CN1224165C - Linear power amplification device with improved structure - Google Patents
Linear power amplification device with improved structure Download PDFInfo
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- CN1224165C CN1224165C CN 01105288 CN01105288A CN1224165C CN 1224165 C CN1224165 C CN 1224165C CN 01105288 CN01105288 CN 01105288 CN 01105288 A CN01105288 A CN 01105288A CN 1224165 C CN1224165 C CN 1224165C
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Abstract
The present invention discloses a linear power amplification device with an improved structure in the communication field, which comprises a driver amplifier 201, a final amplifier 202, an error amplifier 205, a vector modulator 204, a control interface 203, a detection device 207 for frequency spectrum spreading cancellation and a detection device 206 for carrier frequency cancellation, wherein the detection device 207 for frequency spectrum spreading cancellation receives an RF output signal, and sends the signal to the vector modulator 204; the detection device 206 for carrier frequency cancellation receives the signal of the vector modulator 204, and sends the signal back to the vector modulator 204 after treatment. Consequently, the linear power amplification device has the advantages of low cost, simple structure and high precision.
Description
Technical field
The present invention relates to moving communicating field, particularly relate to linear power amplification device.
Background technology
Because development, the especially CDMA of digital mobile communication technology and the development of 3G (Third Generation) Moblie technology (being 3G) have proposed new requirement to the Linear Power Amplifier index.In CDMA or 3G system, even single carrier frequency also needs to adopt linear power amplification device, not so the frequency spectrum diffusion of its generation just is difficult to satisfy the requirement of the spectrum radiation template (Spectrum emission mask) of code requirement.In the linearization technique of power amplifier, comprise the most frequently used digital pre-distortion or feed-forward technique, all must know the frequency spectrum diffusion situation of power amplifier earlier, promptly obtain the amplitude and the phase information of frequency spectrum diffusion component earlier, carry out linearisation then.Detecting the general method of Linear Power Amplifier out of band spectrum diffusion is to introduce pilot signal, differentiates the degree of frequency spectrum diffusion by the size that detects pilot signal.Its concrete way is at different technology, as GSM, W-CDMA etc., design a kind of pilot signal of correspondence, detect the energy of pilot signal then in the output of Linear Power Amplifier, and replace with outer frequency spectrum diffusion component with it, Linear Power Amplifier is exactly to control vector modulator according to the energy of pilot signal by its inner algorithm, thereby reaches the frequency spectrum diffusion component that counteracting is introduced by main power amplifier.Though this scheme can access the frequency spectrum diffusion situation of power amplifier, also exists many weak points,, increased the cost of system because this device needs pilot tone to produce and receiver module; With respect to useful signal, pilot signal is a kind of interference signal, causes systematic function and precision to reduce, and, with the accuracy of detection of the method for the detection pilot signal height that is not easy to do.
Summary of the invention
The purpose of this invention is to provide the linear power amplification device that improves structure that has that a kind of cost is lower, simple in structure, precision is high, cost of the prior art is higher, accuracy of detection is lower to overcome, baroque shortcoming.
To achieve these goals, the present invention has constructed a kind of linear power amplification device that improves structure that has, comprise that exciting amplifier 201, final amplifier 202, error amplifier 205, vector modulator 204, control interface 203 is characterized in that, also comprise frequency spectrum diffusion counteracting checkout gear 207, described frequency spectrum diffusion is offset checkout gear 207 and is received RF output signal (Radio Frequency, radio frequency), the signal after detecting is sent in the described vector modulator 204;
Described frequency spectrum diffusion is offset checkout gear 207 and is comprised RF down-conversion device, broadband analog to digital converter 312, digital filter 313 and dsp processor 314; Described RF down-conversion device receives the analog signal of RF output, and carries out filtering, quantification and processing and amplifying, and the signal after the processing sends to described broadband analog to digital converter 312; 312 pairs of described broadband analog to digital converters receive intermediate-freuqncy signal and carry out analog-to-digital conversion, and the output digital signal is to described digital filter 313; Described digital filter 313 comprises a plurality of digital filter apparatus, and the digital signal that receives is carried out filtering, and outputs to described dsp processor 314; Described dsp processor 314 detects the frequency spectrum diffusion signal of handling through described digital filter 313, sends to described vector modulator 204 after treatment.
