| 1. |
- Gunnarsson, Sten, 1976, et al.
(författare)
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pHEMT and mHEMT Ultra Wideband Millimeterwave Balanced Resistive Mixers
- 2004
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; 2, s. 1141-1144
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Two ultra wideband millimeterwave single balanced resistive mixers utilizing a Marchand balun for the LO-hybrid are simulated, fabricated and characterized for 30-60 GHz in both up and down conversion. Two different versions of the mixer were manufactured in a commercial pHEMT-MMIC and a mHEMT-MMIC process respectively. A measured down conversion loss of approximately 6 to 12 dB over the whole band is obtained for both versions of the mixer with external IF power combining. In spite of the balanced design, the required LO power is quite low, 2 dBm is sufficient for low conversion loss. The LO-RF isolation is excellent, often more than 30 dB for both type of mixers. Low noise figure and high IIP3 figures are obtained. It is also shown that by applying selective drain bias, up to 5 dB improvement of IIP3 can be obtained for the mHEMT mixer with small LO powers.
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| 2. |
- Habibpour, Omid, 1979, et al.
(författare)
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A subharmonic graphene FET mixer
- 2012
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 33:1, s. 71-73
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a subharmonic resistive graphene FET (G-FET) mixer utilizing the symmetrical channel resistance vs. gate voltage characteristic. A down-conversion loss of 24 dB is obtained with fRF=2 GHz, fLO=1.01 GHz and fIF=20 MHz in a 50 Ω impedance system. Unlike the conventional subharmonic resistive FET mixers, this type of mixer operates with only one transistor and does not need any balun at the LO port which makes it more compact.
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| 3. |
- Hanning, Johanna, 1981, et al.
(författare)
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Single Flange 2-port Design For THz Integrated Circuit S-parameter Characterization
- 2013
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- A single flange 2-port TRL calibration and measurement setup for accurate THz S-parameter characterization of integrated membrane circuit devices is proposed. The proposed setup facilitates shorter access waveguides, which greatly improves the calibration uncertainty.
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| 4. |
- Hanning, Johanna, 1981, et al.
(författare)
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Single-Flange 2-Port TRL Calibration for Accurate THz S-Parameter Measurements of Waveguide Integrated Circuits
- 2014
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 4:5, s. 582-587
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a single flange 2-port measurement setup for S-parameter characterization of waveguide integrated devices. The setup greatly reduces calibration and measurement uncertainty by eliminating vector network analyzer (VNA) extender cable movement and minimizing the effect of waveguide manufacturing tolerances. Change time of standards is also improved, reducing the influence of VNA drift on the uncertainty. A TRL calibration kit has been manufactured and measurements are demonstrated in WR-03 (220–325 GHz).
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| 5. |
- Högas, Marcus, et al.
(författare)
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An analytic solution of the magnetic field and inductance in the main region of a coaxial short circuit
- 2014
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Ingår i: CPEM Digest (Conference on Precision Electromagnetic Measurements). - : Institute of Electrical and Electronics Engineers Inc.. - 9781479952052 ; , s. 276-277
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Konferensbidrag (refereegranskat)abstract
- In this paper an analytic solution of the magnetic field and inductance in the main region of a coaxial short circuit is presented. The magnetic field solution is constructed using a mode matching technique when solving the magnetic field differential equation and corresponding boundary conditions. By integrating the absolute square of the magnetic field solution the inductance is obtained.
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| 6. |
- Högås, Marcus, et al.
(författare)
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Analytic Solution of the Magnetic Field and Inductance in a Coaxial Short Circuit
- 2015
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 64:6, s. 1582-1587
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the analytic solution of the magnetic field and the inductance in a coaxial short circuit is derived from Maxwell's equations with the appropriate boundary conditions on the short circuit. Helmholtz equation is thus derived for the magnetic field and is solved by a mode matching technique. By integrating the absolute square of the magnetic field the inductance is obtained. The solution is discussed in the light of earlier approximations and solutions and is evaluated both theoretically and through measurements.
