An ultra-wideband 3 x 3 Butler matrix with unique Vivaldi array structure for high-range resolution radars


Karamzadeh S., Rafiei V., Kartal M.

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, vol.32, no.5, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 5
  • Publication Date: 2022
  • Doi Number: 10.1002/mmce.23086
  • Journal Name: INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: 3 x 3 Butler matrix, beam-steering, low isolation, multilayer array, Vivaldi antenna, wide coverage antenna, ANTENNA, COMPACT, DESIGN, COUPLERS, PHASE
  • Istanbul Technical University Affiliated: Yes

Abstract

Steerable antenna beam capability is an outstanding expectation for the development of automatic tracking systems and target detection. A switched beam array antenna, which can generate multiple fixed beams with enhanced sensitivity, emerges as a solution for beamforming tracking. On the other hand, it is known that the target can be detected with high-range resolution thanks to ultra-wideband (UWB) systems. In this work, a compact switched beam Vivaldi array antenna based on a Butler matrix for a UWB application capable of target detection with accurate target tracking is presented to meet the high gain and low side lobe level requirements. Based on a three-element antenna array, two methods have been applied to obtain small grating lobes and it has been shown that significant improvements can be achieved. Designed with a 3 x 3 UWB Butler matrix, the UWB array antenna can direct its beams in three directions in a direction range from -42 to 42 degrees. The measured result showed that the group delay was less than about 4.5 ns with variation of less than +/- 0.7 ns over the entire operating frequency band.