| 1. |
- Cha, Eunjung, 1985, et al.
(författare)
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0.3-14 and 16-28 GHz Wide-Bandwidth Cryogenic MMIC Low-Noise Amplifiers
- 2018
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 66:11, s. 4860-4869
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Tidskriftsartikel (refereegranskat)abstract
- We present two monolithic microwave integrated circuit (MMIC) cryogenic broadband low-noise amplifiers (LNAs) based on the 100 nm gate length InP high-electron mobility transistor technology for the frequency range of 0.3-14 and 16-28 GHz. The 0.3-14 GHz three-stage LNA exhibited a gain of 41.6 ± 1.4 dB and an average noise temperature of 3.5 K with a minimum noise temperature of 2.2 K at 6 GHz when cooled down to 4 K. The 16-28 GHz three-stage LNA showed a gain of 32.3 ± 1.8 dB and an average noise temperature of 6.3 K with a minimum noise temperature of 4.8 K at 20.8 GHz at the ambient temperature of 4 K. This is the first demonstration of cryogenic MMIC LNA covering the whole K-band. To the best of the authors' knowledge, the cryogenic MMIC LNAs demonstrated the state-of-the-art noise performance in the 0.3-14 and 16-28 GHz frequency range.
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| 2. |
- Cha, Eunjung, 1985, et al.
(författare)
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A 300-mu W Cryogenic HEMT LNA for Quantum Computing
- 2020
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Ingår i: PROCEEDINGS OF THE 2020 IEEE/MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS). - 0149-645X .- 2576-7216. - 9781728168159 ; , s. 1299-1302
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Konferensbidrag (refereegranskat)abstract
- This paper reports on ultra-low power 4-8 GHz (C-band) InP high-electron mobility transistor (HEMT) cryogenic low-noise amplifiers (LNAs) aimed for qubit amplification in quantum computing. We have investigated dc power dissipation in hybrid three-stage cryogenic LNAs using 100-nm gate length InP HEMTs with different indium content in the channel (65% and 80%). The noise performance at 300 K was found to be comparable for both channel structures. At 5 K, an LNA with 65% indium channel exhibited significantly lower noise temperature at any dc power dissipation compared to the LNA with 80% indium channel. The LNA with 65% indium channel achieved an average noise of 3.2 K with 23 dB gain at an ultra-low power consumption of 300 mu W. To the best of authors' knowledge, the LNA exhibited the lowest noise temperature to date for sub-milliwatt power cryogenic C-band LNAs.
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| 3. |
- Cha, Eunjung, 1985, et al.
(författare)
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Cryogenic low-noise InP HEMTs: A source-drain distance study
- 2016
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Ingår i: 2016 Compound Semiconductor Week, CSW 2016. - 9781509019649 ; , s. Article number 7528576-
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Konferensbidrag (refereegranskat)abstract
- The scaling effect of the source-drain distance was investigated in order to improve the performance of low-noise InP HEMTs at cryogenic temperatures 4-15 K. The highest dc transconductance at an operating temperature of 4.8 K and low bias power was achieved at a source-drain distance of 1.4 mu m. The extracted HEMT minimum noise temperature was 0.9 K at 5.8 GHz for a 3-stage 4-8 GHz hybrid low-noise amplifier at 10 K.
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| 4. |
- Cha, Eunjung, 1985, et al.
(författare)
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InP HEMTs for Sub-mW Cryogenic Low-Noise Amplifiers
- 2020
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 41:7, s. 1005-1008
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on a 100-nm gate length InP high-electron-mobility transistor (HEMT) technology for cryogenic low-noise amplifiers (LNAs) with ultra-low power dissipation of 112 mu W. This result was obtained by using 100-nm gate length InP HEMTs with improved transconductance at low drain current through a scaled-down gate-channel distance while maintaining a low gate leakage current with the use of an InP etch stop layer and Pt gate metal. The noise performance of InP HEMTs was demonstrated in a 4-8 GHz (C-band) three-stage hybrid LNA at the ambient temperature of 5 K. At a dc power dissipation of 300 mu W, the average noise temperature was 2.8 K with 27 dB gain. At a dc power dissipation of 112 mu W, the LNA exhibited an average noise temperature of 4.1 K with a gain of 20 dB. The presented results demonstrate the large potential of InP HEMT technology for sub-mW cryogenic LNA design.
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| 5. |
- Cha, Eunjung, 1985, et al.
(författare)
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Optimization of Channel Structures in InP HEMT Technology for Cryogenic Low-Noise and Low-Power Operation
- 2023
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 70:5, s. 2431-2436
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Tidskriftsartikel (refereegranskat)abstract
- We report the impact from channel composition on the cryogenic low-noise performance at low dc power for a 100-nm gate-length InGaAs-InAlAs-InP high-electron mobility transistor (HEMT). Two indium (In) channel compositions, 65% and 80%, were studied by dc and RF characterization at 300 and 5 K. For the cryogenic low-noise optimization, it was important to increase the transconductance to gate–source capacitance ratio in the weak inversion region implying that a higher maximum cutoff frequency in the HEMT does not guarantee lower noise. The HEMT noise performance was obtained from noise measurements in a hybrid three-stage 4–8-GHz ( $\textit{C}$ -band) low-noise amplifier (LNA) down to 300- $\mu$ W dc power dissipation. While the HEMT LNA noise performance for both the channel compositions at 300 K was found to be comparable, the HEMT LNA at 5 K with 65% In channel showed a minimum noise temperature of 1.4 K, whereas the noise temperature in the HEMT LNA with 80% In channel HEMTs increased to 2.4 K. The difference in the noise became more pronounced at reduced dc power dissipation. The ultralow dc power of 300 $\mu$ W demonstrated for a cryogenic $\textit{C}$ -band LNA with an average noise temperature of 2.9 K and 24-dB gain is of interest for future qubit read-out electronics at 4 K.
