  This contribution investigates the connection between Isogeometric Analysis
and Integral Equation methods for full-wave electromagnetic problems. The
proposed spline-based integral equation method allows for an exact
representation of the model geometry described in terms of Non-Uniform Rational
B-Splines without meshing. This is particularly useful when high accuracy is
required or when meshing is cumbersome for instance during optimization of
electric components. The Augmented Electric Field Integral Equation is adopted,
so the low-frequency breakdown is avoided. The extension to higher-order basis
functions is analyzed and the convergence rate discussed. The analogy with the
Partial Element Equivalent Circuit method for the lowest-order case is
established, allowing for a circuit interpretation while maintaining the exact
representation of geometry even for coarse discretizations. Numerical
experiments on academic and realistic test cases demonstrate the high accuracy
of the proposed approach.
