A kind of carrier balancing radio frequency predistortion power amplifier implement device and method
Technical field
The present invention relates to wireless communication technology field, be specifically related to a kind of carrier balancing radio frequency predistortion power amplifier implement device and method.
Background technology
Mobile communication is in China's fast development at present, the bandwidth of signal is more and more wideer, peak-to-average force ratio is more and more higher, for the linearity and the efficient that improves power amplifier, the one, select suitable superlinearity semiconductor device, design high performance radio frequency sending set, this way cost is huge, and technical difficulty is very high; The 2nd, whole transmission channel is carried out back-off, make transmission channel be operated in linear zone, this method greatly reduces the operating efficiency of system; The 3rd, the linearization technique of a lot of power amplifiers has appearred at present, feed forward approach, feedback transmitter, pre-distortion method are arranged and realize linearisation (LINC) etc. with non-linear components, the effect of feed-forward technique is best, but circuit complexity, efficient is lower, and digital pre-distortion technology develops at present than comparatively fast, but the systematic comparison complexity, involve great expense, the producer that grasps mature technology is few.The present invention has introduced the radio frequency distortion power amplifier that a kind of carrier cancellation method realizes.Radio frequency distortion is the non-linear realization predistortion of utilizing diode at present, and this method realizes that bandwidth ratio is more limited, and the improvement degree is lower.
Summary of the invention
The object of the present invention is to provide a kind of carrier balancing radio frequency predistortion power amplifier implement device and method.
A kind of carrier balancing radio frequency predistortion power amplifier implement device provided by the invention comprises first right bridge (102), gain amplifier (103), second right bridge (104), power amplifier (105), distorter, variable gain amplifier (110), first phase shifter (111);
The radiofrequency signal that described first right bridge (102) is used for entering this device is divided into two-way, wherein one the tunnel exports gain amplifier (103) to, and another road exports distorter to, and this two paths of signals amplitude equates, phase phasic difference 90 degree;
Described gain amplifier (103) is used for the road signal that is received is gained amplification to obtain the primary link signal;
Described distorter is used for another road signal that is received is handled with the acquisition error signal, and exports error signal to variable gain amplifier (110);
Described variable gain amplifier (110) is used for the linear amplification error signal, and the error signal after will amplifying exports first phase shifter (111) to;
Described first phase shifter (111) is used for the error signal after amplifying is carried out the phase place adjustment;
Described second right bridge (104) is used for receiving the primary link signal and receiving error signal from described first phase shifter (111) from described gain amplifier (103), and primary link signal and error signal synthesized, the signal that synthetic back produces is exactly the radiofrequency signal of band predistortion;
Described power amplifier (105) is used for from the radiofrequency signal of described second right bridge (104) receiving belt predistortion, and the radiofrequency signal of this band predistortion is carried out power amplification, then from this device output.
Device wherein, according to the output spectrum of power amplifier (105), can be adjusted the gain of variable gain amplifier (110) and the phase place of first phase shifter (111), so that the end product optimum as mentioned above.
Install as mentioned above, wherein, described distorter comprises the 3rd right bridge (106), the first low linear amplifier (107), first attenuator (108), the 4th right bridge (109), second attenuator (113), the second low linear amplifier (114), second phase shifter (115);
Another road radiofrequency signal that described the 3rd right bridge (106) is used for distorter is received is divided into the signal that the two-way amplitude equates, phase phasic difference 90 is spent again, wherein one the tunnel export the first low linear amplifier (107) to, another road exports second attenuator (113) to;
The described first low linear amplifier (107) is operated in the inelastic region, is used for that the signal that receives is carried out nonlinear distortion and amplifies, and exports first attenuator (108) then to;
Described first attenuator (108) and second attenuator (113) all are used for the signal that receives is decayed;
The described second low linear amplifier (114) is operated in linear zone, is used for from second attenuator (113) received signal, and the signal that receives is carried out linear amplification, exports second phase shifter (115) then to;
Described second phase shifter (115) is used for the signal that receives is carried out the phase place adjustment;
Described the 4th right bridge (109) is used for respectively from described first attenuator (108) and described second phase shifter (115) received signal, and the two paths of signals that receives synthesized, synthetic signal carrier is offset, only remaining error signal exports error signal to variable gain amplifier (110) then.
Install as mentioned above, wherein, described second phase shifter (115) can be finely tuned, so that the neutralization effect of carrier wave is better.
Install as mentioned above, wherein, the described first low linear amplifier (107) and the described second low linear amplifier (114) are identical, and described first attenuator (108) and described second attenuator (113) are identical.
Install as mentioned above, wherein, this device also comprises some loads (101,112,116,117), is connected to the input of first right bridge (102) and the 3rd right bridge (106) and the output of second right bridge (104) and the 4th right bridge (109); And described first right bridge (102), second right bridge (104), the 3rd right bridge (106) and the 4th right bridge (109) are respectively the 3dB right bridge.
