Design of COCO Antenna with Bandpass Filter Based on Micro-Coaxial Structure

In order to achieve the further integration of RF terminals, a design scheme of coaxial colinear (COCO) antenna with bandpass filter based on micro-coaxial structure is proposed. For the COCO antenna, the simulated
$\vert S_{11}\vert$
parameter is below -15dB in the frequency range of 28.65-29.75GHz, the maximum omnidirectional gain on the H plane can reach 6.82dBi, and the out of roundness is less than 0.49dB. For the filter, the
$\vert S_{11}\vert$
parameter is below -10dB in the frequency range of 28.3-33.6GHz, the insertion loss is less than 0.5dB, and the 30dB rectangular coefficient is 2.38. When the two parts are connected, the
$\vert S_{11}\vert$
parameter of the filtering antenna is less than -10dB in the frequency range of 29.2-30.5GHz, and the maximum omnidirectional gain on the H plane is 7.44dB. The size of the filter antenna is only
$59 \text{mm} \times 6.3 \text{mm} \times 0.7 \text{mm}$
, using wafer level micro coaxial processing technology. The designed filtering antenna has the characteristics of ultra miniaturization, lightweight and high integration, and can be used in the integrated circuit of various small electronic communication equipment.