Linear analysis of a backward wave oscillator with triangular corrugated slow wave structure Md. Ghulam Saber, Rakibul Hasan Sagor and Md. Ruhul Amin Eur. Phys. J. Plus, 131 5 (2016) 171 Published online: 26 May 2016 DOI: 10.1140/epjp/i2016-16171-x