A Multi-Standard Digital Envelope Modulator for Polar Transmitters in 90nm CMOS

A multistandard digital envelope modulator for a polar transmitter has been designed in a 90 nm digital CMOS process for 802.11 a/b/g and Bluetooth medium-rate. The digital modulator reaches an output power of 9 dBm for 54 Mbit/s using 64 QAM and fulfilling EVM specifications and spectral mask requirements while consuming 108 mW. An output power of 14 dBm is reached for 3 Mbit/s Bluetooth Medium Rate at 204 mW power consumption. Due to 4-phase clocking, envelope aliases at the first, second and third clock harmonic are almost completely cancelled, without the need for envelope-data-interpolation.