High voltage solid dielectric coaxial ferrimagnetic Nonlinear Transmission Line

Previously developed coaxial ferromagnetic Nonlinear Transmission Lines (NLTL) relied solely on pressurized Sulfur Hexaflouride (SF₆) as high-voltage insulating dielectric medium [1]. While the use of SF₆ provides the necessary electric insulation, there are drawbacks including gas storage and pressure fittings that increase system size and add to the design complexity of the NLTLs themselves. We evaluate solid dielectric materials as an alternative. Initial attempts used a standard high voltage (HV) epoxy to pot the NLTL assembly. This method was effective at producing magnetic precession in the NLTL; however, there was a reduction in output power due to the high loss tangent of the epoxy. Sylgard 184, commonly used in solar cells, has been widely used as an HV potting material and has an order of magnitude lower loss tangent than standard HV epoxy at 1 kHz. Samples of HV epoxy and Sylgard 184 are tested in a microwave cavity resonator at 3 GHz to determine their loss tangents. The performance of an NLTL potted with Sylgard 184 is compared to that of the HV epoxy NLTL and the current SF₆ insulated NLTL.