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Frequency Bands and Samplers

by Gustaaf Van Moorsel last modified Jun 23, 2017 by Emmanuel Momjian

Frequency Bands

All VLA antennas are outfitted with eight cryogenically cooled receivers providing continuous frequency coverage from 1 to 50 GHz. These receivers cover the frequency ranges of 1–2 GHz (L-band), 2–4 GHz (S-band), 4–8 GHz (C-band), 8–12 GHz (X-band), 12–18 GHz (Ku-band), 18–26.5 GHz (K-band), 26.5–40 GHz (Ka-band), and 40–50 GHz (Q-band). Additionally, all antennas of the VLA have receivers for lower frequencies, enabling observations at P-band (230–470 MHz). These low frequency receivers also work at 4-band (54–86 MHz), and new feeds have been deployed on fourteen VLA antennas to observe at this frequency range. This number is expected to rise to seventeen in early 2018.

For more information on frequency bands and tuning, please see the VLA Frequency Bands and Tunability section in the VLA Observational Status Summary.

Samplers

The VLA is equipped with two different types of samplers: 8-bit with 1GHz bandwidth each and 3-bit with 2GHz bandwidth each.

The 8-bit set consists of four 8-bit samplers arranged in two pairs, each pair providing 1024 MHz bandwidth in both polarizations. The two pairs are denoted A0/C0 and B0/D0. Taken together, the four samplers offer a maximum of 2048 MHz coverage with full polarization. The frequency spans sampled by the two pairs need not be adjacent. Some restrictions apply, depending on band (e.g., the Ka-band), as described in the section on Frequency Bands and Tunability.

The 3-bit set consists of eight 3-bit samplers arranged as four pairs, each pair providing 2048 MHz bandwidth in both polarizations. Two of these pairs, denoted A1/C1 and A2/C2, cannot span more than 5000 MHz (lower edge of one to the higher edge of the other). The same limitation applies to the second pair, denoted B1/D1 and B2/D2. The tuning restrictions are described in the section on Frequency Bands and Tunability. Taken together, the eight 3-bit samplers offer a maximum of 8192 MHz coverage with full polarization.

For more information on samplers and which set to use, please see the VLA Samplers section in the VLA Observational Status Summary.