Novel Traveling Wave Amplifier Design with Interdigital Grating and 2DEG Substrate for High Gain at 300GHz

We propose a novel traveling wave device operating at sub-THz frequencies. The device structure employs metastuctures for wave slow down to increase gain by 10dB or more. The excitation of the device channel is done using a CPW line with an inserted interdigitated grating. The underlying 2DEG silicon substrate supports an electron beam injected from the drain after source biasing in HEMTs. The proposed device is simulated starting with a 3-D full wave prediction of the field structure to be supported by the interdigital grating within the CPW. This field structure is then used in a 2-D particle-in-cell (PIC) code to predict the device gain. Results from these simulations show more than 10 dB gain at 300 GHz.