Wideband multi-beam forming method using delayed array sensors and two-dimensional digital filter

• Published in: Electronics & communications in Japan. Part 3, Fundamental electronic science Vol. 88; no. 12; pp. 1 - 12
• Main Author: Nishikawa, Kiyoshi
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.12.2005
• Subjects: array sensor; beam forming; fan filter; multi-beam; two-dimensional spectrum
• ISSN: 1042-0967; 1520-6440
• DOI: 10.1002/ecjc.20175

In this paper, a method is proposed for multi‐beam forming of wideband signals by means of delay processors and two‐dimensional fan filters. Only one axially symmetric two‐dimensional fan filter is used. Multi‐beam forming is carried out by multiplexing the delay processors for two‐dimensional signals for each beam direction. The delay processing here corresponds to a rotation of the two‐dimensional spectra in the two‐dimensional frequency domain and provides a delay proportional to the sensor location to each sensor output. Since each delay is a fractional delay, a method of digital signal processing based on high‐speed sampling and thinning is used for realization. A design method for multi‐beam forming is given and a study of expanding the receiving angle range is carried out. It is shown that excellent multi‐beam forming is possible if the method is used within an appropriate receiving signal range, although the beam width is slightly different depending on the beam direction. Finally, a difference of the method from multi‐beam forming by the use of several two‐dimensional fan filters is discussed. The positioning of this method and its effectiveness are clarified. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(12): 1–12, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20175