Development of modular and robust high power solid-state transmit–receive module for Gadanki Ionospheric Radar Interferometer

Abstract

The study of ionospheric effects1 on the satellite-based communication signals has been a continued topic of interest both for academic interest and global positioning system aided navigation applications. These communication signals are affected by the field-aligned irregularities, suffers from fading and range spreading when they pass through the ionosphere. 2 To study the low latitude ionospheric plasma irregularities, dedicated radar with wide beam steering capabilities is required. Recently Gadanki Ionospheric Radar Interferometer, which operates at 30 MHz frequency, has been realized at National Atmospheric Research Laboratory, Gadanki, to scan a larger part of the sky up to ±50° in East-West direction. The radar system employs a 160 element phased antenna array, antenna system, state-of-the-art 8 kW high power solid-state transmit–receive modules, and direct digital receiver. In order to carryout round-the-clock scientific observations, highly reliable, robust designs are required to realize the high power transmit–receive modules. Detailed design philosophies are described with modular concept and better thermal designs in this paper to achieve the high power requirements. Performance results of the transmit–receive module and the sample scientific results obtained by employing these transmit–receive modules are presented in this paper.