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US 7,756,491 B2Granted
Phase shifter
AssigneeAxiom Microdevices, Inc.
InventorsScott D. Kee, Ichiro Aoki, Weifeng Feng
Life of this patent
Estimating the term…
Abstract
A phase shifter includes a plurality of variable gain elements, each variable gain element configured to receive one of a plurality of input signals, each input signal having a phase that is shifted with respect to each other input signal; and a control signal supplied to each variable gain element, where the control signals define a phase shift.
Claims20
A phase shifter, comprising:
- a plurality of variable gain elements, each variable gain element configured to receive one of a plurality of quadrature input signals, each quadrature input signal having a phase that is shifted with respect to each other input signal, wherein each variable gain element comprises a switching transistor and a gain control transistor coupled to the switching transistor, the gain control transistor configured to receive the control signal, and wherein the gain control transistor controls the amount of current flowing through the gain control transistor when the switching transistor is active as a function of the gate-source voltage of the gain control transistor;
- a control signal supplied to each variable gain element, the control signals defining a phase shift;
- and
- a signal combiner configured to combine an output of each of the plurality of variable gain elements, the signal combiner providing a phase shifted output signal.
1 more element
A method for altering the phase of a signal, comprising:
- providing four quadrature components of a phase signal to a respective plurality of variable gain elements;
- providing a control signal to each of the variable gain elements, each control signal corresponding to a quadrature-phase of the quadrature component provided to the variable gain element;
- altering an amplitude of each quadrature component based on the value of the control signal to cause a phase shift in each quadrature component;
- and
- combining each phase shifted quadrature component to provide a phase shifted output signal.
2 more elements
A portable transceiver having a phase shifter, comprising:
- a transmitter coupled to a receiver;
- a power amplifier associated with the transmitter, the power amplifier having a linear control characteristic, the power amplifier configured to amplify a phase-modulated (PM) signal according to the amplitude of an amplitude-modulated (AM) signal;
- a feedback signal taken from the power amplifier;
- a limiter configured to receive the feedback signal;
- a phase shifter comprising:
- a plurality of variable gain elements, each variable gain element configured to receive one of a plurality of quadrature input signals, each quadrature input signal having a phase that is shifted with respect to each other input signal, wherein each variable gain element comprises a switching transistor and a gain control transistor coupled to the switching transistor, the gain control transistor configured to receive the control signal, and wherein the gain control transistor controls the amount of current flowing through the gain control transistor when the switching transistor is active as a function of the gate-source voltage of the gain control transistor;
- a control signal supplied to each variable gain element, the control signals defining a phase shift;
- and
- a signal combiner configured to combine an output of each of the plurality of variable gain elements, the signal combiner providing a phase shifted output signal.
6 more elements
Dependencies are inferred from the claim text.