This paper presents for the first time a systematic algorithm to optimise the bandwidth for a semiconductor junction circulator with minimum magnetic bias requirements. The behaviour of the gyroelectric parameters was studied to describe the optimum biasing magnetic field for millimetre wave operation with maximum bandwidth. Perfect circulation conditions derived using a Green's function approach were analysed to determine the optimum radius and coupling half-angle for the semiconductor disk forming the circulator. Previously measured data for InSb at 77 K were used to find design parameters for optimum bandwidth of circulation at millimetre wave frequencies. The performance of the design was verified using a full-wave electromagnetic simulation package, where up to 90% 10 dB bandwidth centred at 200 GHz was achieved with magnetic biasing as low as 0.214 T.
2. Yong, C. K., R. Sloan, and L. E. Davis, "A Ka-band indium-antimonide junction circulator," IEEE Transactions on Microwave Theory and Techniques, Vol. 49, No. 6, 1101-1106, 2001.
doi:10.1109/22.925497
3. Pardavi-Horvath, M., "Microwave applications of soft ferrites," Journal of Magnetism and Magnetic Materials, Vol. 215, 171-183, 2000.
doi:10.1016/S0304-8853(00)00106-2
4. Weiss, J. A., N. G. Watson, and G. F. Dionne, "New uniaxial-ferrite millimeter-wave junction circulators," IEEE MTT-S International Microwave Symposium Digest, 1989, 145-148, Jun. 1989.
doi:10.1109/MWSYM.1989.38689
5. Chao, L., E. Fu, V. J. Koomson, and M. N. Afsar, "Millimeter wave complementary metal-oxide-semiconductor on-chip hexagonal ferrite circulator," Journal of Applied Physics, Vol. 115, No. 17, 17E511, 2014.
doi:10.1063/1.4864136
6. Cooper, K. B., R. J. Dengler, N. Llombart, B. Thomas, G. Chattopadhyay, and P. H. Siegel, "THz imaging radar for standoff personnel screening," IEEE Transactions on Terahertz Science and Technology, Vol. 1, No. 1, 169-182, 2011.
doi:10.1109/TTHZ.2011.2159556
7. Piesiewicz, R., T. Kleine-Ostmann, N. Krumbholz, D. Mittleman, M. Koch, J. Schoebel, and T. Kurner, "Short-range ultra-broadband terahertz communications: Concepts and perspectives," IEEE Antennas and Propagation Magazine, Vol. 49, No. 6, 24-39, 2007.
doi:10.1109/MAP.2007.4455844
8. Kallfass, I., J. Antes, T. Schneider, F. Kurz, D. Lopez-Diaz, S. Diebold, and A. Tessmann, "All active MMIC-based wireless communication at 220 GHz," IEEE Transactions on Terahertz Science and Technology, Vol. 1, No. 2, 477-487, 2011.
doi:10.1109/TTHZ.2011.2160021
9. Davis, L. E. and R. Sloan, "Semiconductor junction circulators," IEEE MTT-S International Microwave Symposium Digest, 1993, 483-486, Jun. 1993.
doi:10.1109/MWSYM.1993.276774
10. Allis, W. P., S. J. Buchsbaum, and A. Bers, "Waves in anisotropic plasmas," Waves in Anisotropic Plasmas, William Phelps Allis, Solomon J. Buchsbaum, and Abraham Bers, 292, ISBN 0-262-51155-X, The MIT Press, Cambridge, Massachusetts, USA, Feb. 1963.
11. Bosma, H., "On stripline Y-circulation at UHF," IEEE Transactions on Microwave Theory and Techniques, Vol. 12, No. 1, 61-72, 1964.
doi:10.1109/TMTT.1964.1125753
12. Wu, Y. S. and F. J. Rosenbaum, "Wide-band operation of microstrip circulators," IEEE Transactions on Microwave Theory and Techniques, Vol. 22, No. 10, 849-856, 1974.
doi:10.1109/TMTT.1974.1128363
13. Sloan, R., C. K. Yong, and L. E. Davis, "Broadband millimetric semiconductor junction circulators at 77 K," IEEE MTT-S International Microwave Symposium Digest, 1996, Vol. 1, 109-112, Jun. 1996.
doi:10.1109/MWSYM.1996.508474
14. Ng, Z. M., L. E. Davis, and R. Sloan, "Measurements of V-band n-type InSb junction circulators," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 2, 482-488, 2004.
doi:10.1109/TMTT.2003.821924