Modulation and frequency response of GDDs in the millimeter wave/THz region

Alasgarzade, N.
Takan, T.
Uzun Kaymak, İlker Ümit
Altan, Hakan
New methods are being developed for efficient detection of terahertz waves. While many detection techniques show promise their commercial development is still limited due to the overall complexity and cost of the imaging system. Using commercially available neon indicator lamps the interaction mechanism between the glow plasma and the millimeter / THz wave is investigated in detail as a function of the device speed, sensitivity to frequency and polarization of the light. A lock-in amplifier was used to measure the response up to 90kHz when the GDD was placed at the focus of a 113GHz center frequency reconfigured Dielectric Resonating Oscillator (DRO) driven multiplied Schottky diode source. In addition the polarization sensitivity of the GDD was tested for two different scenarios whereby rotating the GDD the detected signal is observed to agree well with Malus's Law for one particular orientation. Furthermore, the frequency dependent GDD-THz interactions are investigated using a 240-380 GHz tunable continuous wave radiation source. Employing both systems allow us to understand the response of GDDs with respect to modulation frequency, RF frequency and polarization orientation. Resonance effects, frequency sensitivity and geometrical structures of GDDs are studied for the purpose of obtaining better performance in THz-GDD interaction for applications including general THz wave detection and imaging.


Understanding the Effect of THz/mm wave - Plasma Interaction on the Brightness of Glow Discharge Detectors
Kusoglu-Sarikaya, Cemre; Akbar, Demiral; Altan, Hakan (2019-01-01)
Today, the fact that non-ionizing THz and mm wave can be used in many areas reveals the necessity of devices that can efficiently detect these waves. Compared to existing commercial detectors, cost-effective neon indicator lamps acting as glow discharge detectors (GDDs) are known to be better in speed and responsivity. In GDDs, detection occurs as a result of the interaction between radiation and plasma. Although there are many studies in the literature trying to explain this interaction, these studies are ...
Utilization of neural networks for simulation of vehicle induced flow in tunnel systems
Koç, Gencer; Albayrak, Kahraman; Sert, Cüneyt; Department of Mechanical Engineering (2012)
Air velocities induced by underground vehicles in complex metro systems are obtained using artificial neural networks. Complex tunnel shaft-systems with any number of tunnels and shafts and with most of the practically possible geometries encountered in underground structures can be simulated with the proposed method. A single neural network, of type feed-forward back propagation, with a single hidden layer is trained for modelling a single tunnel segment. Train and tunnel parameters that have influence on ...
Numerical modeling and optimization of HgCdTe infrared photodetectors for thermal imaging
Koçer, Hasan; Beşikci, Cengiz; Department of Electrical and Electronics Engineering (2011)
This thesis presents a detailed investigation of the performance limiting factors of long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) p on n HgCdTe detectors through numerical simulations at 77 K incorporating all considerable generation-recombination mechanisms including trap assisted tunneling (TAT), Shockley-Read-Hall (SRH), Auger and radiative processes. Numerical simulations under dark and illuminated conditions were performed with different absorber layer thicknesses, material...
Implementation of direction finding with frequency diverse array
Turhaner, Arsen; Demir, Şimşek; Department of Electrical and Electronics Engineering (2017)
Frequency Diverse Array (FDA) is a recent concept with lots of advantages that are emerged for the radar applications. In order to implement FDA practically, Linear Frequency Modulation (LFM) based FDA is recently offered. A tunable oscillator with delay lines is enough for the implementation. This novel design caught up the gaps of the FDA for a cheap implementation. In order to implement radar, there should be lots of features in the signal processing as well as in the RF front-end. One of the important f...
Terahertz modulation using a bandpass filter combined with a Graphene Supercapacitor
Takan, Taylan; Nebioglu, Mehmet A.; Kakenov, Nurbek; Balci, Osman; KOCABAŞ, COŞKUN; Altan, Hakan (2015-09-22)
Graphene is proving to be an efficient medium for the control of mm-wave/THz radiation. Its electrical and dielectric properties allows it to be incorporated into various existing device architectures. One such application is in the modulation of the amplitude of the propagating THz radiation. Due to its electrical properties this interaction is typically broadband in nature. To make this frequency selective we propose the use of metamaterials or frequency selective surfaces. Generally, these structures per...
Citation Formats
N. Alasgarzade, T. Takan, İ. Ü. Uzun Kaymak, A. B. ŞAHİN, and H. Altan, “Modulation and frequency response of GDDs in the millimeter wave/THz region,” 2015, vol. 9651, Accessed: 00, 2020. [Online]. Available: