CN102801387A - Dual-mode dual-band high-efficiency Doherty power amplifier - Google Patents

Abstract

The invention provides a dual-mode dual-band high-efficiency Doherty power amplifier, which comprises a dual-band power divider module, a dual-band input matching module, a main power amplifier, a peak power amplifier, a dual-band output matching module, a dual-band phase compensation line module, a dual-band impedance inverter and a dual-band impedance transformer, wherein the dual-band phase compensation line module comprises a phase compensation line of a main power amplifier branch and a phase compensation line of the peak power amplifier; the phase compensation line of the main power amplifier branch converts the load impedance of the main power amplifier to approach to the optimum efficiency point at a power back-off point; and the phase compensation line of the peak power amplifier makes the output impedance of the peak power amplifier be in an infinite state in a low-power state. The dual-mode dual-band high-efficiency Doherty power amplifier can be simultaneously operated on two communication frequency bands, the input power enters the main power amplifier and the peak power amplifier in a non-equally divided mode, the incomplete modulation effect is reduced, the overall performance of the Doherty is improved, and the dual-mode dual-band high-efficiency Doherty power amplifier can be applied to multimode base stations and software radio and contributes to saving the energy and reducing the cost.

Description

A kind of double-mode double-band high efficiency Doherty power amplifier

Technical field

The present invention relates to wireless communication technology field, relate in particular to a kind of double-mode double-band high efficiency Doherty power amplifier.

Background technology

In the wireless communication system, efficient is two key factors of power amplifier with linearity all the time in modern times.The frequency spectrum resource of communication system and growing tension increasingly high to the transfer of data rate requirement has caused efficient but complicated modulation system, makes signal have very high peak-to-average force ratio (PAR).The tradition power amplifier need be operated in the linear index that big rollback zone could guarantee communication, has so just caused the whole efficiency of power amplifier low.

The Doherty power amplifier was initiated by W.H.Doherty in 1936.The Doherty power amplifier is one of common technology that improves at present the transmitter average efficiency.Tradition Doherty structured flowchart is as shown in Figure 1, and power divider 10 is with the two paths of signals of radiofrequency signal div in par aeq homophase; Radiofrequency signal through five equilibrium gets into main power amplifier 31 and peak value power amplifier 32 respectively through input matching network 21 and 22; The output matching network 41 of main power amplifier and the output matching network of peak value power amplifier 42 provide optimum load to signal; Radiofrequency signal after the phase compensation line 51 of main power amplifier and 52 pairs of amplifications of phase compensation line of peak value power amplifier is carried out Phase Processing, makes two paths of signals carry out with being combined at the synthetic point of power; The load of 50 pairs of main power amplifiers of impedance inverted device is inverted to reach and under the different power state, is carried out rational matching; Impedance transformer 70 is transformed to main power amplifier and the required impedance of peak value power amplifier with load impedance (normally 50 ohm).In the transmitting set field, traditional Doherty power amplifier structure and principle thereof are known, are not described in detail at this.

The Doherty power amplifier technology is through controlling main power amplifier and its peak work and be placed on the impedance of different capacity point and the conducting state of peak value power amplifier obtaining overall high efficiency.Because impedance inverted device and the impedance transformer of Doherty all are to be realized by four/wavelength line, so its bandwidth is narrower.

Along with development of wireless communication devices, emerge more and more advanced communication standards, like WCDMA, TD-SCDMA, WIMAX, LTE or the like.For energy savings is safeguarded with reduction operator, upgrading base station cost, all require the base station can be operated in multiband simultaneously.Seamless transitions and the backward compatibility thereof of communication system from 3G to 4G also proposed demand to the working model of multiband.Because elder generation and then complicated modulation signal have the characteristic of high peak-to-average force ratio (PAR), the double-mode double-band Doherty power amplifier technology that can be operated in the average power of a plurality of frequency bands and lifting signal is a kind of potential scheme.

Because the transistorized bandwidth of operation of frequency microwave is broad often, like GaN, GaAs.The key technology of double-mode double-band Doherty power amplifier is to realize the double frequency passive circuit, like double frequency-band power splitter, double frequency-band match circuit, double frequency-band phase compensation line, double frequency-band four/wavelength line etc.

