Near-field communication using phase-locking and pulse signaling for millimeter-scale systems

An inductive coupling based proximity communication system is proposed for data readout of remote powered sensor systems with ultra small form factor in ∼mm3 range for implantable applications. The passive transponder is powered with a 1×1mm on-chip inductor, which also enables readout signaling using pulse signaling. The required resonance frequency for pulse signaling is obtained using a transponder PLL that locks to the incoming frequency transmitted by the reader system. Communication with a passive 1mm2 sensor node implemented in 0.13μm technology is demonstrated. © 2009 IEEE.