A front-end architecture for inductive RFID transponders using multiple coil antennas for reduced ori- entation sensitivity is presented. The front-end uses multiple antennas for reception and one antenna for transmission. A select function identifies the antenna that is most favorably oriented toward the reader for transmission by comparing the DC charge-up phases of multiple DC generation blocks during power-up of the transponder. CMOS circuit design and simulation results of a front-end for 125 kHz FSK modulation are presented for a pulsed RFID system as well as an archi- tecture for cascaded DC generation. This paper also includes an example of a coil antenna for spherical transponders using three independent orthogonal windings.