Electronically Tuned Local Oscillators for the NOEMA Interferometer

Mattiocco, F.; Garnier, Olivier; Maier, D.; Navarrini, A.; Serres, Patrice

doi:10.1109/tthz.2016.2525813

Cited by 5 publications

(2 citation statements)

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“…Space heritage on multipliers and amplifiers runs thin above 100 GHz. To make the hardware compatible with a possible follow-on demonstration at a high-frequency radio telescope, the output frequency and power level have to be within 93-121 GHz and 13-18 dBm, respectively [8]. This relaxes the output frequency by a factor 5 when compared to EHI though medium power amplifiers are still required at 100 GHz outputs.…”

Section: High-level Block Diagrammentioning

confidence: 99%

Laboratory Demonstration of the Local Oscillator Concept for the Event Horizon Imager

Kudriashov

Martín-Neira

Lia

et al. 2021

J. Astron. Instrum.

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Black hole imaging challenges the third-generation space VLBI, the Very Long Baseline Interferometry, to operate on a 500[Formula: see text]GHz band. The coherent integration time needed here is 450[Formula: see text]s though the available space oscillators cannot offer more than 10[Formula: see text]s. Self-calibration methods might solve this issue in an interferometer formed by three antenna/satellite systems, but the need for the third satellite increases the mission costs. A frequency transfer is of special interest to alleviate both performance and cost issues. A concept of two-way optical frequency transfer is examined to investigate its suitability to enable space-to-space interferometry, in particular, to image the “shadows” of black holes from space. The concept, promising on paper, has been demonstrated by tests. The laboratory test set-up is presented and the verification of the temporal stability using standard analysis tool as TimePod has been passed. The resulting Allan Deviation is dominated by the 1/[Formula: see text] phase noise trend since the frequency transfer timescale of interest is shorter than 0.2[Formula: see text]s. This trend continues into longer integration times, as proven by the longest tests spanning over a few hours. The Allan Deviation between derived 103.2[Formula: see text]GHz oscillators is [Formula: see text]/[Formula: see text] within 10[Formula: see text][Formula: see text][Formula: see text]s that degrades twice towards the longest delay of 0.2[Formula: see text]s. The worst case satisfies the requirement with a margin of 11 times. The obtained coherence in the range of 0.997[Formula: see text]0.9998 is beneficial for space VLBI at 557[Formula: see text]GHz. The result is of special interest to future science missions for black hole imaging from space.

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Section: High-level Block Diagrammentioning

confidence: 99%

Laboratory Demonstration of the Local Oscillator Concept for the Event Horizon Imager

Kudriashov

Martín-Neira

Lia

et al. 2021

J. Astron. Instrum.

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“…Thus, the core of the presented MMIC is an anti-parallel Schottky-diode tripler. Harmonic suppression on an LO-system is further discussed in [11]. The frequency tripler MMIC contains a Ku-band driver PA (PA 1 ), a Schottky-diode-based x3, and an output PA (PA 2 ).…”

Section: Broadband Frequency Tripler Mmicmentioning

confidence: 99%

Frequency Multiplier and Mixer MMICs Based on a Metamorphic HEMT Technology Including Schottky Diodes

et al. 2020

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This paper reports on the monolithic integration of layout-optimized Schottky diodes realized in an established 50-nm gate-length metamorphic high-electron-mobility transistor technology for use in multifunctional nonlinear circuits. The suitability of the realized Schottky diodes is demonstrated by a broadband millimeter-wave I/Q-mixer (In-phase/Quadrature) and local oscillator (LO) chain comprising two power amplifiers and a frequency tripler, fabricated on monolithic microwave integrated circuits (MMICs). Both circuits are based on an anti-parallel Schottky diode topology. The subharmonically-pumped I/Q-mixer covers an RF (radio frequency) and IF (intermediate frequency) range of at least 75 GHz to 110 GHz and 0.5 GHz to 15 GHz, respectively. The single-sideband conversion loss is between 14 dB and 16 dB across most of the entire RF and IF bands. The core of the LO chain consists of a frequency tripler (multiplier by three) and features a bias-adjustable output power with almost constant conversion efficiency and a control range of more than 8 dB. The fully-integrated LO chain MMIC matches the needs of the presented I/Q-mixer and exhibits an average output power of 16.3 dBm with a covered frequency range of 38 GHz to 60 GHz. The unwanted harmonics are suppressed by at least =25.9 dBc below the third harmonic for the entire frequency range and better than =32.1 dBc for most part of the band. Thus, the mixer and tripler MMICs demonstrate state-of-the-art performance with regards to, e.g., covered bandwidth, output power, harmonic suppression, or 1 dB compression point.

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