Theoretical Modeling of a Photoconductive Antenna in a Terahertz Pulsed System

Abstract

Figure 7 depicts the optical-to-THz conversion efficiency versus the average optical power for various temperatures.This figure illustrates that at the same average optical power, the higher temperature leads to the lower optical-to-THz conversion efficiency. It is also observed that there is a good agreement between the analytical results from the proposed model and the measurement results [15]. CONCLUSIONIn this article, we investigated the temperature dependance of a THz photoconductive antenna based on an equivalent circuit model, we studied the effect of temperature on various parameters of a THz photoconductive antenna such as excited THz photocurrent at the antenna gap, radiated electromagnetic field and optical-to-THz power conversion efficiency. It was shown that an increase in the temperature leads to a decreases in the THz photocurrent at the antenna gap, THz radiated field and also optical-to-THz power conversion efficiency. It was also shown that the obtained results from the modified proposed equivalent circuit model are consistent with measurement results. ABSTRACT: Nowadays, the space target characteristics of terahertz steps into a crucial stage, and the research in radar cross-section (RCS) of large calibration objects is the foundation of it. This article gives the simulation and the tests of six conducting spheres of different surface characteristics. And the testing results show the variation of RCS calibrator.

Use of Terahertz Photoconductive Sources to Characterize Tunable Graphene RF Plasmonic Antennas

“…Based on this fundamental principles and under the assumption that the momentum relaxation time τ s is small, Khiabani et al 22 developed an equivalent circuit model using lumped elements that provides accurate estimates -in agreement with published experimental data-taking into account the underlying physical behavior. With this model, the time-dependent voltage at the antenna terminals V can be expressed as:…”

“…where Z a is the impedance of the graphene antenna (assumed as independent of the frequency), V c is the voltage at the antenna gap (derived from its equivalent circuit 22 ) and β is the active area in the semiconductor through which the photocurrent flows. …”

Accurate calculation of excited photocurrent in terahertz photoconductive antennas by using energy balance transport model

“…This structure reduces the drift time because it decreases the length through which the carriers travel. It also enhances the peak of photocurrent since more carriers will reach to the electrodes [8]. In Fig.…”

Broadband THz generation using Interdigitated Photoconductive antennas with a 15 fs, high power oscillator

“…Among the variety of THz sources, photoconductive antennas have been very promising in regards to the generation of picosecond THz pulses using ultrafast, Ti:Sapphire oscillator systems. Here, the ease-of-use and practicality of such systems, combined with high SNR have driven applications in THz spectroscopy, imaging and detection [1].The development of new antenna geometries and system designs continues to be an active area of research to combine or enhance favourable properties like large spectral bandwidths and/or high THz fields with the practicality and high SNR of photoconductive antennas [2]. In particular, the interdigitated antenna structure ( Fig.…”

“…The development of new antenna geometries and system designs continues to be an active area of research to combine or enhance favourable properties like large spectral bandwidths and/or high THz fields with the practicality and high SNR of photoconductive antennas [2]. In particular, the interdigitated antenna structure ( Fig.…”