| 1. |
- Fager, Christian, 1974, et al.
(författare)
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IC Design Aspects for 5G mm-Wave Systems
- 2020
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Ingår i: 2020 50TH EUROPEAN MICROWAVE CONFERENCE (EUMC). - 2325-0305. - 9782874870590 ; , s. 870-871
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Iupikov, Oleg, 1983, et al.
(författare)
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Prediction of Far-Field Pattern Characteristics of Phased Array Fed Reflector Antennas by Modeling Only a Small Part of the Array - Case Study of Spaceborne Radiometer Antennas
- 2017
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Ingår i: Proceedings of the 11th European Conference on Antennas and Propagation, EUCAP 2017, Paris, France, April 2017. - 2164-3342. - 9788890701870 ; , s. 2636-2639.
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Konferensbidrag (refereegranskat)abstract
- In this work we present an approach for the prediction of far-field pattern characteristics of phased array fed reflector antennas by modeling only a small part of the array. In this approach, the simulated EEPs of the FPA are modeled as the phase-shifted versions of the simulated embedded element pattern (EEP) of the central element, and thereafter combined with the optimum weighting coefficients in order to find the total pattern of the feed. Although, the EEPs of dense array antennas are generally not identical (due to the array antenna mutual coupling and edge truncation effects), for typical FPA excitation scenarios, where the array edge elements have relatively low weights to produce the desired illumination of the reflector, this simplified approach has been found sufficiently accurate.
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| 3. |
- Roev, Artem, 1992, et al.
(författare)
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A Wideband and Low-Loss Spatial Power Combining Module for mm-Wave High-Power Amplifiers
- 2020
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 8, s. 194858-194867
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Tidskriftsartikel (refereegranskat)abstract
- We present a low-loss power combiner, providing a highly integrated interface from an array of mm-wave power amplifiers (PAs) to a single standard rectangular waveguide (WG). The PAs are connected to an array of parallel and strongly coupled microstrip lines that excite a substrate integrated waveguide (SIW) based cavity. The spatially distributed modes then couple from the cavity to the rectangular WG mode through an etched aperture and two stepped ridges embedded in the WG flange. A new co-design procedure for the PA-integrated power combining module is presented that targets optimal system-level performance: output power, efficiency, linearity. A commercial SiGe quad-channel configurable transmitter and a standard gain horn antenna were interfaced to both ends of this module to experimentally demonstrate the proposed power combining concept. Since the combiner input ports are non-isolated, we have investigated the effects of mutual coupling on the transmitter performance by using a realistic PA model. This study has shown acceptable relative phase and amplitude differences between the PAs, . within +/- 15 degrees and +/- 1 dB. The increase of generated output power with respect to a single PA at the 1-dB compression point remains virtually constant (5.5 dB) over a 42% bandwidth. The performed statistical active load variation indicates that the interaction between the PAs through the combiner has negligible effect on the overall linearity. Furthermore, the antenna pattern measured with this combiner shows negligible deformation due to non-identical PAs. This represents experimental prove-of-concept of the proposed spatial power combining module, which can be suitable for applications in MIMO array transmitters with potentially coupled array channels.
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| 4. |
- Roev, Artem, 1992, et al.
(författare)
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A Wideband mm-Wave Watt-Level Spatial Power-Combined Power Amplifier With 26% PAE in SiGe BiCMOS Technology
- 2022
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 70:10, s. 4436-4448
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Tidskriftsartikel (refereegranskat)abstract
- We present a widehand watt-level power amplifier (PA) for the K a-band designed and implemented in the 0.25-mu m SiGe:C BiCMOS technology. The core of the design is a chip with multiple custom PA unit cells (PA-cells), which are interfaced with a power combiner placed on a laminate. The power combiner is based on a principle of the recently proposed multichannel transition with spatial power combining functionality, where an array of strongly coupled microstrip lines (MLs) interface a single substrate integrated waveguide (SIW). The realized watt-level PA combining four differential cascode PA-cells achieves a saturated output power (P-sat) of 30.8 dBm with 26.7% power-added efficiency (PAE). The 64-QAM modulation tests confirm the competitive PA performance on multi-Gb/s communication signals. The obtained combination of the high PAE and high P(sat )over a wide frequency band (30%) is an advantageous property of the proposed solution with respect to the previously published designs. This high performance is the result of using the proposed architecture with low-loss (0.6 dB) and wideband (54%) parallel spatial power combiner. Moreover, the presented joint EM-circuit-thermal optimization allows achieving optimal system-level performance by taking into account various critical multiphysics effects occurring in the combined PA. This article describes the design and performance of the whole integrated structure and its individual components.