Adopt the method for the invention and device, compared with prior art, realized having obtained technical upgrading, owing to use digital circuit by the transition of analog circuit to digital circuit, help Linear Power Amplifier to the digitlization transition, it is good to show as flexibility, and the debugging amount reduces, and reliability increases, having reached linear power amplifier (LPA, Linear Power Amplifier) has and detects performance fast; Owing to saved generation, the receiving circuit of pilot signal, thereby reduced the complexity of Linear Power Amplifier and the cost of system, improved the precision that detects frequency spectrum diffusion, lay a good foundation for developing high performance LPA.On the basis that changes part hardware, the software radio overloading detects frequently can be by the flexible configuration of software, make detector can be used for different communication standards, as GSM (Globe System for Mobile communication global system for mobile communications), CDMA (Code Division Multi-Access code division multiple access), WCDMA (Wideband Code DivisionMulti-Access Wideband Code Division Multiple Access (WCDMA)) etc., its function is strengthened greatly.
Description of drawings
Describe the present invention below in conjunction with drawings and Examples.
Fig. 1 is the linear power amplification device structured flowchart of existing band pilot tone feedforward means;
Fig. 2 is the linear power amplification device structure chart with improvement structure that the present invention constructs;
Fig. 3 is the structured flowchart of multiple carrier software radio receiver (detector) shown in Figure 2;
Fig. 4 is a multichannel DDC theory diagram shown in Figure 3.
Embodiment
Existing band pilot tone feedforward linear power amplifier by exciting amplifier 101, art level amplifier 102, error amplifier 105, is formed two loops of feed forward circuit with vector modulator 104 grades as shown in Figure 1; Control interface 103 and pilot tone generator 106, pilot tone receiver 107 etc. are formed the adaptive feedforward control system.High linear radio-frequency signal is exported from transceiver, to the Linear Power Amplifier input, is divided into two-way through power splitter.One the tunnel as main path signal, amplifies through exciting amplifier 101 and final amplifier 102.Because power amplifier effect of nonlinear, output signal produces frequency spectrum diffusion, be coupled out the sub-fraction signal by coupler and send into the carrier frequency offset loop, most of signal enters output coupler after then postponing by delay line, offset with the error signal of error amplifier 105 outputs, thereby obtain satisfactory radio frequency power output signal; After adjusting, delayed line of being told by power splitter of another road input signal and vector modulator 104 enter coupler, the main path signal that is coupled out with coupler carries out the carrier frequency counteracting, insert attenuator and carry out the level adjustment, error signal after the counteracting enters error amplifier 105 after vector modulator 104 is adjusted, error signal is amplified to suitable level, sends into output coupler then and realize the error counteracting function.Pilot tone generator 106, pilot tone receiver 107 are modules that pilot signal produces and receives, and as previously mentioned, they are established for the indication frequency spectrum diffusion component, with control interface 103 and two loops, constitute the adaptive line power amplifier.The weak point of this scheme clearly not only needs extra pilot tone to produce and receiver module, cause cost to improve greatly, and with respect to useful signal, pilot signal is a kind of interference signal, greatly reduces the precision of detection.
