Study on 220GHz On-chip Transmission Structures with GaAs Process

220GHz transmission structures for GaAs process are designed, which include suspended microstrip line, transition structures and low-pass filter. The paper makes a detailed theoretical analysis for design. Simulated results show that the cut-off frequency of 180$\mu$m-width microstrip line is 250GHz, the transmission loss in input and output transition structures are less than 1dB, low-pass filter’s transmission coefficient is less than −30dB for 200GHz~240GHz harmonic. Simulated results indicate all transmission structures have realized its function completely. It has great reference significance for terahertz monolithic integrated chip design.