A kind of carrier balancing radio frequency predistortion power amplifier implementation method of the present invention may further comprise the steps:
Step 1, the radiofrequency signal that receives is divided into two-way, wherein one the tunnel exports gain amplifier to and gain and amplify to obtain the primary link signal, another road exports distorter to, and this two paths of signals amplitude equates, phase phasic difference 90 degree;
Step 2, distorter are handled to obtain error signal another road signal that is received;
Step 3, variable gain amplifier carry out linear amplification to the error signal that obtains in the step 2, and first phase shifter carries out the phase place adjustment to the error signal after amplifying then;
Step 4, the error signal that obtains in the primary link signal that obtains in the step 1 and the step 3 is synthesized, the signal that synthetic back produces is exactly the radiofrequency signal of band predistortion;
Step 5, power amplifier carry out power amplification to the radiofrequency signal of described band predistortion, then output.
Method wherein, also comprises: according to the output spectrum of power amplifier, adjust the gain of variable gain amplifier and the phase place of first phase shifter, so that the end product optimum as mentioned above.
Method as mentioned above, wherein, described step 2 is further comprising the steps of:
(1) another road radiofrequency signal that distorter received is divided into the signal that the two-way amplitude equates, phase phasic difference 90 is spent again, wherein one the tunnel exports the first low linear amplifier to, another road exports second attenuator to;
(2) the described first low linear amplifier is operated in the inelastic region, and it carries out nonlinear distortion to the signal that receives and amplifies, and exports first attenuator then to; Described second attenuator is decayed to the signal that receives, and exports the second low linear amplifier then to;
(3) described first attenuator is decayed to the signal that receives; The described second low linear amplifier is operated in linear zone, and it carries out linear amplification to the signal that receives, and exports second phase shifter (115) then to;
(4) described second phase shifter carries out the phase place adjustment to the signal that receives;
(5) will synthesize from the signal of described first attenuator reception and the signal that receives from described second phase shifter, synthetic signal carrier is offset, and only remaining error signal exports error signal to variable gain amplifier then.
Method as mentioned above, wherein, described step 2 also comprises: finely tune second phase shifter, so that the neutralization effect of carrier wave is best.
Carrier balancing radio frequency predistortion power amplifier implement device provided by the invention and method have solved problems such as the signal transmission power linearity of amplifier is relatively poor, inefficiency.Method of the present invention has mainly been done improvement on the basis of traditional carrier cancellation method, greatly reduce debugging difficulty and time, can realize the amplitude and the phase place of error signal are adjusted flexibly according to end product, make predistortion effect optimum, this method can be used for the power amplifier linearization of various systems, and it is apparent in view to improve effect.
Description of drawings
Fig. 1 is the block diagram of carrier balancing radio frequency predistortion power amplifier implement device;
Fig. 2 is the double-tone intermodulation testing result who does not have predistortion;
Fig. 3 is the double-tone intermodulation testing result that predistortion is arranged;
Fig. 4 is the spectrum modulation signal result who does not have predistortion;
Fig. 5 is the spectrum modulation signal result that predistortion is arranged.
Embodiment
Below in conjunction with description of drawings the specific embodiment of the present invention.
As shown in Figure 1, the carrier balancing radio frequency predistortion power amplifier implement device of one embodiment of the invention comprises 3dB right bridge 102, gain amplifier 103,3dB right bridge 104, power amplifier 105, distorter, variable gain amplifier 110, phase shifter 111; The radiofrequency signal that described 3dB right bridge 102 is used for entering this device is divided into two-way, wherein one the tunnel exports gain amplifier 103 to, and another road exports distorter to, and this two paths of signals amplitude equates, phase phasic difference 90 degree; Described gain amplifier 103 is used for the road radiofrequency signal that is received is gained amplification to obtain the primary link signal; Described distorter is used for another road radiofrequency signal that is received is handled with the acquisition error signal, and exports error signal to variable gain amplifier 110; Described variable gain amplifier 110 is used for the linear amplification error signal, and the error signal after will amplifying exports phase shifter 111 to; Described phase shifter 111 is used for the error signal after amplifying is carried out the phase place adjustment; Described 3dB right bridge 104 is used for receiving the primary link signal and receiving error signal from described phase shifter 111 from described gain amplifier 103, and primary link signal and error signal are synthesized, and the signal that synthetic back produces is exactly the radiofrequency signal of band predistortion; Described power amplifier 105 is used for from the radiofrequency signal of described 3dB right bridge 104 receiving belt predistortions, and the radiofrequency signal of this band predistortion is carried out power amplification, then from this device output.
Described device also comprises load 101,112,116,117, described load 101 is connected to the input of 3dB right bridge 102, described load 112 is connected to the input of 3dB right bridge 106, described load 116 is connected to the output of 3dB right bridge 109, and described load 117 is connected to the output of 3dB right bridge 104.
