Patent ID: 7483687

Claim:
A method for frequency down-converting a first data signal centered at a first frequency to a second data signal containing the same data as said first data signal and centered at a second frequency lower than said first frequency, said method comprising the steps of: (1) receiving said first data signal at said first frequency; (2) mixing said first data signal with a local oscillator signal having a third frequency about one third of said first frequency in a sub-harmonic mixer to produce a third data signal having a fourth frequency that is a harmonic frequency of said first frequency and said third frequency; (3) mixing said third data signal with said first component of said quadrature local oscillator signal at said third frequency to produce a first component of said second data signal centered at said second frequency; and (4) mixing said third data signal with said second component of said quadrature local oscillator signal at said third frequency to produce a second component of said second data signal centered at said second frequency.