PIC Investigations of a Gyro-Like Backward-Wave Oscillator Using Elliptical Metamaterials

A novel elliptical metamaterial unit cell was developed, and a gyro-like backward-wave oscillator (BWO) using this elliptical metamaterial was constructed to release the electromagnetic energy into the desired TE₁₁ mode. PIC simulations found that the gyro-like BWO could operate at TE₁₁ mode below its cutoff frequency. When an applied voltage U=375 kV and a beam current I=1.77 kA, with an applied magnetic field B=0.51 T, the output power can be as high as 450 MW, while the electronic efficiency can be as high as 67.8% at 2.41 GHz. The results suggest a new technique to achieve high-efficiency gyro-like BWO operate below its cutoff frequency using a metamaterial unit cell, and also, this work seeks to design a compact high-power microwave source using metamaterial to radiate the Gaussian-like microwave wave beam.