Zaiki Awang | Universiti Teknologi Mara (original) (raw)
Papers by Zaiki Awang
International Journal on Advanced Science, Engineering and Information Technology, Jun 20, 2017
The prediction of stocks in the stock market is important in investment as it would help the inve... more The prediction of stocks in the stock market is important in investment as it would help the investor to time buy and sell transactions to maximize profits. In this paper, a Multi-Layer Perceptron (MLP)-based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) model was used to predict the prices of the Apple Inc. weekly stock prices over a time horizon of 1995 to 2013. The NARX model is a system identification model that constructs a mathematical model from the dynamic input/output readings of the system and predicts the future behaviour of the system based on the constructed mathematical model. The One Step Ahead (OSA) and correlation tests were used to validate the model. Results demonstrate the predictive ability of the model while producing Gaussian residuals (indicating the validity of the model).
IEICE Proceeding Series
This paper presents an investigation on a microstrip wideband antenna by combining few rectangula... more This paper presents an investigation on a microstrip wideband antenna by combining few rectangular patch antennas from different frequencies. The microstrip patch antenna operates for the range of 5.4-5.5 GHz. Duroid substrates with ε r = 2.33, copper substrate thicknesses and height of 0.0356 mm and 0.5 mm respectively. A data analysis has been done to compare the return loss and VSWR from the antenna.
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](IEEE Microwave Magazine, 2018
Solid State Phenomena, 2021
The microwave absorption properties of La0.85Ag0.15MnO3 prepared by solid state method was invest... more The microwave absorption properties of La0.85Ag0.15MnO3 prepared by solid state method was investigated. Analysis of X-ray diffraction data using a refinement technique confirmed the rhombohedral structure of the samples. The microstructure of the sample characterised from field emission scanning electron microscope micrographs showed irregular grain shapes with grain sizes ranging from 800 to 1500 nm. M-H curves revealed the weak ferromagnetic properties of the sample at room temperature. The real and imaginary parts of permittivity and permeability as well as microwave reflection loss were measured by a vector network analyser in the 8–18 GHz frequency range. The La0.85Ag0.15MnO3 sample showed a minimum reflection loss of –57.2 dB at 16.41 GHz, with a –10dB bandwidth (corresponding to reflection loss below –10 dB, or 90% absorption) of 2.67 GHz. The microwave absorption of La0.85Ag0.15MnO3 mainly arises from the conduction loss and domain wall motion which contributed to diele...
2017 IEEE Regional Symposium on Micro and Nanoelectronics (RSM), 2017
This work reports on the ability of ZnO nanostructures deposited using thermal chemical vapour de... more This work reports on the ability of ZnO nanostructures deposited using thermal chemical vapour deposition (TCVD) method as the sensing membrane for extendend-gate field effect transistor (EGFET) application. Four samples was prepared at different deposition time ranging from 500 to 650 °C in order to study the effect of deposition temperature on EGFET pH sensor performance. The surface morphology of ZnO was examined using FESEM while its ability as EGFET sensing membrane was evaluated using semiconductor device analyzer. From the FESEM results, the ZnO nanostructures varied when the temperature was increased. The best sensitivity of ZnO nanostructures was found at 600 °C with 51.2 mV/pH of sensitivity and 0.9885 of linearity.
Zinc Oxide (ZnO) nanostructures deposited using simple chemical bath deposition (CBD) at differen... more Zinc Oxide (ZnO) nanostructures deposited using simple chemical bath deposition (CBD) at different deposition time ranging from 1 to 4 hours on indium tin oxide (ITO) substrates are proposed as sensing membrane of extended-gate field effect transistor (EGFET) pH sensor. The ZnO nanostructures were grown without any seed or catalyst layer. The deposited samples were characterized on their physical properties in order to investigate the correlation between physical properties and pH sensing behavior based on the influence of various deposition time to the physical properties. It is evident from the FESEM result that the nanostructures growth density is directly proportional to the growth time. Same goes on crystallinity quality of the samples that shows the same pattern as growth density. The physical properties of the ZnO nanostructures can be related to the immersion time and in turn influence the pH sensor performance. All deposited samples showed the ability to be applied as the s...