Described distorter comprises 3dB right bridge 106, low linear amplifier 107, attenuator 108,3dB right bridge 109, attenuator 113, low linear amplifier 114, phase shifter 115; Another road radiofrequency signal that described 3dB right bridge 106 is used for distorter is received is divided into the signal that the two-way amplitude equates, phase phasic difference 90 is spent again, wherein one the tunnel exports low linear amplifier 107 to, and another road exports attenuator 113 to; Described low linear amplifier 107 is operated in the inelastic region, is used for that the signal that receives is carried out nonlinear distortion and amplifies, and exports attenuator 108 then to; Described attenuator 108 and attenuator 113 all are used for the signal that receives is decayed; Described low linear amplifier 114 is operated in linear zone, is used for from attenuator 113 received signals, and the signal that receives is carried out linear amplification, exports phase shifter 115 then to; Described phase shifter 115 is used for the signal that receives is carried out the phase place adjustment; Described 3dB right bridge 109 is used for respectively from described attenuator 108 and described phase shifter 115 received signals, and the two paths of signals that receives synthesized, synthetic signal carrier is offset, and only remaining error signal exports error signal to variable gain amplifier 110 then.
Device shown in Figure 1 according to the output spectrum of power amplifier 105, can be adjusted the gain of variable gain amplifier 110 and the phase place of phase shifter 111, so that the end product optimum.Described phase shifter 115 can be finely tuned, so that the neutralization effect of carrier wave is better.
Device shown in Figure 1, wherein said low linear amplifier 107 and described low linear amplifier 114 can be identical, and described attenuator 108 and described attenuator 113 can be identical.
One embodiment of the invention the carrier balancing radio frequency predistortion power amplifier method comprise that error signal is extracted, error signal is amplified and phase place adjustment, error signal and main signal are synthetic, composite signal power amplification etc., concrete job step is as follows:
Step 1: radiofrequency signal enters the power amplifier implement device, be divided into two-way by 3dB right bridge 102, one the tunnel enters primary link (being the link at gain amplifier 103 places), and amplification gains, one the tunnel enters the error signal that distorter produces to be needed, and this two paths of signals amplitude equates, phase phasic difference 90 degree.
Step 2: the signal that enters distorter is divided into the signal that the two-way amplitude equates, phase phasic difference 90 is spent again by 3dB right bridge 106, and through amplifying and then decay, the phase place adjustment is amplified, carried out then in another road signal elder generation decay to road signal more earlier.Amplifier that this two paths of signals is selected for use and attenuator are duplicate, and different is that a road of amplification earlier is operated in the inelastic region, and a road of back amplification is operated in linear zone, and promptly amplifier 107 is operated in the inelastic region, and amplifier 114 is operated in linear zone.
Step 3: enter 3dB right bridge 109 from the next two paths of signals of step 2 and synthesize, because this two paths of signals carrier amplitude is the same, phase difference 90 degree are offset only remaining error signal through 3dB right bridge 109 synthetic signal carriers like this.Can make neutralization effect best by fine setting phase shifter 115 during this time.
Step 4: the error signal from step 3 is come, enter variable gain amplifier 110 and carry out linear amplification, enter phase shifter 111 again and carry out the phase place adjustment.
Step 5: the error signal of coming from step 4 and from step 1 the primary link signal of gain amplifier 103 enter 3dB right bridge 104 and synthesize, the signal that produces through 3dB right bridge 104 backs is exactly the radiofrequency signal of band predistortion like this.
Step 6: the radiofrequency signal of band predistortion enters amplifier 105 and carries out power amplification, owing to non-linear reason, offsets at the distorted signal of 105 li generations of power amplifier and the error signal of generation like this, thereby reaches the linearity of improving power amplifier.
Step 7: according to the output spectrum of power amplifier, the gain that we can be by adjusting variable amplifier 110 and the phase place of phase shifter 111 make the end product optimum.
Below by experimental result beneficial effect of the present invention is described.
Fig. 2 is not having under the situation of predistortion, and double-tone intermodulation testing result indicates that wherein m1 is the third order intermodulation result.
Fig. 3 is having under the situation of radio frequency distortion, and double-tone intermodulation testing result indicates that wherein m1 is the third order intermodulation result.
By the m1 of comparison diagram 2 and the m1 of Fig. 3, we have the third order intermodulation of predistortion to have clear improvement as can be seen.
Fig. 4 is not having under the situation of predistortion, adds modulation signal test, last output spectrum.
Fig. 5 is having under the situation of radio frequency distortion, adds a modulation signal, the last output spectrum of test.
By comparison diagram 4 and Fig. 5, the band of Fig. 5 is outer as can be seen spuiously has clear improvement than Fig. 4 for we.
The invention solves problems such as the signal transmission power linearity of amplifier is relatively poor, inefficiency, carrier balancing radio frequency predistortion power amplifier implement device and method that the present invention proposes, on the basis of traditional carrier cancellation method, do improvement, greatly reduced debugging difficulty and time.And compare the phase place and the big I of amplitude that have realized error signal with the conventional radio frequency pre-distortion technology and carry out the certain limit adjustment according to end product, make predistortion effect optimum, this method can be used for the power amplifier linearization of various systems, and it is apparent in view to improve effect.
More than under be preferred embodiment of the present invention only, be not limited to the present invention, all any modifications of within the present invention spirit and principle, being made, be equal to replacement and improvement etc., all be contained within protection scope of the present invention.