Title :
Design of SIS Mixers for SMA 400 - 520 GHz Band
Author :
Li, C.T. ; Chang, C.M. ; Wang, M.J. ; Shi, S.C.
Author_Institution :
Inst. of Astron. & Astrophys., Acad. Sinica, Taipei
Abstract :
SIS junction mixers were designed for SMA 400 - 520 GHz band, which is similar to ALMA band 8 (380 - 500 GHz). Two schemes were used to tune out the parasitic capacitance of the junction. When shunt inductors were employed, the input resistance is equal to R (close to R0), much higher than R/(omegaRC)2 when series inductors were used. This facilitates the impedance matching between the junction and the waveguide probe. Waveguide probe design was varied to achieve a low feed-point impedance to match the junction resistance. The optimal feed- point impedances for lower receiver noise temperature were also discussed.
Keywords :
electric impedance; impedance matching; inductors; mixers (circuits); submillimetre waves; waveguide couplers; SIS junction mixers; bandwidth 400 GHz to 520 GHz; feed-point impedance; impedance matching; parasitic capacitance; receiver noise; resistance; shunt inductor; submillimeter array; waveguide probe design; Astronomy; Astrophysics; Feeds; Impedance; Inductors; Microstrip; Observatories; Probes; Radio frequency; Waveguide junctions;
Conference_Titel :
Millimeter Waves, 2008. GSMM 2008. Global Symposium on
Conference_Location :
Nanjing
Print_ISBN :
978-1-4244-1885-5
Electronic_ISBN :
978-1-4244-1886-2
DOI :
10.1109/GSMM.2008.4534595
