Half-Height-Pin Gap Waveguide Technology and Its Applications in High Gain Planar Array Antennas at Millimeter Wave Frequency

Jian YANG  Fangfang FAN  Parastoo TAGHIKHANI  Abbas VOSOOGH  

IEICE TRANSACTIONS on Communications   Vol.E101-B   No.2   pp.285-292
Publication Date: 2018/02/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2017ISI0002
Type of Manuscript: INVITED PAPER (Special Section on Recent Progress in Antennas and Propagation in Conjunction with Main Topics of ISAP2016)
gap waveguide,  half-height pins,  Q factor,  planar slot array,  60GHz band,  

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This paper presents a new form of gap waveguide technology - the half-height-pin gap waveguide. The gap waveguide technology is a new transmission line technology introduced recently, which makes use of the stopband of wave propagation created by a pair of parallel plates, one PEC (perfect electric conductor) and one PMC (perfect magnetic conductor), with an air gap in between less than a quarter of the wavelength at operation frequency. Applying this PEC/PMC gap plate structure to ridged waveguides, rectangular hollow waveguides and microstrip lines, we can have the ridged gap waveguides, groove gap waveguides and inverted gap waveguide microstrip lines, respectively, without requiring a conductive or galvanic contact between the upper PEC and the lower PMC plates. This contactless property of the gap waveguide technology relaxes significantly the manufacturing requirements for devices and antennas at millimeter wave frequencies. PMC material does not exist in nature, and an artificial PMC boundary can be made by such as periodic pin array with the pin length about a quarter wavelength. However, the quarter-wavelength pins, referred to as the full-height pins, are often too long for manufacturing. In order to overcome this difficulty, a new half-height-pin gap waveguide is introduced. The working principles and Q factors for the half-height-pin gap waveguides are described, analyzed and verified with measurements in this paper. It is concluded that half-height-pin gap waveguides have similar Q factors and operation bandwidth to the full-height-pin gap waveguides. As an example of the applications, a high gain planar array antenna at V band by using the half-height-pin gap waveguide has been designed and is presented in the paper with a good reflection coefficient and high aperture efficiency.