The difference of Fig. 2 and Fig. 1 is to have omitted pilot tone to produce circuit and pilot tone receiving circuit, replaces existing analog circuit with the Digital Detecting circuit.After the high linear radio-frequency signal input, the power splitter in exciting amplifier 201 is divided into two-way.One the tunnel as main path signal, amplifies through exciting amplifier 201 and final amplifier 202.Because the influence of nonlinear device in the power amplifier, the power output signal produces frequency spectrum diffusion, be coupled out part signal by the coupler of final amplifier 202 back and send into carrier frequency offset loop in the vector modulator 204, enter the coupler in the vector modulator 204 after the delayed line time delay of telling by power splitter of another road input signal, carry out the carrier frequency counteracting at this and main path signal, for the amplitude that makes two paths of signals equates, after main path signal is coupled out, insert attenuator and carry out the level adjustment, error signal after the counteracting is through phase shifter, enter error amplifier 205 after the attenuator adjustment, error signal is amplified to suitable level, sends into output coupler then and realize the error counteracting function.Final stage power amplifier 202 output signals enter output coupler after by the delay line phase shift, carry out frequency spectrum diffusion component with the error amplification signal of error amplifier 205 outputs and offset, and obtain satisfactory radio frequency power output signal.Two paths of signals carries out the carrier frequency counteracting on first ring up and down, and carrier frequency is offset checkout gear 206 can reflect the carrier frequency neutralization effect.The state that control interface (LCI, Linear power amplifier control interface) 203 offsets by carrier frequency removes to control phase shifter and the amplitude fading device on the carrier frequency counteracting ring.Error signal after carrier frequency is offset is offset in the output of Linear Power Amplifier through processing such as amplification, Vector Modulation back and the frequency spectrum diffusion component that main power amplifier produces.Frequency spectrum diffusion is offset the neutralization effect that checkout gear 207 can reflect frequency spectrum diffusion component.Control interface 203 goes departure to offset interior phase shifter and the amplitude fading device of ring (second ring) by the counteracting state of frequency spectrum diffusion.Carrier frequency is offset checkout gear 206 and is had identical structure with frequency spectrum diffusion counteracting checkout gear 207.
Fig. 3 is the structure chart that the frequency spectrum diffusion shown in Fig. 2 is offset checkout gear 207 or carrier frequency counteracting checkout gear 206.As required, can when carry out the frequency spectrum diffusion detection, carry out carrier frequency and offset detection.In gsm system, because the frequency spectrum of signal is narrower, the frequency spectrum diffusion of signal can be described with crosstalk, for example can produce three rank, the five rank intermodulations of serious interference to signal, can make system produce serious distortion; In CDMA and 3G system, because the frequency spectrum broad of signal, can leak (ACLR, Adjacent Channel Leakage power Ratio) with the parameter adjacent-channel power represents: corresponding to cdma system, signal has 750KHz and four frequency shift (FS) points of 1.98MHz up and down up and down.Corresponding to the W-CDMA system, signal has 5MHz and four offset points of 10MHz up and down up and down.Because the symmetry of same frequency offset channel spectrum diffusion up and down, when realizing, can reduce the channel of detection, generally speaking, carry out two-way and detect (this moment, M was 2) and can satisfy present most application.Below be that example further specifies just with the two-way detection, frequency spectrum diffusion is offset checkout gear 207 or carrier frequency and is offset checkout gear 206 and comprise RF down-conversion device, broadband analog to digital converter 312, digital filter 313 and dsp processor 314; Described RF down-conversion device receives the analog signal of RF output, and carry out filtering, quantification and processing and amplifying, signal after the processing sends to described broadband analog to digital converter 312, be used for the two-way intermediate-freuqncy signal in the RF down-conversion device is carried out analog-to-digital conversion, analog to digital converter number in the broadband analog to digital converter 312 is decided on its interface, for broadband signal, need the corresponding analog to digital converter of branch road in the described RF down-conversion device; Digital filter 313 is made of M road DDC (Digit down convert, Digital Down Convert), receive the signal of broadband analog to digital converter 312 outputs, and the frequency spectrum diffusion signal after will handling outputs in the dsp processor 314; Dsp processor 314 is used for detecting the information of the frequency spectrum diffusion signal after DDC handles and testing result is outputed in the vector modulator 204 in the major loop.The RF down-conversion device comprises: a broadband filter 301, be used for multicarrier RF broadband signal is carried out filtering, and the filtering far-end disturbs; Two-way intermediate frequency receive path, every road intermediate frequency receive path all comprises a frequency mixer 302/307 and a reception local vibration source LO1/LO2 (LO, Localoscillation), by the frequency of control reception local vibration source LO1/LO2, the RF channel signal (as the frequency spectrum diffusion signal) that needs are handled is mixed in the quantification frequency band of intermediate frequency ADC; Two Surface Acoustic Wave Filter 303/308 and 305/310 are used for the neighboring trace analog signal is carried out filtering; An intermediate frequency amplifier is respectively arranged after each Surface Acoustic Wave Filter, be intermediate frequency amplifier 304/309 and intermediate frequency amplifier 306/311, receive the filtered signal of Surface Acoustic Wave Filter, and amplify.
