In the transmit signal path of a cellular terminal that supports the Long-Term Evolution (LTE) standard, the third-order counter-intermodulation (CIM3) product can be a significant contributor to spurious emissions in protected bands, primarily in cases where all the transmit power is concentrated in one resource block at the edge of the allocated bandwidth. This problem can be addressed with a harmonic rejection architecture for the up-conversion mixer in the transceiver. Prior work in this area retains the four-phase baseband inputs of a conventional quadrature mixer, utilizes various techniques in the local oscillator (LO) path involving overlapping LO waveforms to suppress harmonics and requires the digitally-controlled oscillator (DCO) to be operated at two or more times the LO frequency. The harmonic rejection architecture presented in this paper has six baseband phases and six non-overlapping LO phases and, for higher-frequency bands, allows the DCO to run at 1.5 times the LO frequency. It also provides an inherently higher uncalibrated image rejection than architectures with quadrature baseband inputs, which is advantageous for any wireless communication standard that supports higher-order quadrature amplitude modulation (QAM) schemes such as 1024-QAM and 4096-QAM.

中文翻译：

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具有抵消互调失真和改进的图像抑制功能的660 MHz–5 GHz 6相/ 3相发射机

在支持长期演进（LTE）标准的蜂窝终端的发射信号路径中，三阶反互调（CIM3）产品可能是受保护频段内杂散发射的重要贡献者，主要是在所有发射功率集中在分配带宽边缘的一个资源块中。该问题可以通过收发器中上变频混频器的谐波抑制架构解决。该领域的现有技术保留了传统正交混频器的四相基带输入，在本地振荡器（LO）路径中利用了涉及重叠LO波形的多种技术来抑制谐波，并要求数字振荡器（DCO）的工作频率为LO频率的两倍或更多倍。本文提出的谐波抑制架构具有六个基带相位和六个不重叠的LO相位，对于更高的频段，允许DCO以LO频率的1.5倍运行。与具有正交基带输入的体系结构相比，它还提供了固有的更高的未校准图像抑制能力，这对于支持诸如1024-QAM和4096-QAM之类的支持更高阶正交幅度调制（QAM）方案的任何无线通信标准都是有利的。