Scientific Research Journal, 2005
A contactless and non-destructive microwave method has been developed to characterize silicon sem... more A contactless and non-destructive microwave method has been developed to characterize silicon semiconductor wafers from reflection and transmission measurements made at normal incidence using MNDT. The measurement system consists of a pair of spot-focusing horn lens antenna, mode transitions, coaxial cables and a vector network analyzer (VNA). In this method, the free-space reflection and transmission coefficients, S11 and S21 are measured for silicon wafers sandwiched between two Teflon plates of 5mm thickness which act as a quarter-wave transformer at mid-band. The actual reflection and transmission coefficients, S11 and S21 of the silicon wafers are then calculated from the measured S11 and S21 using ABCD matrix transformation in which the complex permittivity and thickness of the Teflon plates are known. From the complex permittivity, the resistivity and conductivity can be obtained. Results for p-type and n-type doped silicon wafers are reported in the frequency range of 11 – 1...
Scientific Research Journal, 2005
A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes... more A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes of varied lengths are used to excite TE112-mode wave into the cavity to give a resonant frequency of 5.86 GHz. The experiments show that the resonant frequency of the cavity resonator decreases as the lengths of the probes are increased. The shortest probe in the range of study gives the closest resonant frequency to the one desired.
Materials Research Express, 2018
Ceramics International, 2019
Multiferroic BiFeO 3 (BFO) has garnered interest in recent years due to its magneto-electric coup... more Multiferroic BiFeO 3 (BFO) has garnered interest in recent years due to its magneto-electric coupling between ferroelectric and magnetic ordering. This unique property offers some advantages when applied as electromagnetic (EM) wave absorbers. In work reported here, the microwave absorption properties of multiferroic BFO/epoxy resin composites with different weight percentage (wt%) of BFO fillers of various thicknesses were investigated. The BFO powders were synthesized using high energy ball milling (HEBM) and sintered at 775°C in a furnace with an ambient air condition. The sintered BFO powders with different weight ratios (50 wt%, 60 wt% and 70 wt%) were mixed with epoxy resin as a matrix to form a composite with thicknesses of 1, 2 and 3 mm. Phase identification, grain size and morphology, magnetic and microwave absorption properties of prepared samples were characterized. The absorption performances of samples were measured in the frequency range of 8-18 GHz. As a result, the compressed BFO powders and BFO/epoxy resin composites with 50-70 wt% BFO filler showed dual-band microwave absorption resonance behavior. The best performances were demonstrated by a 3 mm thick BFO70 composite sample which exhibited a primary reflection loss (RL 1) of −26.0 dB at 9.1 GHz and a secondary reflection loss (RL 2) of −40.5 dB at 11.3 GHz, along with an associated −10 dB bandwidth of 1.31 GHz. The minimum reflection loss (RL) peaks were shifted to a lower frequency as the thicknesses were increased due to the λ 4 condition. Theoretical studies on the absorbing wave mechanism reveal a unique combination of dielectric loss relaxations and antiferromagnetic resonance effects in the BFO absorbers.
International Journal on Advanced Science, Engineering and Information Technology, 2017
2 nd order pseudo-elliptic resonator topologies are presented in this paper. Based on the closed ... more 2 nd order pseudo-elliptic resonator topologies are presented in this paper. Based on the closed loop with coupled-line resonator, three 2 nd order bandpass filter topologies were built. Each of these topologies offered pseudo-elliptic bandpass response with high selectivity that is suitable for RF and wireless applications. The main advantage of these topologies is that the structures were built from a closed-loop with coupled-line resonator which is easy to control to obtain desired electrical responses. To demonstrate the proposed concepts, the resonators were realized using microstrip technology and all the measurement results showing good agreement with those from the simulations.
2010 IEEE Symposium on Industrial Electronics and Applications (ISIEA), 2010
... 129-133, 2001. [10] H. Adam, A. Ismail, MA Mahdi, MS Razalli, A. Alhawari and B. K. Esfeh, X... more ... 129-133, 2001. [10] H. Adam, A. Ismail, MA Mahdi, MS Razalli, A. Alhawari and B. K. Esfeh, X-band miniaturized wideband bandpass filter utilizing multilayered microstrip hairpin resonator, Progress in Electromagnetics Research, PIER 93, pp. 177-188, 2009. ...
2008 IEEE International RF and Microwave Conference, 2008
... Mohamad Huzaimy Jusoh, Norsuzila Ya'acob, Hasnida Saad, Ahmad As... more ... Mohamad Huzaimy Jusoh, Norsuzila Ya'acob, Hasnida Saad, Ahmad Asari Sulaiman, Noor Hasimah Baba, Robi'atun Adayiah Awang and Zuhani Ismail Khan ... Where N is the electron densityin el/m3, n denotes the refractive index, and f and fN represent radio wave and ...
