| 1. |
- Abdulaziz, Mohammed, 1983, et al.
(författare)
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A 10-mW mm-wave phase-locked loop with improved lock time in 28-nm FD-SOI CMOS
- 2019
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 67:4, s. 1588-1600
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 IEEE. This paper presents a millimeter-wave (mm-wave) phase-locked loop (PLL), with an output frequency centered at 54.65 GHz. It demonstrates a mode-switching architecture that considerably improves the lock time, by seamlessly switching between a low-noise mode and a fast-locking mode that is only used during settling. The improvement is used to counteract the increased lock-time caused by cycle-slips that results from using a high reference frequency of 2280 MHz, which is several hundred times the loop bandwidth. Such a reference frequency alleviates the noise requirements on the PLL and is readily available in 5G systems, from the radio frequency PLL. The mm-wave PLL is implemented in a low-power 28-nm fully depleted silicon-on-insulator CMOS process, and its active area is just 0.19 mm 2 . The PLL also features a novel double injection-locked divide-by-3 circuit and a charge-pump mismatch compensation scheme, resulting in state-of-the-art power consumption, and jitter performance in the low-noise mode. In this mode, the in-band phase noise is between-93 and-96 dBc/Hz across the tuning range, and the integrated jitter is between 176 and 212 fs. The total power consumption of the mm-wave PLL is only 10.1 mW, resulting in a best-case PLL figure-of-merit (FOM) of-245 dB. The lock time in low-noise mode is up to 12μs, which is improved to 3μs by switching to the fast-locking mode, at the temporary expense of a power consumption increase to 15.1 mW, an integrated jitter increase to between 245 and 433 fs, and an FOM increase to between-235 and-240 dB.
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| 2. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
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Design and Validation of Microstrip Gap Waveguides and Their Transitions to Rectangular Waveguide, for Millimeter-Wave Applications
- 2015
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 63:12, s. 4035-4050
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Tidskriftsartikel (refereegranskat)abstract
- The paper describes the design methodology, experimentalvalidation and practical considerations of two millimeterwave wideband vertical transitions from two gap waveguide versions (inverted microstrip gap waveguide, and microstrip packaged by using gap waveguide) to standard WR-15 rectangular waveguide. The experimental results show S11 smaller than -10 dB over relative bandwidths larger than 25% and 26.6% when Rogers RO3003 and RO4003 materials are used respectively. The vertical transition from standard microstrip line packaged by a lid of pins to WR-15, shows measured return loss better than 15 dB over 13.8% relative bandwidth. The new transitions can be used as interfaces between gap waveguide feed-networks for 60 GHz antenna systems, testing equipment (like Vector Network Analyzers) and components with WR-15 ports, such as transmitting/receiving amplifiers. Moreover, the paper documents the losses of different gap waveguide prototypes compared to unpackaged microstrip line and Substrate Integrated Waveguide (SIW). This investigation shows that in V-band the lowest losses are achieved with inverted microstrip gap waveguide.
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| 3. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
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Design of F-Band Transition From Microstrip to Ridge Gap Waveguide Including Monte Carlo Assembly Tolerance Analysis
- 2016
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 64:4, s. 1245-1254
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the design and realization of a transition from a microstrip line to a ridge gap waveguide operating between 95 and 115 GHz. The study includes simulations, measurements, and a Monte Carlo analysis of the assembly tolerances. The purpose of this tolerance study is to identify the most critical misalignments that affect the circuit performance and to provide guidelines about the assembly tolerance requirements for the proposed transition design.
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| 4. |
- Amin, Shoaib, et al.
(författare)
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Digital Predistortion of Single and Concurrent Dual BandRadio Frequency GaN Amplifiers with Strong NonlinearMemory Effects
- 2017
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Ingår i: IEEE transactions on microwave theory and techniques. - : IEEE Press. - 0018-9480 .- 1557-9670. ; 65:7, s. 2453-2464
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Tidskriftsartikel (refereegranskat)abstract
- Electrical anomalies due to trapping effects in gallium nitride (GaN) power amplifiers (PAs) give rise to long-term or strong memory effects. We propose novel models based on infinite impulse response fixed pole expansion techniques for the behavioral modeling and digital predistortion of single-input single-output (SISO) and concurrent dual-band GaN PAs. Experimental results show that the proposed models outperform the corresponding finite impulse response (FIR) models by up to 17 dB for the same number of model parameters. For the linearization of a SISO GaN PA, the proposed models give adjacent channel power ratios (ACPRs) that are 7-17 dB lower than the FIR models. For the concurrent dual-band case, the proposed models give ACPRs that are 9-14 dB lower than the FIR models.
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| 5. |
- ANDERSSON, MICHAEL, 1988, et al.
(författare)
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A 185-215-GHz Subharmonic Resistive Graphene FET Integrated Mixer on Silicon
- 2017
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 65:1, s. 165-172
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Tidskriftsartikel (refereegranskat)abstract
- A 200-GHz integrated resistive subharmonic mixer based on a single chemical vapor deposition graphene field-effect transistor (G-FET) is demonstrated experimentally. This device has a gate length of 0.5 μm and a gate width of 2x40 μm. The G-FET channel is patterned into an array of bow-tie-shaped nanoconstrictions, resulting in the device impedance levels of ~50 Ω and the ON-OFF ratios of ≥4. The integrated mixer circuit is implemented in coplanar waveguide technology and realized on a 100-μm-thick highly resistive silicon substrate. The mixer conversion loss is measured to be 29 ± 2 dB across the 185-210-GHz band with 12.5-11.5 dBm of local oscillator (LO) pump power and >15-dB LO-RF isolation. The estimated 3-dB IF bandwidth is 15 GHz.
