W-Band Modular Antenna/Detector Array for the Electron Cyclotron Emission Imaging System in KSTAR

Abstract

A design of a modular antenna/detector array for the electron cyclotron emission (ECE) imaging system at the Korea Superconducting Tokamak Advanced Research (KSTAR) is proposed. The modular antenna/detector array is based on a unit antenna/detector module, which consists of an elliptical mini-lens, a dual-dipole antenna, an antenna balun, a low-noise amplifier, and a metal frame. The proposed modular antenna/detector array resolves the problem in the conventional antenna/detector array where one faulty channel requires the entire array to be removed for the service. With the proposed modular array, each channel module can be easily and independently removed and replaced without interference to the rest of the array, thus minimizing the interrupted service time for maintenance. Moreover, the unit channel modules can be efficiently updated under a variety of the tokamak operation conditions. The antenna/detector modules are optimized to have improved performance, and are tested in a W-band test setup, and consistently provide the gain increase by 10~20 dB as compared with the conventional antenna/detector array. A set of the proposed modular antenna/detector array is currently installed and tested in the KSTAR ECE imaging system, and will consistently produce the improved ECE imaging to monitor MHD instability activities under various plasma operation conditions.

Line integrated density measurements on the Versatile Experiment Spherical Torus (VEST) using frequency sweep interferometer

“…This demonstrates that FSI can be used as a complementary diagnostic useful for If the main reason for the IF amplitude reduction is the beam displacements due to refraction, the magnitude of displacement can be estimated from the magnitude of the signal reduction. The detector module of the 94 GHz interferometer is developed based on the integrated lens antenna (ILA) [35] installed in the KSTAR electron cyclotron emission imaging system. The ILA sensitivity is investigated against the incident beam angle and the measured radiation pattern is represented in figure 13(a).…”

A Simplified Radiation Characteristic Analysis Method for Defocus-Fed Parabolic Antennas in a W-Band Communication System

“…The subsequent studies serve as examples of W-band high-gain radiation characteristics. A modular array antenna for an electron cyclotron emission imaging system [5], a substrate-integrated waveguide (SIW) for microwave power transmission (MPT) and wireless communications [6], and a folded Fresnel reflector (FFR) for a helicopter collision avoidance radar and a microstrip patch array antenna fed by SIW for an operating range from 91 GHz to 97 GHz [7] were all previously designed and studied. The mentioned antennas use dielectrics.…”