Lead Niobate-based Tunable Dielectrics for Smart Microwave and Millimeter-wave Systems
Lead Research Organisation:
University of Southampton
Department Name: Sch of Chemistry
Abstract
Electronically beam-steerable array antennas (phased arrays or smart antennas) at microwave and millimetre-wave (mm-wave) frequencies are extremely important for various wireless systems including satellite communications, terrestrial mobile communications, radars, "Internet Of Things", wireless power transmission, satellite navigations and deep-space communication. Traditionally, beam steering of antenna is achieved by moving the reflector mechanically, which is slow, bulky and not reliable. Phased arrays, which integrate antennas and phase shifter circuits, are an attractive alternative to gimbaled parabolic reflectors as they offer rapid beam steering towards the desired targets and better reliability. Phase shifters are critical components in phased arrays as the beam steering is achieved by controlling phase shifters electronically.
A promising research direction to create small, fast, reliable phase shifters with low insertion loss at high frequency is the use of tunable dielectric materials due to its potential of monolithic fabrication of array antennas and circuits. A breakthrough in such materials came recently when we demonstrated that Lead Niobate Pyrochlores PbnNb2O5+n gives the best combination of dielectric constant, tunability and low loss of any known thin film system. Translating these superior materials properties into actual device performance and high-performance electronically beam-steerable arrays antennas at microwave and mm-wave bands are the key aims of this project
A promising research direction to create small, fast, reliable phase shifters with low insertion loss at high frequency is the use of tunable dielectric materials due to its potential of monolithic fabrication of array antennas and circuits. A breakthrough in such materials came recently when we demonstrated that Lead Niobate Pyrochlores PbnNb2O5+n gives the best combination of dielectric constant, tunability and low loss of any known thin film system. Translating these superior materials properties into actual device performance and high-performance electronically beam-steerable arrays antennas at microwave and mm-wave bands are the key aims of this project
Planned Impact
The proposed program aims to find tunable dielectric materials which have low loss and high tunability for meeting the requirements of future wireless communication systems where all RF/microwave/millimeter-wave components and circuits need to be "tuneable". To investigate the performance of the materials in practical devices, circuits and sub-systems, tuneable dielectric will then be applied into microwave and millimeter-wave phase shifter circuits and phased arrays. Phased arrays, due to advantages of electronically beam steering and high gain, are the critical technology for next-generation mobile communications (5G), broadband satellite communications and radar systems.
The general public and communication service subscribers will benefit from broadband multimedia services with enhanced efficiency, speed, range, performance and sustainability.
This research facilitates generation of innovative applications in communication systems, benefits the communications industry with low cost improvements to the wireless link and enhances the UK's economic competiveness. The research finds will also be useful for UK national security and defence as the phased arrays will increase the performance of radars significantly.
Our industrial partners Ilika plc, BAE Systems, Keysight Technologies, Rohde Schwarz, Huawei Technologies UK Ltd, and NEC Europe have expressed their strong interests in the proposed project. Their involvement is a valuable asset for our project due to their strong focus on research and development, early deployment and commercial exploitation capabilities.
Public engagement activities will ensure a wider education of the population concerning the importance of materials in advanced technology in everyday lives.
The general public and communication service subscribers will benefit from broadband multimedia services with enhanced efficiency, speed, range, performance and sustainability.
This research facilitates generation of innovative applications in communication systems, benefits the communications industry with low cost improvements to the wireless link and enhances the UK's economic competiveness. The research finds will also be useful for UK national security and defence as the phased arrays will increase the performance of radars significantly.
Our industrial partners Ilika plc, BAE Systems, Keysight Technologies, Rohde Schwarz, Huawei Technologies UK Ltd, and NEC Europe have expressed their strong interests in the proposed project. Their involvement is a valuable asset for our project due to their strong focus on research and development, early deployment and commercial exploitation capabilities.
Public engagement activities will ensure a wider education of the population concerning the importance of materials in advanced technology in everyday lives.