The digital filter 313 that shown in Figure 4 is among Fig. 3 is the structure chart of multichannel DDC, comprise: a multi-channel data input unit 400, a plural number control local oscillator (NCO, Numerically controlledoscillator) 405/411 and digital I, Q quadrature demodulation unit 401/410 are used for two-way I, Q signal that the digital signal branch is orthogonal; Comb shape series connection integration (CIC, a Cascaded integrator comb FIRfilter) decimation filter 402/412 is used for I, Q signal are carried out CIC filtering and data pick-up; A programmable digital-filter 403/413 is used for I, Q signal are carried out digital filtering and data pick-up; A data output format converting unit 404 is carried out the serial or parallel conversion to each passage I, Q signal as required.The quantified precision of ADC is 14, and operating rate is 80MSPS, and it can be sampled at intermediate frequency 70MHz to multi-carrier signal, quantizes bandwidth greater than 20M.By the Nyquist sampling thheorem, sampling rate is 4 times of signal bandwidth, satisfies sampling request.For the example of a W-CDMA, signal bandwidth is the 5MHz signal, and ADC sampling back is by providing about behind the DDC digital filtering: the processing gain of 101g (80M/5M)=12dB.The operation principle of multichannel DDC is described according to Fig. 4 below.At first the if sampling data are carried out frequency spectrum shift, finish digital demodulation: the digital medium-frequency signal that will be input to each passage DDC is moved base band by plural number control local oscillator (NCO) 405/411 and digital I, Q quadrature demodulation unit 401/410, the orthogonal local oscillation output signal of digital medium-frequency signal and NCO multiplies each other and can obtain digital I, Q signal, by software the numerical value of plural number control local oscillator NCO is carried out different being provided with and the intermediate-freuqncy signal of different frequency can be moved base band.Then to digital I, Q signal carries out the CIC filtering extraction: by plural number control local oscillator (NCO) 405/411 and digital I, the I that Q quadrature demodulation unit 401/410 obtains, Q signal, enter CIC decimation filter 402/412 and carry out CIC filtering and data pick-up, this part is mainly finished when reducing data pass rate and is played anti-aliased effect again, because the signal rate of DDC output is certain, the input rate of programmable digital-filter 403/413 reduces behind the adding CIC, the passband of digital filter and transition band can be done widelyer like this, suppress just can strengthen outside the band like this under the certain situation of programmable digital-filter progression.The 3rd step was carried out filtering extraction to digital I, Q signal exactly: the signal by 402/412 output of CIC decimation filter is finished baseband filtering at decimation filter of digital 403/413, digital filter has the irreplaceable function of analog filter, it is a linear phase filter, fluctuating in its exponent number, filtering bandwidth, the band, passband and stopband characteristic etc. can be realized by software, characteristic by the software change digital filter, can make this detector applies in different communication standards, as GSM, CDMA, WCDMA etc.At last data based needs are carried out format conversion, select parallel or serial output: corresponding to different late-class circuits (the input data format is required different dsp processors), the dateout format conversion unit can be carried out the serial or parallel conversion to I, Q data, baseband I, Q signal that final output is satisfied the demand.Because the diversity of power amplifier testing circuit, above step is not all to need in each step, can delete on demand.
