Abstract: We designed a coplanar waveguidefed 2.45 GHz flexible microstrip antenna. The threelayer human tissue model (skinfatmuscle) was constructed in the high frequency structure simulator (HFSS) software, the influence of human tissue on the key parameters of the antenna was analyzed, the structural parameters of the flexible antenna were optimized, and the sensing performance of the flexible microstrip antenna under bending condition was studied. The test results show that the return loss of the antenna is -26 dB at 2.40 GHz and the frequency band is 2 030—2 770 MHz. When the antenna is bent, the centre frequency is offset, which can be used to meature different radius of curvature in the bending state.

Key words: flexible antenna, wearable, bending sensing, polyimide