Organisations
- University of Southampton (Lead Research Organisation)
- Huawei Technologies (Collaboration)
- Zepler Institute (Collaboration)
- Rohde and Schwarz (Collaboration)
- Ilika (Collaboration)
- Keysight Technologies (Collaboration)
- BAE Systems (United Kingdom) (Collaboration, Project Partner)
- Rohde & Schwarz (United Kingdom) (Project Partner)
- Ilika (United Kingdom) (Project Partner)
- Huawei Technologies (China) (Project Partner)
- NEC Europe Ltd (Project Partner)
Publications
Bakaimi I
(2018)
Combinatorial synthesis and screening of (Ba,Sr)(Ti,Mn)O 3 thin films for optimization of tunable co-planar waveguides
in Journal of Materials Chemistry C
Gao S
(2018)
Advanced Antennas for Small Satellites
in Proceedings of the IEEE
Luo Q
(2018)
Wideband Transmitarray With Reduced Profile
in IEEE Antennas and Wireless Propagation Letters
Luo Q
(2019)
Multibeam Dual-Circularly Polarized Reflectarray for Connected and Autonomous Vehicles
in IEEE Transactions on Vehicular Technology
Luo Q
(2019)
A Hybrid Design Method for Thin-Panel Transmitarray Antennas
in IEEE Transactions on Antennas and Propagation
Mostaed A
(2020)
Origin of improved tunability and loss in N 2 annealed barium strontium titanate films
in Physical Review Materials
Wen L
(2020)
A Wideband Series-Fed Circularly Polarized Differential Antenna by Using Crossed Open Slot-Pairs
in IEEE Transactions on Antennas and Propagation
Wen L
(2018)
Compact Dual-Polarized Shared-Dipole Antennas for Base Station Applications
in IEEE Transactions on Antennas and Propagation
| Description | 5G communications are based on the transmission of a signal from one device to another at high frequencies. The devices that are widely used such as antennas, navigation systems and cell phones use capacitors which store electric energy. The capacitors are composed of insulating materials which are called dielectrics. The quality of the dielectric will determine the losses when a signal is transmitted. In this research we have focused on the elimination of losses at high frequencies in order to make 5G communications more reliable, fast and effective. Our strategy was based on the improvement of the dielectric materials but also on the design and better performance of the devices that transfer the signal (waveguides and antennas). We have grown high quality thin films with high though put physical vapor deposition (HT-PVD). This method is based on the evaporation of sources (chemical elements) and results in the formation of numerous compositions in very short time. Using HT-PVD we managed to identify the best compositions of a known system ,called BaTiO3, that resulted in lower losses when doped with small amount of Mn. We have fabricated an array of devices on small chips (35 mm x 35 mm)and compared their performance at high frequencies. We investigated the electric properties of alternative materials called pyroclores which showed low losses. Our key findings can be summarized to the following: 1) we proved the high throughput growth and screening of capacitive devices at high frequencies 2) Investigated and achieved the in situ growth of ubic crystalline PbNbO and Bi-doped PbNbO. 3) Measured electric properties at room temperature of PbNbO and Bi-doped PbNbO. |
| Exploitation Route | The elimination of losses on dielectric materials at high frequencies has been a known and challenging problem for many decades. Our strategy to address this problem is based on a multidisciplinary approach based on the synergy of scientists with backgrounds from applied materials science to cutting edge engineering research. The results of this work can have a useful impact on the academic society as it will lead on the discovery of new compositions of materials with excellent dielectric properties. The integration of these materials in devices will provide critical information about the maximum performance of the devices at high frequencies. These findings can be used by companies whose products and devices for high frequency communication systems such as Huawei, Murata etc. |
| Sectors | Digital/Communication/Information Technologies (including Software),Electronics,Energy,Other |
| Title | Development of probe station for the highthrouput characterization of dielectric properties |
| Description | An experimental set up is currently being developed for the electrical measurements of the dielectric thin films fabricated. The experimental set up, herafter refferred to as 'probe station' allows the electric characterization as it measures the dielectric tunability of the thin films, the Seebeck coefficient the current -voltage loops etc. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2018 |
| Provided To Others? | No |
| Impact | High Throughput mapping of the dielectric properties of the thin films. |
| Title | Donation from Ilika Technologies( £3.4M) of Combinatorial Synthesis and Characterisation Tools to ACMF |
| Description | Donation of new High Thoughput-Physical Vapor Deposition (HT-PVD) System and HT characterization tools. Specifically the list of instruments that has been donated includes the following: HT-PVD (Purchase price £2,000,000, Age/years 11) SEM/EDX (Purchase price £140,000, Age/Years 8) XRD (Purchase price £240,000,Age/Years 10) Probe Station (Purchase price £106,000, Age/Years 11) HT-XPS (Purchase price £94,000, Age/Years 10) Spectroscopic Ellispometer (Purchase price £102,000 Age/Years 11) Optical Profilometer (Purchase price £65,000, Age/Years 11) 8 XRD £240,000 10 Probe Station £106,000 11 HT-XPS £94,000 10 Spectroscopic Ellipsometer £102,000 11 Optical Profilometer £65,000 13 |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2019 |
