Injection Phase-locking of a High-power Transit-time Oscillator
The enhancement of microwave power density at a certain extent is one of the most significant problems in the development and application of the high power microwave(HPM)sources.Limited by the power capacity and radio frequency(RF)breakdown issues,a single HPM device can hardly achieve high output power.The spatial power combining among several HPM sources is a feasible method.A transit-time oscillator(TTO)with advantages of stability,simple structure,and high beam-wave interaction efficiency,is one candidate for spatial power combining.To lock the phases of the output microwaves of different TTOs,a Ku-band coaxial transit-time oscillator with an injection structure is presented.Between the independent input cavity and the trinal-cavity buncher,a reflector with reflection efficiency of 99.9%is introduced to prevent the leakage power propagating to the input cavity.The RF signal is injected into the input cavity through a coaxial waveguide along the guiding magnet,which avoids separating the magnet coils,and suppresses the asymmetric modes excited in the device.Particle-in-cell(PIC)simulation results indicate that when the injection power ratio ρ(ρ2 = Pin/Pout,where Pin is the injection power,and Pout is the output power of the oscillator)is large(ρ~0.1),the phase-locking is achieved for a frequency difference of 67 MHz.When the injection power ratio is small(ρ~0.01),the phase of the device with the same frequency can be locked(Δf~2MHz).It has also been found that the injected signal of high power results in higher output power and earlier saturation than that of a TTO without the injection structure.Moreover,a wider locking bandwidth is expected by the results than that obtained by the Adlers condition.
Lin Lian Juntao He Junpu Ling Zumin Qi Yi Hu
College of Optoelectronic Science and Engineering,National University of Defence Technology,China
国际会议
Progress in Electromagnetics Research Symposium 2014(2014年电磁学研究新进展学术研讨会)
广州
英文
2281-2285
2014-08-01（万方平台首次上网日期，不代表论文的发表时间）