Scientific Reports, 2020
Microwave absorption properties were systematically studied for double-layer carbon black/epoxy r... more Microwave absorption properties were systematically studied for double-layer carbon black/epoxy resin (CB) and Ni0.6Zn0.4Fe2O4/epoxy resin (F) nanocomposites in the frequency range of 8 to 18 GHz. The Ni0.6Zn0.4Fe2O4 nanoparticles were synthesized via high energy ball milling with subsequent sintering while carbon black was commercially purchased. The materials were later incorporated into epoxy resin to fabricate double-layer composite structures with total thicknesses of 2 and 3 mm. The CB1/F1, in which carbon black as matching and ferrite as absorbing layer with each thickness of 1 mm, showed the highest microwave absorption of more than 99.9%, with minimum reflection loss of −33.8 dB but with an absorption bandwidth of only 2.7 GHz. Double layer absorbers with F1/CB1(ferrite as matching and carbon black as absorbing layer with each thickness of 1 mm) structure showed the best microwave absorption performance in which more than 99% microwave energy were absorbed, with promising m...
2004 RF and Microwave Conference (IEEE Cat No 04EX924) RFM-04, 2004
Nano-, Bio-, Info-Tech Sensors, and 3D Systems II, 2018
Antennas made using rigid substrates are unsuitable in applications where space and surface confo... more Antennas made using rigid substrates are unsuitable in applications where space and surface conformability are a concern. This is a common issue for RFID, smart tags and wearable electronics applications which require conformability to the mounting structure, in addition to being weather-proof. Commercially available designs employ bendable substrates such as synthetic rubber, polymer, microfluids and plastics, but these materials are costly, at times difficult to manufacture, and offer limited electrical and mechanical properties. More importantly they are not environmental-friendly. On the other hand, natural rubber is abundant and easily produced. Being a natural product, they are weather-proof and environmental-friendly, the electrical properties are easily controlled and are stable at elevated frequencies. It is also one of the most flexible natural material available and yet can be designed to almost any shape. We report for the first time in this paper detailed characterization of RFID antennas based on natural rubber formulated with carbon black filler. Prototype patch and meander dipole antennas were simulated using CST Microwave Studio to operate at 921 MHz, using copper as the conductor and natural rubber as the substrate. Full characterization using scattering parameters and radiation patterns were carried out for flat and bent conditions. The prototypes offered performances comparable to existing designs which use synthetic materials, with maximum read range of about 1.8 m. Optimum processing conditions and the effects of material on the antenna performance are described here. The performance obtained is comparable to commercially-available designs, with added benefits offered by a natural material.
2015 IEEE International RF and Microwave Conference (RFM), 2015
2014 IEEE 2nd International Symposium on Telecommunication Technologies (ISTT), 2014
In this paper, we compare several calibration methods available for on-wafer microwave measuremen... more In this paper, we compare several calibration methods available for on-wafer microwave measurements conducted on transmission lines made of graphene. Multi-layered graphene films were grown on Si wafers coated with SiO2 and Ni using chemical vapor deposition. In order to facilitate high frequency characterization, and to replicate their function as radio frequency integrated circuits (RFIC) interconnects, the graphene films were constructed in the form of co-planar transmission lines using electron beam lithography. The transmission lines are in the form of co-planar waveguide (CPW) so that it they are compatible with the RF probes used to measure the properties of this material. In order to compare the accuracy, three on-wafer calibration techniques were considered, namely the popular Short-Open-Load-Thru (SOLT) method, and the new Line-Reflect-Match (LRM) and Thru-Reflect-Line (TRL) methods. This study aims to improve the accuracy of graphene measurement so that the behaviors of this material will be better understood.
2007 Asia-Pacific Conference on Applied Electromagnetics, 2007
This paper describes the 3D simulation and measurements of free space characterization for the co... more This paper describes the 3D simulation and measurements of free space characterization for the complex permittivity of p-type and n-type doped silicon wafers at K-Band. The component of this free space measurement system (FSMM) consists of Millitech series GOA Gaussian optics lens antennas, Vector Network Analyzer (VNA) and a high performance workstation. The antennas were modeled and simulated using Computer Simulation Technology (CST) software. The thru, reflect and line (TRL) calibration technique were used to eliminate the effect of undesirable multiple reflections. The simulation and measurement results are presented where good agreements are observed.
International Journal on Advanced Science, Engineering and Information Technology, Jun 20, 2017
The prediction of stocks in the stock market is important in investment as it would help the inve... more The prediction of stocks in the stock market is important in investment as it would help the investor to time buy and sell transactions to maximize profits. In this paper, a Multi-Layer Perceptron (MLP)-based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) model was used to predict the prices of the Apple Inc. weekly stock prices over a time horizon of 1995 to 2013. The NARX model is a system identification model that constructs a mathematical model from the dynamic input/output readings of the system and predicts the future behaviour of the system based on the constructed mathematical model. The One Step Ahead (OSA) and correlation tests were used to validate the model. Results demonstrate the predictive ability of the model while producing Gaussian residuals (indicating the validity of the model).
IEICE Proceeding Series
This paper presents an investigation on a microstrip wideband antenna by combining few rectangula... more This paper presents an investigation on a microstrip wideband antenna by combining few rectangular patch antennas from different frequencies. The microstrip patch antenna operates for the range of 5.4-5.5 GHz. Duroid substrates with ε r = 2.33, copper substrate thicknesses and height of 0.0356 mm and 0.5 mm respectively. A data analysis has been done to compare the return loss and VSWR from the antenna.
IEEE Microwave Magazine, 2018
Solid State Phenomena, 2021
The microwave absorption properties of La0.85Ag0.15MnO3 prepared by solid state method was invest... more The microwave absorption properties of La0.85Ag0.15MnO3 prepared by solid state method was investigated. Analysis of X-ray diffraction data using a refinement technique confirmed the rhombohedral structure of the samples. The microstructure of the sample characterised from field emission scanning electron microscope micrographs showed irregular grain shapes with grain sizes ranging from 800 to 1500 nm. M-H curves revealed the weak ferromagnetic properties of the sample at room temperature. The real and imaginary parts of permittivity and permeability as well as microwave reflection loss were measured by a vector network analyser in the 8–18 GHz frequency range. The La0.85Ag0.15MnO3 sample showed a minimum reflection loss of –57.2 dB at 16.41 GHz, with a –10dB bandwidth (corresponding to reflection loss below –10 dB, or 90% absorption) of 2.67 GHz. The microwave absorption of La0.85Ag0.15MnO3 mainly arises from the conduction loss and domain wall motion which contributed to diele...
2017 IEEE Regional Symposium on Micro and Nanoelectronics (RSM), 2017
This work reports on the ability of ZnO nanostructures deposited using thermal chemical vapour de... more This work reports on the ability of ZnO nanostructures deposited using thermal chemical vapour deposition (TCVD) method as the sensing membrane for extendend-gate field effect transistor (EGFET) application. Four samples was prepared at different deposition time ranging from 500 to 650 °C in order to study the effect of deposition temperature on EGFET pH sensor performance. The surface morphology of ZnO was examined using FESEM while its ability as EGFET sensing membrane was evaluated using semiconductor device analyzer. From the FESEM results, the ZnO nanostructures varied when the temperature was increased. The best sensitivity of ZnO nanostructures was found at 600 °C with 51.2 mV/pH of sensitivity and 0.9885 of linearity.
Zinc Oxide (ZnO) nanostructures deposited using simple chemical bath deposition (CBD) at differen... more Zinc Oxide (ZnO) nanostructures deposited using simple chemical bath deposition (CBD) at different deposition time ranging from 1 to 4 hours on indium tin oxide (ITO) substrates are proposed as sensing membrane of extended-gate field effect transistor (EGFET) pH sensor. The ZnO nanostructures were grown without any seed or catalyst layer. The deposited samples were characterized on their physical properties in order to investigate the correlation between physical properties and pH sensing behavior based on the influence of various deposition time to the physical properties. It is evident from the FESEM result that the nanostructures growth density is directly proportional to the growth time. Same goes on crystallinity quality of the samples that shows the same pattern as growth density. The physical properties of the ZnO nanostructures can be related to the immersion time and in turn influence the pH sensor performance. All deposited samples showed the ability to be applied as the s...