Summary of the invention

The technical problem that the present invention will solve is: provide a kind of in more high-power rollback scope, can be operated in the Doherty power amplifier of double frequency-band simultaneously.

For solving the problems of the technologies described above, the present invention realizes through following technical scheme:

A kind of double-mode double-band high efficiency Doherty power amplifier, this amplifier comprises:

-double frequency-band power divider 100 distributes the signal of two optional frequencies;

-double frequency-band input coupling 200 to the two-way power amplifier coupling that reasonably gains, obtains the suitable voltage standing-wave ratio;

-core amplifying unit 300; Adopt the Doherty power amplifier, it has at least one peak value power amplifier 302 and at least one main power amplifier 301, through the conducting state of control peak value power amplifier 302 under different capacity; Main power amplifier 301 is carried out load-modulate, to improve average efficiency;

-double frequency-band output coupling 400 is carried out power match to the two-way power amplifier, to obtain peak power output;

-double frequency-band phase compensation line 500; Comprise main power amplifier branch road phase compensation line 501 and peak value power amplifier phase compensation line 502; Main power amplifier branch road phase compensation line 501 transforms to and closes on best efficiency point at the name a person for a particular job load impedance of main power amplifier 301 of back-off; Peak value power amplifier phase compensation line 502 makes the output impedance of peak value power amplifier 302 present infinitely great state under the small-power state, with the Power leakage that prevents main power amplifier branch road to peak value power amplifier branch road;

-double frequency-band impedance inverted device 600 and double frequency-band impedance transformer 700; Be that equivalence is four molecule wavelength lines on two frequencies; The characteristic impedance of double frequency-band impedance inverted device 600 is 50 Ω; The characteristic impedance of double frequency-band impedance transformer 700 is 35.35 Ω, and they carry out inverted and conversion to load impedance respectively;

The output of the input termination signal source of said double frequency-band power divider 100; Input, the output port of said double frequency-band input coupling 200 link to each other with the output of double frequency-band power divider 100 and the input of core amplifying unit 300 respectively; Input, the output port of said double frequency-band output coupling 400 link to each other with the output of core amplifying unit 300 and the input of double frequency-band phase compensation line 500 respectively; The input of said double frequency-band impedance inverted device 600 links to each other with double frequency-band phase compensation line 501 outputs; Its output links to each other with the input of double frequency-band impedance transformer 700, the output of double frequency-band phase compensation line 501; The input of said double frequency-band impedance transformer 700 is synthetic points of two-way power, its output termination terminate load.

Described double frequency-band power divider 100 comprises a double frequency-band constant power distributor or the non-constant power distributor of double frequency-band at least, and the constant power distributor carries out equivalent to power and distributes, and non-constant power distributor carries out non-equivalent to power and distributes.

Described double frequency-band input coupling 200 comprises that at least 201 and peak value power amplifiers inputs of a main power amplifier input coupling mate 202, to the active device coupling that gains.

Described double frequency-band output coupling 400 comprises that at least 401 and peak value power amplifiers inputs of a main power amplifier input coupling mate 402, and the plural source impedance and the plural load impedance of active device mated.

Described double frequency-band phase compensation line 500 comprises at least one main power amplifier phase compensation line 501 and at least one peak value power amplifier phase compensation line 502, and Doherty is optimized in the performance of rollback power region.

The invention provides a kind of double-mode double-band high efficiency Doherty power amplifier; This double-mode double-band high efficiency Doherty power amplifier comprises: double frequency-band power divider module (five equilibrium power divider and non-five equilibrium power divider), the signal of two optional frequencies is distributed; The double frequency-band input matching module to the two-way power amplifier coupling that reasonably gains, obtains the suitable voltage standing-wave ratio; Main power amplifier and peak value power amplifier are placed on the conducting state under the different capacity through the control its peak work, and main power amplifier is carried out load-modulate, to improve average efficiency; Double frequency-band output coupling is carried out power match to the two-way power amplifier, to obtain peak power output; Double frequency-band phase compensation wire module; The phase compensation line and the peak value power amplifier phase compensation line that comprise main power amplifier branch road; The phase compensation line of main power amplifier branch road transforms to and closes on best efficiency point at the name a person for a particular job load impedance of main power amplifier of back-off; The phase compensation line of peak value power amplifier branch road makes the output impedance of peak value power amplifier present infinitely great state under the small-power state, with the Power leakage that prevents main power amplifier branch road to peak value power amplifier branch road; Double frequency-band impedance inverted device and double frequency-band impedance transformer, its equivalence on two frequencies is four molecule wavelength lines, and they carry out impedance inverted and impedance conversion respectively, and the while also synthesizes the power of two branch roads.

