APEX-2 receiver (SHeFI 345 GHz band)
The SHeFI APEX Band 2 mixer is based on SIS mixers and used sideband rejection (2SB) scheme.
Following the success of the APEX-2A receiver, the same type of mixer design is used.
In this design the middle piece made of two symmetric parts (split-block technique) and comprises
the RF 90° waveguide hybrid and LO division scheme with LO injection directional
waveguide couplers using novel on-substrate coupling elements.
The figure shows details of the SFeHI B2 Mixer assembly consisting of the mixers, the middle piece, the IF amplifiers, 3 dB IF hybrid, IF isolators, IF amplifiers (2-stage GaAs HEMT, designed by GARD), LO and RF optical components all integrated on a single bracket and, provided it is necessary, could be removed from the dewar as a single package.
The receiver is characterized by its capabilities and performance. Please find the corresponding information below:
Calibration PlanThe calibration plan for APEX-2 comprises regular observations of a set of spectral line calibrators at frequencies accesible for this receivers.
- APEX-2 Calibration Plan main page
For a set of frequently used spectral lines, we have a database of comparison spectra from some sources that are widely used as line calibrators. Plots of these spectra can be accessed either through the database interface, or in a table on a static web page.
Spectral Line Catalog
We maintain a system line catalog for APEX-2 which contains frequently (and also not so frequently) used spectral lines in the tuning range.