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| 4 | | 26 | reduces power consumption, has greater programmability, and higher integration levels. Thus, the Xilinx Zynq UltraScale+ RFSoC enables the system designer to create highly flexible SDR applications while simultaneously addressing many of the challenges associated with competitive direct RF-sampling solutions. Noise Spectral Density SNR and ENOB metrics consider a data converter's entire Nyquist bandwidth. However, this is not relevant to today's RF-sampling data converters, especially for SDR applications. In real applications, tight bandpass filters around the band of interest are often employed. Many RF-sampling analog digital converters (ADCs) include decimation features to extract only the signal bandwidth of interest. Both aspects always eliminate all the noise outside of those bands. NSD is a more appropriate metric to quantify the RF-sampling data converter's ability because NSD provides the amount of noise energy in 1Hz bandwidth for a data converter (Figure 1). Third-Order Intermodulation Distortion (IM3) Any complex signal contains components at several frequencies simultaneously. Nonlinearity in the converter's transfer function not only distorts a pure tone, but also causes two or more signal frequencies to interact and produce intermodulation products. When this happens, the result is called intermodulation distortion, or IM3. IM3 can lead to severe issues in RF communication systems that create additional frequency components (called spectral regrowth) in bands adjacent to the modulated signals. In a receive path, spectral regrowth can cause out-of-band signals to interfere with the signal of interest. On the other hand, in a transit path, bad IM3 can affect adjacent channels, which then cannot pass the frequency mask of the wireless protocol (Figure 2). Figure 1: Noise Spectral Density. (Source: Xilinx) Figure 2: Third-Order Intermodulation Distortion. (Source: Xilinx)