本文關(guān)鍵詞： 包絡(luò)跟蹤 Doherty 線性度 效率　出處：《電子科技大學》2014年碩士論文　論文類型：學位論文

【摘要】：LTE通信系統(tǒng)的下行信號是具有高峰均比的多載波信號,這種信號對基站功率放大器的線性度提出了更高的要求。同時,出于對環(huán)保節(jié)能的需要,基站功放也必須達到高效率的要求�；谏鲜龅膽�(yīng)用要求,本文研究了將包絡(luò)跟蹤技術(shù)應(yīng)用到Doherty功率放大器中,以達到在保證基站功放高效率的同時,提升系統(tǒng)高功率輸入狀態(tài)下的線性度。本文的主要工作是在對Doherty放大器的研究基礎(chǔ)上,提出利用包絡(luò)跟蹤信號控制Doherty放大器中峰值功放柵極電壓的方法。通過這種方法,實現(xiàn)在小功率輸入時降低柵壓以獲得高效率;在大功率輸入時提升柵壓,在犧牲小部分效率的情況下提升線性度。本文的研究主要包括:1.對功率放大器基本理論進行了研究,并分析了Doherty放大器的基本原理。2.對包絡(luò)跟蹤技術(shù)進行分析和研究,并對當前主流的包絡(luò)跟蹤電路結(jié)構(gòu)進行了系統(tǒng)的總結(jié)。3.詳細分析、研究了包絡(luò)跟蹤技術(shù)對Doherty放大器的電路性能的影響,并給出了分別控制載波、峰值功放柵壓和漏壓的結(jié)果比較。在此基礎(chǔ)上,針對2.59GHz的LTE系統(tǒng),提出了一種利用包絡(luò)跟蹤控制峰值功放柵壓的電路結(jié)構(gòu),以改善Doherty放大器的線性性能。4.對包絡(luò)跟蹤的Doherty放大器進行了設(shè)計和制作,并在實驗室條件下進行了測試。測試結(jié)果顯示,在功率回退8d B內(nèi),包絡(luò)跟蹤的Doherty放大器相對于傳統(tǒng)的Doherty放大器,三階互調(diào)改善了約3~5d Bc,而效率僅惡化了2~4%左右。
[Abstract]:The downlink signal of LTE communication system is a multi-carrier signal with peak-to-average ratio, which requires higher linearity of the base station power amplifier. At the same time, it is necessary for environmental protection and energy saving. The base station power amplifier must also meet the requirements of high efficiency. Based on the above application requirements, this paper studies the application of envelope tracking technology to Doherty power amplifier. In order to ensure the high efficiency of the base station power amplifier at the same time to enhance the linearity of the system under the high power input state. The main work of this paper is based on the research of Doherty amplifier. An envelope tracking signal is proposed to control the peak gate voltage in the Doherty amplifier, by which the gate voltage can be reduced at low power input to achieve high efficiency. In the case of high power input, the grid voltage is raised, and the linearity is raised at the expense of a small part of efficiency. The research in this paper mainly includes: 1. The basic theory of power amplifier is studied. The basic principle of Doherty amplifier is analyzed. 2. The envelope tracking technology is analyzed and studied, and the structure of the current mainstream envelope tracking circuit is systematically summarized. 3. The influence of envelope tracking technology on the circuit performance of Doherty amplifier is studied, and the results of control carrier, peak power amplifier gate voltage and leakage voltage are compared. For the 2.59GHz LTE system, a circuit structure using envelope tracking to control the peak power amplifier gate voltage is proposed. In order to improve the linear performance of Doherty amplifier. 4. The envelope tracking Doherty amplifier is designed and fabricated, and tested in the laboratory. The test results show. Compared with the traditional Doherty amplifiers, the third-order intermodulation of the envelop tracking Doherty amplifiers is improved by about 3dBc in 8 dB power recoil. The efficiency only deteriorated by 2% or 4%.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN722.75;TN929.5
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本文編號：1485656