| 1. |
- Andersson, Christer, 1982, et al.
(författare)
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Decade bandwidth high efficiency GaN HEMT power amplifier designed with resistive harmonic loading
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- The use of resistive loading at higher harmonics in wideband power amplifier design is proposed. Although the theoretical efficiency of such operation is lower than other classes the significantly simplified load network design potentially allows for multi-octave realizations. A decade bandwidth (0.4-4.1 GHz) GaN HEMT power amplifier was thereby designed, delivering more than 40 dBm output power with 10-15 dB gain and 40-62% drain efficiency. Linearized modulated signal amplification was then successfully demonstrated at multiple frequencies (0.9 to 3.5 GHz), using various downlink signals (LTE, WCDMA, WiMAX), with resulting ACLR lower than 46 dBc.
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| 2. |
- ANDERSSON, MICHAEL, 1988, et al.
(författare)
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Noise Figure Characterization of a Subharmonic Graphene FET Mixer
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- We report on the first room temperature noise figure measurement of a graphene FET subharmonic resistive mixer in the interval fRF = 2-5 GHz. Due to an 8 nm thin Al2O3 gate dielectric it can operate with a conversion loss in the range 20-22 dB at only 0 dBm of local oscillator power. The measurement yields a noise figure close to the conversion loss, thus determining the noise to be thermal in origin, which is promising for cryogenic applications. The general route to lower noise figure is an improvement of the conversion loss.
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| 3. |
- Angelov, Iltcho, 1943, et al.
(författare)
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On the large-signal modeling of High Power AlGaN/GaN HEMTs
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- In this paper are given some recent results on modeling of High Power GaN HEMT devices. The GaN HEMT is very promising for high power application, but we push device to the limits, so many issues are becoming critical. For example, access resistances Rs, Rd in high power GAN HEMT are bias and temperature dependent-their extraction from cold FET measurements can lead to over optimistic prediction for output power. Thermal management, self-heating modeling are another very important issue-they influence reliability, power and PAE. Models without dynamic self-heating are not practical for GaN. The models without breakdown can easily predict world records for PAE, output power/mm etc. Some examples are given using vectorial Large Signal Measurements (LSNA/NVNA) to provide useful, global info about device behavior, influence of traps, knee voltage walkout etc.
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| 4. |
- Avolio, G., et al.
(författare)
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Waveforms-based large-signal identification of transistor models
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
-
Konferensbidrag (refereegranskat)abstract
- Measurements of low-and high-frequency vector-calibrated large-signal waveforms are exploited in this work to identify the parameters of a FET nonlinear model. The I DS nonlinear current source and the nonlinear charge sources' parameters are respectively determined from a small set of low-(2 MHz) and high-frequency (8 GHz) load-pull measurements by using a least square numerical optimization. Under low-frequency operation the contribution of the charge sources and any other reactive element can be neglected. In this way the identification of the IDS parameters is more accurate while remarkably speeding up the optimization routine as well. The proposed procedure is quite general and can be applied to different types of active devices. As case study, a 0.25-μm GaAs pHEMT is considered and the extracted model is validated under conditions different than the ones exploited within the identification step. A very good agreement between model predictions and experimental data is achieved.
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| 5. |
- Chehrenegar, Pirooz, 1964, et al.
(författare)
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Highly linear 1-3 GHz GaN HEMT low-noise amplifier
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- A highly linear low-noise amplifier (LNA) based on a commercial Gallium Nitride (GaN) high electron mobility transistor (HEMT) technology is presented. The amplifier can be operated at three frequency bands of 1, 2 and 3 GHz. The maximum measured gain is 31 dB at 1GHz and the output referred third-order intercept point (OIP3) is constant for all three frequency bands and equal to 41±1 dBm at a power consumption of L.2 W. A minimum noise figure (NF) of 0.5 dB is measured for the amplifier at the same bias point demonstrating the simultaneous linearity and low noise performance. The presented performance together with the reasonably low power consumption is outstanding in comparison with recently published amplifiers in GaN technology and available commercial GaAs LNAs.
