Nikfalazar, Mohammad (2016)
Beam-Steering Passive Phased Array with Integrated Printed Ferroelectric Phase Shifters.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung
Kurzbeschreibung (Abstract)
The phased array antenna (PAA) is a key concept in the realization of electronic beam forming and beam steering for numerous radar and communication applications such as detection and tracking, satellite communications and weather research. In on-the-move applications, where the beam of the antenna needs to be steered towards the transmitter or receiver, the phased array antennas offer a compact, fast, and compatible alternative to the mechanical beam steering. Significant research and development efforts towards the successful implementation and commercialization of cost-effective and efficient phased array antennas are currently underway. One of the most important components determining the cost and performance of the phased array antennas is the phase shifter. A number of technologies have been employed for tunable phase shifters, equipped by variable capacitors. Among other technologies, ferroelectric tunable varactors offer quick tuning, low power consumption, high durability, and adequate tunability and quality factor. In this work, the fabrication and optimization of ferroelectric varactors and their integration in a phased array antenna are discussed. In particular, barium strontium titanate (BST) material is investigated in both thin- and thick-film technologies within the framework of a number of interdisciplinary collaborations. Furthermore, thick-film technology is proposed as a low-cost and integrable solution for reconfigurable front ends. In this context, the potential of BST thick-film technology is discussed in two phase shifter structures, using the right- and left-handed loaded lines concepts. The major scientific contributions of this thesis are: First: Design and implementation of a compact phase shifter with more than 360 ° differential phase shift for two-dimensional beam steering, which enables the array to theoretically provide a semi hemisphere area coverage. The proposed left-handed phase shifter with a compact structure based on inkjet-printed thick film achieved a phase shift of 390 ° with a FoM of 38 °/dB at 12 GHz. Consequently, the left-handed phase shifter was integrated in a two-dimensional phased array antenna on a system level. The array archived a beam scanning range of up to ±25 ° in both E- and H-planes. Second: Further investigation of the feasibility of fully printed phase shifters where conductive electrodes are printed as well as the ferroelectric film. Several configurations and methods for the fabrication of fully printed phase shifters were established, offering significant performance improvement in comparison to the previously reported fully printed phase shifters. This investigation include the material processing, development, fabrication, and integration of tunable components based on inkjet- and screen-printing technologies. The fully printed phase shifter in microstrip environment achieved a phase shift of 274 ° with a FoM of 37.3 °/dB at 3 GHz. This phase shifter was implemented in a phased array with a beam scanning range reaching up to ±30 ° for operation at S-band. Third: The reduction of the biasing voltage has been investigated and demonstrated, which is essential to ease the system integration. Further investigation have been made to reduce the biasing voltage of the varactors based on the BST thick film. The available biasing voltage is limited in some particular applications. Therefore, it is important to develop technologies with functionality at low voltages. This work will reveal how the use of novel inkjet printing technology for the fabrication of metal-insulator-metal (MIM) varactors can reduce the biasing voltage of the tunable phase shifter based on BST thick film to a variable below 50V with maximum tunability of 46%, which is significant improvement in comparison to the conventional tunbale phase shifters based on BST think film with biasing voltage up to 400V. These varactors were integrated in a right-handed phase shifter at 8 GHz with a phase shift of 260 ° with a FoM of 44 °/dB. The phase shifter functionality is presented in a linear phased array antenna with a beam scanning range reaching up to ±30 °. Moreover, the array is equipped by a dielectric resonator antenna as a compact and high efficiency-radiating element. For further reduction of the biasing voltage below 5V, novel processing method based on BST thin film is presented. This method employes low resistivity oxide material as a conducting bottom layer for the MIM structure. This material has a similar lattice structure compared to the BST40:60 and hence significantly reduces the defect density. Consequently, thinner BST layer are feasible without risking high leakage currents or short circuits between the top and bottom electrodes. Reduced defect density is also, ideally, accompanied by a lower film loss tangent.