Claims (8)
1, a kind of linear power amplification device with improvement structure, comprise exciting amplifier (201), final amplifier (202), error amplifier (205), vector modulator (204), control interface (203), it is characterized in that, also comprise frequency spectrum diffusion counteracting checkout gear (207), receive the RF output signal, deliver to after the detected signal processing in the described vector modulator (204);
Described frequency spectrum diffusion is offset checkout gear (207) and is comprised RF down-conversion device, broadband analog to digital converter (312), digital filter (313) and dsp processor (314); The analog signal of described RF down-conversion device received RF output, and carry out filtering, amplification and quantification treatment, the signal after the processing sends to described broadband analog to digital converter (312); Described broadband analog to digital converter (312) carries out analog-to-digital conversion to receiving intermediate-freuqncy signal, and the output digital signal is to described digital filter (313); Described digital filter (313) carries out filtering to the digital signal that receives, and outputs to described dsp processor (314); Described dsp processor (314) detects the frequency spectrum diffusion signal of handling through described digital filter (313), and sends to described vector modulator (204).
2, according to the described linear power amplification device with improvement structure of claim 1, it is characterized in that described RF down-conversion device also comprises: broadband filter (301) and two-way have the intermediate frequency receive path of same structure:
First via intermediate frequency receive path comprises: receive local vibration source LO1; Frequency mixer (302), by the frequency of control reception local vibration source LO1, the RF channel signal that needs are handled is mixed in the quantification frequency band of intermediate frequency ADC; First Surface Acoustic Wave Filter (303) and second Surface Acoustic Wave Filter (305) are carried out filtering to the neighboring trace analog signal; An intermediate frequency amplifier (304) and intermediate frequency amplifier (306) are respectively arranged after each Surface Acoustic Wave Filter, receive the filtered signal of Surface Acoustic Wave Filter, and amplify, send signal to described broadband analog to digital converter (312);
The second road intermediate frequency receive path comprises: receive local vibration source LO2; Frequency mixer (307), by the frequency of control reception local vibration source LO2, the RF channel signal that needs are handled is mixed in the quantification frequency band of intermediate frequency ADC; First Surface Acoustic Wave Filter (308) and second Surface Acoustic Wave Filter (310) are carried out filtering to the neighboring trace analog signal; An intermediate frequency amplifier (309) and intermediate frequency amplifier (311) are respectively arranged after each Surface Acoustic Wave Filter, receive the filtered signal of Surface Acoustic Wave Filter, and amplify, send signal to described broadband analog to digital converter (312) at last.
3, according to the described linear power amplification device of claim 2 with improvement structure, it is characterized in that, described digital filter (313) comprises a plurality of digital filter apparatus, and described digital filter apparatus is corresponding one by one with branch road in the described described RF down-conversion device.
4, have a linear power amplification device that improves structure according to claim 1 is described, it is characterized in that, the number of the analog to digital converter in the described broadband analog to digital converter (312) is identical and corresponding one by one with number of branches in the described RF down-conversion device.
5, according to the described linear power amplification device of claim 1 with improvement structure, it is characterized in that, also comprise carrier frequency counteracting checkout gear (206), described carrier frequency is offset the signal that checkout gear (206) receives described vector modulator (204) output, and the signal after handling is sent it back described vector modulator (204) again;
Described carrier frequency is offset checkout gear (206) and is comprised RF down-conversion device, broadband analog to digital converter (312), digital filter (313) and dsp processor (314); Described RF down-conversion device connects the signal of described vector modulator (204) output, and carries out filtering, quantification and processing and amplifying, and the signal after the processing sends to described broadband analog to digital converter (312); Described broadband analog to digital converter (312) carries out analog-to-digital conversion to receiving intermediate-freuqncy signal, and the output digital signal is to described digital filter (313); Described digital filter (313) carries out filtering to the digital signal that receives, and outputs to described dsp processor (314); Described dsp processor (314) detects the frequency spectrum diffusion signal of handling through described digital filter (313), and sends to described vector modulator (204).
