| 1. |
- Gunnarsson, Sten, 1976, et al.
(author)
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pHEMT and mHEMT Ultra Wideband Millimeterwave Balanced Resistive Mixers
- 2004
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In: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; 2, s. 1141-1144
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Conference paper (other academic/artistic)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.
(author)
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A subharmonic graphene FET mixer
- 2012
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In: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 33:1, s. 71-73
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Journal article (peer-reviewed)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.
(author)
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Single Flange 2-port Design For THz Integrated Circuit S-parameter Characterization
- 2013
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. ; , s. 1-2
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Conference paper (peer-reviewed)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.
(author)
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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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In: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 4:5, s. 582-587
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Journal article (peer-reviewed)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. |
- Prasad, Ankur, 1987, et al.
(author)
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Symmetrical Large-Signal Modeling of Microwave Switch FETs
- 2014
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In: 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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Journal article (peer-reviewed)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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| 6. |
- Prasad, Ankur, 1987, et al.
(author)
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Symmetrical modeling of GaN HEMTS
- 2014
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In: Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC. - 1550-8781. - 9781479936229
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Conference paper (peer-reviewed)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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| 7. |
- Prasad, Ankur, 1987, et al.
(author)
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Symmetry based Nonlinear Model for GaN
- 2015
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In: 2015 10th European Microwave Integrated Circuits Conference (Eumic). - 9782874870408 ; , s. 85-88
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Journal article (peer-reviewed)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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| 8. |
- Stenarson, Jörgen, 1972, et al.
(author)
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Influence of waveguide width errors on TRL and LRL calibrations
- 2012
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In: 79th Automatic RF Techniques Microwave Measurement Conference (ARFTG). - 9781467312301
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Conference paper (peer-reviewed)abstract
- This paper investigates the impact of the waveguide width tolerance in TE10 mode waveguide TRL/LRL calibration kits. This is important for vector network analyzer measurements in the THZ range where waveguide tolerances become large compared the wavelength and to cross sectional dimensions. Besides causing reflections in the waveguide interface, the waveguide width tolerance also causes a change in the propagation constant that can shift the reference planes and cause problems in estimating the propagation constant of the Line standard. We conclude that the tolerances may cause a significant uncertainty contribution and may limit the useful band of the calibration kit.
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| 9. |
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| 10. |
- Stenarson, Jörgen, 1972, et al.
(author)
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Sensitivity Analysis of TRL Calibration in Waveguide Integrated Membrane Circuits
- 2013
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In: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 3:5, s. 558-565
-
Journal article (peer-reviewed)abstract
- We present a sensitivity analysis on TRL calibrated S-parameter measurements of membrane circuits in the WR-03 waveguide band (220-325 GHz). The impact of waveguide and membrane circuit misalignment, as well as waveguide dimension mismatch is investigated. The analysis is performed for the thru-reflect-line (TRL) calibration applied to E-plane split waveguide blocks carrying membrane circuits. The analysis shows a large influence of the waveguide width tolerance on transmission and reflection phase after the TRL calibration. For a 20 mm long rectangular waveguide with a ± 5 µm width tolerance a phase uncertainty as large as ± 45° for reflection and ± 30° for transmission measurements is observed.
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| 11. |
- Tang, Aik-Yean, 1980, et al.
(author)
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Analytical Extraction of a Schottky Diode Model from Broadband S-parameters
- 2013
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In: IEEE transactions on microwave theory and techniques. - 0018-9480 .- 1557-9670. ; 61:5, s. 1870-1878
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Journal article (peer-reviewed)abstract
- We present an analytic method to extract Schottky diode parasitic model parameters. All the ten unknown model parameters are extracted via a straightforward step-by-step procedure. The challenges for a proper finger inductance and series resistance extraction are discussed and solutions are recommended. The proposed method is evaluated using three sets of S-parameter data for GaAs-based planar Schottky diodes, i.e., data from measurement up to 110 GHz and 3-D electromagnetic full-wave simulations up to 600 GHz. The extracted models agree well with the measured and simulated data.
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| 12. |
- Yhland, Klas, 1964, et al.
(author)
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A tuneable probe for noncontacting microwave measurements
- 2010
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In: 2010 European Microwave Conference. - 9781424472321 ; , s. 775-778
-
Conference paper (peer-reviewed)abstract
- This paper describes an electrically tuneable loop coupler and its use for noncontacting measurements in microstrip circuits. Earlier loop coupler probes have the disadvantage of needing mechanical tuning to give sufficient directivity for scalar measurements on substrates having different dielectric constants. This problem is overcome through the use of a PIN diode as an adjustable termination on one of the coupler ports. The probe is evaluated for microstrip substrates with an εr ranging from 2:33 to 10 with transmission line characteristic impedances ranging from 30Ω to 80Ω. After tuning, the coupler shows a directivity better than 20 dB up to 3:8 GHz for εr = 2:33 and up to 1 GHz for εr = 10.
