Lsi Logic Corporation

Brian E Merrigan

Philip J Armitage

Asad Ali

A Gaussian family filter (e.g. an equiripple filter) comprises a first pole, a second pole, a third pole and a signal combiner. The first pole has a biquadratic low pass characteristic and is configured to provide a first low pass signal. The second pole is coupled to the first low pass signal, the second pole having a first-order low pass characteristic, and providing a second low pass signal and a high pass signal. The third pole is coupled to the second low pass signal and has a biquadratic low pass characteristic for generating a third low pass signal. The signal combiner is configured to combine the third low pass signal and the high pass signal to provide a combined signal.

Filter for broadcast receiver tuner

A variable gain amplifier includes a differential transconductor, a differential gain stage, a DC compensation circuit and first and second load resistors. The differential transconductor has first and second differential voltage signal inputs and first and second differential current outputs. The differential gain stage selectively steers current from the first and second differential current outputs to first and second variable current outputs, respectively, and to first and second compensation current outputs, respectively, based on a differential gain control input. The first and second load resistors are coupled to the first and second variable current outputs, respectively. The DC compensation circuit combines current in the first and second compensation current outputs to form a DC compensation current and couples the DC compensation current to the first and second load resistors.

Low voltage variable gain amplifier having constant common mode DC output

An mixer includes a differential signal input, a differential local oscillator input, a gain control input and a differential signal output. The mixer has a stepped signal gain from the differential signal input to the differential signal output which is variable from a first gain to a second, different gain as a function of the gain control input and has a substantially constant DC common mode output bias voltage at the differential signal output.

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Urmston, United Kingdom

Brian E Merrigan