Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5404589 | Journal of Magnetic Resonance | 2017 | 10 Pages |
â¢Arbitrary waveform generated pulsed EPR is demonstrated at 200 GHz.â¢High fidelity phase-modulated pulses are generated using solid-state 200 GHz Amplifier Multiplier Chain.â¢AWG integration allows for order of magnitude improvements in bandwidth for 200 GHz pulsed EPR.
We report here on the implementation of arbitrary waveform generation (AWG) capabilities at â¼200Â GHz into an Electron Paramagnetic Resonance (EPR) and Dynamic Nuclear Polarization (DNP) instrument platform operating at 7Â T. This is achieved with the integration of a 1Â GHz, 2 channel, digital to analog converter (DAC) board that enables the generation of coherent arbitrary waveforms at Ku-band frequencies with 1Â ns resolution into an existing architecture of a solid state amplifier multiplier chain (AMC). This allows for the generation of arbitrary phase- and amplitude-modulated waveforms at 200Â GHz with >150Â mW power. We find that the non-linearity of the AMC poses significant difficulties in generating amplitude-modulated pulses at 200Â GHz. We demonstrate that in the power-limited regime of Ï1Â <Â 1Â MHz phase-modulated pulses were sufficient to achieve significant improvements in broadband (>10Â MHz) spin manipulation in incoherent (inversion), as well as coherent (echo formation) experiments. Highlights include the improvement by one order of magnitude in inversion bandwidth compared to that of conventional rectangular pulses, as well as a factor of two in improvement in the refocused echo intensity at 200Â GHz.
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