DESIGN AND IMPLEMENTATION OF A PLANAR 4x4 BUTLER MATRIX IN SIW TECHNOLOGY FOR WIDE BAND HIGH POWER APPLICATIONS

Abstract

Abstract-This paper introduces a novel design of Butler matrix in substrate integrated waveguide (SIW) technology with wide frequency band characteristics. Butler matrices are particularly useful in advanced antenna design and characteristics such as wideband operation, power handling, manufacturing, integration, cost, etc. are typical issues to be addressed in many applications. The proposed planar 4 × 4 Butler matrix provides an interesting solution to most of these issues. Wideband operation is achieved thanks to improved cross-couplers. These components are also characterized by higher power handling when compared to E-plane couplers. The use of SIW technology enables to reduce insertion losses compared to other printed technologies, while maintaining most advantages of such technologies such as high integration, manufacturing simplicity, low weight, etc. The proposed design is fully described, from the elementary building blocks to the full assembly performances. The design is optimized for operation in Ku-band with a center frequency at 12.5 GHz. A prototype of the 4 × 4 Butler matrix is manufactured, and good performances are confirmed over 24% relative frequency bandwidth. Potential use of this sub-system in multibeam antenna design is also discussed.

DESIGN AND IMPLEMENTATION OF A COMPACT PLANAR 4 x 4 MICROSTRIP BUTLER MATRIX FOR WIDEBAND APPLICATION

“…As previously mentioned in the introduction, compared with the planar wideband Butler matrix in published literatures, this proposed Butler matrix is compact with good performances. Specifically, the performance in [4] is almost the same as that in this work while the size is about 8.64λ g ×8.76λ g , and [5] adopts fewer couplers which brings some problems when connecting to antennas and also occupies 2.49λ g × 2.49λ g . As a result, the performance is much worse.…”

“…One method is using multilayer technology, such as two-layer substrate integrated waveguide (SIW) [1], multilayer coplanar waveguide (CPW) [2] and stripline coupled line [3]. The other method is based on planar printed circuit technology such as SIW [4] and microstrip lines [5,6].…”

“…These Butler matrices own their superiorities in some aspects as well as some disadvantages in other aspects. For example, a SIW wideband Butler matrix which is proposed in [4] has low loss and can be fabricated easily, but the overall size is too large. In [5], disk hybrids are basically used as components of a Butler matrix, and half-wavelength open stubs are employed to generate phase differences among output ports.…”

“…In addition, the processing requirements are more rigorous than the single-layer planar circuits. In the study of planar wideband matrices, some researchers adopted SIW technology to design a Butler matrix for wideband applications [4], and some other researchers use disk hybrids [5] or wideband branch-line couplers [6] to compose wideband Butler matrices. These Butler matrices own their superiorities in some aspects as well as some disadvantages in other aspects.…”

A Substrate Integrated Waveguide Bandpass Filter Using Novel Defected Ground Structure Shape

“…Substrate integrated waveguide (SIW), early introduced by Wu et al, has attracted plenty of attention and utilized in different applications due to its merits of higher quality factor, easy integration, low cost, high power handling and mass production [1][2][3][4][5]. The half-mode substrate integrated waveguide (HMSIW) has been developed for microwave and millimeter wave applications [6,7].…”