A Shared Aperture Antenna for LTE/MMW Mobile Phones With Strengthened MMW Dual-Polarized Radiation in the Front-Side Direction

This letter exploits a shared aperture antenna for Long-Term Evolution (LTE) and millimeter-wave (MMW) mobile phones with strengthened MMW dual-polarized (DP) radiation in the front-side direction (vertical to the display panel). The MMW antenna, which is a 1$\ \times $ 4 DP slot array, is integrated into the clearance area of the LTE antenna by using distributed capacitors. The DP slot array suits for the mobile phone with a minimal-sized notch. To realize the MMW DP radiation, the orthogonal feedings are applied. Two sets of floating reflectors are deployed to improve the MMW DP radiation in the front-side direction. A prototype is manufactured and measured to validate the design. For the LTE antenna, the measured −6 dB bandwidths cover the frequency band of 700 MHz to 1000 MHz and 1675 MHz to 2763 MHz. For the MMW DP array, the measured −8.5 dB bandwidths for vertical polarization (VP) and horizontal polarization (HP) cover the frequency band of 25.5 GHz to 27.5 GHz. In the front-side direction, the measured maximum realized gains are 8.6 dBi for VP and 7 dBi for HP at 26.5 GHz. The measured 3 dB beam steering range reaches ±40° for VP and ±30° for HP.