Design considerations for multi-band OFDM polar transmitter of UWB system

The requirements for the envelope and phase paths in a multi-band orthogonal frequency division modulation (OFDM) polar transmitter for ultra-wideband (UWB) are studied at system level. The results show that the bandwidth of the envelope of the polar signal require at least 1.1 times the bandwidth of in-phase (I) and quadrature-phase (Q). But the bandwidth of the phase of polar signals should be at least 7.1 times in order to pass the error vector magnitude requirement in the ECMA standard. In addition, time delay mismatch of less than 0.36 ns is also required.