Effects of Random Delay Errors in Continuous-Time Semi-Digital Transversal Filters

The implementation of transversal filters requires basic circuit elements such as adders, multipliers and (unit) delay elements. The filters designed under infinite precision of these elements may behave differently when implemented with components with limited accuracy. In fact, the effects of the coefficient inaccuracies in analog and digital transversal filters have been investigated extensively in the literature [1], [2]. On the other hand, the effects of the unit delays with limited precision have not received similar attention. In this paper, we find that such effects especially in very high frequency continuous-time semi-digital transversal filters may not be ignored. As an example, we analyze the impact of delay errors in the implementation of the direct modulation transmitter. Specifically, we provide the analytical statistical performance bounds and confirm the results with simulations.