Typ des Eintrags: | Dissertation | ||||
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Erschienen: | 2016 | ||||
Autor(en): | Nikfalazar, Mohammad | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | Beam-Steering Passive Phased Array with Integrated Printed Ferroelectric Phase Shifters | ||||
Sprache: | Englisch | ||||
Referenten: | Jakoby, Prof. Dr. Rolf ; Alff, Prof. Dr. Lambert | ||||
Publikationsjahr: | 6 Juli 2016 | ||||
Ort: | Darmstadt | ||||
Datum der mündlichen Prüfung: | 23 November 2016 | ||||
URL / URN: | http://tuprints.ulb.tu-darmstadt.de/5961 | ||||
Kurzbeschreibung (Abstract): | The phased array antenna (PAA) is a key concept in the realization of electronic beam forming and beam steering for numerous radar and communication applications such as detection and tracking, satellite communications and weather research. In on-the-move applications, where the beam of the antenna needs to be steered towards the transmitter or receiver, the phased array antennas offer a compact, fast, and compatible alternative to the mechanical beam steering. Significant research and development efforts towards the successful implementation and commercialization of cost-effective and efficient phased array antennas are currently underway. One of the most important components determining the cost and performance of the phased array antennas is the phase shifter. A number of technologies have been employed for tunable phase shifters, equipped by variable capacitors. Among other technologies, ferroelectric tunable varactors offer quick tuning, low power consumption, high durability, and adequate tunability and quality factor. In this work, the fabrication and optimization of ferroelectric varactors and their integration in a phased array antenna are discussed. In particular, barium strontium titanate (BST) material is investigated in both thin- and thick-film technologies within the framework of a number of interdisciplinary collaborations. Furthermore, thick-film technology is proposed as a low-cost and integrable solution for reconfigurable front ends. In this context, the potential of BST thick-film technology is discussed in two phase shifter structures, using the right- and left-handed loaded lines concepts. The major scientific contributions of this thesis are: First: Design and implementation of a compact phase shifter with more than 360 ° differential phase shift for two-dimensional beam steering, which enables the array to theoretically provide a semi hemisphere area coverage. The proposed left-handed phase shifter with a compact structure based on inkjet-printed thick film achieved a phase shift of 390 ° with a FoM of 38 °/dB at 12 GHz. Consequently, the left-handed phase shifter was integrated in a two-dimensional phased array antenna on a system level. The array archived a beam scanning range of up to ±25 ° in both E- and H-planes. Second: Further investigation of the feasibility of fully printed phase shifters where conductive electrodes are printed as well as the ferroelectric film. Several configurations and methods for the fabrication of fully printed phase shifters were established, offering significant performance improvement in comparison to the previously reported fully printed phase shifters. This investigation include the material processing, development, fabrication, and integration of tunable components based on inkjet- and screen-printing technologies. The fully printed phase shifter in microstrip environment achieved a phase shift of 274 ° with a FoM of 37.3 °/dB at 3 GHz. This phase shifter was implemented in a phased array with a beam scanning range reaching up to ±30 ° for operation at S-band. Third: The reduction of the biasing voltage has been investigated and demonstrated, which is essential to ease the system integration. Further investigation have been made to reduce the biasing voltage of the varactors based on the BST thick film. The available biasing voltage is limited in some particular applications. Therefore, it is important to develop technologies with functionality at low voltages. This work will reveal how the use of novel inkjet printing technology for the fabrication of metal-insulator-metal (MIM) varactors can reduce the biasing voltage of the tunable phase shifter based on BST thick film to a variable below 50V with maximum tunability of 46%, which is significant improvement in comparison to the conventional tunbale phase shifters based on BST think film with biasing voltage up to 400V. These varactors were integrated in a right-handed phase shifter at 8 GHz with a phase shift of 260 ° with a FoM of 44 °/dB. The phase shifter functionality is presented in a linear phased array antenna with a beam scanning range reaching up to ±30 °. Moreover, the array is equipped by a dielectric resonator antenna as a compact and high efficiency-radiating element. For further reduction of the biasing voltage below 5V, novel processing method based on BST thin film is presented. This method employes low resistivity oxide material as a conducting bottom layer for the MIM structure. This material has a similar lattice structure compared to the BST40:60 and hence significantly reduces the defect density. Consequently, thinner BST layer are feasible without risking high leakage currents or short circuits between the top and bottom electrodes. Reduced defect density is also, ideally, accompanied by a lower film loss tangent. |
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URN: | urn:nbn:de:tuda-tuprints-59612 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau | ||||
Fachbereich(e)/-gebiet(e): | 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Mikrowellentechnik und Photonik (IMP) > Mikrowellentechnik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Mikrowellentechnik und Photonik (IMP) 18 Fachbereich Elektrotechnik und Informationstechnik |
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Hinterlegungsdatum: | 05 Feb 2017 20:55 | ||||
Letzte Änderung: | 05 Feb 2017 20:55 | ||||
PPN: | |||||
Referenten: | Jakoby, Prof. Dr. Rolf ; Alff, Prof. Dr. Lambert | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 23 November 2016 | ||||
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