【正文】 ry important type of amplifiers in the modern wireless access technology and remote munication system. Over the past 10 years, phased array radar systems have developed rapidly in the field of military and civilian areas.. In recent years, phased array radar, especially active phased array radar, has been developed rapidly, and the main reason is that the radar performance is increasing.. Due to the microwave power amplifier in a radar system of heart function, and microwave power amplifier bee key ponents of the constraints of the system performance and the level of technology, the advantage of its performance will directly affect the quality of the whole system. 1 broadband microwave power amplifier matching circuit broadband microwave power amplifier input and output matching circuit for single stage power amplifier, mainly is the design of input matching circuit and an output matching circuit, and the design of multistage power amplifier need to design the stage matching circuit. In the power amplifier design, the input and output matching circuits are based on the specialSet the matching function and follow the different design principles. The input matching circuit is used to realize the matching between the amplifier input port and a signal source, it amplifier presents the plex impedance transform and signal source impedance conjugate matching, in order to obtain the maximum power gain matching. The input matching circuit mainly solves the problems such as stability, gain, gain flatness, input standing wave and so on.. The output matching circuit is used to plete the matching between the output port of the amplifier and the load, and the main function of the output matching circuit is to improve the output power, improve the output power, and suppress the harmonic of the output of the Bobbi. Thus, the gain and its flatness are mainly solved by the input, and the gain of the microwave transistor is pensated.. The input and output impedances of the microwave power amplifier are small, and only a few of the order of Ohm are. The input impedance is smaller and the imaginary part is changed with the frequency.. So the input impedance of microwave power amplifier is relatively large and the matching circuit is hard to design.. In the guarantee of the gain and its flatness, it is difficult to get smaller input in Bobbi, the broadband design is more prominent [3]. matching network main methods of the microwave power amplifier matching network are: lumped element method, distributed parameter method. Using distributed parameter method to achieve the impedance matching method mainly in the following three ways: (1) a quarter wavelength stepped impedance transformer。 II microstrip tapered line impedance converter。 third, microstrip low pass impedance filter impedance converter. 1/4 wavelength stepped impedance transformer usually requires impedance change ratio is less than 5, and the frequency range is not easy too wide, otherwise difficult to match. Taper microstrip line and microstrip low pass filter impedance converter two methods matching bandwidth is wide, small volume, especially microstrip lowpass filter impedance converter. It not only has the nature of the stepped impedance transformer, but also has the advantages of pact structure, large stop band attenuation to the dual role of filtering and impedance transformation. 附錄C : 由于無線通信的飛速發(fā)展,滿足不同需求的通信系統(tǒng)應(yīng)運(yùn)而生，不同通信標(biāo)準(zhǔn)、不同工作模式的多種系統(tǒng)并存，給人類生活帶來極大的方便。人們希望不僅能在不同地方進(jìn)行通話，而且要求開展數(shù)據(jù)、傳真等非話業(yè)務(wù)的服務(wù)。這些需求促使移動通信技術(shù)高速發(fā)展,通信的頻率不斷提高, 通信的帶寬逐漸增加,使用的設(shè)備快速更新?lián)Q代，對于核心部件的微波功率放大器的要求也越來越高[12]。寬帶微波功率放大器以其低非線性失真以及良好的匹配性等特點(diǎn)，成為現(xiàn)代無線接入技術(shù)和遠(yuǎn)程通信系統(tǒng)中的一種極為重要的放大器類型。在過去的10 年里，相控陣?yán)走_(dá)系統(tǒng)在軍用和民用領(lǐng)域發(fā)展迅速。相控陣?yán)走_(dá)特別是有源相控陣?yán)走_(dá)近年來有了高速發(fā)展，推動其發(fā)展的主要原因是對雷達(dá)性能的要求日益提高。由于微波功率放大器在雷達(dá)系統(tǒng)中的心臟作用，因而微波功率放大器成為制約系統(tǒng)性能和技術(shù)水平的關(guān)鍵部件，其性能的優(yōu)勢將直接影響到整個系統(tǒng)的質(zhì)量。1 寬帶微波功率放大器匹配電路 寬帶微波功率放大器輸入輸出匹配電路對于單級功率放大器而言，主要是設(shè)計(jì)輸入匹配電路和輸出匹配電路，而設(shè)計(jì)多級功率放大器則還需要設(shè)計(jì)級間匹配電路。在功率放大器設(shè)計(jì)中，輸入和輸出匹配電路基于特定的匹配功能而遵循不同的設(shè)計(jì)原則。輸入匹配電路是用來實(shí)現(xiàn)放大器輸入端口與信號源之間的匹配，它把放大器呈現(xiàn)的復(fù)數(shù)阻抗變換為與信號源阻抗共軛匹配，以獲得最大功率增益匹配。輸入匹配電路主要解決穩(wěn)定性、增益、增益平坦度、輸入駐波等問題。輸出匹配電路用來完成放大器的輸出端口與負(fù)載之間的匹配，其主要作用是提高輸出功率、改善輸出駐波比和抑制諧波。因此，增益及其平坦度的問題主要放在輸入端來解決，補(bǔ)償微波晶體管的自身增益滾降。微波功率放大器的輸入輸出阻抗都很小，大概只有幾歐姆的量級。其中輸入阻抗更小，而且虛部隨頻率變化較大。因此微波功率放大器的輸入阻抗變換比較大，匹配電路較難設(shè)計(jì)。在保證增益及其平坦度的同時很難獲得較小的輸入駐波比，寬帶設(shè)計(jì)中此問題更加突出。 匹配網(wǎng)絡(luò)實(shí)現(xiàn)微波功率放大器的匹配網(wǎng)絡(luò)的實(shí)現(xiàn)途徑主要有：集總元件法，分布參數(shù)法。利用分布參數(shù)法來實(shí)現(xiàn)阻抗匹配的方法主要有以下三種方法：①1/4 波長階梯阻抗變換器；②微帶漸變線阻抗變換器；③微帶低通阻抗濾波阻抗變換器。1/4 波長階梯阻抗變換器通常要求阻抗變化比小于5，且頻率范圍不易太寬，否則不易匹配。微帶漸變線和微帶低通濾波阻抗變換器兩種方法匹配帶寬比較寬，體積小，尤其是微帶低通濾波阻抗變換器，它不僅具有階梯阻抗變換器的性質(zhì)，而且結(jié)構(gòu)緊湊，阻帶衰減大，可起到濾波和阻抗變換雙重作用。 第 35 頁 共 35頁第 36 頁 共 42 頁