【摘要】：隨著無(wú)線通信的快速發(fā)展，TD-LTE標(biāo)準(zhǔn)已成為我國(guó)有自主知識(shí)產(chǎn)權(quán)的TD-SCDMA標(biāo)準(zhǔn)向第四代移動(dòng)通信演進(jìn)的新標(biāo)準(zhǔn)。 TD-SCDMA和TD-LTE系統(tǒng)屬于時(shí)分系統(tǒng)，其工作模式是時(shí)分雙工（TDD），其無(wú)線幀劃分為不同的時(shí)隙，上下行數(shù)據(jù)通過時(shí)隙傳輸，同時(shí)可以靈活配置不同的上下行時(shí)隙比。對(duì)于時(shí)分系統(tǒng)，為了減少對(duì)接收通道的干擾和降低系統(tǒng)功耗，系統(tǒng)中耗能最大的射頻功放僅在發(fā)射時(shí)隙才工作，在接收時(shí)隙將關(guān)斷，因此時(shí)分無(wú)線系統(tǒng)射頻功率放大器不同于頻分系統(tǒng)射頻功率放大器，需根據(jù)上下行信號(hào)分時(shí)工作，對(duì)時(shí)分無(wú)線系統(tǒng)射頻功放的切換時(shí)間有嚴(yán)格限制，必須在規(guī)定的打開時(shí)間內(nèi)啟動(dòng)射頻功放并進(jìn)入穩(wěn)定工作狀態(tài)，同時(shí)在規(guī)定的關(guān)斷時(shí)間內(nèi)徹底關(guān)斷射頻功放，停止發(fā)射信號(hào)輸出，確保收發(fā)通道的隔離度，因此，本文將針對(duì)時(shí)分系統(tǒng)射頻功放的開關(guān)切換特性進(jìn)行研究，探索改善開關(guān)特性的方法，并進(jìn)行功放偏置電路設(shè)計(jì)，以滿足不同時(shí)分無(wú)線系統(tǒng)對(duì)射頻功放切換特性的苛刻要求。 本文參考3GPP R1-081181標(biāo)準(zhǔn)要求，TD-SCDMA信號(hào)上下行信道切換控制信號(hào)開啟時(shí)間至少提前2μs，關(guān)斷時(shí)間也需滯后2μs；TD-LTE從下行接收轉(zhuǎn)換到上行發(fā)送為10-40us，從上行發(fā)送轉(zhuǎn)換到下行接收為15-20us。根據(jù)切換時(shí)間要求，提出了在功放柵極偏置電路中添加切換控制電路，實(shí)現(xiàn)在時(shí)分系統(tǒng)下對(duì)功放工作狀態(tài)的控制，并通過可控放電回路改善其切換性能，提高切換靈敏度。實(shí)驗(yàn)測(cè)試結(jié)果表明，未加可控加放電回路時(shí)，功放柵極電壓切換的下降沿大約為50us；增加可控放電回路之后，下降沿縮短到20ns，切換速度完全可以滿足TD-LTE系統(tǒng)對(duì)射頻功放切換時(shí)間的要求。 由于在TD-LTE系統(tǒng)中使用了正交頻分復(fù)用(OFDM)的調(diào)制方式，而OFDM調(diào)制技術(shù)使信號(hào)產(chǎn)生高峰均比。為提高功放效率，射頻功放采用了Doherty技術(shù)，以便在峰值功率有較大回退時(shí)仍能保持高效率特性。同時(shí)考慮到第三代移動(dòng)通信（3G）能向第四代移動(dòng)通信（4G）平滑演進(jìn)，基站中射頻功率放大器要求可以工作在TDS/TDL的雙模狀態(tài)中，以降低基站設(shè)計(jì)運(yùn)營(yíng)成本，避免重復(fù)性建設(shè)。因此，本文對(duì)雙波段Doherty功率放大器進(jìn)行了仿真研究。 對(duì)于雙波段Doherty功率放大器，其輸入輸出匹配電路和Doherty結(jié)構(gòu)中的四分之一波長(zhǎng)線和補(bǔ)償線均需實(shí)現(xiàn)雙波段特性，因此，本文提出運(yùn)用雙波段阻抗變換器和復(fù)合左右手傳輸線來實(shí)現(xiàn)其雙波段傳輸特性�？紤]到TD-SCDMA工作頻段有2010-2025MHz，F(xiàn)uTURE4G TDD試驗(yàn)系統(tǒng)采用工作頻率為3.45GHz，，頻帶寬度為20MHz，因此本文采用這兩個(gè)頻段設(shè)計(jì)雙波段功放。設(shè)計(jì)仿真結(jié)果顯示f=3.45GHz時(shí)，輸出功率達(dá)到37.5dBm時(shí)，即Doherty功率放大器在6dB功率回退點(diǎn)時(shí)其功率附加效率PAE為50%，比平衡式功率放大器提高了19%；當(dāng)f=2.017GHz時(shí)，輸出功率為37dBm時(shí)，Doherty功率放大器到達(dá)6dB功率回退點(diǎn)，此時(shí)其功率附加效率PAE為50%，比平衡式功率放大器提高了24%。仿真結(jié)果顯示證明了在輸出飽和功率回退6dB范圍時(shí)，功放在兩個(gè)頻段均獲得了較高的效率。
[Abstract]:With the rapid development of the wireless communication, the TD-LTE standard has become the new standard for the evolution of the TD-SCDMA standard with the independent intellectual property in our country to the fourth-generation mobile communication. The TD-SCDMA and TD-LTE system belong to time division system, its working mode is time division duplex (TDD), its wireless frame is divided into different time slots, and the uplink and downlink data is transmitted through time slot, and different uplink and downlink time slot ratios can be flexibly configured. in the time-division system, in order to reduce the interference to the receiving channel and reduce the power consumption of the system, the radio-frequency power amplifier with the largest energy consumption in the system works only in the transmission time slot, and the radio-frequency power amplifier of the time-division wireless system is different from the radio-frequency power amplifier of the frequency subsystem, according to the uplink and downlink signals, the switching time of the radio frequency power amplifier of the time division wireless system is strictly limited, the radio frequency power amplifier is started to be started in a specified opening time and enters a stable working state, The output of the transmitting signal is stopped, and the isolation degree of the transmitting/ receiving channel is ensured. Therefore, the switching characteristic of the radio frequency power amplifier of the time division system is researched, the method for improving the switching characteristic is explored, and the circuit design of the bias circuit of the power amplifier is carried out, so as to meet the severe requirements of the radio frequency power amplifier switching characteristics of different time division wireless systems. According to the requirements of 3GPP R1-081181, the switching control signal of TD-SCDMA signal is at least 2. m in advance, and the turn-off time is 2. m according to the switching time requirement, a switching control circuit is added to the power amplifier grid bias circuit, the control of the power amplifier working state under the time division system is realized, the switching performance of the power amplifier is improved through a controllable discharge loop, and the switching sensitivity is improved The results of the experiment show that the falling edge of the voltage switching of the power amplifier is about 50us when the control and discharge loop is not applied; after the controllable discharging loop is increased, the falling edge is shortened to 20ns, and the switching speed can completely meet the requirement of the TD-LTE system to switch the radio frequency power amplifier An orthogonal frequency division multiplexing (OFDM) modulation scheme is used in a TD-LTE system, and an OFDM modulation technique causes a high signal to be generated. The peak-to-average ratio. In order to improve the efficiency of the power amplifier, the radio-frequency power amplifier adopts the Doherty technique, so that the high-efficiency can be maintained when the peak power has a large roll-off. rate characteristics. Considering that the third generation mobile communication (3G) can be smoothly evolved to the fourth generation mobile communication (4G), the requirements of the radio frequency power amplifier in the base station can be in the dual mode state of the TDS/ TDL to reduce the design and operation cost of the base station and avoid the repetition. In this paper, the double-band Doherty power amplifier is simulated. The dual-band Doherty power amplifier, the input-output matching circuit and the one-quarter wavelength line and the compensation line in the Doherty structure all need to realize the dual-band characteristic, therefore, the dual-band impedance transformer and the composite left-right-hand transmission line are used to realize the dual-wave band characteristic. The transmission characteristics of the section are considered. Considering that the TD-SCDMA working frequency band is 2010-2025MHz, the FuturE4G TDD test system adopts the operating frequency of 3.45GHz and the bandwidth of the frequency band is 20MHz, so the two frequency bands are designed in this paper Dual-band power amplifier. The simulation results show that when f = 3.45GHz, the power of Doherty power amplifier is 50% at 6dB power back-off point, which is 19% higher than that of balanced power amplifier. When f = 2.017GHz, the Doherty power amplifier reaches 6dB when the output power is 37dBm. The power back-off point, at which time its power-added efficiency PAE is 50%, is higher than the balanced power amplifier The simulation results show that the work is obtained in both frequency bands when the output saturation power is off the 6dB range.
【學(xué)位授予單位】：寧波大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TN722.75