The invention has the beneficial effects as follows:

The present invention is on the basis of traditional Doherty, and the double-mode double-band Doherty that utilizes double frequency-band passive circuit art designs to go out may be simultaneously operated on two communications bands.Especially the asymmetric double band power distributor that adopts makes the non-five equilibrium of input power ground get into main power amplifier and peak value power amplifier; Alleviated non-complete mudulation effect; Improve the overall performance of Doherty, can be applicable to Multi-Mode Base Station and software radio, helped energy savings and cutting down cost.

Description of drawings

For the clearer explanation embodiment of the invention or scheme of the prior art, below will be through embodiment being described simply with reference to accompanying drawing.Obviously, the accompanying drawing in describing below is some embodiments of the present invention, to those skilled in the art, under the prerequisite of not paying creative work, can also obtain other accompanying drawings according to these accompanying drawings.Wherein:

Fig. 1 is traditional Doherty power amplifier structure block diagram;

Fig. 2 is the double-mode double-band high efficiency Doherty power amplifier structure block diagram that the embodiment of the invention provides;

Fig. 3 is the double frequency-band homophase equal power dispensing arrangement block diagram that the embodiment of the invention provides;

Fig. 4 is the structured flowchart of the double frequency-band matching network that provides of the embodiment of the invention;

Fig. 5 is the double frequency-band phase compensation line structure block diagram that the embodiment of the invention provides;

Fig. 6 is double frequency-band impedance inverted device and the impedance transformer structured flowchart that the embodiment of the invention provides;

Fig. 7 is the double frequency-band power divider structured flowchart of the non-five equilibrium that provides of the embodiment of the invention.

Embodiment

For the purpose, the technical scheme that make the embodiment of the invention is clearer, hereinafter, will be with reference to the accompanying drawing of the embodiment of the invention, to the technical scheme in the embodiment of the invention carry out clear, intactly describe.Obviously, embodiment described herein is a part of embodiment of the present invention, rather than whole embodiment.Based on the embodiment among the present invention,, all belong to the scope of the present invention's protection so those skilled in the art is not making other embodiment that obtained under the creative work prerequisite.

Double-mode double-band Doherty structural representation as shown in Figure 2, it comprises:

-double frequency-band power divider 100 distributes the signal of two optional frequencies.Double frequency-band power divider 100 comprises a double frequency-band constant power distributor or the non-constant power distributor of double frequency-band at least, and the constant power distributor carries out equivalent to power and distributes, and non-constant power distributor carries out non-equivalent to power and distributes.

-double frequency-band input coupling 200 to the two-way power amplifier coupling that reasonably gains, obtains the suitable voltage standing-wave ratio.Double frequency-band input coupling 200 comprises that at least 201 and peak value power amplifiers inputs of a main power amplifier input coupling mate 202, to the active device coupling that gains.

-core amplifying unit 300; Adopt the Doherty power amplifier, it has at least one peak value power amplifier 302 and at least one main power amplifier 301, through the conducting state of control peak value power amplifier 302 under different capacity; Main power amplifier 301 is carried out load-modulate, to improve average efficiency.

-double frequency-band output coupling 400 is carried out power match to the two-way power amplifier, to obtain peak power output.Double frequency-band output coupling 400 comprises that at least 401 and peak value power amplifiers inputs of a main power amplifier input coupling mate 402, and the plural source impedance and the plural load impedance of active device mated.

