This paper presents a 16-slot continuous transverse stub (CTS) array antenna that can achieve high gain, high efficiency and lower transmission loss. The antenna can reduce losses and increase radiation efficiency by using series connection stubs. To improve the impedance matching and the directivity, the CTS unit is fed by a combination of a power divider and a radiator. The proposed antenna can exactly operate on dual-frequency. The designed CTS array antenna is simulated by HFSS. The simulated results show that S₁₁ is less than ?10 dB from 75 GHz to 80 GHz and from 85 GHz to 89 GHz. The peak gain reaches 28.6 dB at 78.8 GHz and 28.4 dB at 87.5 GHz. Antenna aperture efficiency is higher than 50% and the main beamwidth of antenna is about 4.4°.