A monolithic phased array using 3-bit distributed RF MEMS phase shifters

Topalli K., Civi O. A., Demir Ş., Koc S., Akın T.

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol.56, pp.270-277, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 56
  • Publication Date: 2008
  • Doi Number: 10.1109/tmtt.2007.914377
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.270-277
  • Keywords: microelectromechanical systems (MEMS), micromachining, microwave, phased array, phase shifter, BAND
  • Middle East Technical University Affiliated: Yes


This paper presents a novel electronically scanning phased-array antenna with 128 switches monolithically implemented using RF microelectromechanical systems (MEMS) technology. The structure, which is designed at 15 GHz, consists of four linearly placed microstrip patch antennas, 3-bit distributed RF MEMS low-loss phase shifters, and a corporate feed network. MEMS switches and high-Q metal-air-metal capacitors are employed as loading elements in the phase shifter. The system is fabricated monolithically using an in-house surface micromachining process on a glass substrate and occupies an area of 6 cm x 5 cm. The measurement results show that the phase shifter can provide nearly 20 degrees/50 degrees/95 degrees phase shifts and their combinations at the expense of 1.5-dB average insertion loss at 15 GHz for eight combinations. It is also shown by measurements that the main beam can be steered to required directions by suitable settings of the RF MEMS phase shifters.