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| 5. |
- Roev, Artem, 1992
(författare)
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Compact and Wideband Spatial Power Combining Module for mm-Wave High-Power Amplifiers
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The continued growth of data traffic in wireless communication applications demands to launch next-generation communication services at millimeter wave frequencies. Despite the obvious advantage of a large available spectrum, using millimeter wave bands is accompanied by many technological challenges. Mainly, this is due to the increased propagation and material loss, as well as limitations of the existing semiconductors, which deliver less power at these frequencies. The latter could be partly overcome by combining the power of multiple active devices on each antenna array element. However, conventional on-chip power combining networks have inherently high insertion losses, which significantly increase with the number of interconnected devices. This work presents a novel power combining solution where an array of multiple power amplifiers (PAs) are interfaced to a single substrate integrated waveguide (to be integrated with an antenna element) in the context of high-power array transmitters. Its operation principle is based on the direct excitation of TEm0 modes by an array of electrically short and coupled microstrip lines. This allows one to directly excite waveguide modes with high power, and hence, realize a desired spatial power combing functionality, which obviates the need for a potentially lossy on-chip power combiners. The proposed structure has wide impedance bandwidth (50%) and low insertion losses (0.4 dB) while offers a small form-factor. Moreover, the insertion losses are virtually independent from the number of interfaced PAs in contrast to conventional power combining techniques. The work also evaluates the approximate scalability bounds of such a structure as well as discusses the critical effects of coupled non-identical PAs. These undesired effects are reduced by employing on-chip isolation load resistors, which make the proposed configuration comparable with the classic Wilkinson power combiner in terms of the sensitivity to a non-uniform excitation. The direction of the ongoing work is a realization of a Watt-level PA, which combines power of multiple PA-cells integrated in the same compact module. For this purpose, a single cascode differential PA-cell is designed and implemented in a SiGe:C BiCMOS technology. It has a wideband performance (22—34 GHz) with both high efficiency (30%) and high output power (24.2 dBm), which outperforms the state-of-the-art single-cell silicon-based PAs.
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| 6. |
- Roev, Artem, 1992, et al.
(författare)
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Efficient Millimeter-Wave High Power Generation with Spatial Power-Combined Feeding Element
- 2018
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Ingår i: IET Conference Publications. - : Institution of Engineering and Technology. ; 2018
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Konferensbidrag (refereegranskat)abstract
- An efficient transition from a grid of amplifiers to a single substrate integrated waveguide (SIW) is presented.It is based on the excitation of the spatially distributed SIW mode with an array of parallel and strongly coupled microstrip lines (MLs), each of which is connected to an amplifier. The proposed configuration is optimized by minimizing the ‘active’ reflection coefficients at the TL ports. This equalizes the amplifier optimal load impedances and excites the TE10 SIW mode most efficiently. Also, signals are transferred with nearly uniform power distribution at the amplifier outputs. Numerical results show that this configuration can generate 16x more power per unit volume relative to a single microstripto- SIW transition, while offering a larger bandwidth. A prototype has been developed to validate the proof-of-concept.
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| 7. |
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| 8. |
- Roev, Artem, 1992, et al.
(författare)
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N-way spatial power combining in SIW for high power generation MMICs-scalability bounds
- 2019
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Ingår i: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings. ; July 2019, s. 1789-1790
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Konferensbidrag (refereegranskat)abstract
- An N-way transition between an array of amplifiers and a single substrate integrated waveguide (SIW) is presented. Its operation principle is based on excitation of the spatially distributed TE10 mode with an array of parallel and strongly coupled microstrip lines (MLs). The paper discusses and evaluates the approximate scalability bounds of such a structure in terms of the number of input channels. The model shows that, by employing a thin substrate, more amplifiers are capable of interfacing a single SIW to increase the output power, which is an important conclusion in regards to a future on-chip implementation of the structure. The model has also been validated by numerical simulations.
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| 9. |
- Roev, Artem, 1992, et al.
