ATTENZIONE!!! IL SISTEMA E' UTILIZZABILE ESCLUSIVAMENTE IN MODALITA' "CONSULTAZIONE". CAUSA PROBLEMI TECNICI, SI PREGA DI NON EFFETTUARE L'AUTENTICAZIONE, FINO A NUOVA COMUNICAZIONE. GRAZIE
 

Electronically Tuned Local Oscillators for the NOEMA Interferometer

Journal
Date Issued
2016
Author(s)
Mattiocco, Francois
•
Garnier, Olivier
•
Maier, Doris
•
•
Serres, Patrice
DOI
Abstract
We present an overview of the electronically tuned local oscillator (LO) system developed at the Institut de RadioAstronomie millimetrique (IRAM) for the superconductor-insulator-superconductor (SIS) receivers of the NOrthern Extended Millimeter Array interferometer (NOEMA). We modified the frequency bands and extended the bandwidths of the LO designs developed by the National Radio Astronomy Observatory (NRAO) for the Atacama Large Millimeter Array (ALMA) project to cover the four NOEMA LO frequency ranges 82-108.3 GHz (Band 1), 138.6-171.3 GHz (Band 2), 207.7-264.4 GHz (Band 3), and 283-365 GHz (Band 4). The NOEMA LO system employs commercially available MMICs and GaAs millimeter MMICs from NRAO which are micro-assembled into active multiplied chain (AMC) and power amplifier (PA) modules. We discuss the problem of the LO spurious harmonics and of the LO signal directly multiplied by the SIS mixers that add extra noise and lead to detections of unwanted spectral lines from higher order sidebands. A waveguide filter in the LO path is used to reduce the higher order harmonics level of the LO at the output of the final frequency multiplier, thus mitigating the undesired effects and improving the system noise temperature.
Volume
6
Issue
2
Start page
212
Uri
Url
Issn Identifier
2156-342X
Ads BibCode
2016ITTST...6..212M
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

Mattiocco-IEEE-TTHzST-LO-NOEMA-March2016_preprint.pdf

Description
preprint
Size

2.62 MB

Format

Adobe PDF

Checksum (MD5)

5306d08efd896061c8823930d97955aa

Loading...
Thumbnail Image
Name

07416252.pdf

Description
[administrators only]
Size

2.49 MB

Format

Adobe PDF

Checksum (MD5)

1c33e9fb32e5ff8666fdabdda9417451