The dynamic range of an analog link is defined in relation to two-lone third-order intermodulation frequencies. First consider two large equal-power signals at fundamental frequencies f_1 and f_2, as shown in Fig. 9.15. These two signals will produce second-order modulation products at 〖2f〗_1 ,f_2, and f_1 ±f_2 and third-order intermodulation products at frequencies 〖2f〗_1 ±f_2 and f_2 ±f_1. The second-order terms normally fall outside of the passband of a system, so they can be ignored. However, the third-order products are of concern since they could fall on a signal frequency within the system bandwidth and cannot be removed by a simple Filtering technique. To determine system operating requirements, consider the case shown in