Design of a Partially-Corporate Feed Double-Layer Slotted Waveguide Array Antenna in 39 GHz Band and Fabrication by Diffusion Bonding of Laminated Thin Metal Plates

Miao ZHANG  Jiro HIROKAWA  Makoto ANDO  

Publication
IEICE TRANSACTIONS on Communications   Vol.E93-B   No.10   pp.2538-2544
Publication Date: 2010/10/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E93.B.2538
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Advanced Technologies in Antennas and Propagation in Conjunction with Main Topics of ISAP2009)
Category: Antennas
Keyword: 
double-layer,  slotted waveguide array,  partially-corporate feed,  diffusion bonding,  thin metal plate,  

Full Text: PDF(1.6MB)>>
Buy this Article




Summary: 
Introducing diffusion bonding of laminated thin metal plates to the fabrication of slotted waveguide arrays enlightens the high potential and the feasibility of multi-layer antennas with high-performance. It is a promising process with low cost even for a double-layer antenna, because the number of etching patterns for thin metal plates is only five. In this paper, a double-layer antenna for broadband characteristics is designed in 39 GHz band as demonstration. A 20 20-element antenna is composed of 2 2 sub-arrays by installing a partially-corporate feed circuit in the bottom layer underneath radiating waveguides in the top layer. The five-element sub-arrays in both the feeding and radiating parts are designed first. A new structure for the last slot coupler with shortened termination is also proposed to avoid an extra slot-free region when assembling the neighbor sub-arrays. As the simulation results by HFSS, the maximum gain of 34.55 dBi with the antenna efficiency of 85.5% is estimated at 38.5 GHz. The test antenna is fabricated by the diffusion bonding of thin copper plates. As the measurement results, a very high aperture efficiency of 83.2% with the directivity of 34.5 dBi is realized at the center frequency of 38.75 GHz, where the antenna gain of 34.4 dBi with the high antenna efficiency of 81.4% is achieved. The bandwidth of 5.0% defined as 1 dB down from the maximum gain is achieved.