| Popis: |
A narrowband low-power low-sensitivity, IoT TxRx compliant to ARIB STD-T-67 & T-30, is presented. It employs (1) an injection locked IQ-divider without power-hungry high speed logic gates and flip flops to generate 25% duty cycle LO that drives the mixer following a simultaneously noise and impedance matched gm-boosted LNA, and (2) A dedicated pilot-less direct automatic frequency correction of the PLL forcing the IF to be free of offset. The second feature (a) enables lowest noise bandwidth in the detector, (b) positions the signal spectrum at the center of the pass band of the high-Q IF chain away from the phase distortions in the 3-dB transition region, and (c) simplifies the base band design. Measured sensitivity is −121dBm (@4.8kbps), Rx energy efficiency is 2.81pJ/bit and Tx efficiency is 47.5%, all of which advances the state of the art, to the authors knowledge. |