-double frequency-band phase compensation line 500; Comprise main power amplifier branch road phase compensation line 501 and peak value power amplifier phase compensation line 502; Main power amplifier branch road phase compensation line 501 transforms to and closes on best efficiency point at the name a person for a particular job load impedance of main power amplifier 301 of back-off; Peak value power amplifier phase compensation line 502 makes the output impedance of peak value power amplifier 302 present infinitely great state under the small-power state, with the Power leakage that prevents main power amplifier branch road to peak value power amplifier branch road.Double frequency-band phase compensation line 500 comprises at least one main power amplifier phase compensation line 501 and at least one peak value power amplifier phase compensation line 502, and Doherty is optimized in the performance of rollback power region.

-double frequency-band impedance inverted device 600 and double frequency-band impedance transformer 700; Be that equivalence is four molecule wavelength lines on two frequencies; The characteristic impedance of double frequency-band impedance inverted device 600 is 50 Ω; The characteristic impedance of double frequency-band impedance transformer 700 is 35.35 Ω, and they carry out inverted and conversion to load impedance respectively.

Concrete: the output of the input termination signal source of double frequency-band power divider 100; The input of double frequency-band input matching network 200, output port link to each other with the output of double frequency-band power divider 100 and the input of active device (core amplifying unit 300) respectively, and the input of double frequency-band output matching network 400, output port link to each other with the output of active device (core amplifying unit 300) and the input of double frequency-band phase compensation line 500 respectively.The input of double frequency-band impedance inverted device 600 links to each other with main power amplifier branch road phase compensation line 501 outputs, and its output links to each other with the input of double frequency-band impedance transformer 700, the output of peak value power amplifier phase compensation line 502.The input of double frequency-band impedance transformer 700 is synthetic points of two-way power, its output termination terminate load.Because the designing technique of traditional Doherty power amplifier is known, so this paper sets forth the application of double frequency-band passive circuit in the Doherty design circuit in detail.Among the present invention,, make the input power of peak value power amplifier 302, improved the non-complete mudulation effect of saturation point greater than main power amplifier 301 if use asymmetric double band power distributor 100.

Concrete, double frequency-band complex impedance match circuit need be in frequency f ₁, f ₂Match impedance Z (f respectively from 50 Ω simultaneously ₁)=R ₁+ jX ₁, Z (f ₂)=R ₂+ jX ₂, its real part matching network parameter Z _s, θ _S, Z _p, θ _pBe following solution of equations: Z _T1=Z _sSin θ _S, Z _T2=Z _sSin n θ _S, $Z_p=Z_{T1}{Z}_s\mathrm{Tan}\left({\mathrm{\&theta;}}_p\right)/\sqrt{Z_s^2-{\mathrm{<figure-callout\; id="1"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^1},$ $Z_p=Z_{T2}{Z}_s\mathrm{Tan}\left(n{\mathrm{\&theta;}}_p\right)/\sqrt{Z_s^2-{\mathrm{<figure-callout\; id="2"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^2},$ Wherein

G ₁, G ₂Be susceptance, n=f ₂/ f ₁＞1.Choose reasonable characteristic impedance Z _C, Z _C1, Z _C2After, its imaginary part matching network parameter θ _C1, θ _C2Be following solution of equations: θ _C1(f ₁)=tan ^-1(1/Z _C1B _S(f ₁)), θ _C2(f ₂)=tan ^-1(Z _C2Imag (Y _B(f ₂))).

Concrete, double frequency-band phase compensation line 500 need be in frequency f ₁, f ₂, difference phase shift θ _T1, θ _T2, and its characteristic impedance all is 50 Ω, the transmission line characteristic impedance and the electrical length of double frequency-band phase compensation line 500 are respectively Z _S=Z _T| sin θ _T1|/| sin θ _S|, | sinn θ _S|/| sin θ _S|=| sin θ _T2|/| sin θ _T1|, Z _T=50 Ω, n=f ₂/ f ₁＞1.

