Vol. 139

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2023-11-19

Design of True Time Delay Line Based Octal Transmit Receive Module for Wideband Phased Arrays

By Kilari Sreenivasulu, Kamla Prasan Ray, Alagarswami Vengadarajan, and Dharmavarapu Srinivasa Rao
Progress In Electromagnetics Research C, Vol. 139, 1-10, 2024
doi:10.2528/PIERC23081802

Abstract

Wideband phased arrays for Electronic Warfare (EW) applications utilize narrowband phase shifters in a switched configuration to cover a multi-octave bandwidth in split bands. Wideband True Time Delay (TTD) line circuits are the best candidates to replace narrowband phase shifters in such systems, covering the complete operating bandwidth in a single step. The Transmit Receive Module (TRM) is a critical component of any phased array system. A novel design of a TTD line-based Octal Transmit Receive Module (OTRM) for a 32-element EW phased array over a frequency range of 1-6 GHz is presented in this paper. The OTRM is designed on a single multi-layer PCB by integrating eight transmit-receive (TR) channels, associated controllers, and power conditioning circuitry in a compact size and weight of 800 grams. The paper addresses challenges associated in design of TR channels to fit within the inter-element spacing of 14 mm and to achieve isolation of ≥40 dB between channels. The designed OTRM tunes time delay up to 508 ps maximum with a step of 2 ps by using a single TTD line circuit for ±45° scan coverage. The OTRM has demonstrated its potential capability for use in wideband Radar, EW, and Communication system applications. Efficient thermal management of the OTRM is achieved by introducing Copper coins below the final power amplifiers and a liquid cold plate to dissipate a heat load of 32 watts per TR channel. The proposed OTRM delivers transmit power of 8 watts (CW), receive gain of 25 dB, and a noise figure of 6 dB per TR channel with an overall efficiency of 19% (min) over a 5 GHz bandwidth. RF path analysis of the TR channel in transmit and receive paths is carried out using the Systemvue software tool. To verify the design of the OTRM over different time delay and attenuator states, measurements are conducted using a Vector Network Analyzer (VNA).

Citation


Kilari Sreenivasulu, Kamla Prasan Ray, Alagarswami Vengadarajan, and Dharmavarapu Srinivasa Rao, "Design of True Time Delay Line Based Octal Transmit Receive Module for Wideband Phased Arrays," Progress In Electromagnetics Research C, Vol. 139, 1-10, 2024.
doi:10.2528/PIERC23081802
http://test.jpier.org/PIERC/pier.php?paper=23081802

References