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| 6. |
- Gevorgian, Spartak, 1948, et al.
(författare)
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Tunable FBARs: Intrinsic vs. extrinsic tunability
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- The methods used to make the Film Bulk Acoustic Resonators (FBAR) tunable is reviewed. Intrinsically tunable FBARs make use ferroelectrics in ferroelectric and paraelectric (non-polar) phases have tunabilities up to 5% and more. Extrinsically tunable resonators are based on traditional piezoelectric FBARs and make use of external varactors and inductors. The low tunability (
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| 7. |
- Gustafsson, David, 1983, et al.
(författare)
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A novel wideband and reconfigurable high average efficiency power amplifier
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
-
Konferensbidrag (refereegranskat)abstract
- This work presents theory and measurements of a new power amplifier based on the Doherty topology. It is theoretically shown that, by using a new set of design parameters with a Doherty power amplifier topology, the proposed amplifier can provide high efficiency, both at full output power and at power back-off, over a much improved bandwidth compared to the conventional Doherty power amplifier configuration. It is also shown that the proposed amplifier allows for simple reconfiguration of the efficiency in power back-off. A demonstrator circuit using individually controlled main and peak amplifier input signals is designed to validate the theoretical findings. Measurements show state-of-the art efficiency bandwidth at both full output power and at power back-off, as well as reconfigurable efficiency, thus validating the theory and demonstrating the potential of the proposed PA for use in future wireless transmitter applications.
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| 8. |
- Kozhuharov, Rumen, 1949, et al.
(författare)
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A W-and G-band MMIC source using InP HBT technology
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871 ; , s. 1 - 3
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Konferensbidrag (refereegranskat)abstract
- A frequency doubler/quadrupler for W-and G-band application is designed and fabricated utilizing an InP 250nm heterojunction bipolar transistor process. The multiplier is integrated with balanced V-band VCO. The VCO can be tuned between 57 to 61 GHz with average output power of 6 dBm and phase noise lower than 95 dBc/Hz at 1 MHz offset frequency. The circuit VCO plus multiplier can be used as a source with output power of 2dBm in 113-118 GHz bandwidth and 4dBm from 212 to 228 GHz.
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| 9. |
- Lai, Szhau, 1985, et al.
(författare)
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A method to lower VCO phase noise by using HBT darlington pair
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- The paper presents a novel method to enhance tank voltage swing in LC VCOs design using bipolar transistor. The method is successfully demonstrated in an InGaP/GaAs HBT MMIC process. A gm-boosted VCO and a modified version, using Darlington-pair transistors, are compared. The latter exhibits lower phase noise, increased tuning range, and less variation in output power. The gm-boosted VCO has tuning range of 22.8% centered at 5.7GHz and phase noise ranging from 103 to 95 dBc/Hz at offset frequency of 100kHz. The modified version using Darlington pair has tuning range of 26% centered at 5.9 GHz and phase noise ranging from 103.5 to 98.5 dBc/Hz at offset frequency of 100kHz.
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| 10. |
- Schleeh, Joel, 1986, et al.
(författare)
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Cryogenic 0.5-13 GHz low noise amplifier with 3 K mid-band noise temperature
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
-
Konferensbidrag (refereegranskat)abstract
- A 0.5-13 GHz cryogenic MMIC low-noise amplifier (LNA) was designed and fabricated using a 130 nm InP HEMT process. A packaged LNA has been measured at both 300 K and 15 K. At 300 K the measured minimum noise temperature was 48 K at 7 GHz. At 15 K the measured minimum noise temperature was 3 K at 7 GHz and below 7 K within the entire 0.5-13 GHz band. The gain was between 34 dB and 40 dB at 300 K and between 38 dB and 44 dB at 4 K.
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