A wireless passive chip-less power sensor consists of a current sensor and a voltage sensor. Current sensing systems utilize giant magneto-impedance (GMI) sensors and voltage sensor systems utilize static capacitors, resistors, one-port SAW reflection delay lines, and antennas. One-port SAW reflection delay line replaces the existing transceiver system consisting of thousands of transistors to achieve chip-less, passive and wireless operation. We confirm that the amplitude of the SAW reflection peak varies greatly due to the change in impedance of the GMI sensor due to the current through the conductor and the change in charge accumulated on the capacitor by the input voltage. For current sensor, currents in the range of 0-12 A shows good linearity and 0.72 dB/A sensitivity were observed. For voltage sensor, voltages in the range of 0-5 V shows good linearity and sensitivity of 1.85 dB/V. Coupling of mode (COM) modeling and impedance matching analysis also predicts device performance in advance and compares them to experiments.
