Analysis and Design of a Novel Photonic Crystal-Based Sub-mm/THz Backward-Wave Oscillator

Analysis of a novel 200GHz Cherenkov radiation based backward wave oscillator

“…Furthermore, the figure shows that axial electric field (E z ) dominates the transverse fields (E x and E y ), while the axial magnetic field (H z ) is almost zero compared to transverse magnetic fields (H x and H y ). Thus, as predicted in the theoretical analysis [3][7], the generated propagating mode is a TM-like mode.…”

“…5(a) and (b). The figure shows that the transverse electric field components (E x and E y ) are in phase while the transverse magnetic field component s (H x and H y ) are out of phase, therefore, the Poynting vector power flow -in zdirection-is always positive and produces a constructive summation [3]. The corresponding frequency domain analysis -calculated by applying Fast Fourier Transfer (FFT) to time sampled fields-of the same signals are plotted in Fig.…”

“…Using the power calculation procedure described in [3], the normalized power density, at 0.10L z , is plotted in Fig. 6(a).…”

“…The figure indicates that the interaction impedance decreases rapidly with the increase of the frequency. According to [3] [6] and the dispersion curve ( Fig. 2(b)), as the electromagnetic fields becomes slower (i.e., the modal phase velocity gradually decreases), the frequency of the mode increases and the concentration of the electric field migrates towards the conducting walls and the slow wave defects.…”

“…In this paper, a novel BWO, using the Axial loaded Double Defected Phonic Crystal (ADD-PC), is introduced. Using the advantage of high power capabilities and mode selectivity introduced in the DD-PC SWS [3], the ADD-PC SWS was introduced to further reduce modal phase velocity, and hence the associated electron beam requirements can be reduced [3 -4]. A cross sectional figure of the ADD-PC structure and the axial discontinuity are presented in Fig.…”