Dependence of noise temperature on physical temperature for cryogenic low-noise amplifiers

McCulloch, M.; Grahn, Jan; Melhuish, S. J.; Nilsson, Per Åke; Piccirillo, L.; Schleeh, Joel; Wadefalk, Niklas

doi:10.1117/1.jatis.3.1.014003

Cited by 16 publications

(10 citation statements)

References 18 publications

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“…The reduction in gain is consistent with a lower current consumption. The measured noise temperature at 77 K agrees well with previously reported data for HEMT cryogenic low‐noise amplifiers …”

Section: Resultssupporting

confidence: 90%

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Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Sánchez‐Heredia

Baron

Hansen

et al. 2019

Magnetic Resonance in Med

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Purpose To develop an autonomous, in‐bore, MR‐compatible cryostat cooled with liquid nitrogen that provides full‐day operation, and to demonstrate that the theoretical signal‐to‐noise benefit can be achieved for 13C imaging at 3 T (32.13 MHz). Methods The cryogenic setup uses a vacuum‐insulated fiberglass cryostat, which indirectly cools a cold finger where the RF coil is attached. The cryostat was evacuated before use and had a reservoir of liquid nitrogen for full‐day operation. A 30 × 40 mm2 copper coil was mounted inside the cryostat with a 3‐mm distance to the sample. Two examples of in vivo experiments of rat brain metabolism after a hyperpolarized [1‐13C]pyruvate injection are reported. Results A coil Q‐factor ratio of Q88K/Q290K = 550/280 was obtained, and the theoretical SNR enhancement was verified with MR measurements. We achieved a coil temperature of 88 K and a preamplifier temperature of 77 K. A 2‐fold overall SNR enhancement was achieved, compared with the best case at room temperature. The thermal performance of the coil was adequate for in vivo experiments, with an autonomy of 5 hours consuming 6 L of LN2, extendable to over 12 hours by LN2 refilling. Conclusion Cryogenic surface coils can be highly beneficial for 13C imaging, provided that the coil‐to‐sample distance remains short. An autonomous, in‐bore cryostat was developed that achieved the theoretical improvement in SNR.

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Section: Resultssupporting

confidence: 90%

“…The measured noise temperature at 77 K agrees well with previously reported data for HEMT cryogenic low-noise amplifiers. 34…”

Section: Q-factorsmentioning

confidence: 99%

Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Sánchez‐Heredia

Baron

Hansen

et al. 2019

Magnetic Resonance in Med

View full text Add to dashboard Cite

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“…15 are for power dissipations between 3.24 mW and 6.81 mW, which produces a variation of 2.4 K of the DUT physical temperature. These variations of the low-noise amplifier physical temperature do not imply a linear change of its noise temperature, since according to previous works, the noise temperature ceases to decrease at very low physical temperatures below 20 K [33][34].…”

Section: Cryogenic Temperature (13 K)mentioning

confidence: 71%

Cryogenic performance of a 3–14 GHz bipolar SiGe low-noise amplifier

et al. 2019

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The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analyzed. The design and characterization of a 3-14 GHz low-noise amplifier (LNA) using SiGe transistors at 300 K and at 13 K are presented. A three stage amplifier is implemented with bipolar transistors model BFU910F from NXP commercially available with a plastic package. The amplifier exhibits 36.8 dB average gain with average noise temperature of 103 K and 42 mW DC power consumption at 300 K ambient temperature. Whereas cooled down to 13 K ambient temperature, it provides 32.4 dB average gain, 11.4 K average noise temperature with a minimum of 7.2 K at 3.5 GHz and a DC power dissipation of 5.8 mW. The presented LNA demonstrates an outstanding performance at cryogenic temperature for a commercial plastic packaged transistor.

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“…Although the noise temperature does decrease with base temperature over a range of temperatures as predicted, at liquid helium temperatures the noise temperature is observed to plateau to a value several times the quantum noise limit [15][16][17]. This noise temperature plateau has been attributed to a variety of mechanisms, including drain shot noise [18], gate leakage current [9], and self-heating [15,19].…”

Section: Introductionmentioning

confidence: 90%

Characterization of self-heating in cryogenic high electron mobility transistors using Schottky thermometry

Choi

Esho

Gabritchidze

et al. 2021

Journal of Applied Physics

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Cryogenic low noise amplifiers based on high electron mobility transistors (HEMTs) are widely used in applications such as radio astronomy, deep space communications, and quantum computing, and the physical mechanisms governing the microwave noise figure are therefore of practical interest. In particular, the contribution of thermal noise from the gate at cryogenic temperatures remains unclear owing to a lack of experimental measurements of thermal resistance under these conditions. Here, we report measurements of gate junction temperature and thermal resistance in a HEMT at cryogenic and room temperatures using a Schottky thermometry method. At temperatures ∼ 20 K, we observe a nonlinear trend of thermal resistance versus power that is consistent with heat dissipation by phonon radiation. Based on this finding, we consider heat transport by phonon radiation at the low-noise bias and liquid helium temperatures and estimate that the thermal noise from the gate is several times larger than previously assumed owing to self-heating. We conclude that without improvements in thermal management, self-heating results in a practical lower limit for microwave noise figure of HEMTs at cryogenic temperatures.

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Dependence of noise temperature on physical temperature for cryogenic low-noise amplifiers

Cited by 16 publications

References 18 publications

Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Cryogenic performance of a 3–14 GHz bipolar SiGe low-noise amplifier

Characterization of self-heating in cryogenic high electron mobility transistors using Schottky thermometry

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Dependence of noise temperature on physical temperature for cryogenic low-noise amplifiers

Cited by 16 publications

References 18 publications

Autonomous cryogenic RF receive coil for 13C imaging of rodents at 3 T

Autonomous cryogenic RF receive coil for 13C imaging of rodents at 3 T

Cryogenic performance of a 3–14 GHz bipolar SiGe low-noise amplifier

Characterization of self-heating in cryogenic high electron mobility transistors using Schottky thermometry

Contact Info

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Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Autonomous cryogenic RF receive coil for ¹³C imaging of rodents at 3 T

Cryogenic performance of a 3–14 GHz bipolar SiGe low-noise amplifier