Scientific Research Journal, 2005
A contactless and non-destructive microwave method has been developed to characterize silicon sem... more A contactless and non-destructive microwave method has been developed to characterize silicon semiconductor wafers from reflection and transmission measurements made at normal incidence using MNDT. The measurement system consists of a pair of spot-focusing horn lens antenna, mode transitions, coaxial cables and a vector network analyzer (VNA). In this method, the free-space reflection and transmission coefficients, S11 and S21 are measured for silicon wafers sandwiched between two Teflon plates of 5mm thickness which act as a quarter-wave transformer at mid-band. The actual reflection and transmission coefficients, S11 and S21 of the silicon wafers are then calculated from the measured S11 and S21 using ABCD matrix transformation in which the complex permittivity and thickness of the Teflon plates are known. From the complex permittivity, the resistivity and conductivity can be obtained. Results for p-type and n-type doped silicon wafers are reported in the frequency range of 11 – 1...
Scientific Research Journal, 2005
A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes... more A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes of varied lengths are used to excite TE112-mode wave into the cavity to give a resonant frequency of 5.86 GHz. The experiments show that the resonant frequency of the cavity resonator decreases as the lengths of the probes are increased. The shortest probe in the range of study gives the closest resonant frequency to the one desired.
Materials Research Express, 2018
Ceramics International, 2019
Multiferroic BiFeO 3 (BFO) has garnered interest in recent years due to its magneto-electric coup... more Multiferroic BiFeO 3 (BFO) has garnered interest in recent years due to its magneto-electric coupling between ferroelectric and magnetic ordering. This unique property offers some advantages when applied as electromagnetic (EM) wave absorbers. In work reported here, the microwave absorption properties of multiferroic BFO/epoxy resin composites with different weight percentage (wt%) of BFO fillers of various thicknesses were investigated. The BFO powders were synthesized using high energy ball milling (HEBM) and sintered at 775°C in a furnace with an ambient air condition. The sintered BFO powders with different weight ratios (50 wt%, 60 wt% and 70 wt%) were mixed with epoxy resin as a matrix to form a composite with thicknesses of 1, 2 and 3 mm. Phase identification, grain size and morphology, magnetic and microwave absorption properties of prepared samples were characterized. The absorption performances of samples were measured in the frequency range of 8-18 GHz. As a result, the compressed BFO powders and BFO/epoxy resin composites with 50-70 wt% BFO filler showed dual-band microwave absorption resonance behavior. The best performances were demonstrated by a 3 mm thick BFO70 composite sample which exhibited a primary reflection loss (RL 1) of −26.0 dB at 9.1 GHz and a secondary reflection loss (RL 2) of −40.5 dB at 11.3 GHz, along with an associated −10 dB bandwidth of 1.31 GHz. The minimum reflection loss (RL) peaks were shifted to a lower frequency as the thicknesses were increased due to the λ 4 condition. Theoretical studies on the absorbing wave mechanism reveal a unique combination of dielectric loss relaxations and antiferromagnetic resonance effects in the BFO absorbers.
International Journal on Advanced Science, Engineering and Information Technology, 2017
2 nd order pseudo-elliptic resonator topologies are presented in this paper. Based on the closed ... more 2 nd order pseudo-elliptic resonator topologies are presented in this paper. Based on the closed loop with coupled-line resonator, three 2 nd order bandpass filter topologies were built. Each of these topologies offered pseudo-elliptic bandpass response with high selectivity that is suitable for RF and wireless applications. The main advantage of these topologies is that the structures were built from a closed-loop with coupled-line resonator which is easy to control to obtain desired electrical responses. To demonstrate the proposed concepts, the resonators were realized using microstrip technology and all the measurement results showing good agreement with those from the simulations.
2010 IEEE Symposium on Industrial Electronics and Applications (ISIEA), 2010
... 129-133, 2001. [10] H. Adam, A. Ismail, MA Mahdi, MS Razalli, A. Alhawari and B. K. Esfeh, X... more ... 129-133, 2001. [10] H. Adam, A. Ismail, MA Mahdi, MS Razalli, A. Alhawari and B. K. Esfeh, X-band miniaturized wideband bandpass filter utilizing multilayered microstrip hairpin resonator, Progress in Electromagnetics Research, PIER 93, pp. 177-188, 2009. ...
2008 IEEE International RF and Microwave Conference, 2008
... Mohamad Huzaimy Jusoh, Norsuzila Ya'acob, Hasnida Saad, Ahmad As... more ... Mohamad Huzaimy Jusoh, Norsuzila Ya'acob, Hasnida Saad, Ahmad Asari Sulaiman, Noor Hasimah Baba, Robi'atun Adayiah Awang and Zuhani Ismail Khan ... Where N is the electron densityin el/m3, n denotes the refractive index, and f and fN represent radio wave and ...
