Difficult to obtain proper match in the E plane, compared to a reasonable match in the H plane
Dual Horn: H sectoral rectangular horn with Length:
Commercial MMIC at K band
cmd163_ver_2.3_0516Kband.pdf: F = 1.3 dB, Te= 290(F-1) = 102 K; @ 15 K: ~ 102/10 = 10.2 K comparable to Cryo3 devices. 120 mA of current probably too high.
cmd160_ver_3.5_0516.pdf: F = 1.4 dB, Te= 290(F-1) = 110 K; @ 15 K: ~ 110/10 = 11.0 K comparable to Cryo3 devices. 26 mA but gain rolls off but still > 20 dB at 26.5 GHz. Two 1020 could cool ~ 300 devices.
Some Notes from the Old KFPA Internal NRAO Proposal
The old KFPA internal proposal is here: KFPA Proposal. The proposed, total cost in 2007 dollars, was $1.7M. Steve may have an estimate of the actual cost.
The old proposal was based around the capabilities of the GBT spectrometer, but it was noted that the GBT spectrometer provided a reasonable match to the required capabilities. A useful, if somewhat dated overview of ammonia is available in this AARA review paper. The principal lines are NH3 (1,1), (2,2) and (3,3) at 23.6945, 23.7226 and 23.8701 GHz (separation 176 MHz).
Many o
The configurations discussed in the old proposal were:
50 MHz total width and 16384 channels, giving, at 22 GHZ, a total velocity coverage of 680 km/s at a channel spacing of 0.04 km/s. This is a good match to surveys in the Galactic plane and allows in-band frequency switching as well.
12.5 Mhz bandwidth and 16384 channels which gives, at 22 GHz, a total velocity coverage of 170 km/s at 0.01 km/s channel spacing. This is likely to be the main mode for study of individual molecular clouds.
200 MHz total bandwidth with 8k channels or 800 MHz total bandwidth with 2k channels. At 22 GHz these modes give 2700 km/s at 1.3 km/s channel spacing, and 11,000 km/s at 5.3 km/s channel spacing, respectively. The broad band modes are well matched to observations of extragalactic molecular clouds, galactic nucleii, and high-redshift molecular lines.