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| 13. |
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| 14. |
- Yhland, Klas, 1964
(author)
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Resitive FET Mixers
- 1999
-
Doctoral thesis (other academic/artistic)abstract
- This thesis presents theory, device models and circuits related to resistive FET mixers: A wave analysis for resistive mixers The analysis gives an intuitive estimate of resistive mixer performance when most parameters are unknown. It is based on the assumption that all mixing terms generated in the mixer are terminated with the same impedance. An expression for the conversion efficiency is therefore simple to derive in time domain. For HFETs and MESFETs, the wave analysis is extended to incorporate the effect of the local oscillator power level. The analysis methods are successfully verified by measurements. A symmetrical HFET/MESFET nonlinear model The nonlinear FET model reflects the intrinsic symmetry of microwave HFETs and MESFETs. The model is successfully verified by intermodulation measurements on mixers and amplifiers. Single device balanced resistive FET mixers Two types of single device balanced resistive HEMT mixers are presented. The mixers utilize the inherent symmetry of the FET to achieve balanced operation. The first type has a balanced, and the other a single ended, extraction of the intermediate frequency. Both types are successfully verified at 20 GHz. A FET transceiver suitable for FMCW radars The FET transceiver uses the same device for output power generation as for down-conversion of the received signal. The FET operates simultaneously as an amplifier and as a resistive mixer. It, thereby, avoids the problems associated with the separation of the transmitted and received signals which are closely spaced in frequency. The circuit is, empirically, shown to be insensitive to DC-bias variations. We also derive a method to optimize the output power simultaneously with the mixer conversion efficiency. A resistive FET frequency multiplier The operation of the multiplier is analogous to that of the resistive FET mixer. The wave analysis mentioned above is used to deduce the optimum way of operating the FET as well as estimating the conversion efficiency of a multiply-by-n circuit. The theoretical analysis is verified with two different 2 to 4 GHz multipliers. The verification shows good agreement between theory and measurements.
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| 15. |
- Zhao Ternehäll, Huan, 1982, et al.
(author)
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Characterization of thin film resistors and capacitors integrated on GaAs membranes for submillimeter wave circuit applications
- 2011
-
In: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. 2011 Compound Semiconductor Week and 23rd International Conference on Indium Phosphide and Related Materials, CSW/IPRM 2011, Berlin, 22-26 May 2011. - 1092-8669. - 9781457717536 ; , s. 1-4
-
Conference paper (peer-reviewed)abstract
- In this paper we describe the fabrication and characterization of thin film resistors and capacitors integrated on a 3 μm thick GaAs membrane. The thin film resistors and capacitors are based on NiCr and SiN x materials respectively. Onwafer probing DC characterization of these thin film components was performed before removing the GaAs substrate. The corresponding high frequency characterization in the WR-03 frequency band (220-325 GHz) was demonstrated utilizing a membrane-based two-port TRL calibration technique. The measurement results have shown a good agreement with the simulation.
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| 16. |
- Zhao Ternehäll, Huan, 1982, et al.
(author)
-
Submillimeter Wave S-Parameter Characterization of Integrated Membrane Circuits
- 2011
-
In: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 21:2, s. 110-112
-
Journal article (peer-reviewed)abstract
- We demonstrate S-parameter characterization of membrane circuits in the WR-03 frequency band (220-325 GHz) utilizing thru-reflect-line (TRL) -calibration technique. The TRL calibration kit design features 3 μm thick GaAs membrane circuits packaged in E-plane split waveguide blocks with the reference planes inside the membrane circuit structure. A 300 GHz membrane ring resonator filter circuit has been characterized by applying the proposed calibration kit, showing good agreement with simulations.
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| 17. |
- Zhao Ternehäll, Huan, 1982, et al.
(author)
-
VNA-calibration and S-parameter characterization of submillimeter wave integrated membrane circuits
- 2010
-
In: 21st International Symposium on Space Terahertz Technology 2010, ISSTT 2010; Oxford; United Kingdom; 23 March 2010 through 25 March 2010. - 9781617823626 ; , s. 299-300
-
Conference paper (peer-reviewed)abstract
- A TRL-calibration kit enabling S-parameter characterization of membrane circuits has been developed for the WR-03 band. The TRL-design features 3 μm thick GaAs membrane circuits packaged in E-plane split waveguide blocks. Membrane filters have been characterized after the calibration.
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