Leaky-Wave Antennas as Metal Rims of Mobile Handset for mm-Wave Communications

In this communication, leaky-wave antennas (LWAs) at mm-wave bands are designed on the metal rims of the mobile handsets for mm-wave communications. Two different LWAs, constructed from the rectangular slits and the stepped slits, respectively, are designed at the same frequency band, with their main lobes pointing to different directions. Since the LWAs are narrow, two layers of LWAs can be accommodated along the height of the frame. Hence, the metal frames around the mobile chassis are built by twelve LWAs in total, with four LWAs along each longer edge and two LWAs along each shorter edge of the chassis. Unlike traditional mm-wave antennas in the mobile handset, phased array or feeding networks are not required for the proposed antenna system. The antenna covers a bandwidth from 26.8 to 28.3 GHz. Its coverage efficiency reaches 50% for the gain of above 5.4 dBi, which is better or at least comparable with the phased arrays in the handsets. Due to the distributed arrangement, the antenna system is robust to hand effects and real-life components integrated in the handset. In addition, the LWAs are codesigned with the sub-6 GHz antenna, which reutilizes the shorter frames as the radiator. The whole antenna system has been fabricated, with the measured results agreeing well with the simulated ones.