High-performance Schottky diodes based on amorphous IGZO (Indium-Gallium-Zinc Oxide) semiconductor were fabricated and fully characterized. S-parameter measurements and subsequent analysis prove that these diodes have a cut-off frequency over 900MHz at 0V bias, making these diodes a promising choice for UHF applications, such as energy-harvesters for passive RFID tags on foil. Moreover, when used in a single stage rectifier, the diodes provide DC voltages higher than 1.2V at 900MHz, which is enough supply for circuitry on foil based on current metal-oxides technologies (1,2).