Patent ID: 7860482

Claim:
A method of tuning a signal of interest from a channelized spectrum, comprising: (a) splitting an incoming signal into two signal paths; (b) generating an approximately quadrature local oscillator signal; (c) quadrature mixing the split incoming signal with the local oscillator signal, thereby producing I and Q signals in approximate quadrature relation; (d) filtering the I signal with a first passband filter and filtering the Q signal with a second passband filter, wherein each filter defines a near-baseband passband, the lower edge of which is spaced from DC by at least about the passband width; (e) subjecting one of the filtered I and Q signals to a phase shift of about 90 degrees relative to the other, thereby producing second I and Q signals; and (f) summing the second I and Q signals, thereby producing a real-valued signal.