In this paper, we present a novel procedure for an efficient and accurate electromagnetic simulation of microstrip circuits and printed antennas etched in layered media. The proposed approach, based on a new algorithm referred to herein as the equivalent medium approach (EMA), is applied for a rapid design of the preliminary desired circuit prototype. The illustrated technique yields reliable results and reduces the computational time in comparison with the conventional method of moments (MoM). Some examples that demonstrate the accuracy and the efficiency of the described procedure are included.

In multilevel QAM radio systems affected by selective fading, countermeasures such as adaptive baseband equalization allow a drastic reduction of signatures. Linear and decision feedback equalization are investigated from an analytical and experimental point of view. The performance is evaluated and compared, dependence on accuracy of circuit implementation is analyzed, and simple asymptotic formulas describing the system behavior are given.