5 Advantages of proper frequency planning using decimation

Effective frequency planning delivers several benefits to enhance receiver system design. One advantage is improved spur suppression. Digital decimation filters effectively attenuate spurs, often achieving suppression levels around –85dBFS, which lead to cleaner signal performance and better utilization of the ADC’s dynamic range for the intended signal rather than out-of-band spurious noise.

Another benefit is the reduction of data throughput from the ADC. By reducing the ADC’s output data rate through decimation, you can interface the ADC with lower-speed, smaller and more cost-effective FPGAs. This reduction in transmitted data not only simplifies hardware requirements but also enables systems to operate in dual band or quad band, thus enabling the sampling of multiple RF bands simultaneously.

The ability of a system to be fully reconfigured in software alone is another significant advantage of using decimation on ADCs. You can plan the hardware interface between the ADC and FPGA to support the maximum data rate expected of the system, which would facilitate the ability to operate many other systems at lower data rates or more narrow bandwidths. Software-reconfigurable systems are particularly valuable in applications that require deployment into multiple scenarios.

Resource savings are also a notable outcome of effective frequency planning. By requiring fewer output lanes, whether high-speed serial data lanes or low-voltage differential signaling pairs, you can conserve valuable pins on both the ADC and FPGA, increasing the utilization factor. This is especially important in high-channel systems with printed circuit board area and power constraints.