US 5,454,007 A · Arrangement for and method of concurrent quadrature downconversion input sampling of a bandpass signal

Abstract

An arrangement for generating a digital, downconverted complex baseband signal from a bandpass signal comprises a signal source for providing first and second clock signals at first and second clocking rates, respectively. The first clocking rate is at four times the expected center frequency of the bandpass signal, and the second clocking rate is at an exact subharmonic frequency of the bandpass frequency. The bandpass signal is sampled by a composite sampling event of two sampling pulses which occur once during each period of the second clocking signals and which are time-spaced from each other by the inverse of the first clocking rate. The complex baseband samples are ready as an A/D converter output, with no requirement for DSP processing to complete the downconversion to zero-IF.

Claims15

Dependent claims

A sampling circuit for concurrent quadrature downconversion and input sampling of a bandpass signal comprising:

means for generating first timing signals time-spaced by an inverse of a first timing signal rate of four times a center frequency of the bandpass signal;
means for generating second timing signals time-spaced by an inverse of a second timing signal rate, the second timing signal rate being a subharmonic rate of the center frequency of the bandpass signal;
and
means for sampling the bandpass signal at the second timing signal rate with a single set of composite, phase-quadrature double pulses, the double pulses being time-spaced by the inverse of the first timing signal rate.

1 more element

Dependencies are inferred from the claim text.

Arrangement for and method of concurrent quadrature downconversion input sampling of a bandpass signal

Life of this patent

Arrangement for and method of concurrent quadrature downconversion input sampling of a bandpass signal

Life of this patent

Abstract

Claims15