摘要
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。
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.
出处
《西安邮电学院学报》
2012年第6期20-23,共4页
Journal of Xi'an Institute of Posts and Telecommunications
基金
陕西省重大科技创新基金资助项目(2010ZKC02-08)
关键词
交调干扰
LNA
单音抗扰度
IIP3
cross modulation interference
low-power amplifier
single-tone desensitization
IIP3
