A Novel X-Band Diplexer Based on Overmoded Circular Waveguides for High-Power Microwaves

On the basis of mode-matching techniques and numerical optimization, a novel X-band diplexer based on overmoded waveguides for high-power microwaves is presented in this paper. Two ridged overmoded circular waveguides are proposed as bandpass filters operating at TM01 mode and through mode-matching techniques, filters are designed with central frequency of 9.7 and 9.3 GHz and ±100-MHz bandwidth, respectively. The radial waveguide structure with six rectangular ports is used as diplexing manifold. Moreover, one radial waveguide structure placed between two filters efficiently extracts the microwave after filtering. The other radial waveguide structure is placed coaxially, which is connected with the first one through six rectangular waveguides and whereafter combines and outputs the microwave after extraction. For practical integration with two high power microwave (HPM) sources, a high efficiency 90 ° circular waveguide bend operating at TM01 mode is designed. Simulation results show that the designed diplexer can handle gigawatt-class HPM with transmission efficiency up to 97% for each channel in ±100 MHz.

[1]  C. H. Chen,et al.  Efficient generation of multi-gigawatt power by a klystron-like relativistic backward wave oscillator , 2010 .

[2]  E. Schamiloglu,et al.  Initial studies of a long-pulse relativistic backward-wave oscillator utilizing a disk cathode , 2002 .

[3]  Changhua Chen,et al.  Experimental verification of improving high-power microwave window breakdown thresholds by resonant magnetic field , 2010 .

[4]  Zhang Xiaowei,et al.  An X band synthesizer for a few hundred megawatt level power microwaves , 2011 .

[5]  I. R. Ciric,et al.  Recurrence model analysis for multiple waveguide discontinuities and its application to circular structures , 1993 .

[6]  Robert J. Barker,et al.  High-power microwave sources and technologies , 2001 .

[7]  Jun Sun,et al.  Efficiency enhancement of a high power microwave generator based on a relativistic backward wave oscillator with a resonant reflector , 2009 .

[8]  S. D. Korovin,et al.  Pulsewidth limitation in the relativistic backward wave oscillator , 2000 .

[9]  Jun Zhang,et al.  Generation of gigawatt level beat waves , 2010 .

[10]  S. D. Korovin,et al.  Relativistic X-band BWO with 3-GW output power , 1998 .

[11]  M. Thumm,et al.  Design of short high-power TE/sub 11/-HE/sub 11/ mode converters in highly overmoded corrugated waveguides , 1991 .

[12]  A. Wexler.  Solution of Waveguide Discontinuities by Modal Analysis , 1967 .

[13]  F. J. Agee,et al.  Evolution of pulse shortening research in narrow band, high power microwave sources , 1998 .

[14]  Changhua Chen,et al.  A repetitive X-band relativistic backward-wave oscillator , 2002 .

[15]  Changhua Chen,et al.  Single and repetitive short-pulse high-power microwave window breakdown , 2010 .