Co-design of LTE/MMW Antenna in Mobile Phones with Switchable MMW Beams in the Display Direction Using Chassis Surface Waves

In this communication, co-design of LTE and MMW antennas with switchable MMW beams in the display direction for mobile phones is studied. The MMW antenna is composed of three monopoles, which is positioned at three distinct places on the chassis of a mobile phone. By selecting different monopoles and utilizing the chassis surface waves, three switchable MMW beams in the display direction are achieved with high gains. Also, three folded plates are employed to improve the MMW radiation performance in the display direction. To realize the co-design, the interdigital capacitor (IDC) structure is applied as the ground of the MMW antenna, which affects the LTE antenna slightly. For the LTE antenna, the measured band of -6 dB cover 700-962 MHz and 1637-2763 MHz. The measured efficiencies are higher than 45% and 53%, respectively. For the MMW antenna, the measured band of -10 dB cover 24.25-27.5 GHz. Within the band of 24.25-27.5 GHz, the measured peak gain reaches 11.3 dBi. A beam steering range of 80° (-40°-40°) is realized in the display direction, with a gain exceeding 9.8 dBi. The proposed antenna, using chassis surface waves, with switchable MMW beams in the display direction can be a potential candidate for LTE/MMW mobile phones.