Embodiment 1

The double frequency-band power divider 100 of five equilibrium, as shown in Figure 3, the radiofrequency signal of input to be carried out distributing with equal quantities, its method for designing is based on branch-line power divider and pi type four/wavelength line.Operating frequency is f ₁, f ₂, n=f ₂/ f ₁＞1, Z ₀Be system standard characteristic impedance 50 Ω, relative bandwidth δ=(f ₂-f ₁)/(f ₂+ f), if type circuit compact to design, the electrical length of three kinds of microstrip lines all does

θ＝π(1-δ)/2f ₁ （1）

Characteristic impedance is respectively

$Z_1=\frac{{\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="HDA00002134014200021.png,HDA00002134014200022.png"\; state="\{\{state\}\}">Z</figure-callout>}}_0}{\sqrt{2}\cos (\mathrm{\&delta;\&pi;}/2)}---\left(2\right)$

$Z_2=\frac{{\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="HDA00002134014200021.png,HDA00002134014200022.png"\; state="\{\{state\}\}">Z</figure-callout>}}_0}{\cos (\mathrm{\&delta;\&pi;}/2)}---\left(3\right)$

${\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_3=\frac{Z_0}{(1+\sqrt{2})\sin (\mathrm{\&delta;\&pi;}/2)\tan (\mathrm{\&delta;\&pi;}/2)}---\left(4\right)$

Through the p (p is any positive integer) among adjustment formula θ=p π (1-δ)/2, the parameter that can regulate double frequency-band power divider 100 circuit structures.

200 pairs of Doherty Amplifier Gain of double frequency-band input matching network are mated, and see Fig. 4 for details.Its whole design idea is, at first realizes two real part of impedance through open circuit pi type network (four/wavelength line of equivalence), then through with the imaginary part of open circuit pi network two impedances of minor matters spider lines reality arranged side by side.The optimum source impedance at two frequency places is respectively Z (f ₁)=R ₁+ jX ₁, Z (f ₂)=R ₂+ jX ₂, corresponding admittance is Y (f ₁)=G ₁+ jB ₁, Y (f ₂)=G ₂+ jB ₂So the pi network is at f ₁, f ₂The equivalent features impedance at place is respectively

Through following formula

Z _T1=Z _ssinθ _S

Z _T2=Z _ssinnθ _S

$Z_p=\frac{Z_{T1}{Z}_s\tan \left({\mathrm{\&theta;}}_p\right)}{\sqrt{Z_s^2-{\mathrm{<figure-callout\; id="1"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^1}}$

$Z_p=\frac{Z_{T2}{Z}_s\tan \left({\mathrm{n\&theta;}}_p\right)}{\sqrt{Z_s^2-{\mathrm{<figure-callout\; id="2"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^2}}$

Can calculate four parameter Z of open circuit pi network _s, θ _S, Z _p, θ _p

The coupling of imaginary impedance realizes through the minor matters network on Fig. 4 left side.At first be utilized in frequency f ₁The quarter-wave open circuit minor matters line Z at place _C, make Y _C(f ₁)=0 is reasonably selected the characteristic impedance Z of microstrip line then _C, Z _C1, Z _C2Utilize formula

${\mathrm{\&theta;}}_{C1}\left(f_1\right)={\tan }^{-1}\left(\frac{-1}{Z_{C1}{B}_S\left(f_1\right)}\right)$

$Y_A\left(f_2\right)=\frac{j(Z_{C1}{B}_S\left(f_2\right)-\tan \left(n{\mathrm{\&theta;}}_{C1}\left(f_1\right)\right))}{Z_{C1}(1+Z_{C1}{B}_S\left(f_2\right)\tan \left(n{\mathrm{\&theta;}}_{C1}\left(f_1\right)\right))}$

Y _A(f ₂)＝Y _C(f ₂)+Y _B(f ₂)

$Y_C\left(f_2\right)=\frac{j\tan (\mathrm{n\&pi;}/2)}{Z_C}$

$Y_B\left(f_2\right)=Y_A\left(f_2\right)-\frac{j\tan (\mathrm{n\&pi;}/2)}{Z_C}$

θ _C2(f ₂)=tan ^-1(Z _C2imag(Y _B(f ₂)))

Calculate the phase parameter θ of other two microstrip lines _C1, θ _C2

The method for designing of double frequency-band output matching network 400 is the same with the principle of double frequency-band input matching network 200 designs, sets forth no longer in detail at this.