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| 6. |
- Cha, Eunjung, et al.
(författare)
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Two-Finger InP HEMT Design for Stable Cryogenic Operation of Ultra-Low-Noise Ka-and Q-Band LNAs
- 2017
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Ingår i: IEEE transactions on microwave theory and techniques. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9480 .- 1557-9670. ; 65:12, s. 5171-5180
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the cryogenic stability of two-finger 100-nm gate-length InP HEMTs aimed for Ka-and Q-band ultra-low noise amplifiers (LNAs). InP HEMTs with unit gate widths ranging between 30 and 50 mu text{m} exhibit unstable cryogenic behavior with jumps in drain current and discontinuous peaks in transconductance. We also find that shorter gate length enhances the cryogenic instability. We demonstrate that the instability of two-finger transistors can be suppressed by either adding a source air bridge, connecting the back end of gates, or increasing the gate resistance. A three-stage 24-40 GHz and a four-stage 28-52-GHz monolithic microwave-integrated circuit LNA using the stabilized InP HEMTs are presented. The Ka-band amplifier achieves a minimum noise temperature of 7 K at 25.6 GHz with an average noise temperature of 10.6 K at an ambient temperature of 5.5 K. The amplifier gain is 29 dB ± 0.6 dB. The Q-band amplifier exhibits minimum noise temperature of 6.7 K at 32.8 GHz with average noise temperature of 10 K at ambient temperature of 5.5 K. The amplifier gain is 34 dB ± 0.8 dB. To our knowledge, the Ka-and Q-band amplifiers demonstrate the lowest noise temperature reported so far for InP cryogenic LNAs. © 1963-2012 IEEE.
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| 7. |
- Cha, Eunjung, 1985, et al.
(författare)
-
Two-Finger InP HEMT Design for Stable Cryogenic Operation of Ultra-Low-Noise Ka- and Q-Band LNAs
- 2017
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 65:12, s. 5171-5180
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the cryogenic stability of two-finger 100-nm gate-length InP HEMTs aimed for Ka- and Q-band ultra-low noise amplifiers (LNAs). InP HEMTs with unit gate widths ranging between 30 and 50 mu m exhibit unstable cryogenic behavior with jumps in drain current and discontinuous peaks in transconductance. We also find that shorter gate length enhances the cryogenic instability. We demonstrate that the instability of two-finger transistors can be suppressed by either adding a source air bridge, connecting the back end of gates, or increasing the gate resistance. A three-stage 24-40 GHz and a four-stage 28-52-GHz monolithic microwave-integrated circuit LNA using the stabilized InP HEMTs are presented. The Ka-band amplifier achieves a minimum noise temperature of 7 K at 25.6 GHz with an average noise temperature of 10.6 K at an ambient temperature of 5.5 K. The amplifier gain is 29 dB +/- 0.6 dB. The Q-band amplifier exhibits minimum noise temperature of 6.7 K at 32.8 GHz with average noise temperature of 10 K at ambient temperature of 5.5 K. The amplifier gain is 34 dB +/- 0.8 dB. To our knowledge, the Ka- and Q-band amplifiers demonstrate the lowest noise temperature reported so far for InP cryogenic LNAs.
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| 8. |
- Cha, Eunjung, 1985, et al.
(författare)
-
Two-finger InP HEMT design for stable cryogenic operation of ultra-low-noise Ka-band LNAs
- 2017
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781509063604 ; , s. 168-171
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Konferensbidrag (refereegranskat)abstract
- We have investigated the cryogenic stability of two-finger InP HEMTs aimed for Ka-band ultra-low noise amplifiers (LNAs). Unlike two-finger transistors with a large gate-width above 2 χ 50 μm, the transistors with a small gate-width exhibit unstable cryogenic behavior. The instability is suppressed by adding a source air-bridge. The stabilizing effect of the air-bridge is demonstrated both on device and circuit level. A three-stage 2440 GHz monolithic microwave integrated circuit (MMIC) LNA using a stabilized 100-nm HEMT technology is presented. The amplifier achieves a record noise temperature of 7 K at 25.6 GHz with an average noise of 10.6 K across the whole band at an ambient temperature of 5.5 K. The amplifier gain is 29 dB ± 0.6 dB exhibiting very stable and repeatable operation. To our knowledge, this amplifier presents the lowest noise temperature reported so far for InP cryogenic LNAs covering the Ka-band.
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| 9. |
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| 10. |
- Desplanque, L., et al.
(författare)
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AlSb nucleation induced anisotropic electron mobility in AlSb/InAs heterostructures on GaAs
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:26
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the growth conditions at the AlSb/GaAs interface on the electron mobility in AlSb/InAs heterostructures is investigated. We show that an excessive antimony flux during the initial stage of the AlSb buffer growth leads to a strong anisotropy of electron mobility in InAs between [110] and [1-10] crystallographic orientations. This anisotropy is attributed to the formation of trenches oriented along the [1-10] direction in the InAs channel. Transmission electron microscopy reveals that these trenches are directly related to twinning defects originating from the AlSb/GaAs interface.
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