The goal of this SBIR Phase I research project is to develop batteryless, wireless magnetic sensors with orthogonal frequency coding (OFC). These sensors will be based on surface acoustic wave (SAW) technology already in common use in microwave filters and signal processing elements for communications devices. We will develop new magnetostrictive structures to be combined on-chip with SAW devices to create innovative magnetic field sensors that can be individually interrogated from a distance with a microwave reader. Combining the magnetostrictive materials with OFC SAW transponders will provide new sensor capabilities that are compatible with the orthogonal frequency coding scheme recently demonstrated under NASA funding. The novel magnetic field sensors will be individually coded, inexpensive to manufacture, and require no on-board power?making them ideal for distributed and embedded monitoring technologies, for both government and commercial use.