The frequencies of next generation mmWave wireless communication and WiGig standard focus at 28, 38, and 60 GHz in recent researches. This technique successfully developed a miniaturized triband antenna, satisfying mmWave 5G and WiGig standards simultaneously. This antenna possesses small size and moderate antenna gain. It is suitable for multiband operating mobile devices and wearable devices.

How to design a multiband high gain antenna within limited area for mobile and wearable devices is a great challenge. This technique, based on quasi-yagi type antenna, multifunctional arms, and spiral directors, successfully developed a miniaturized triband antenna, satisfying mmWave 5G and WiGig standards simultaneously. This antenna possesses small size and moderate antenna gain (higher than 6 dBi). The antenna consists of three resonant arms and six spiral-type directors. In order to meet the need of 28/38/60 GHz band, this tri-band antenna based on quasi-Yagi antenna with three arms and bended structures. The arms dominate the impedance matching and the radiation performance. Each arm has multiple functions, the resonator arm for lower frequencies can be a reflector for higher frequencies, enhancing the radiation gain within limited area. In addition, the bended structures provide another resonance to satisfy the 57-71 GHz frequency band, and also gain better radiation performance as directors simultaneously. The triangles in the end of ground and the open stub on the common path are exploited to increase antenna bandwidth without increasing the overall antenna size. On the other hand, the spiral-type directors enhance the antenna gain and adjust the imaginary part of the input impedance for bandwidth requirements. The proposed antenna covers major bands of 5G (27.5 – 28.35, 37 – 40 and 64 – 71 GHz) and WiGig (57 – 71 GHz). The impedance matching bandwidth are 26.9 %, 13.5 %, and 33 %. The measured peak gains of the proposed antenna are 6.2, 7.56 and 9.42 dBi corresponding to 28, 38 and 60 GHz, respectively even with a small size of the antenna 5 × 8 × 0.203 mm3. It is suitable for multiband operating device. This prototype antenna has contribute to the developments of compact wireless communication module, utilizing in the future mmWave multiband compact mobile devices and wearable devices.

28、38與60 GHz目前鎖定的應用情境不盡相同，微小化毫米波三頻天線將有助於多頻行動裝置與穿戴裝置的開發與實現，應用於未來毫米波5G與WiGig的裝置中。