Wideband coupled resonator based ultra-wideband 3dB power divider
In this paper, a 3dB ultra-wideband (UWB) power divider has been designed using three wide-band coupled resonators. The resonator unit which consists of symmetric interdigital coupled input/output lines, resonates in two basic for broadening the operating bandwidth. Output ports maintains equal distance from the input in order to achieve in-phase power divisions. The prototype structure provides an equal magnitude, in-phase power division and adequate isolation at outputs from 3.82 to 10.2 GHz, which almost complies the FCC defined UWB frequency range. It has advantages like single layer, via free and compact in size.
Compact Ultra-Wideband In-Phase Multilayer Power Divider
A novel compact ultra-wideband (UWB) in-phase multilayer slotline power divider with high isolation is presented as a complement in slotline power divider field. The new structure proposed in this paper overcomes the shortcoming that power divider based on slotline almost cannot obtain high isolation between output ports. Based on the equivalent-circuit of microstrip-to-slotline transition and the method of odd-mode and even-mode analysis, the designing expressions of the proposed compact power divider have been obtained. The simulated and measured results have shown good agreement, and both of which have also shown that all the ports of the novel compact in-phase power divider have good impedance matching, and shown high isolation between the output ports over the band 3.4 GHz-12 GHz.
DESIGN CONSIDERATION TO PPM KLYSTRONS FOR INDUSTRIAL LINAC
Toshiba has been developing the C-band and X-band Periodic Permanent Magnet (PPM) focused klystron in collaboration with KEK and manufactured prototypes for the JLC project. [1] The PPM klystron has an advantage to enhance the total efficiency as a result of eliminating the electric power for the focusing magnet. From experience on the development the PPM focused klystrons for the JLC project, we plan to apply the PPM focused klystron to the medical and industrial linac. The periodic magnet focusing scheme has some technical difficulties such as stop band voltage. To design the PPM klystron for the medical and industrial linac, it is necessary to give heed to electron beam instability; so that the tube parameters of the PPM focused klystrons have some constraints. The size of the accelerator system is substantially reduced if a PPM focused klystron is used. The majority of medical and industrial linacs use frequencies of S-band range. We discuss the availability of the S-band PPM focused klystron in this paper.