US 4,736,328 AGranted

Apparatus for shifting the phase of transmitter and receiver analog baseband signals in an NMR system

AssigneeGeneral Electric Company

InventorsDimitrios Vatis, Charles L. Dumoulin

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Abstract

Apparatus for shifting the phase of a phase-quadrature signal pair, in at least one of the transmitter and receiver of an NMR system, uses a circuit for shifting the phase of each of the pair of signals by a substantially similar amount responsive to a control signal, and a microcontroller for programmably establishing the control signal data to provide a desired phase shift. Typically, the control signal is of digital data nature and the phase shifter operates to shift signal phase through an angle equal to a selected multiple N of a basic angle. The basic angle is selected such that a plurality of equal angle increments are established by the resolving properties of the data signal. A plurality of phase shifters can be controlled by a single microcontroller.

Claims12

Dependent claims

Apparatus for shifting the phase of each of a pair if pahse-quadrature analog input signals, in at least one of a transmitter and a receiver of a nuclear magnetic resonance (NMR) system, comprising:

first and second input means each for receiving a different one of apair of quadrature-phased analog-input signals A and B;
first and second output means each for providing a location at which an associated one of a pair of phase-shifted analog output signals will be provided;
means for shifting the phase of that one analog input signal received at the associated one of each of said first and second input means by a substantially similar phase angle in an identical one of four phase-shift increments each substantially equal to 90.degree., responsive to a common phase angle control signal, each shifted phase signal being coupled as the analog output signal to an associated one of said first second output means, said shifting means comprising:
means for providing a signal A which is the polarity inverse of the first input means signal A and for providing another signal B which is the polarity inverse of the second input means signal B;
and means for selecting a first one and a different second one of the resulting A, A , B and B signals for the signal at the first output means and at the second output means, respectively;
and
means for programmably establishing the control signal to provide a desired phase-shift angle for both of said pair of signals in said shifting means.

4 more elements

Apparatus for shifting the phase of each of pair of phase-quadrature analog input signals, in at least one of a transmitter and a received of a nuclear magnetic rsonance (NMR) system, comprising:

first and second input means each for receiving a different one of the pair of phase-quadrature analog input signals,
first and second output means each for providing a location at which an associated one of a pair of phase-shifted analog output signals will be provided;
means for shifting the phase of that one analog input signal received at the associated one of each of said first and second input means by a substantially similar phase angle responsive to a common phase-angle control signal, each shifted-phase signal being coupled as the analog output signal to an associated one of said first and second output means;
and
means for programmably establishing the control signal to provide a desired phase-shift angle for both of said pair of signals in said shifting means, and comprising:
microprocessor means for directing each of at least one associated phase-shifting means to a designated one of N different phase shifts therethrough;
random-access memory (RAM) means for storing at least one sequence of phase-shift instructions to be carried out by the microprocessor means;
and rear-only memory (ROM) means for fixedly storing an operating program allowing said at least one phase-shifting sequence to be stored in said RAM means and for causing said microproessor means to carry out said sequence.

5 more elements

Dependencies are inferred from the claim text.