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張安學(xué);范世毅;蔣延生;徐卓;;基于左右手復(fù)合傳輸線的威爾金森功分器[J];電波科學(xué)學(xué)報(bào);2009年01期

2 張麟兮;魯新建;廣闊天;;高效率Doherty功率放大器的研究與設(shè)計(jì)[J];電聲技術(shù);2011年03期

3 宋起柱;劉紅杰;李書芳;;WCDMA與TD-SCDMA終端射頻測(cè)試的差異性分析[J];電信科學(xué);2006年10期

4 劉道生;;TD-SCDMA直放站實(shí)現(xiàn)同步和切換的方法[J];光通信研究;2007年01期

5 王似旭;;一種LTE TDD系統(tǒng)的幀定時(shí)同步方法[J];廣東通信技術(shù);2009年01期

6 劉昶;;LTE TDD測(cè)試介紹及R&S解決方案[J];國(guó)外電子測(cè)量技術(shù);2009年04期

7 龔劍;張祖蔭;郭偉;;射頻功率放大器模塊的設(shè)計(jì)與實(shí)現(xiàn)[J];計(jì)算機(jī)與數(shù)字工程;2006年11期

8 童富;劉海文;曹銳;胡衛(wèi)東;于奇;;Doherty功率放大器的研究進(jìn)展[J];雷達(dá)科學(xué)與技術(shù);2008年05期

9 曹韜;劉友江;呂立明;;基于復(fù)合左右手傳輸線結(jié)構(gòu)的多頻高效功放[J];微電子學(xué);2011年05期

10 楊雪梅,鐘章隊(duì);TD-SCDMA中同步技術(shù)的探討[J];數(shù)據(jù)通信;2003年05期

相關(guān)博士學(xué)位論文 前1條

1 黃闖;基于左右手復(fù)合傳輸線和MEMS的新型微波器件研究[D];上海交通大學(xué);2010年

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