The phase compensation line is most important in the design of Doherty, and it not only carries out impedance matching at low power state to main power amplifier 301, and the Power leakage that also prevents main power amplifier branch road is to peak value power amplifier branch road.In order to make whole Doherty reach optimum efficiency, need phase shift to be respectively θ in two frequency places _T1, θ _T250 ohm of traditional phase compensation lines can not satisfy the phase shift of two frequencies simultaneously, need specialized designs double frequency-band phase compensation line 500, and are as shown in Figure 5.Its ABCD parameter matrix does

$\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_S-B_S{Z}_S\sin {\mathrm{\&theta;}}_S& j{Z}_S\sin {\mathrm{\&theta;}}_S\\ j\sin {\mathrm{\&theta;}}_S(1-Z_S^2{\mathrm{<figure-callout\; id="2"\; label="B\; S"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">B</figure-callout>}}_S^{}+2B_S{Z}_S\cot {\mathrm{\&theta;}}_S)& \cos {\mathrm{\&theta;}}_S-B_S{Z}_S\sin {\mathrm{\&theta;}}_S\end{array}\right]$

B _SBe the equivalent susceptance of open circuit minor matters line, be respectively B at two frequency places _S(f ₁), B _S(f ₂), the equivalent features impedance and the phase place of this network are respectively

$\cos \left({\mathrm{\&theta;}}_T\right)=\frac{A+\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}=\cos {\mathrm{\&theta;}}_S-B_S{Z}_S\sin {\mathrm{\&theta;}}_S$

$Z_T=\sqrt{\frac{B}{C}}={\mathrm{<figure-callout\; id="1"\; label="Z\; S"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_S\sqrt{\frac{1}{1-Z_S^2{\mathrm{<figure-callout\; id="2"\; label="B\; S"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">B</figure-callout>}}_S^{}+2B_S{Z}_S\cot {\mathrm{\&theta;}}_S}}$

The present invention need produce phase shift theta arbitrarily on two operating frequencies _T1, θ _T2, through following formula

${\mathrm{<figure-callout\; id="2"\; label="Z\; S"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_S^{}/{\mathrm{<figure-callout\; id="2"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^{}=1-K^2\left(f_1\right)+2K\left(f_1\right)\cot {\mathrm{\&theta;}}_S$

${\mathrm{<figure-callout\; id="2"\; label="Z\; S"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_S^{}/{\mathrm{<figure-callout\; id="2"\; label="Z\; T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T^{}=1-K^2\left(f_2\right)+2K\left(f_2\right)\cot n{\mathrm{\&theta;}}_S$

$Z_S=Z_T\frac{\left|\sin {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">T</figure-callout>}1}\right|}{\left|\sin {\mathrm{\&theta;}}_S\right|}$

$Z_S=Z_T\frac{\left|\sin {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">T</figure-callout>}2}\right|}{\left|\sin n{\mathrm{\&theta;}}_S\right|}$

$\frac{\left|\sin n{\mathrm{\&theta;}}_S\right|}{\left|\sin {\mathrm{\&theta;}}_S\right|}=\frac{\left|\sin {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">T</figure-callout>}2}\right|}{\left|\sin {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">T</figure-callout>}1}\right|}$

Wherein K (f) does

K(f ₁)＝Z _SB _S(f ₁)

K(f ₂)＝Z _SB _S(f ₂)

Can calculate the series transmission lines parameter Z _SAnd θ _SUtilize open circuit minor matters network to realize susceptance B _S(f ₁) and B _S(f ₂) method the same with the imaginary part matching Design of input and output matching network, be not described in detail in this.

