About UWB A co-basis is a special orthonormal basis, of the Hilbert function space, whose base functions are shape-invariant to Fourier transform except for phase shifts known a priori. A notable advantage of the co-basis orthonormal-expansion method lies in that it essentially conceals the difference between time- and frequency-domains expansions, such that expanding the UWB spectra (frequency domain) is almost equivalent to expanding the pulse shapes (time domain), making the designing task significantly simple. This paper highlights this advantages through tutorial examples on the design of UWB pulses with DAA functionality that meets Korea spectrum regulations.-About UWB