K-band Wideband Miniaturized Six-port Junction Designed for Millimeter Wave Application

This paper designs a K-band six-port receiving circuit for millimeter wave application. The six-port circuit is cascaded by a Wilkinson power splitter and three orthogonal circular slot couplers. This architecture ensures the phase consistency of the six-port junction, and at the same time, the ground planes of the two output ports at the bottom of the power splitter are opened with annular slots to improve the return loss of the input ports. The working frequency band of the six-port junction is 20.65~27.6 GHz, and the relative bandwidth is 29.2%. The isolation of the two input ports of the six-port junction is lower than -15dB in the whole working frequency band, and the maximum isolation is -37.3dB. For the traditional six-port circuit, the port circuit designed in this article is small in size, has high input port isolation and is easy to integrate with planar circuits, and can be well applied in the millimeter wave application.