Double frequency-band impedance inverted device 600 all is the same with double frequency-band impedance transformer 700 in itself; It all is the function that on two frequencies, realizes four/wavelength line simultaneously; But the characteristic impedance of double frequency-band impedance inverted device 600 is 50 Ω, and the characteristic impedance of double frequency-band impedance transformer 700 is 35.35 Ω.The double frequency-band impedance inverted device 600 that utilizes open circuit pi network to realize is as shown in Figure 6.f ₁And f ₂Be operating frequency, δ=f ₂-f ₁/ f ₂+ f ₁, n=f ₂/ f ₁＞1, the ABCD parameter matrix of Pi network does

$\left[\begin{array}{cc}\cos \mathrm{\&theta;}-Z_{A}Y\sin \mathrm{\&theta;}& j{Z}_A\sin \mathrm{\&theta;}\\ j{Z}_A\sin \mathrm{\&theta;}(1-Z_A^2{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2+2Z_{A}Y\cot \mathrm{\&theta;})& \cos \mathrm{\&theta;}-Z_{A}Y\sin \mathrm{\&theta;}\end{array}\right]$

Y is the susceptance of minor matters line, if will realize that characteristic impedance is Z _TThe function of four/wavelength line, then above-mentioned matrix does

$\left[\begin{array}{cc}0& j{Z}_A\sin \mathrm{\&theta;}\\ j\frac{1}{j{Z}_A\sin \mathrm{\&theta;}}& 0\end{array}\right]=\left[\begin{array}{cc}0& \&PlusMinus;j{Z}_T\\ \&PlusMinus;j\frac{1}{{\mathrm{<figure-callout\; id="0"\; label="Z\; T"\; filenames="HDA00002134014200021.png,HDA00002134014200022.png"\; state="\{\{state\}\}">Z</figure-callout>}}_T}& 0\end{array}\right]$

Through following formula

θ＝π(1-δ)/2

$Z_A=\frac{Z_T}{\left|\sin \left(\frac{\mathrm{\&delta;\&pi;}}{2}\right)\right|}$

$Z_B=\frac{Z_T}{\sin \left(\frac{\mathrm{\&delta;\&pi;}}{2}\right)\tan \left(\frac{\mathrm{\&delta;\&pi;}}{2}\right)}$

Can calculate the phase theta and the characteristic impedance Z of series connection microstrip line _A, the characteristic impedance Z of open circuit minor matters line _B

Embodiment 2

Can alleviate the non-complete mudulation effect of saturation point through the input power of non-five equilibrium.The double frequency-band power divider 100 of non-five equilibrium is as shown in Figure 7, and its power-division ratios is K ²=| S ₃₁/ S ₂₁| ², r is an isolation resistance.Can calculate the parameter of the non-equivalent double frequency-band of double frequency-band power divider 100 through following formula.

Z ₁＝K ²Z ₃

${\mathrm{<figure-callout\; id="2"\; label="Z"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_2=\frac{\sqrt{Z_{02}-{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_0}}{\sin {\mathrm{\&theta;}}_0}$

${\mathrm{<figure-callout\; id="3"\; label="Z"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_3=\frac{\sqrt{({\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">K</figure-callout>}}^2+1)Z_{03}}}{K\sin {\mathrm{\&theta;}}_0}$

$Z_4=\frac{\sqrt{Z_{03}-{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_0}}{\sin {\mathrm{\&theta;}}_0}$

$Z_{s1}=Z_3\frac{K^2}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">K</figure-callout>}}^2+1}{\tan }^2{\mathrm{\&theta;}}_0$

θ _sGet θ ₀Or 2 θ ₀, guarantee Z _S2For on the occasion of, the computing formula of intermediate parameters is following: Z ₀₂=K ²Z ₀₃, Z _S21=K ²Z _S31, Z _S31=Z ₃Tan ²θ ₀, r=(K ²+ 1) Z ₀₃, ${\mathrm{<figure-callout\; id="03"\; label="Z"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Z</figure-callout>}}_{03}=A-\sqrt{A^2-K^2-1},A=K^2(1+{\mathrm{<figure-callout\; id="2"\; label="Sin"\; filenames="HDA00002134014200021.png"\; state="\{\{state\}\}">Sin</figure-callout>}}^2{\mathrm{\&theta;}}_0)/2+1.$ The input power that the non-equivalent double frequency-band power divider 100 of input makes peak value power amplifier 302 is greater than main power amplifier 301, and two-way phase compensation line 501 and 502 is done corresponding adjustment according to above-mentioned formula and got final product.

