| 1. |
- Avolio, G., et al.
(författare)
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A novel technique for the extraction of nonlinear model for microwave transistors under dynamic-bias operation
- 2013
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467361767 ; , s. Art. no. 6697394-
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Konferensbidrag (refereegranskat)abstract
- In this work we describe a novel technique for the extraction of nonlinear model for microwave transistors from nonlinear measurements obtained by simultaneously driving the device under test with low- and high-frequency excitations. Specifically, the large-signal operating point of the device is set by large-signal low-frequency excitations. On top of these a tickle tone at high-frequency is applied. In this way, one can separate the contributions of the IDS current source and the charge sources by a single measurement. The nonlinear model, based on equations available in commercial CAD tools, is extracted for a 0.15 μm GaAs pHEMT. Good agreement is obtained between model predictions and experimental data.
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| 2. |
- Fritzin, Jonas, et al.
(författare)
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Linearity, intermodulation distortion and ACLR in outphasing amplifiers
- 2013
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Ingår i: 2013 IEEE MTT-S International Microwave Symposium Digest. - : IEEE conference proceedings. - 0149-645X. - 9781467361767 - 9781467321419
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Konferensbidrag (refereegranskat)abstract
- The distortion from amplitude and phase imbalance in outphasing amplifiers is discussed. The relation between dynamic range (DR) and suppression of distortion is shown to approximately follow a simple linear relationship depending on the DR. Approximate relations between adjacent channel leakage power ratio (ACLR) for different kinds of commonly used communication signals and two-tone intermodulation distortion are given. Relations between loss in output power and reduction of DR as functions of duty cycle in switching-based outphasing amplifiers are also given. An approximate method to evaluate the possible performance of digital pre-distortion (DPD) is also given by considering a DPD capable of correcting all distortions except amplitude imbalance. The predicted performance is compared to the performance obtained using a DPD-model found in the literature. The results show that the method is in good agreement, demonstrating that the proposed method can be used for design and evaluation of predistorted outphasing amplifiers.
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| 3. |
- Landin, Per, et al.
(författare)
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Behavioral modeling of outphasing amplifiers considering memory effects
- 2013
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Ingår i: 2013 IEEE MTT-S International Microwave Symposium Digest. - : IEEE conference proceedings. - 0149-645X. - 9781467361767
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a behavioral model structure for outphasing amplifiers. The model performance is evaluated on a class-D CMOS outphasing amplifier and compared with two models found in the literature. The proposed model structure also allows the use of memory in a parallel Hammerstein-like setting. The proposed models show improvements in adjacent channel error power ratio (ACEPR) of approximately 5 dB in addition to being linear in the parameters. The lower model errors enable the use and design of improved predistorters taking frequency dependency (memory effects) in outphasing amplifiers into account.
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| 4. |
- Norling, Martin, 1981, et al.
(författare)
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A 2 GHz oscillator using a monolithically integrated AlN TFBAR
- 2008
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781424417803 ; 1:1, s. 843-846
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Konferensbidrag (refereegranskat)abstract
- A 2 GHz oscillator based on a solidly mounted AlN thin-film bulk acoustic resonator (TFBAR) is reported. The oscillator is realised as a silicon-on-silicon multi-chip module (MCM) where all passive elements, including the TFBAR, are monolithically integrated on a high-resistivity silicon (HRS) carrier. SiGe transistors are flip-chip mounted on the MCM carrier. Measurements of the oscillators reveal a best phase-noise of -125 dBc/Hz at 100 kHz offset.
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| 5. |
- Abbasi, Morteza, 1982, et al.
(författare)
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A Broadband 60-to-120 GHz single-chip MMIC multiplier chain
- 2009
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; , s. 441-444
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Konferensbidrag (refereegranskat)abstract
- This paper presents a single-chip 60 GHz to 120 GHz frequency multiplier chain based on 0.1 ?m GaAs mHEMT. The MMIC can deliver 3 to 5 dBm of output power from 110 GHz to 130 GHz with 2 dBm input power and consumes only 65 mW of DC power. The signal at the fundamental frequency is suppressed more than 20 dB over the band of interest. The impedance matching networks are realized using coupled transmission lines.
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| 6. |
- Alfonso, E., et al.
(författare)
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Design of microwave circuits in ridge gap waveguide technology
- 2010
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781424460564 ; , s. 1544 - 1547
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Konferensbidrag (refereegranskat)abstract
- This paper presents recent advances is a new waveguiding technology referred to as ridge gap waveguides. The main advantages of the ridge gap waveguides compared to hollow waveguides are that they are planar and much cheaper to manufacture, in particular at high frequencies such as for millimeter and submillimeter waves. In these waveguides there are no mechanical joints across which electric currents must float. The gap waveguides have lower losses than microstrip lines, and they are completely shielded by metal so no additional packaging is needed, in contrast to the severe packaging problems associated with microstrip circuits. The gap waveguides are realized in a narrow gap between two parallel metal plates by using a texture on one of the surfaces. The waves follow metal ridges in the textured surface. All wave propagation in other directions is prohibited (in cutoff) by realizing a high impedance (ideally a perfect magnetic conductor) through the textured surface at both sides of all ridges. Thereby, cavity resonances do not appear within the band of operation. The paper studies the characteristic impedance of the line and presents simulations and measurements of circuits designed using this technology.
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| 7. |
- Alleaume, Pierre Franck, et al.
(författare)
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A highly integrated heterogeneous micro- and mm-wave platform
- 2010
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781424477326 ; , s. 461-464
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A highly integrated platform for micro- and mmwave frequency applications is introduced. The platform utilizes heterogeneous process modules with integrated passive and tunable devices together with silicon and GaAs MMIC technology to achieve outstanding flexibility. The different process modules are accounted for and their feasibility is proven through a number of application demonstrators from 23GHz telecom backhauling and 77GHz automotive radar indicating excellent performance. © 2010 IEEE.
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| 8. |
- Anderberg, Martin, 1992, et al.
(författare)
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A 183-GHz Schottky diode receiver with 4 dB noise figure
- 2019
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - : IEEE. - 0149-645X. ; 2019-June, s. 172-175
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Konferensbidrag (refereegranskat)abstract
- Atmospheric science based on space-borne millimeter wave measurements require reliable and state-of-the art receivers. In particular, the water vapor line at 183.3 GHz motivates the development of sensitive mixers at this frequency. Traditional assembly techniques employed in the production of Schottky diode receivers involve flip-chip mounting and soldering of discrete dies, which prohibit the implementation of reliable and repeatable production processes. In this work, we present a subharmonic 183 GHz mixer implementing a repeatable assembly method using beamlead Schottky diodes. The mixer was integrated with a InP HEMT MMIC low noise intermediate frequency amplifier resulting in a record-low receiver noise temperature of 450 K at 1 mW of local oscillator power measured at room-temperature. The measured Allan time was 10 s and the third order local oscillator spurious power was less than -60 dBm. The proposed assembly method is of particular importance for space-borne missions but also applicable to a wide range of terahertz applications.
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| 9. |
- 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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| 10. |
- 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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