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| 6. |
- ANDERSSON, MICHAEL, 1988, et al.
(författare)
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An Accurate Empirical Model Based on Volterra Series for FET Power Detectors
- 2016
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 64:5, s. 1431-1441
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Tidskriftsartikel (refereegranskat)abstract
- An empirical model for field-effect transistor (FET) based power detectors is presented. The electrical model constitutes a Volterra analysis based on a Taylor series expansion of the drain current together with a linear embedding small-signal circuit. It is fully extracted from S-parameters and IV curves. The final result are closed-form expressions for the frequency dependence of the noise equivalent power (NEP) in terms of the FET intrinsic capacitances and parasitic resistances. Excellent model agreement to measured NEP of coplanar access graphene FETs with varying channel dimensions up to 67 GHz is obtained. The influence of gate length on responsivity and NEP is theoretically and experimentally studied.
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| 7. |
- Asbeck, Peter M., et al.
(författare)
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Power Amplifiers for mm-Wave 5G Applications: Technology Comparisons and CMOS-SOI Demonstration Circuits
- 2019
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 67:7, s. 3099-3109
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Tidskriftsartikel (refereegranskat)abstract
- A review is presented of key power amplifier (PA) performance requirements for millimeter-wave 5G systems, along with a comparison of the potential of different semiconductor technologies for meeting those requirements. Output power, efficiency, and linearity considerations are highlighted, and related to semiconductor material characteristics. Prototype 5G PAs based on silicon technologies are then reviewed, with primary emphasis on CMOS-SOI. Stacked FET PAs based on nMOS and pMOS for 28-GHz operation are presented, along with outphasing and Doherty amplifiers. Peak power-added efficiency (PAE) up to 46% is demonstrated for a two-stack pMOS amplifier with saturation power (Psat) above 19 dBm. PAE at 6 dB backoff above 27% is shown for an nMOS Doherty PA with 22-dBm Psat. Operation with 64QAM OFDM modulation signals at 800-MHz bandwidth is reported, with up to 13-dBm output power and more than 17% PAE, without the use of digital predistortion. Future challenges for PA development are discussed.
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| 8. |
- Bagheriasl, Mohammad, et al.
(författare)
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Bloch Analysis of Artificial Lines and Surfaces Exhibiting Glide Symmetry
- 2019
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Ingår i: IEEE transactions on microwave theory and techniques. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9480 .- 1557-9670. ; 67:7, s. 2618-2628
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Tidskriftsartikel (refereegranskat)abstract
- Glide-symmetric structures have recently emerged as a smart choice to design planar lenses and electromagnetic bandgap materials. We discuss here the conditions under which a glide-symmetric structure is equivalent to a nonglide-symmetric structure with a reduced period. To this aim, we propose an analysis method based on network theory to efficiently derive the dispersive behavior of these periodic structures. Both phase and attenuation constants can be determined, with potential applications to both guiding and radiating structures. Retaining higher order modal interactions among cells helps to derive the dispersive behavior of periodic structures more accurately. Furthermore, we take advantage of the higher symmetry of these structures to decrease the computational cost by considering only one half or one-quarter of a unit cell instead of the entire cell. We study one and 2-D glide-symmetric structures and confirm the validity of our analysis with comparisons from commercial software.
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| 9. |
- Bechter, Jonathan, et al.
(författare)
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Analytical and Experimental Investigations on Mitigation of Interference in a DBF MIMO Radar
- 2017
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Ingår i: IEEE transactions on microwave theory and techniques. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9480 .- 1557-9670. ; 65:5, s. 1727-1734
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Tidskriftsartikel (refereegranskat)abstract
- As driver assistance systems and autonomous driving are on the rise, radar sensors become a common device for automobiles. The high sensor density leads to the occurrence of interference, which decreases the detection capabilities. Here, digital beamforming (DBF) is applied to mitigate such interference. A DBF system requires a calibration of the different receiving channels. It is shown how this calibration completely changes the DBF beam pattern required to cancel interferences, if the system has no IQ receiver. Afterward, the application of DBF on a multiple-input multiple-output (MIMO) radar is investigated. It is shown that only the real aperture and not the virtual one can be used for interference suppression, leading to wide notches in the pattern. However, for any target the large virtual aperture can be exploited, even if interferers are blinded out. Moreover, the wide notches for interference suppression of the real aperture appear narrow in the virtual aperture for target localization. The results are verified by measurements with time-multiplexing MIMO radar.
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| 10. |
- Bremer, Johan, 1991, et al.
(författare)
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Analysis of Lateral Thermal Coupling for GaN MMIC Technologies
- 2018
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 66:10, s. 4430-4438
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a study of the lateral heat propagation in an aluminum gallium nitride/gallium nitride (AlGaN/GaN) heterostructure grown on a silicon carbide substrate. The study is enabled by the design of a temperature sensor that utilizes the temperature-dependent I-V characteristic of a semiconductor resistor, making it suitable for integration in GaN monolithic microwave integrated circuit technologies. Using the sensor, we are able to characterize the thermal transient response and extract lateral thermal time constants from the measurements. Time constants in the range from 25 mu s to 1.2 ms are identified. Furthermore, the heat propagation properties are characterized for heat source-to-sensor distances of 86-484 mu m, resulting in delay times from 3.5 to 111 mu s. It is shown that both the time constants and propagation delay increase with temperature. An empirical model of the sensor current versus temperature and voltage is proposed and used to predict the junction temperature of the sensor. The study provides knowledge for heat management design and proposes an integrated temperature measurement solution for future highly integrated GaN applications.
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