The IEEE 802.15.6 Wireless Body-Area-Network (WBAN) standard has recently specified narrowband (NB) PHY covering GMSK and D-PSK modulations targeted at varying data rates [1]. There are also reported energy efficient FSK or QPSK transmitters for biomedical applications [2,3]. Hence, a reconfigurable TX that can support multichannel and multimodulation with reconfigurable data rate, spectrum and energy efficiency would be desirable. Although a conventional mixer-based or fractional-N-PLL-based TX with two-point modulation [4] can achieve the aim, the need of power hungry blocks and sophisticated calibration does not lead to power-efficient solutions. On the other hand, energy efficient injection-locked FSK or QPSK TX with good noise performance does not provide multichannel support due to the use of fixed references [2-3]. Energy efficient FSK TXs [5] with open-loop VCO have also been reported. However, they exhibit poor spectrum efficiency and do not support PSK modulation due to the poor phase noise of free-running VCOs.