CAJ | 학술논문

针对CDMA（Code Division Multiple Access）射频接收机中LNA（low noise amplifier）的非线性度引发的交调干扰问题,本文基于CDMA手机平台,结合CDMA单音抗扰度实验,定性地分析了交调干扰的产生过程以及此干扰对射频单音指标的影响。并利用单音裕量值计算出了满足CDMA BC0（cellular）频段的LNA IIP3（inputthird-order intercept point）指标：＋7.8dBm。同时进行IP3（third-order intercept point）实验验证IIP3计算值与实际值的一致性。分析表明射频接收机中的交调干扰是发射泄露的信号与邻道单音干扰信号交叉调制产生。LNA的线性度指标IIP3对交调干扰起决定性作用。要使交调产物越小,所需要的IIP3值越大。
침대CDMA（Code Division Multiple Access）사빈접수궤중LNA（low noise amplifier）적비선성도인발적교조간우문제,본문기우CDMA수궤평태,결합CDMA단음항우도실험,정성지분석료교조간우적산생과정이급차간우대사빈단음지표적영향。병이용단음유량치계산출료만족CDMA BC0（cellular）빈단적LNA IIP3（inputthird-order intercept point）지표：＋7.8dBm。동시진행IP3（third-order intercept point）실험험증IIP3계산치여실제치적일치성。분석표명사빈접수궤중적교조간우시발사설로적신호여린도단음간우신호교차조제산생。LNA적선성도지표IIP3대교조간우기결정성작용。요사교조산물월소,소수요적IIP3치월대。
The nonlinearity of LNA(low noise amplifier) which have caused the problem of cross modulation interference in CDMA(Code Division Multiple Access) RF receiver is studied.Based on the CDMA cell phone,simultaneously using CDMA single-tone desensitization test,the factors which trigger the interference are qualitatively analyzed,simultaneously the wanted IIP3(input third-order intercept point) of LNA for CDMA cellular is designed: +7.8 dBm.Making use of the IP3 test,the agreement between the calculation and the actual value is verified.The results showed that the IIP3 of LNA determined the cross modulation interference.The smaller the product to make,the greater IIP3 value we need.