A novel 16-31 GHz quadruple subharmonic monolithic passive mixer with a chip dimension of 0.82×0.7 mm2 is designed and fabricated using the 0.15 μm GaAs pHEMT process. The novel configuration of the quadruple subharmonic mixer consists of a lumped frequency diplexer and a low-pass filter utilizing a pair of anti-parallel Schottky barrier diode to achieve quadruple subharmonic mixing mechanism. The lumped frequency diplexer formed with a low-pass network and a high-pass network is used to reduce the chip dimension while operating at low frequency band and to improve the isolation between the RF and LO ports with a broadband operation. The low-pass filter supports an IF frequency range from DC to 2.5 GHz. From the measured results, the mixer exhibits a 12.5-16.5 dB conversion loss, a LO-to-RF isolation better than 15 dB, a 50-59 dB high 4LO-to-RF isolation over 16-31 GHz RF bandwidth, and an input 1 dB compression power of 2 dBm.
2. Kanaya, K., K. Kawakami, T. Hisaka, T. Ishikawa, and S. Sakamoto, "A 94 GHz high performance quadruple subharmonic mixer MMIC," IEEE MTT-S Int. Microwave Symp. Dig., Vol. 2, 1249-1252, June 2002.
3. Uhm, W.-Y., W.-S. Sul, H.-J. Han, S.-C. Kim, H.-S. Lee, D. An, S.-D. Kim, D.-H. Shin, H.-M. Park, and J.-K. Rhee, "A high performance v-band monolithic quadruple sub-harmonic mixer," IEEE MTT-S Int. Microwave Symp. Dig., Vol. 2, 1319-1322, June 2003.
4. Lin, C. H., Y. A. Lai, J. C. Chiu, and Y. H. Wang, "A 23-37 GHz miniature MMIC subharmonic mixer," IEEE Microw. Wireless Compon. Lett., Vol. 17, 679-681, September 2007.
5. Lin, C. M., H. K. Lin, Y. A. Lai, C. P. Chang, and Y. H.Wang, "A 10-40 GHz broadband subharmonic monolithic mixer in 0.18 μm CMOS technology," IEEE Microw. Wireless Compon. Lett., Vol. 19, 95-97, February 2009.
6. Shamsinejad, S., M. Soleimani, M. Tayarani, and N. Komjani, "Novel even harmonic mixer for 3G mobile receivers," Progress In Electromagnetics Research M, Vol. 1, 69-77, 2008.
7. Jackson, B. R. and C. E. Saavedra, "A CMOS Ku-band 4x subharmonic mixer," IEEE J. Solid-State Circuits, Vol. 43, No. 6, 1351-1359, June 2008.
8. Srisathit, S., S. Patisang, R. Phromloungsri, S. Bunnjaweht, S. Kosulvit, and M. Chongcheawchamnan, "High isolation and compact size microstrip hairpin diplexer," IEEE Microw. Wireless Compon. Lett., Vol. 15, 101-103, February 2005.
9. Weng, M. H., C. Y. Hung, and Y. K. Su, "A hairpin line diplexer for direct sequence ultra-wideband wireless communications," IEEE Microw. Wireless Compon. Lett., Vol. 17, 519-521, July 2007.
10. Medley, M. W., Microwave and RF Circuits: Analysis, Synthesis, and Design, Artech House, Inc., Norwood, MA, 1992.