Ultra-wide band frequency offset estimation systems and methods for analog coherent receivers

An analog circuit for adjusting frequency offset, the analog circuit comprising:

• a first polyphase filter that receives a modulated input signal to determine a first power metric;
• a second polyphase filter that that receives the modulated input signal to determine a second power metric, the power estimation circuit uses the first and second power metrics to obtain a measure of an imbalance between positive and negative halves of a frequency spectrum, the measure being substantially proportional to a first frequency offset relative to the modulated input signal;
• and p1 a fine frequency offset detector circuit that, in response to being operated, determines a second frequency offset relative to the modulated input signal, the fine frequency offset detector circuit dominating an output of the analog circuit.

The analog circuit according to claim 11, wherein each of the first and second polyphase filters comprises a passive polyphase RC network that comprises capacitors and resistors that are cross-coupled between in-phase and quadrature branches of a receiver.

A frequency offset detector comprising:

• a set of polyphase filters that generate an asymmetric response for positive and negative frequencies and that determine a first power metric and a second power metric;
• and
• a comparator circuit that uses the first and second power metrics to generate a measure of an imbalance between positive and negative halves of a frequency spectrum, the measure being substantially proportional to a frequency offset.