Dynamic modulation arrangement for transponder with compact structure

摘要

One or more semiconductor diodes with a nonlinear current/voltage characteristic are inserted between the resonant antenna or circuit (L, C) requiring to be damped and the controlled electronic switch operated by pulses at the rate of the interrogating signal. In one application for temp. measurement with a semiconductor switch (MT) integrated in CMOS technology, a single diode (MD) provides dynamic modulation current limitation in conjunction with a rectifier (GD) which charges a capacitor (CL) storing energy for the ASIC. A small computing circuit (CPU) evaluates the difference between a temp.-dependent resistance (MTC) and a reference (RR), and produces corresp. pulse-code modulation (M).