared to an impedance of _zero and Z ₂ has the extremely large impedance, the impedance of Z ₀ and Z ₂ Should be the same.

Therefore, it can be determined as shown in the following equation (1).

Assuming that the power to be distributed to P ₁ is 0, and the impedance of Z ₀ is 50, it can be determined as in Equation (2) below.

Therefore, the impedance of the first impedance connecting line 107 and the impedance of the second impedance connecting line 108 can be determined as shown in Equation (3) below because the impedance of the first impedance connecting line 107 and the impedance of the second impedance connecting line 108 are twice as large as those of the impedance lines connected to the first impedance connecting line 107 and the second impedance connecting line 108, respectively.

The impedances of the first impedance connecting line 107 and the second impedance connecting line 108 are determined by the first impedance converting line 104 and the second impedance converting line 105, respectively.

Assuming that the impedance of the first impedance conversion line 104 is 50 ohms and the impedance of the second impedance conversion line 105 is 25 ohms, ] Can be calculated as follows.

When the impedance values calculated as shown in Equation (4) are applied to the Doherty coupler 100 of the present invention to have a center frequency of 1 gigahertz (GHz), the result as shown in FIG. 3 can be derived .

3 illustrates characteristics of a Doherty coupler by three input signal sources according to an embodiment of the present invention.

Referring to FIG. 3, when a signal source having R ₀ , R ₁ , and R _{2 has} a signal source according to an embodiment of the present invention, the signal source R ₀ , R ₁ , R ₂ are equal to each other.

Reference numeral 402 denotes a reflection coefficient graph as viewed from the output load, and reference numeral 403 denotes a usable section when the loss of the signal sources is assumed to be -0.5 dB.

When the frequency up to the point where a loss of about -0.5 dB is additionally generated based on the loss of the center frequency band is defined as the frequency improvement band of the signal sources, the operating frequency band is lower than that of the conventional Doherty combiner shown in FIG. Which is more than two times higher than that of the conventional model.

FIG. 4 shows characteristics of a Doherty coupler according to three input signal sources used in the prior art.

When the above referring to Figure 4, in the conventional Doherty combiner For example, with a signal source of R _0, R _1, R _2, has a coupling loss characteristic, such as in reference numeral 404, a signal source R _0, R _1, And the coupling losses of R ₂ are all the same. In this case, reference numeral 405 denotes a section in which an additional loss of about -0.5 dB is generated based on the coupling loss at the center frequency for the signal sources R ₀ , R ₁ , and R ₂ . It can be seen that the frequency band is considerably narrow compared to the additional loss occurrence period of FIG.

5 shows a detailed circuit structure of a high-efficiency low-loss broadband Doherty combiner according to another embodiment of the present invention.

5, the Doherty combiner 500 of the present invention includes two input signal sources R ₁ and R ₂ and signal impedance lines 501 and 503 having characteristic impedances of signals and an impedance of Z _k a first impedance conversion tracks 502, the third impedance conversion tracks 505, the first connected to the first impedance conversion lines Z _o having a second impedance conversion impedance of the line (504), Z _n having the impedance Z _m with A fifth impedance connection line 507 having an impedance of Z _p connected to the second impedance conversion line, and an output load 701 having an impedance of Z ₀ . have.

Hereinafter, the operation of each component of the Doherty combiner 500 shown in FIG. 5 will be described.

First, the impedance lines 501 and 503 of the signal source and the output load 701 may have the same impedance. The two signal sources R ₁ and R ₂ received through the impedance lines 501 and 503 are coupled at the node C 601 via the first impedance conversion line 502 and the second impedance conversion line 504, And output to the output load 701 through the third impedance conversion line 505. [

In the Doherty coupler 500 of the present invention, the first and second impedance conversion lines 502 and 504 having the impedance of Z _{j and} the impedance of Z _k are used to convert the input signal sources R ₁ , R ₂ ), and a third impedance conversion line 505 having an impedance of Z ₁ forms a load impedance of the first impedance conversion line 502 and the second impedance conversion line 504 do. The thus generated load impedance is matched with the output impedance of the output load 701.

The first impedance connection line 506 and the second impedance connection line 507 are connected to the third impedance conversion line 505 through the first impedance conversion line 502 and the second impedance conversion line 504, And serves to reduce coupling loss when coupled therewith.

At this time, a specific value of the impedance Z _o of the first impedance connecting line 506 and the impedance Z _p of the second impedance connecting line 507 can be determined as shown in Equation (5) below.

It will be apparent to those skilled in the art that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. .

100: Doherty combiner
101: first signal impedance line
102: second signal impedance line
103: third signal impedance line
104: first impedance conversion line
105: second impedance conversion line
106: third impedance conversion line
107: first impedance connection line
108: second impedance connection line
301: Output load

Claims (10)

A signal source for providing respective input signals;
Each signal impedance line connected to the signal source and having a respective characteristic impedance according to the respective input signal;
A first impedance conversion line for converting a characteristic impedance output from a signal impedance line of each of the signal impedance lines to a predetermined first impedance;
A second impedance conversion line for converting a characteristic impedance output from another signal impedance line of each of the signal impedance lines to a predetermined second impedance;
A third impedance conversion line for matching the first impedance and the second impedance converted from the first impedance and the second impedance conversion line with the output load;
A first impedance connection line connected to the first impedance conversion line; And
And a second impedance connection line connected to the second impedance conversion line.
2. The semiconductor device according to claim 1, wherein the first impedance conversion line and the second impedance conversion line comprise:
And the third impedance conversion line is coupled to the third impedance conversion line at one node.
2. The semiconductor device according to claim 1, wherein the third impedance conversion line comprises:
Wherein the first impedance conversion line and the second impedance conversion line are combined at one node to match an impedance generated from the node with an output impedance of the output load.
The impedance matching circuit according to claim 1, wherein the impedance of the first impedance connecting line
Wherein the impedance of the first impedance conversion line is larger than the impedance of the first impedance conversion line, and the phase value has a value of 10 degrees or more.
The impedance matching circuit according to claim 1, wherein the impedance of the first impedance connecting line
And has a value of the impedance of the first impedance conversion line x 2.
The impedance matching circuit according to claim 1, wherein the impedance of the second impedance connecting line
Wherein the impedance of the second impedance conversion line is larger than the impedance of the second impedance conversion line, and the phase value has a value of 10 degrees or more.
The impedance matching circuit according to claim 1, wherein the impedance of the second impedance connecting line
And the impedance of the second impedance conversion line is 2 x the value of the impedance of the second impedance conversion line.
The method according to claim 1,
The first impedance conversion line varies in length depending on the phase of the input signal,
Wherein the second impedance conversion line and the third impedance conversion line have phase values of 90 degrees or more.
The method according to claim 1,
Wherein the input signal is at least two,
Wherein the impedance line is two or more, and corresponds to the input signal.
A first signal source providing a first input signal;
A second signal source for providing a second input signal;
A third signal source for providing a third input signal;
A first signal impedance line coupled to the first signal source and having a first characteristic impedance in accordance with the first input signal;
A second signal impedance line coupled to the second signal source and having a second characteristic impedance in accordance with the second input signal;
A third signal impedance line coupled to the third signal source and having a third characteristic impedance in accordance with the third input signal;
A first impedance conversion line for converting the first characteristic impedance into a predetermined first impedance;
A second impedance conversion line for converting the second characteristic impedance and the third characteristic impedance coupled through the node to a predetermined second impedance;
A third impedance conversion line for matching the first impedance and the second impedance to an output load;
A first impedance connection line connected to the first impedance conversion line; And
And a second impedance connection line connected to the second impedance conversion line.

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