Kęstutis Ikamas

Kęstutis Ikamas
Vilnius University · Applied electrodynamic and telecommunication institute

MSc

About

30
Publications
2,354
Reads
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220
Citations
Introduction
Kęstutis Ikamas currently works at the Institute of Applied Electrodynamics and Telecommunications, Vilnius University. Kęstutis does research in Electronic Engineering and Semiconductor Physics. Their current project is 'Field-effect-transistor THz detector'.

Publications

Publications (30)
Article
Full-text available
The spread of practical terahertz (THz) systems dedicated to the telecommunication, pharmacy, civil security, or medical markets requires the use of mainstream semiconductor technologies, such as complementary metal-oxide-semiconductor (CMOS) lines. In this paper, we discuss the operation of a CMOS-based free space all-electronic system operating n...
Article
Full-text available
This paper presents an overview of the different methods used for sensitivity (i.e., responsivity and noise equivalent power) determination of state-of-the-art field-effect transistor-based THz detectors/sensors. We point out that the reported result may depend very much on the method used to determine the effective area of the sensor, often leadin...
Article
We report the successful implementation of antenna-coupled terahertz field-effect transistors (TeraFETs) as homodyne detectors in a scattering-type scanning near-field optical microscope (s-SNOM) operating with radiation at 246.5 GHz. The devices were fabricated in Si CMOS foundry technology with two different technologies, a 90 nm process, which p...
Article
Full-text available
Over the last two decades, photomixer-based continuous wave systems developed into versatile and practical tools for terahertz (THz) spectroscopy. The high responsivity to the THz field amplitude of photomixer-based systems is predetermined by the homodyne detection principle that allows the system to have high sensitivity. Here, we show that the a...
Conference Paper
Full-text available
In this paper we report the terahertz detection by field-effect transistors in 65-nm CMOS technology with on-chip integrated patch antennas. In conjunction with continuous wave photomixer source, detectors demonstrate > 40 dB signal-to-noise ratio and minimal NEP of 12 pW/√Hz at 1 kHz of chopping at the resonant frequency of 620 GHz. This NEP value...
Article
Full-text available
This work presents, to our knowledge, the first completely passive imaging with human-body-emitted radiation in the lower THz frequency range using a broadband uncooled detector. The sensor consists of a Si CMOS field-effect transistor with an integrated log-spiral THz antenna. This THz sensor was measured to exhibit a rather flat responsivity over...
Conference Paper
We use a THz dual-comb optical source to perform high-speed hyperspectral imaging in the 300 GHz range with high sensitivity field-effect transistor-based THz detectors. First hyperspectral imaging results of different samples are shown using a scanning system, demonstrating the localization of interesting spectral features in the specimens.
Article
Many emerging applications in the terahertz (THz) frequency range demand highly sensitive, broadband detectors for room-temperature operation. Field-effect transistors with integrated antennas for terahertz detection (TeraFETs) have proven to meet these requirements, at the same time offering great potential for scalability, high-speed operation an...
Article
Full-text available
In the above paper [1] , the footnote acknowledges financial support received from the Research Council of Lithuania with wrong project number. The statement “This work was supported by the Research Council of Lithuania under contract TAP LZ-06/2015, …” should be read as “This work was supported by the Research Council of Lithuania under contract...
Article
We report on circuit simulation, modeling and characterization of field-effect transistor-based terahertz (THz) detectors (TeraFETs) with integrated patch antennas for discrete frequencies from 1.3 THz to 5.7 THz. The devices have been fabricated using a standard 90 nm CMOS technology. Here, we focus in particular on a device showing the highest se...
Article
Full-text available
We demonstrate that the rectifying field effect transistor, biased to the subthreshold regime, in a large signal regime exhibits a super-linear response to the incident terahertz (THz) power. This phenomenon can be exploited in a variety of experiments which exploit a nonlinear response, such as nonlinear autocorrelation measurements, for direct as...
Article
Many THz applications require detection of sub-picosecond THz pulses. Electronic detectors, in particular, can address this challenge. We report on the detection of sub-picosecond THz pulses generated by a large-area interdigitated photoconductive antenna using a AlGaN/GaN high electron mobility transistor with integrated bow-tie antenna. We demons...
Article
We present broadband high sensitivity THz detectors based on 90 nm CMOS technology with state-of-the-art performance. The devices are based on bow-tie and log-spiral antennacoupled field-effect transistors (FETs) for the detection of freespace terahertz (THz) radiation (TeraFETs). We report on optimized performance, which was achieved by employing...
Article
We propose to exploit rectification in field-effect transistors as an electrically controllable higher-order nonlinear phenomenon for the convenient monitoring of the temporal characteristics of THz pulses, for example, by autocorrelation measurements. This option arises because of the existence of a gate-bias-controlled super-linear response at su...
Article
Full-text available
In this paper, we report on efficient detection of the radiation emitted by a THz quantum cascade laser (QCL) using an antenna-coupled field effect transistor (TeraFET). In the limiting case when all radiated power would be collected, the investigated TeraFET can show up to 230 V/W responsivity with the noise equivalent power being as low as 85 pW/...
Conference Paper
Here we discuss on detection using antenna-coupled field effect transistors. We show, that gate-to-channel separation plays strong role for the dispersion of plasmons excited within the channel changing from gated 2D to ungated 2D plasmon. This change also strongly affects the impedance and the efficiency of rectification. We present experimental d...

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Projects

Projects (3)
Project
This project aims to prepare the first Lithuanian cyber competence map together with recommendations on how to attract specialists to the Cybersecurity (CS) sector and how to advance their competencies. During the project, we will explore the demand for CS specialists in Lithuania and the world, survey the opinions of CS professionals, management and specialists from private and public sector organizations, including national defence sector. Also, we will determine the career path of the specialists, analyze job offers, distinguish work roles, and gather findings and recommendations from scientific research papers and similar reports of other countries. The results of the project will include a publicly available database of collected data, expert findings of the research and recommendations for stakeholders, and a submitted scientific article to promote the results.
Archived project
The aim of this project is to investigate and design plasmonic THz detectors and apply them for high resolution THz camera.