| 1. |
- Andersson, Christer, 1982, et al.
(författare)
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A packaged 86 W GaN transmitter with SiC varactor-based dynamic load modulation
- 2013
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Ingår i: 43rd European Microwave Conference, EuMC 2013 - Held as Part of the 16th European Microwave Week, EuMW 2013, Nuremberg, Germany, 7-10 October 2013. - 9782874870316 ; , s. 283-286
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Konferensbidrag (refereegranskat)abstract
- Output power scaling based on class-J dynamic load modulation (DLM) theory is used to design an unprecedentedly high power microwave transmitter with varactor-based DLM functionality. Matching networks are realized on high dielectric constant substrates in order to reduce the form factor. The fully matched DLM PA incorporates a 24-mm GaN HEMT powerbar and a stack of four SiC varactors, all fit into a CuW package (40 mm × 20 mm). Peak output power is reconfigurable by changing the drain voltage, while retaining the DLMeffect. Under pulsed conditions at 40 V the PA delivers a peak power of 86 W at 2.14 GHz. Efficiency enhancement by DLM is 10-15 percentage-units at 6 dB output power back-off (OPBO). Employing digital predistortion (DPD) with a vector switched generalized memory polynomial (VS-GMP) the ACLR is -46 dBc at an average output power of 17 W and a drain efficiency of 34%. These results prove the potential for high output power levels in varactor-based DLM transmitters.
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| 2. |
- Angelov, Iltcho, 1943, et al.
(författare)
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Hybrid measurement-based extraction of consistent large-signal models for microwave FETs
- 2013
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Ingår i: 43rd European Microwave Conference, EuMC 2013 - Held as Part of the 16th European Microwave Week, EuMW 2013; Nuremberg; Germany; 7 October 2013 through 10 October 2013. - 9782874870316 ; , s. 267-270
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Konferensbidrag (refereegranskat)abstract
- This paper discusses a procedure to extract large-signal models for microwave transistors. By using experimental data, which not necessarily reflect the actual operating conditions, accurate large-signal models, suitable for CAD tools and working at high frequencies, can be obtained by combining direct extraction of basic parameters and numerical optimization. The idea consists of linking the model parameters directly to experimental data. In this way the extraction procedure is sped up. Examples of large-signal models for GaAs and GaN transistors are reported.
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| 3. |
- Frank, Markus, 1970, et al.
(författare)
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Differential Impedance Measurement Method of RFID Transponder Chips at UHF
- 2013
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Ingår i: Proceedings of the 43rd European Microwave Conference. - 9782874870316 ; 2013, s. 68-71
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Konferensbidrag (refereegranskat)abstract
- A novel on-wafer measurement method of RFID transponder chips is presented. A comparison is made between single ended one-port, single ended two-port and differential two-port excitation. The two-port method is a flexible way of measuring chips consisting of both several individuals as well as chip types with different geometries with one and the same probe type. The theory of un-terminating and de-embedding is described and verified by measurements. A qualitative analysis is defined, which explains certain phenomena seen in communication tests performed on RFID protocol level. This is further supported by measurement results from the presented method.
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| 4. |
- Gevorgian, Spartak, 1948, et al.
(författare)
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Loss balance in tunable ferroelectric FBARs
- 2013
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Ingår i: 43rd European Microwave Conference, EuMC 2013 - Held as Part of the 16th European Microwave Week, EuMW 2013, Nuremberg, Germany, 7-10 October 2013. - 9782874870316 - 9782874870323 ; , s. 1343-1346
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Konferensbidrag (refereegranskat)abstract
- Distinguishing between different loss mechanisms and their distribution between different parts of the Film Bulk Acoustic Wave Resonators (FBAR) is an issue. In this work a scaling rule (based on the analysis of the loss mechanisms) is proposed for initial specification of the losses in different structural components of the tunable FBARs. Simple ADS based calibration procedure is then applied allowing for correction of these losses and identifying the lossiest component. It is shown, in the provided example that the losses due to scattering at the roughness of the top Al electrode is dominating. Polishing of Al is proposed as a possible way of scattering losses reduction.
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| 5. |
- Gustafsson, David, 1983, et al.
(författare)
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An analysis of the suitability of using CW-theory when designing Doherty PAs for wideband or concurrent multi-band operation
- 2013
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Ingår i: 43rd European Microwave Conference, EuMC 2013 - Held as Part of the 16th European Microwave Week, EuMW 2013, Nuremberg, Germany, 7-10 October 2013. - 9782874870316 ; , s. 287-290
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Konferensbidrag (refereegranskat)abstract
- In this paper it is analyzed whether the commonly used continuous-wave (CW) based theory can properly describe and predict the behavior of the Doherty power amplifier (DPA) under wideband or concurrent multi-band operation. The analysis shows that the CW-theory in fact fails to do so and that the functionality of the DPA is strongly dependent on how intermodulation frequencies are terminated. In particular, it is shown that the network connecting the main and auxiliary amplifiers needs to function as an impedance inverter at specific odd order intermodulation frequencies, such as the cross-carrier intermodulation in the multi-band case. The theoretical analysis is verified by simulations, demonstrating how the functionality of a concurrent dual-band DPA is distorted despite CW-theory predicting ideal performance in each band. The findings in this paper are an important contribution to the understanding of how to further improve the performance of wideband or concurrent multi-band DPAs.
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| 6. |
- Shah, Umer, et al.
(författare)
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Characterization of High-Q Laterally Moving RF MEMS Tuneable Capacitor
- 2013
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Ingår i: European Microwave Week 2013, EuMW 2013 - Conference Proceedings; EuMC 2013. - : IEEE. - 9782874870316 ; , s. 1323-1326, s. 352-355
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Konferensbidrag (refereegranskat)abstract
- This paper investigates an implementation of RF MEMS tuneable capacitors based on the lateral displacement of the sidewalls of a three-dimensional micromachined coplanar transmission line. The concept achieves high Q since the mechanical actuation elements are completely de-coupled from the RF path, which is achieved by capacitive coupling of the ground signal to the moving sidewall. The fabricated capacitor has a tuning range of 40.53 to 60 fF (C-max/C-min = 1.48) in three discrete steps. This paper reports for the first time on Q-factor measurements, reliability, self-actuation robustness measurements, and linearity analysis. The Q-factor was determined by a transmission-line resonator as 88 at 40 GHz, resulting in a Qxf product of 3.52x10(12) which is higher than of any previously reported tuneable capacitor. Measurement data demonstrates high self-actuation robustness of 41.5 dBm at actuation and release voltages of 30.7 V and 21.15 V, a pull-in time of 60 mu s, and a mechanical resonance frequency of 5.3 kHz. The linearity of the device has been determined to an IIP3 of 71.4, 74.4 and 91.0 dBm for the three states of the capacitor. Reliability tests up to 1 billion cycles show no detectable performance degradation of this all-metal tuneable capacitor concept.
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| 7. |
- Vorobiev, Andrei, 1963, et al.
(författare)
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Tunable FBARs based on sol-gel grown PMN-PT films
- 2013
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Ingår i: 43rd European Microwave Conference, EuMC 2013 - Held as Part of the 16th European Microwave Week, EuMW 2013, Nuremberg, Germany, 7-10 October 2013. - 9782874870316 ; , s. 1339-1342
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Konferensbidrag (refereegranskat)abstract
- In this work possibilities of using of sol-gel grown PMN-PT films in tunable film bulk acoustic wave resonators are considered. More than 4% tuning of resonance frequency under DC field less than 15 V/μm is demonstrated. Linear and nonlinear electrostriction and induced piezoelectric coefficients of the PMN-PT films are evaluated.
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