×

Down/up-conversion apparatus and method

  • US 6,611,569 B1
  • Filed: 10/02/1998
  • Issued: 08/26/2003
  • Est. Priority Date: 10/03/1997
  • Status: Expired due to Term
First Claim
Patent Images

1. A down-converter for converting a modulated high frequency signal into a low frequency signal, including a first mixer for mixing said high frequency signal into a composite signal having an in-phase component and a quadrature component, said down-converter comprising:

  • A/D converters for A/D conversion of the components of said composite signal;

    a complex bandpass filter, coupled to the output of said first mixer, for bandwidth limiting said composite signal into a bandwidth limited signal having an in-phase component and a quadrature component, wherein said complex bandpass filter is a digital bandpass filter, and wherein said complex bandpass filter is a complex bilinear ladder filter;

    a second mixer, coupled to the output of said complex bandpass filter, for mixing said bandwidth limited signal into an intermediate signal having an in-phase component and a quadrature component, wherein said second mixer is a digital mixer; and

    an adder, coupled to the output of said second mixer, for adding (subtracting) one component of said intermediate signal to (from) the other component, wherein said adder is a digital adder.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×