Receiver IF system with active filters
AssigneeEricsson Inc.
InventorsRoss W. Lampe, John T. Gillette, Rodney A. Dolman, Antonio Montalvo
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Abstract
A high dynamic range receiver IF system using limited dynamic range IF filters is disclosed. A variable gain amplifier amplifies a first IF signal. The amplified first IF signal is then applied to an image suppression mixer for suppressing an image component of the amplified first IF signal to provide adequate image suppression for a radio system, wherein the image suppression mixer outputting an image suppressed second IF signal. An active bandpass filter then filters the unwanted components from the second IF signal. The filtered signal is then hard limited in a limiting amplifier which outputs a limited IF signal. A logarithmic detector then provides a received signal strength indicator.
Claims17
A high dynamic range receiver IF system using limited dynamic range IF filters, comprising:
- a variable gain amplifier for amplifying a first IF signal;
- an image suppression mixer for suppressing an image component of the amplified first IF signal to provide adequate image suppression for a radio system, said image suppression mixer outputting an image suppressed second IF signal;
- first active bandpass filter means for filtering the unwanted components from the second IF signal;
- limiting amplifier means for hard limiting the filtered signal and outputting a limited IF signal;
- and
- a logarithmic detector means for providing a received signal strength indicator.
A high dynamic range receiver IF system using limited dynamic range IF filters, comprising:
- an image suppression mixer for suppressing an image component of a first IF signal to provide adequate image suppression for a radio system, said image suppression mixer outputting an image suppressed second IF signal;
- a variable gain amplifier for amplifying said second IF signal;
- first active bandpass filter means for filtering undesired components from the second IF signal;
- limiting amplifier means for hard limiting the second IF signal and outputting a limited IF signal;
- and
- a logarithmic detector means for providing a received signal strength indicator from said filtered signal.
Dependencies are inferred from the claim text.