Shahrir Rizal Kasjoo
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Preferred name
Shahrir Rizal Kasjoo
Official Name
Shahrir Rizal, Kasjoo
Alternative Name
Kasjoo, S.
Kasjoo, Shahrir R.
Kasjoo, S. R.
Shah K.
Main Affiliation
Scopus Author ID
36809748400
Researcher ID
ABI-6061-2020

Research Output
Now showing 1 - 6 of 6
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Publication

Terahertz imaging using nanorectifier-based detectors and broadband thermal sources

2023-12 , Shahrir Rizal Kasjoo , Arun K. Singh , Claudio Balocco , Aimin Song

Several terahertz imaging experiments have been conducted at room temperature using a self-switching diode (SSD) rectenna as a detector, and a broadband thermal source (at 610 °C) as a continuous-wave terahertz generator. Since the terahertz emission produced by the source is non-coherent with random polarizations and has a wide-ranging spectrum, the SSD-based rectenna employed in this work utilizes a planar spiral micro- antenna which has a circular polarization that able to effectively capture all incident radiation regardless of the angles. The antenna has been designed for a broadband frequency response in the range of 0.1-10 THz. This is to ensure the terahertz images produced are ascribed to the terahertz radiation collected by the antenna, but without eliminating the possibility of thermal effects at frequencies higher than the terahertz region. In order to further validate the results obtained, an Airy pattern experiment has been conducted. Based on this experiment, the effective frequency response of the SSD rectenna is estimated at 2.29 THz. The utilization of thermal source and micro-size rectenna in this work may pave the way to explore many opportunities in developing flexible, compact, and low-cost terahertz imaging systems without the use of expensive components (e.g., typically lasers are used as terahertz sources).

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Simulation of InGaAs-based self-switching diodes as sub-terahertz rectifiers

2022-12 , Faradilla Aziz , Shahrir Rizal Kasjoo , Nor Farhani Zakaria , Fauzi Packeer , A.K. Singh

Abstract. A self-switching device (SSD) is a new device concept -which can be simply realized by forming insulating trenches into a semiconductor layer, using a single nanolithography process. SSDs can be utilized as rectifiers since the device's current-voltage (I-V) characteristic is comparable to that of a conventional diode. The simulation of two InGaAsbased SSDs with parallel connection using ATLAS device simulator for similar and different lengths of both SSDs (L1 and L2) is presented in this paper. The simulation results show that the InGaAs-based SSDs are able to operate up to sub-terahertz (THz) frequencies. As expected, lowering either L1 or L2 will not only increase the device’s cut-off frequency, fc, but also degrading the device’s rectification performance (i.e., reducing the value of curvature coefficient, γ). The highest cut-off frequency achieved in this work was 0.27 THz with γ ~18V-1 when L1 = 0.8 μm and L2 = 0.4 μm.

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Silicon Self-Switching Diode (SSD) as a Full-Wave Bridge Rectifier in 5G networks frequencies

2022 , Tan Yi Liang , Nor Farhani Zakaria , Shahrir Rizal Kasjoo , Safizan Shaari , Muammar Mohamad Isa , Arun Kumar Singh , Mohd Khairuddin Md Arshad

The rapid growth of wireless technology has improved the network’s technology from 4G to 5G, with sub-6 GHz being the centre of attention as the primary communication spectrum band. To effectively benefit this exclusive network, the improvement in the mm-wave detection of this range is crucial. In this work, a silicon self-switching device (SSD) based full-wave bridge rectifier was proposed as a candidate for a usable RF-DC converter in this frequency range. SSD has a similar operation to a conventional pn junction diode, but with advantages in fabrication simplicity where it does not require doping and junctions. The optimized structure of the SSD was cascaded and arranged to create a functional full-wave bridge rectifier with a quadratic relationship between the input voltage and outputs current. AC transient analysis and theoretical calculation performed on the full-wave rectifier shows an estimated cut-off frequency at ~12 GHz, with calculated responsivity and noise equivalent power of 1956.72 V/W and 2.3753 pW/Hz1/2, respectively. These results show the capability of silicon SSD to function as a full-wave bridge rectifier and is a potential candidate for RF-DC conversion in the targeted 5G frequency band and can be exploited for future energy harvesting application.

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Noise properties of unipolar nanodiodes at elevated temperatures

2021-12 , Shahrir Rizal Kasjoo , Arun K. Singh , Claudio Balocco , Aimin Song

A unipolar nanodiode known as the self-switching diode has been demonstrated as a room-temperature terahertz detector, with its noise-equivalent-power value comparable to those of the state-of-the-art Schottky diodes. Here, we study its performance at elevated temperatures and show an unusual reduction in low-frequency noise, which may be useful for practical applications. The experiments suggest that the increased thermionic emissions result in the reduced device resistance and hence the lowered noise. The observed noise behavior appears to be in good agreement with Hooge’s mobility fluctuation theory.

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Simulation and characterization of an inverter logic gate by utilizing InGaAs-based planar devices

2023-12 , Faradilla Aziz , Shahrir Rizal Kasjoo , Nor Farhani Zakaria , Fauzi Packeer , A. K. Singh

Electronic circuits known as logic gates can perform basic logical operations like inverters, AND, and OR gates. These logic gates serve as the basis for digital electronics, and they are a common component in various electronic devices, such as computers, smartphones, and other types of digital systems. This research presents an inverter logic gate made of planar devices, which have significantly simpler structures than multi-layered transistors and diodes, namely the self-switching diode (SSD) and side-gated transistor (SGT). The inverter logic gate is realized by simply connecting both SSD and SGT in parallel. The electrical characteristics and performances of the inverter logic gate are assessed based on InGaAs material using SILVACO Inc.'s ATLAS device simulator software. The simulation results show that the functionality of the proposed planar inverter is comparable to that of a conventional inverter logic gate based on the standard truth table of the device. This has demonstrated the feasibility of building logic gates using a combination of SSDs and SGTs. In addition, the planar structure of SSD and SGT allows for a relatively low-cost device fabrication process as well as offering a high-frequency operation due to low parasitic elements in the devices.

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Hybrid statistical and numerical analysis in structural optimization of silicon-based RF detector in 5G network

2022-01-21 , Tan Yi Liang , Nor Farhani Zakaria , Shahrir Rizal Kasjoo , Safizan Shaari , Muammar Mohamad Isa , Mohd Khairuddin Md Arshad , Arun Kumar Singh , Sharizal Ahmad Sobri

In this study, a hybrid statistical analysis (Taguchi method supported by analysis of variance (ANOVA) and regression analysis) and numerical analysis (utilizing a Silvaco device simulator) was implemented to optimize the structural parameters of silicon-on-insulator (SOI)-based self-switching diodes (SSDs) to achieve a high responsivity value as a radio frequency (RF) detector. Statistical calculation was applied to study the relationship between the control factors and the output performance of an RF detector in terms of the peak curvature coefficient value and its corresponding bias voltage. Subsequently, a series of numerical simulations were performed based on Taguchi’s experimental design. The optimization results indicated an optimized curvature coefficient and voltage peak of 26.4260 V−1 and 0.05 V, respectively. The alternating current transient analysis from 3 to 10 GHz showed the highest mean current at 5 GHz and a cut-off frequency of approximately 6.50 GHz, indicating a prominent ability to function as an RF detector at 5G related frequencies.

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