Last Update: 1 November 2022

Frontend

Receivers

H22

Parameter Value Notes
# of Beams 1
Polarisations per Beam RHCP
LHCP
Receiver Type HEMT
RF Frequency Coverage (GHz) 20 - 25
IF Frequency Range (GHz) USB: 5 - 7
LO Frequency Range (GHz) 14 - 19
Tsys (K) typ. 100
sidebands of H22

H40

Parameter Value Notes
# of Beams 1
Polarisations per Beam LHCP
Receiver Type HEMT
RF Frequency Coverage (GHz) 42.5 - 44.5
IF Frequency Range (GHz) USB: 5 - 7
LO Frequency Range (GHz) 36 - 40
Tsys (K) typ. 150
sidebands of H40

Z45

Parameter Value Notes
# of Beams 1
Polarisations per Beam H
V
Receiver Type HEMT
RF Frequency Coverage (GHz) 42 - 46
IF Frequency Range (GHz) USB: 4 - 8
LO Frequency Range (GHz) 36 - 40
Tsys (K) typ. 100
sidebands of Z45

T70

The T70 receiver has been decommissioned.

FOREST (FOur-beam REceiver System on the 45-m Telescope)

Parameter Value Notes
# of Beams 4 Beam separations: 50 arcsec
Polarisations per Beam H
V
Receiver Type SIS (2SB)
RF Frequency Coverage (GHz) 80 - 116 70 GHz band observation was opened from season 2023 as teh alternative of T70. However, its Tsys is 20% higher than that of T70. NRO does not compensate this time loss.
IF Frequency Range (GHz) USB-L: 4 - 8
USB-H: 7 - 11
LSB-L: 4 - 8
LSB-H: 7-11
LO Frequency Range (GHz) 86 - 116
Tsys (K) typ. 150 - 300 300 K @ 72 GHz
150 K @ 80-110 GHz
300 K @ 115 GHz
sidebands of FOREST


system noise temperature of FOREST

Figure 2: System noise temperature of FOREST.

Detailed Information on Frequency Down-Conversions in FOREST and IF Chain


Frequency down-conversions of FOREST

Figure 3: Schematic diagram of frequency down-conversions from 2SB mixer to AD converters.

- FOREST 4-Beam:


Available IF selections of FOREST 4-Beam

Figure 4: Schematic diagram of frequency down-conversions from 2SB mixer to AD converters and available IF selections of FOREST 4-Beam.

- FOREST 2-Beam On-On:


Available IF selections of FOREST 2-Beam

Figure 5: Schematic diagram of frequency down-conversions from 2SB mixer to AD converters and available IF selections of FOREST 2-Beam.

- FOREST 1-Beam (Singel-Beam):


Available IF selections of FOREST 1-Beam

Figure 6: Schematic diagram of frequency down-conversions from 2SB mixer to AD converters and available IF selections of FOREST 1-Beam.


2023-11-06