Mechanically-controlled, Wide-angle Scanning, Series-fed Antenna Array with Low Profile for High-Power Radar Systems

Christos Milias, Rasmus B. Andersen, Thomas H. Jorgensen, Bilal Muhammad, Jes T.B. Kristensen, Albena Mihosvka, Dan D.S. Hermansen, Pavlos I. Lazaridis, Zaharias D. Zaharis

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


This article presents the design and implementation of a mechanically controlled, series-fed antenna array featuring wide-angle beamsteering at the X-band. A theoretical model of a series-fed array, including phase shifters inserted between consecutive elements, is initially developed to derive design rules and gain insight into crucial performance tradeoffs. Subsequently, a mechanically controlled, reflection-type phase shifter consisting of a branch line coupler and two Pi-network reflective loads is presented. A movable metallic overlay tunes the impedance of the reflective loads, thus effectively modifying the output phase. While requiring a minimal linear displacement of only 0.06λ _0 , this topology provides a maximum phase shift of 300° with an average insertion loss of 1 dB and is exploited for synthesizing a series-fed patch array. Based on simulations and measurements, the proposed antenna offers an almost constant realized gain of about 15 dBi within a wide scanning range of ±50°, and the sidelobe level is better than -12 dB. The average total efficiency is 50%, and the cross-polarization levels are at least 11 dB below the maximum realized gain. The main weaknesses are the narrow bandwidth of 2.5% and the slight beam squint as the frequency varies. The proposed design is ideal for radars due to its excellent performance and high power-handling capability.

Original languageEnglish
Article number10151777
Pages (from-to)6454-6469
Number of pages16
JournalIEEE Transactions on Antennas and Propagation
Issue number8
Early online date13 Jun 2023
Publication statusPublished - 1 Aug 2023

Cite this