6, according to the described linear power amplification device with improvement structure of claim 5, it is characterized in that described RF down-conversion device also comprises: broadband filter (301) and two-way have the intermediate frequency receive path of same structure:
First via intermediate frequency receive path comprises: receive local vibration source LO1; Frequency mixer (302), by the frequency of control reception local vibration source LO1, the RF channel signal that needs are handled is mixed in the quantification frequency band of intermediate frequency ADC; First Surface Acoustic Wave Filter (303) and second Surface Acoustic Wave Filter (305) are carried out filtering to the neighboring trace analog signal; An intermediate frequency amplifier (304) and intermediate frequency amplifier (306) are respectively arranged after each Surface Acoustic Wave Filter, receive the filtered signal of Surface Acoustic Wave Filter, and amplify, send signal to described broadband analog to digital converter (312);
The second road intermediate frequency receive path comprises: receive local vibration source LO2; Frequency mixer (307), by the frequency of control reception local vibration source LO2, the RF channel signal that needs are handled is mixed in the quantification frequency band of intermediate frequency ADC; First Surface Acoustic Wave Filter (308) and second Surface Acoustic Wave Filter (310) are carried out filtering to the neighboring trace analog signal; An intermediate frequency amplifier (309) and intermediate frequency amplifier (306) are respectively arranged after each Surface Acoustic Wave Filter, receive the filtered signal of Surface Acoustic Wave Filter, and amplify, send signal to described broadband analog to digital converter (312) at last.
7, according to the described linear power amplification device of claim 5 with improvement structure, it is characterized in that, described digital filter (313) comprises a plurality of digital filter apparatus, and described digital filter apparatus is corresponding one by one with branch road in the described described RF down-conversion device.
8, have a linear power amplification device that improves structure according to claim 5 is described, it is characterized in that, the number of the analog to digital converter in the described broadband analog to digital converter (312) is identical and corresponding one by one with number of branches in the described RF down-conversion device.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 01105288 CN1224165C (en) | 2001-01-21 | 2001-01-21 | Linear power amplification device with improved structure |
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| CN 01105288 CN1224165C (en) | 2001-01-21 | 2001-01-21 | Linear power amplification device with improved structure |
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| CN1224165C true CN1224165C (en) | 2005-10-19 |
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| CN 01105288 Expired - Fee Related CN1224165C (en) | 2001-01-21 | 2001-01-21 | Linear power amplification device with improved structure |
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100433575C (en) * | 2004-09-30 | 2008-11-12 | 中兴通讯股份有限公司 | Redundancy backup system and RF switching device for base station backward link |
| CN100555846C (en) * | 2006-11-20 | 2009-10-28 | 财团法人交大思源基金会 | A kind of D class A amplifier A and use it to drive three-line dual track speaker based method |
| CN106093666A (en) * | 2016-08-08 | 2016-11-09 | 深圳市鼎阳科技有限公司 | A kind of method and apparatus of quick detection signal generator amplitude-frequency characteristic |
| CN106411435B (en) * | 2016-09-29 | 2019-06-11 | 宇龙计算机通信科技(深圳)有限公司 | A kind of RF transmitter and method of adjust automatically ACLR |
| CN109120291B (en) * | 2017-06-23 | 2020-06-19 | 北京遥感设备研究所 | Three-channel variable frequency receiving assembly |
| CN115412111B (en) * | 2022-07-12 | 2023-07-04 | 北京中科睿谱科技有限公司 | Self-adaptive time-frequency domain receiver with spectrum sensing capability |
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