本文選題：無(wú)線通信　切入點(diǎn)：Doherty功率放大器　出處：《杭州電子科技大學(xué)》2017年碩士論文

【摘要】：自從上世紀(jì)80年代移動(dòng)手機(jī)的出現(xiàn)以來(lái),無(wú)線通信技術(shù)經(jīng)歷了前所未有的飛速發(fā)展。直到今天,它已經(jīng)主導(dǎo)了人們的生活和交流方式。隨著無(wú)線通信行業(yè)的高速發(fā)展,人們對(duì)大容量信息傳輸?shù)男枨笠苍谥饾u增加,因而,對(duì)無(wú)線通信技術(shù)的要求也越來(lái)越嚴(yán)苛。功率放大器作為無(wú)線通信系統(tǒng)中最耗能的組件,其效率對(duì)整個(gè)通信網(wǎng)的能耗都至關(guān)重要。同時(shí),受節(jié)能環(huán)保生活方式的影響,我們更應(yīng)致力于提高其效率。由于人們對(duì)高信息容量傳輸?shù)男枨笕找嬖黾?各種復(fù)雜的調(diào)制方案得到了廣泛應(yīng)用。因此,當(dāng)今的無(wú)線通信中的信號(hào)通常具有很高的峰值-平均功率比(峰均比)。傳統(tǒng)的功率放大器,在處理這些信號(hào)的時(shí)候很難保證在回退區(qū)和飽和區(qū)同時(shí)達(dá)到高效。因此以Doherty功率放大器為代表的功率放大器成為了當(dāng)今基站功放的主流結(jié)構(gòu)。該結(jié)構(gòu)通常由兩路偏置點(diǎn)不同的子功率放大器組成,即峰值功率放大器(主功放)和載波功率放大器(副功放)。其工作原理是隨著輸入信號(hào)的增加,兩者依次導(dǎo)通,在主功放達(dá)到飽和的時(shí)候,副功放才開(kāi)始工作。這樣就可以保證整體電路在回退點(diǎn)和飽和點(diǎn)都能夠高效的放大信號(hào)。本文將主要對(duì)Doherty這種結(jié)構(gòu)進(jìn)行研究。雖然傳統(tǒng)的Doherty功率放大器具有突出的效率優(yōu)勢(shì),但是存在工作帶寬較窄的缺陷。這主要是因?yàn)槠湄?fù)載調(diào)制網(wǎng)絡(luò)是由兩條四分之一波長(zhǎng)線組成的,其阻抗隨工作頻率的變化而變化,這一特點(diǎn)大大限制了整體電路的帶寬。本文中將會(huì)提出一種新型的負(fù)載調(diào)制網(wǎng)絡(luò),對(duì)傳統(tǒng)的結(jié)構(gòu)進(jìn)行優(yōu)化,極大的改善阻抗隨頻率的漂移效應(yīng),從而保持阻抗穩(wěn)定的同時(shí)提升Doherty功放的整體效率。另外,隨著人們對(duì)大容量信息的需求越來(lái)越大,無(wú)線通信系統(tǒng)中的調(diào)制信號(hào)也越來(lái)越復(fù)雜,峰均比前所未有的高。所以我們希望Doherty功率放大器能夠在更大的功率范圍內(nèi)都保持高效。相比于傳統(tǒng)兩路Doherty,新加一路峰值功率放大器的三路Doherty,可以完成這個(gè)目標(biāo)。三路Doherty的負(fù)載調(diào)制網(wǎng)絡(luò)同樣存在上面提到的阻抗漂移問(wèn)題。因此,同樣需要對(duì)其負(fù)載調(diào)制網(wǎng)絡(luò)進(jìn)行優(yōu)化以拓寬其帶寬。本論文在傳統(tǒng)的負(fù)載調(diào)制網(wǎng)絡(luò)中新增一條并聯(lián)的四分之一波長(zhǎng)短路線,這種新型的負(fù)載調(diào)制網(wǎng)絡(luò)可有效限制阻抗隨頻率的漂移,并設(shè)計(jì)了一個(gè)三路Doherty功率放大器來(lái)驗(yàn)證其有效性,通過(guò)對(duì)實(shí)物電路的加工測(cè)試,最終得到,在2-2.6GHz的工作帶寬內(nèi),8dB回退點(diǎn)的漏極效率在40%以上,飽和點(diǎn)的效率在53%以上,在2.6GHz處可達(dá)76%,工作帶寬內(nèi)的飽和輸出功率都在43.6dBm以上,在2.2GHz處可達(dá)45.4dBm。
[Abstract]:Since the emergence of mobile phones in the 1980s, wireless communication technology has experienced unprecedented rapid development.To this day, it has dominated the way people live and communicate.With the rapid development of wireless communication industry, the demand for mass information transmission is gradually increasing, so the requirements of wireless communication technology are becoming more and more stringent.Power amplifier is the most energy-consuming component in wireless communication system. Its efficiency is very important to the energy consumption of the whole communication network.At the same time, under the influence of energy conservation and environmental protection lifestyle, we should focus on improving its efficiency.Due to the increasing demand for high information capacity transmission, a variety of complex modulation schemes have been widely used.Therefore, in today's wireless communications, signals usually have a high peak-to-average power ratio (PAPR).It is difficult for traditional power amplifiers to process these signals with high efficiency in both the fallback and saturation regions.Therefore, the power amplifier, represented by Doherty power amplifier, has become the mainstream structure of base station power amplifier.This structure usually consists of two sub-power amplifiers with different bias points, namely, peak power amplifier (main power amplifier) and carrier power amplifier (secondary power amplifier).Its working principle is that with the increase of input signal, both of them are switched on in turn. When the main power amplifier reaches saturation, the secondary power amplifier begins to work.This ensures that the whole circuit can amplify the signal efficiently at both the back-off point and the saturation point.This paper will mainly study the structure of Doherty.Although the traditional Doherty power amplifier has the outstanding efficiency advantage, it has the limitation of narrow working bandwidth.This is mainly due to the fact that the load modulation network is composed of two 1/4 wave long lines, and its impedance varies with the operating frequency, which greatly limits the bandwidth of the whole circuit.In this paper, a new type of load modulation network is proposed, which optimizes the traditional structure and greatly improves the drift effect of impedance with frequency, thus maintaining the stability of impedance and improving the overall efficiency of Doherty power amplifier.In addition, with the increasing demand for large capacity information, modulation signals in wireless communication systems are becoming more and more complex, the peak to average ratio is higher than ever before.So we want the Doherty power amplifier to remain efficient in a larger power range.Compared with the traditional two-channel Doherty, a new three-way Doherty with a peak power amplifier can achieve this goal.The impedance drift problem mentioned above also exists in the three-channel Doherty load modulation network.Therefore, it is also necessary to optimize the load modulation network to broaden its bandwidth.In this paper, a parallel 1/4 wavelength short path is added to the traditional load modulation network. This novel load modulation network can effectively limit the drift of impedance with frequency.At 2.6GHz, the saturation output power is above 43.6dBm and 45.4 dBm. at 2.2GHz.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN722.75

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 張韌;C波段GaAs HBT-MMIC功率放大器的研制[D];電子科技大學(xué);2012年

，

本文編號(hào)：1721457