Radio frequency digital filter group delay mismatch reduction

摘要

A radio frequency (RF) front end having group delay mismatch reduction is provided. One embodiment provides a first feed forward path and a second feed forward path. The second feed forward path is electrically in parallel with the first feed forward. The second feed forward path has a first signal path and a second signal path. The first and second signal paths are arranged to be electrically in parallel. The first signal path has a digital filter. The second signal path has a tunable analog filter. The tunable analog filter operates to reduce a delay associated with the second feed forward path as compared with a delay associated with the first feed forward path.

主权项

1. A radio frequency, RF, filter, the RF filter having:
a first feed forward path having a delay line; a second feed forward path, the first and second feed forward path arranged to be electrically in parallel, the second feed forward path having:
a splitter configured to provide a first signal path and a second signal path, the first and second signal paths arranged to be electrically in parallel;a digital filter in the first signal path of the second feed forward path;a tunable analog filter in the second signal path of the second feed forward path;a delay device electrically in series with the tunable analog filter, a delay of the delay device being adjustable, the tunable analog filter and the delay device combining to reduce a difference between a delay of the first signal path and a delay of the second signal path; anda combiner arranged to combine outputs of the first signal path and the second signal path.