(författare)
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Wide-Band Spatially Distributed TE10 Substrate Integrated Waveguide Transition for High-Power Generation at mm-Wave Frequencies
- 2017
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Ingår i: International Symposium on Antennas and Propagation (ISAP2017), Phuket, Thailand, 30 Oct. - 2 Nov., 2017. ; 2017-January
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Konferensbidrag (refereegranskat)abstract
- An efficient transition from a grid of amplifiers to a single substrate integrated waveguide (SIW) is presented.It is based on the excitation of the spatially distributed SIW mode with an array of parallel and strongly coupled microstrip lines (MLs), each of which is connected to an amplifier. The proposed configuration is optimized by minimizing the ‘active’reflection coefficients at the TL ports. This equalizes the amplifier optimal load impedances and excites the TE10 SIW mode most efficiently. Also, signals are transferred with nearly uniform power distribution at the amplifier outputs.Numerical results show that this configuration can generate16x more power per unit volume relative to a single microstripto-SIW transition, while offering a larger bandwidth. Aprototype has been developed to validate the proof-of-concept.
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| 10. |
- Roev, Artem, 1992, et al.
(författare)
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Wideband mm-Wave Transition Between a Coupled Microstrip Line Array and SIW for High-Power Generation MMICs
- 2018
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 28:10, s. 867-869
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Tidskriftsartikel (refereegranskat)abstract
- A compact wideband transition between an array of microstrip lines (MLs) and a single substrate integrated waveguide (SIW) is presented. The spatially distributed fundamental SIW mode is excited by an array of parallel and strongly coupled MIA. The proposed configuration is optimized by minimizing the "active" reflection coefficient at each ML port. Signals are transferred with nearly uniform power distribution across the ML ports, which facilitate an effective utilization of power amplifiers once interconnected. Measured results of the proof-of-concept demonstrator are in good agreement with simulations. The proposed configuration is capable of generating more power per footprint size relative to a single microstrip-to-SIW transition while offering a 50% bandwidth. At the same time, the compactness of the ML-to-SIW transition makes it suitable for tight integration with monolithic microwave integrated circuits and applications in wideband array antennas.
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| 11. |
- Roev, Artem, 1992
(författare)
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Wideband Watt-Level Spatial Power-Combined Power Amplifier in SiGe BiCMOS Technology for Efficient mm-Wave Array Transmitters
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The continued demand for high-speed wireless communications is driving the development of integrated high-power transmitters at millimeter wave (mm-Wave) frequencies. Si-based technologies allow achieving a high level of integration but usually provide insufficient generated RF power to compensate for the increased propagation and material losses at mm-Wave bands due to the relatively low breakdown voltage of their devices. This problem can be reduced significantly if one could combine the power of multiple active devices on each antenna element. However, conventional on-chip power combining networks have inherently high insertion losses reducing transmitter efficiency and limiting its maximum achievable output power. This work presents a non-conventional design approach for mm-Wave Si-based Watt-level power amplifiers that is based on novel power-combining architecture, where an array of parallel custom PA-cells suited on the same chip is interfaced to a single substrate integrated waveguide (to be a part of an antenna element). This allows one to directly excite TEm0 waveguide modes with high power through spatial power combining functionality, obviating the need for intermediate and potentially lossy on-chip power combiners. The proposed solution offers wide impedance bandwidth (50%) and low insertion losses (0.4 dB), which are virtually independent from the number of interfaced PA-cells. The work evaluates the scalability bounds of the architecture as well as discusses the critical effects of coupled non-identical PA-cells, which are efficiently reduced by employing on-chip isolation load resistors. The proposed architecture has been demonstrated through an example of the combined PA with four differential cascode PA-cells suited on the same chip, which is flip-chip interconnected to the combiner placed on a laminate. This design is implemented in a 0.25 um SiGe BiCMOS technology. The PA-cell has a wideband performance (38.6%) with both high peak efficiency (30%) and high saturated output power (24.9 dBm), which is the highest reported output power level obtained without the use of circuit-level power combining in Si-based technologies at Ka-band. In order to achieve the optimal system-level performance of the combined PA, an EM-circuit-thermal optimization flow has been proposed, which accounts for various multiphysics effects occurring in the joint structure. The final PA achieves the peak PAE of 26.7% in combination with 30.8 dBm maximum saturated output power, which is the highest achievable output power in practical applications, where the 50-Ohms load is placed on a laminate. The high efficiency (>20%) and output power (>29.8 dBm) over a wide frequency range (30%) exceed the state-of-the-art in Si-based PAs.
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| 12. |
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