U-blox Ag

Eric De Mey

Andreas Thiel

For suppression of continuous wave interferers at, e.g., up to four interferer frequencies (f, f, f, f) in a GNSS receiver base band circuit a raw digital signal is, in a band stop unit (), shifted, by a first mixer (), by the negative of the first interferer frequency (f) in the frequency domain whereupon the continuous wave interferer is suppressed by a band stop filter (), a linear phase FIR filter with a suppression band centered at zero, e.g., a filter subtracting a mean over previous subsequent signal values from the actual signal value. After further shifting of the shifted digital signal by the negative of the difference between the second interferer frequency (f) and the first interferer frequency (f) the shifted digital signal is again filtered by an identical band stop filter () and so on. After the last filtering step the shifted digital signal is shifted back to its original position in the frequency domain to provide a filtered digital signal which corresponds to the raw digital signal with narrow interferer bands centered at the interferer frequencies (f, f, f, f) suppressed.

Method of processing a digital signal derived from an analog input signal of a GNSS receiver, a GNSS receiver base band circuit for carrying out the method and a GNSS receiver

An analog die () and a digital die () are supported by a plate () consisting of an electrically conductive material. Pads () of the dies () are connected to each other, to plate () or to pins () surrounding the latter by bond wires (). The upper side of the plate () is covered by a plastic mold () encapsulating the dies (), the bond wires () and, in part, the pins (). For the suppression of external jamming signals as well as internal ones picked up by bond wires the digital die () comprises an adjustable notch filter which suppresses narrow frequency bands where jamming signals have been detected.

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Aeugst am Albis, Switzerland

Eric De Mey