Basic RF Characteristics of Fishbone‐Type Transmission Line Employing Comb‐Type Ground Plane (FTLCGP) on PES Substrate for Use in Flexible Passive Circuits

In this work, a fishbone‐type transmission line employing a comb‐type ground plane (FTLCGP) was fabricated on polyethersulfone (PES) substrate, and its RF characteristics were thoroughly investigated. According to the results, it was found that the FTLCGP on PES showed periodic capacitance values much higher than other types of transmission lines due to a coupling capacitance between the signal line and ground, which resulted in a reduction of wavelength and line width. Using the theoretical analysis, we also extracted the bandwidth characteristic of the FTLCGP on PES. According to the result, the FTLCGP structure showed a cut‐off frequency of 280 GHz.