【摘要】：功率放大器通常位于射頻前端發(fā)射機(jī),將輸入信號(hào)放大到足夠功率電平以供天線對(duì)外輻射,對(duì)系統(tǒng)整機(jī)的性能至關(guān)重要。受限于傳統(tǒng)半導(dǎo)體材料的性能缺陷,微波功放的輸出功率有限;第三代半導(dǎo)體器件GaN HEMTs由于其寬禁帶特性,具有高擊穿電壓、高電子遷移率以及適應(yīng)高溫環(huán)境等優(yōu)點(diǎn),在微波固態(tài)功率放大器領(lǐng)域有著巨大潛力。隨著通信、雷達(dá)等系統(tǒng)的發(fā)展,對(duì)小尺寸大功率固態(tài)功放的要求也隨之提高。內(nèi)匹配形式的功放器件在體積和重量上優(yōu)于外匹配功放,在研制難度和成本上優(yōu)于MMIC功放;在如超大功率相控陣?yán)走_(dá)的應(yīng)用中,GaN HEMT內(nèi)匹配功率模塊在具有小體積的同時(shí),還可實(shí)現(xiàn)大功率輸出,使系統(tǒng)獲得更強(qiáng)的遠(yuǎn)程作用能力。內(nèi)匹配形式由于封裝面積有限,復(fù)雜結(jié)構(gòu)難以集成,同時(shí)這種現(xiàn)象在寬帶低頻時(shí)更加明顯。因此,本文就L波段GaN內(nèi)匹配功率放大器的設(shè)計(jì)進(jìn)行研究,主要工作如下:功放工作頻帶達(dá)到一個(gè)倍頻程,因此設(shè)計(jì)采用寬帶匹配技術(shù)理論,對(duì)寬頻帶下阻抗匹配進(jìn)行研究。對(duì)比傳統(tǒng)寬帶結(jié)構(gòu)的優(yōu)劣,選用在尺寸方面更具優(yōu)勢(shì)的多級(jí)低Q值低通LC匹配結(jié)構(gòu);針對(duì)小封裝,功放電路輸入輸出將兩路并為一路進(jìn)行阻抗匹配;為使管芯之間相位幅度平衡,在兩管芯兩端直接進(jìn)行功分合成;公式推導(dǎo)單級(jí)LC匹配網(wǎng)絡(luò)參量計(jì)算式,并依據(jù)低Q寬帶思想將公式應(yīng)用于三級(jí)LC匹配網(wǎng)絡(luò),對(duì)源/負(fù)載阻抗進(jìn)行中心頻點(diǎn)的匹配,ADS電路仿真驗(yàn)證公式準(zhǔn)確有效;推導(dǎo)計(jì)算公式將集總參量轉(zhuǎn)為分布參量,進(jìn)行ADS多頻點(diǎn)寬帶匹配仿真,實(shí)現(xiàn)功放1-2GHz范圍的源/負(fù)載阻抗匹配。最終設(shè)計(jì)并制作一款L波段GaN基內(nèi)匹配功率放大器。管芯選用國(guó)內(nèi)某公司自主研發(fā)的大柵寬GaN HEMT;匹配網(wǎng)絡(luò)中,電容器采用金屬-絕緣層-金屬(MIM)實(shí)現(xiàn),電感采用高阻線實(shí)現(xiàn),使用金絲進(jìn)行鍵合。功放封裝在14.5mm*14.5mm的管殼中,工作在1-2 GHz,偏置在VGS=-2.8V、VDS=28V,對(duì)高溫(85℃)、常溫(25℃)環(huán)境溫度下,實(shí)測(cè)連續(xù)波模式輸入Pin=37dBm時(shí),均有輸出功率Pout45dBm、漏極效率ηD44%;低溫(-55℃)時(shí)更有輸出功率Pout47dBm、漏極效率ηD52%;小信號(hào)增益帶內(nèi)均大于10.5dB。與傳統(tǒng)使用T型網(wǎng)絡(luò)對(duì)端口阻抗進(jìn)行輸入預(yù)匹配,再結(jié)合電橋或Wilkinson功分器進(jìn)行兩路合成實(shí)現(xiàn)寬帶匹配相比,本文使用的匹配結(jié)構(gòu)可以集成在更小的封裝內(nèi)。
[Abstract]:The power amplifier is usually located in the RF front-end transmitter. It is very important for the whole system to amplify the input signal to a sufficient power level for external radiation of the antenna. The output power of microwave power amplifier is limited due to the performance defects of traditional semiconductor materials, and the third generation semiconductor device GaN HEMTs has the advantages of high breakdown voltage, high electron mobility and high temperature environment due to its wide band gap. There is great potential in the field of microwave solid-state power amplifier. With the development of communication, radar and other systems, the requirement of small-size high-power solid-state power amplifier is raised. The internal matching power amplifier is superior to the external power amplifier in volume and weight, and is superior to the MMIC power amplifier in the development difficulty and cost. For example, in the application of super large power phased array radar, the matching power module of gan HEMT has small volume. It can also achieve high power output, so that the system can achieve stronger remote operation ability. Due to the limited packaging area, it is difficult to integrate the complex structure, and this phenomenon is more obvious in the broadband low frequency. Therefore, the design of L-band GaN internal matched power amplifier is studied in this paper. The main work is as follows: the working band of power amplifier reaches a frequency doubling path, so broadband matching theory is adopted to study impedance matching in wide band. Comparing the advantages and disadvantages of traditional wideband structure, the multi-stage low-Q low-pass LC matching structure with more advantages in dimension is selected, and for small package, the input and output of power amplifier circuit will match the impedance together. In order to balance the phase amplitude between the tube cores, the power division synthesis is carried out directly at both ends of the two cores, the formula for calculating the parameters of the single-stage LC matching network is derived, and the formula is applied to the three-stage LC matching network according to the low-Q broadband theory. The simulation results of central frequency points matching ads circuit for source / load impedance show that the formula is accurate and effective, and the formula is derived to convert the lumped parameters into distributed parameters, and the ADS multi-frequency wideband matching simulation is carried out. The source / load impedance matching in the 1-2GHz range of power amplifier is realized. Finally, a L band GaN power amplifier is designed and fabricated. In the large gate width GaN HEMT; matching network developed by a domestic company, the capacitor is realized by metal-insulator-metal (MIM), the inductance is realized by high resistance wire, and the gold wire is used for bonding. The power amplifier is encapsulated in the tube and shell of 14.5mm*14.5mm, working in 1-2 GHz, bias at the ambient temperature of high temperature (85 鈩，

本文編號(hào)：2215175