Patent ID: 8015872

Claim:
A humidity sensor apparatus with integrated signal conditioning, said apparatus comprising: a micro-electronic circuit processed on a substrate to provide on-chip signal conditioning internally, wherein said substrate is covered with a protective layer to protect said micro-electronic circuit; a film of surface acoustic wave media coated on top of said protective layer to couple with a surface acoustic wave, wherein a thickness of said film of surface acoustic wave media is configured to raise a coupling rate of said surface acoustic wave and to improve a resolution and a sensitivity thereof; and at least two sets of interdigital transducers and a humidity-sensitive film deposited on top of said film of surface acoustic wave media and associated with said micro-electronic circuit, wherein said micro-electronic circuit processes a frequency signal output from said at least two sets of interdigital transducers to thereby eliminate common mode noise from external interference and generate an output signal proportional only to a humidity value tested, thereby providing a single-chip solution with respect to said humidity sensor apparatus that includes a high signal-to-noise, a quick response time, and an enhanced sensing accuracy.