Can find out that from above embodiment the double frequency-band circuit that adopts the present invention to propose can be designed double-mode double-band Doherty power amplifier.Double-mode double-band Doherty power amplifier can improve the average efficiency of transmitter system, is applied to Multi-Mode Base Station, helps energy savings and reduces operator's cost.

Above embodiment shows particularly and has described technical scheme of the present invention, but not limits it; Be to be understood that for those of ordinary skill in the art: it still can be made amendment to thought or technical scheme that above-mentioned each embodiment set forth, perhaps to wherein certain part or certain several part are replaced on an equal basis; And these are revised or replacement, do not make the spirit and the scope of the essence disengaging various embodiments of the present invention technical scheme of relevant art scheme.

Claims (5)

1. double-mode double-band high efficiency Doherty power amplifier is characterized in that this amplifier comprises:

-double frequency-band power divider (100) distributes the signal of two optional frequencies;

-double frequency-band input coupling (200) to the two-way power amplifier coupling that reasonably gains, obtains the suitable voltage standing-wave ratio;

-core amplifying unit (300); Adopt the Doherty power amplifier, it has at least one peak value power amplifier (302) and at least one main power amplifier (301), through the conducting state of control peak value power amplifier (302) under different capacity; Main power amplifier (301) is carried out load-modulate, to improve average efficiency;

-double frequency-band output coupling (400) is carried out power match to the two-way power amplifier, to obtain peak power output;

-double frequency-band phase compensation line (500); Comprise main power amplifier branch road phase compensation line (501) and peak value power amplifier phase compensation line (502); Main power amplifier branch road phase compensation line (501) transforms to and closes on best efficiency point at the name a person for a particular job load impedance of main power amplifier (301) of back-off; Peak value power amplifier phase compensation line (502) makes the output impedance of peak value power amplifier (302) present infinitely great state under the small-power state, with the Power leakage that prevents main power amplifier branch road to peak value power amplifier branch road;

-double frequency-band impedance inverted device (600) and double frequency-band impedance transformer (700); Be that equivalence is four molecule wavelength lines on two frequencies; The characteristic impedance of double frequency-band impedance inverted device (600) is 50 Ω; The characteristic impedance of double frequency-band impedance transformer (700) is 35.35 Ω, and they carry out inverted and conversion to load impedance respectively;

The output of the input termination signal source of said double frequency-band power divider (100); Input, the output port of said double frequency-band input coupling (200) link to each other with the output of double frequency-band power divider (100) and the input of core amplifying unit (300) respectively; Input, the output port of said double frequency-band output coupling (400) link to each other with the output of core amplifying unit (300) and the input of double frequency-band phase compensation line (500) respectively; The input of said double frequency-band impedance inverted device (600) links to each other with double frequency-band phase compensation line (501) output; Its output links to each other with the input of double frequency-band impedance transformer (700), the output of double frequency-band phase compensation line (501); The input of said double frequency-band impedance transformer (700) is the synthetic point of two-way power, its output termination terminate load.

2. double-mode double-band high efficiency Doherty power amplifier according to claim 1; It is characterized in that; Described double frequency-band power divider (100) comprises a double frequency-band constant power distributor or the non-constant power distributor of double frequency-band at least; The constant power distributor carries out equivalent to power and distributes, and non-constant power distributor carries out non-equivalent to power and distributes.

3. double-mode double-band high efficiency Doherty power amplifier according to claim 1; It is characterized in that; Described double frequency-band input coupling (200) comprises that at least a main power amplifier input coupling (201) and a peak value power amplifier input mate (202), to the active device coupling that gains.

4. double-mode double-band high efficiency Doherty power amplifier according to claim 1; It is characterized in that; Described double frequency-band output coupling (400) comprises that at least a main power amplifier input coupling (401) and a peak value power amplifier input mate (402), and the plural source impedance and the plural load impedance of active device mated.

5. double-mode double-band high efficiency Doherty power amplifier according to claim 1; It is characterized in that; Described double frequency-band phase compensation line (500) comprises at least one main power amplifier phase compensation line (501) and at least one peak value power amplifier phase compensation line (502), and Doherty is optimized in the performance of rollback power region.

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