An Improved Corrugated Interaction Structure for 0.34 THz Sheet Beam Backward Wave Oscillator

Terahertz (THz) backward wave oscillators (BWOs) represent a promising technology with a wide array of potential applications in both industrial and military domains. Due to the minute sizes of interaction structures at THz frequencies, the problems of electrical breakdowns often restrict the use of higher voltages thus limiting the bandwidth of the device. Rectangular corrugated slow wave structures are widely used in terahertz frequency bands. This research proposes an improved corrugated interaction structure to minimize the possibilities of electrical breakdowns in rectangular corrugated slow wave structures. The interaction structure interacts with a 17.5 kV, 30 mA electron sheet beam producing an output power of 3.3 W at 0.338 THz. The interaction impedance of the slow wave structure is
$\boldsymbol{2.1}\ \mathbf{\Omega}$
and the -3dB bandwidth of the device is approximately 15 GHz. The design exhibits
$\boldsymbol{S_{11}}$
below
$-\boldsymbol{20}\ \boldsymbol{dB}$
and
$\boldsymbol{S_{21}}$
close to
$\boldsymbol{0}\ \boldsymbol{dB}$
.