| Provided To Others? | Yes |
| Impact | Improvement of infrastructure of the Advanced Composite Materials Facility besed in Chemistry Southampton. These instruments are accessible for other research teams as well. |
| Description | Collaboration with Zepler Insitute and Prof. Goran Mashanovich for the growth of large Pockels coeffiecient Pb(ZrTi)O3 and BaTiO3 on Si substrates |
| Organisation | Zepler Institute |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The ACMF team (Prof. Hayden and Dr. Bakaimi) have recently demonstrated the high throughput growth of BaTiO3 on Pt coated waveguides in order to increase the band width of high frequency electronic devices. The findings of this research have attracted interest from engineers of the Zepler Institute who focus on the fabrication of efficient and cost effective Si optical phase shifters based on the Pockels effect. Dr. Bakaimi is applying the combinatorial synthesis and characterization to grow efficient PZT optical phase shifters on Si substrates. Prof Hayden has provided access to the ACMF facility where no facility charge is levied in order to establish the groundwork for a follow on EPSRC proposal. |
| Collaborator Contribution | The collaboration with Prof. Mashanovic and the Zepler Institute has started on October 2019 and has been funded by the EPSRC photonics hub on December 2019 with a budget of £50.000. The experimental work (starting on March 2020) of this project aims to prove the combinatorial growth and characterization of BaTiO3 and Pb(ZrTiO3) optical phase shifters on Si to achieve large Pockels coefficients. The Zepler Institute partners (Prof. Mashanovich, Dr. Cao Wei) will evaluate the phase shifters in terms of their DC and RF performance and the Pockels coefficient will be estimated. This is important as it will confirm high quality HT-ePVD growth on SOI which will represent a very significant milestone and be used as preliminary work for an EPSRC proposal on high efficiency Si optical modulators that we would submit later in 2020. Rockley Photonics has expressed their enthusiastic support with an in kind contribution of £13,000 after Prof. Mashanovich has explained the significance of this project. |
| Impact | The project starts on 14/3/2020/ therefore there is no outcome yet to report. This collaboration is multidisciplinary as it stems from the need to improve the efficiency of low power silicon photonic phase shifters through the optimazation of the material that is used in order to obtain the large Pockels coeffient. Therefore it is an exceptional example of applied materials science towards the requirements of cutting edge engineering research. |
| Start Year | 2019 |
| Description | Ilika Technologies Ltd |
| Organisation | BAE Systems |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Use of facilities for the synthesis of BST based libraries, and analytical facilities. |
| Collaborator Contribution | Designs for waveguide fabrication. |
| Impact | No output yet |
| Start Year | 2016 |
| Description | Ilika Technologies Ltd |
| Organisation | Huawei Technologies |
| Country | China |
| Sector | Private |
| PI Contribution | Use of facilities for the synthesis of BST based libraries, and analytical facilities. |
| Collaborator Contribution | Designs for waveguide fabrication. |
| Impact | No output yet |
| Start Year | 2016 |
| Description | Ilika Technologies Ltd |
| Organisation | Ilika |
| Department | Ilika Technologies Ltd. |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Use of facilities for the synthesis of BST based libraries, and analytical facilities. |
| Collaborator Contribution | Designs for waveguide fabrication. |
| Impact | No output yet |
| Start Year | 2016 |
| Description | Ilika Technologies Ltd |
| Organisation | Keysight Technologies |
| Country | United States |
| Sector | Private |
| PI Contribution | Use of facilities for the synthesis of BST based libraries, and analytical facilities. |
| Collaborator Contribution | Designs for waveguide fabrication. |
| Impact | No output yet |
| Start Year | 2016 |
| Description | Ilika Technologies Ltd |
| Organisation | Rohde and Schwarz |
| Country | Germany |
| Sector | Private |
| PI Contribution | Use of facilities for the synthesis of BST based libraries, and analytical facilities. |
| Collaborator Contribution | Designs for waveguide fabrication. |
| Impact | No output yet |
| Start Year | 2016 |
| Title | DetectColumns |
| Description | This program has been designed to analyze the intensity of atom columns in ADF-STEM images. |
| Type Of Technology | Software |
| Year Produced | 2018 |
| Impact | Intensity of atom columns in ADF-STEM images can be analysed by this software. For instance, the resulting data of this program can reveal presence of atom site swapping, dopants, vacancies, etc. in the structure of materials. Using this software, we resolved light atoms (e.g. oxygen) in the ADF images obtain from oxides containing relatively heavy atoms. |
| URL | https://www.researchgate.net/publication/320673454_DetectColumns_Program |
| Title | Development of LabView Software for the HighThrouput Screening of the Thin Films Electrical Measurements |
| Description | We have developed a Labview programme for the screening of electrical properties such as measurement of capacitance versus an applied electric field which is necessary in order to characterize tunable dielectrics. Software is under development for obtaining other electric properties such as Seebeck coefficient. |
| Type Of Technology | Software |
| Year Produced | 2018 |
| Impact | It is essential for the dielectric properties combinatorial screening of the fabricated thin films. |