Patent ID: 8169279
Filing Date: 2012-05-01
Classification: H03H

Abstract:
1. A notched SAW image frequency rejection filter system comprising: a SAW filter having an input, an output and a ground output; an impedance matching network including a first matching inductance connected to said SAW filter output and a second matching inductance connected to said ground output of the said SAW filter; said SAW filter having an inherent internal capacitance that produces a predetermined capacitive leakage current at the image frequency; an inherent internal inductance that produces an inductance leakage current at the image frequency; and a boosted inherent parasitic ground inductance at said ground output of said SAW filter for generating a voltage across said second matching inductance to produce a compensation current which is substantially opposite in phase and substantially matched in magnitude with said capacitive leakage current for reducing said capacitive leakage current and increasing the image frequency rejection.