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| 7. |
- Prasad, Ankur, et al.
(författare)
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Symmetrical large-signal modeling of microwave switch FETs
- 2014
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Ingår i: IEEE transactions on microwave theory and techniques. - 0018-9480 .- 1557-9670. ; 62:8, s. 1590-1598
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new symmetrical field-effect transistor (FET) model suitable for microwave switches. The model takes advantage of the inherent symmetry of typical switch devices, justifying a new small-signal model where all intrinsic model parameters can be mirrored between the positive and negative drain-source bias regions. This small-signal model is utilized in a new and simplified approach to large-signal modeling of these type of devices. It is shown that the proposed large-signal model only needs a single charge expression to model all intrinsic capacitances. For validation of the proposed model, small-signal measurements from 100 MHz to 50 GHz and large-signal measurements at 600 MHz and 16 GHz, are carried out on a GaAs pHEMT. Good agreement between the model and the measurements is observed under both small- and large-signal conditions with particularly accurate prediction of higher harmonic content. The reduced measurement requirements and complexity of the symmetrical model demonstrates its advantages. Further, supporting operation in the negative drain-source voltage region, the model is robust and applicable to a variety of circuits, e.g., switches, resistive mixers, oscillators, etc.
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| 8. |
- Prasad, Ankur, 1987, et al.
(författare)
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Symmetrical Large-Signal Modeling of Microwave Switch FETs
- 2014
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 62:8, s. 1590-1598
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new symmetrical field-effect transistor (FET) model suitable for microwave switches. The model takes advantage of the inherent symmetry of typical switch devices, justifying a new small-signal model where all intrinsic model parameters can be mirrored between the positive and negative drain-source bias regions. This small-signal model is utilized in a new and simplified approach to large-signal modeling of these type of devices. It is shown that the proposed large-signal model only needs a single charge expression to model all intrinsic capacitances. For validation of the proposed model, small-signal measurements from 100 MHz to 50 GHz and large-signal measurements at 600 MHz and 16 GHz, are carried out on a GaAs pHEMT. Good agreement between the model and the measurements is observed under both small-and large-signal conditions with particularly accurate prediction of higher harmonic content. The reduced measurement requirements and complexity of the symmetrical model demonstrates its advantages. Further, supporting operation in the negative drain-source voltage region, the model is robust and applicable to a variety of circuits, e. g., switches, resistive mixers, oscillators, etc.
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| 9. |
- Prasad, Ankur, 1987, et al.
(författare)
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Symmetrical modeling of GaN HEMTS
- 2014
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Ingår i: Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC. - 1550-8781. - 9781479936229
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Konferensbidrag (refereegranskat)abstract
- This paper presents a symmetrical small signal model for GaN HEMTs valid for both positive and negative Vds. The model takes advantage of the intrinsic symmetry of the devices typically used for switches. The parameters of the model are extracted using a new symmetrical optimization based extraction method, optimizing simultaneously for both positive and negative drain-source bias points. This ensures a symmetrical small signal model with lower modeling error. The small signal model can be further used to simplify the development of a large-signal model. The small signal model is validated with measured S- parameters of a commercial GaN HEMT.
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| 10. |
- Prasad, Ankur, 1987, et al.
(författare)
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Symmetry based Nonlinear Model for GaN
- 2015
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Ingår i: 2015 10th European Microwave Integrated Circuits Conference (Eumic). - 9782874870408 ; , s. 85-88
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new nonlinear transistor model based on a symmetrical small-signal model far GaN HEMTs. The intrinsic symmetry reflected into the small signal equivalent circuit is used to build a new model to describe the nonlinear behavior of the device. The model consists of a new nonlinear charge expression with only 6 parameters, while the nonlinear current expression is extended front an existing model to enable validity in both the positive and negative Vis region. Therefore, it can be used for transistors in switches, resistive mixers as well as amplifiers. The model is validated with both small-signal and nonlinear measurements showing good agreements.
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