Seog-Tae Han (Taeduk Radio Astronomy Observatory)

"Taeduk Radio Astronomy Observatory and Its Dual Channel SIS
Receiver System for 100 and 150 GHz Radio Astronomical Observations"

SUMMARY: We present a brief history and actual status of
TRAO in this talk. In addition, a dual channel SIS receiver system made
in TRAO will be explained. The dual channel receiver system is now used
for 100 and 150 GHz bands radio astronomical observations. Our SIS receiver
system consists of polarization beam-splitter, quasi-optical SSB filters,
and SIS mixers for 3 and 2 mm bands. One of characteristics of our system
is using auto-tuning system. The noise temperatures of SIS receivers are   
40 K for 100 GHz and 80 K for 150 GHz respectively. The overall system
temperature of the dual receiver system is the following: 200-500 K for 
100 GHz band and 400-700 K for 150 GHz band. The radio astronomical observation
has been done using this dual channel SIS receiver since October 1998. 
Now, the optimization of the receiver performance and making the receiver
system further stable are under way.