Scientific Reports, 2020
Microwave absorption properties were systematically studied for double-layer carbon black/epoxy r... more Microwave absorption properties were systematically studied for double-layer carbon black/epoxy resin (CB) and Ni0.6Zn0.4Fe2O4/epoxy resin (F) nanocomposites in the frequency range of 8 to 18 GHz. The Ni0.6Zn0.4Fe2O4 nanoparticles were synthesized via high energy ball milling with subsequent sintering while carbon black was commercially purchased. The materials were later incorporated into epoxy resin to fabricate double-layer composite structures with total thicknesses of 2 and 3 mm. The CB1/F1, in which carbon black as matching and ferrite as absorbing layer with each thickness of 1 mm, showed the highest microwave absorption of more than 99.9%, with minimum reflection loss of −33.8 dB but with an absorption bandwidth of only 2.7 GHz. Double layer absorbers with F1/CB1(ferrite as matching and carbon black as absorbing layer with each thickness of 1 mm) structure showed the best microwave absorption performance in which more than 99% microwave energy were absorbed, with promising m...
2004 RF and Microwave Conference (IEEE Cat No 04EX924) RFM-04, 2004
Nano-, Bio-, Info-Tech Sensors, and 3D Systems II, 2018
Antennas made using rigid substrates are unsuitable in applications where space and surface confo... more Antennas made using rigid substrates are unsuitable in applications where space and surface conformability are a concern. This is a common issue for RFID, smart tags and wearable electronics applications which require conformability to the mounting structure, in addition to being weather-proof. Commercially available designs employ bendable substrates such as synthetic rubber, polymer, microfluids and plastics, but these materials are costly, at times difficult to manufacture, and offer limited electrical and mechanical properties. More importantly they are not environmental-friendly. On the other hand, natural rubber is abundant and easily produced. Being a natural product, they are weather-proof and environmental-friendly, the electrical properties are easily controlled and are stable at elevated frequencies. It is also one of the most flexible natural material available and yet can be designed to almost any shape. We report for the first time in this paper detailed characterization of RFID antennas based on natural rubber formulated with carbon black filler. Prototype patch and meander dipole antennas were simulated using CST Microwave Studio to operate at 921 MHz, using copper as the conductor and natural rubber as the substrate. Full characterization using scattering parameters and radiation patterns were carried out for flat and bent conditions. The prototypes offered performances comparable to existing designs which use synthetic materials, with maximum read range of about 1.8 m. Optimum processing conditions and the effects of material on the antenna performance are described here. The performance obtained is comparable to commercially-available designs, with added benefits offered by a natural material.
2015 IEEE International RF and Microwave Conference (RFM), 2015
2014 IEEE 2nd International Symposium on Telecommunication Technologies (ISTT), 2014
In this paper, we compare several calibration methods available for on-wafer microwave measuremen... more In this paper, we compare several calibration methods available for on-wafer microwave measurements conducted on transmission lines made of graphene. Multi-layered graphene films were grown on Si wafers coated with SiO2 and Ni using chemical vapor deposition. In order to facilitate high frequency characterization, and to replicate their function as radio frequency integrated circuits (RFIC) interconnects, the graphene films were constructed in the form of co-planar transmission lines using electron beam lithography. The transmission lines are in the form of co-planar waveguide (CPW) so that it they are compatible with the RF probes used to measure the properties of this material. In order to compare the accuracy, three on-wafer calibration techniques were considered, namely the popular Short-Open-Load-Thru (SOLT) method, and the new Line-Reflect-Match (LRM) and Thru-Reflect-Line (TRL) methods. This study aims to improve the accuracy of graphene measurement so that the behaviors of this material will be better understood.
2007 Asia-Pacific Conference on Applied Electromagnetics, 2007
This paper describes the 3D simulation and measurements of free space characterization for the co... more This paper describes the 3D simulation and measurements of free space characterization for the complex permittivity of p-type and n-type doped silicon wafers at K-Band. The component of this free space measurement system (FSMM) consists of Millitech series GOA Gaussian optics lens antennas, Vector Network Analyzer (VNA) and a high performance workstation. The antennas were modeled and simulated using Computer Simulation Technology (CST) software. The thru, reflect and line (TRL) calibration technique were used to eliminate the effect of undesirable multiple reflections. The simulation and measurement results are presented where good agreements are observed.