MRAM-based pre-distortion linearization and amplification circuits
A circuit has a magnetic device to produce a pre-distorted signal from a sinusoidal input signal. The magnetic device has physical attributes selected to produce characteristics of the pre-distorted signal. A power amplifier is coupled to the magnetic device. The power amplifier processes the pre-distorted signal to produce an output signal with reduced nonlinear behavior associated with the power amplifier.
1. A circuit, comprising:
a magnetic device to produce a pre-distorted signal from a sinusoidal input signal, wherein the magnetic device has physical attributes selected to produce characteristics of the pre-distorted signal, wherein the magnetic device includes an array of magnetic tunnel junctions, each magnetic tunnel junction comprising a reference layer having a reference magnetization, a tunnel barrier layer, and a storage layer having a storage magnetization; and
a power amplifier coupled to the magnetic device, the power amplifier processing the pre-distorted signal to produce an output signal with reduced nonlinear behavior associated with the power amplifier.
2. The circuit of claim 1 wherein the sinusoidal input signal is a radio frequency signal.
3. The circuit of claim 2 wherein the radio frequency signal is a modulated signal.
4. The circuit of claim 1 wherein the array of magnetic tunnel junctions is biased in the linear operating domain.
5. The circuit of claim 1 wherein at least one of the reference layer, the tunnel barrier layer and the storage layer has physical attributes selected to produce characteristics of the pre-distorted signal.
6. The circuit of claim 1 wherein the physical attributes are selected to compensate for third order and higher order intermodulation distortion products of the sinusoidal signal.
7. The circuit of claim 1 wherein the power amplifier is a magnetic device.
8. The circuit of claim 1 further comprising a controller for adjusting the bias of the magnetic device and thereby adjust the pre-distorted signal.
9. The circuit of claim 1 further comprising a feedback loop between the power amplifier and the magnetic device to dynamically adjust the pre-distorted signal.
10. The circuit of claim 9 wherein the feedback loop includes an envelope detector for detecting an envelope of the output signal, and wherein the magnetic device generates the pre-distortion signal based on the envelope.