A low-cost closed-loop antenna tuner module for mobile phone single-feed multi-band antennas

Mobile phones operate in many frequency bands, while antenna volume is restricted. In addition, effects of user interaction can change matching between antenna and front-end module drastically. We show a multi-band multi-mode Antenna Tuner Module (ATM) that improves antenna matching automatically. It measures 4 × 4 × 1 mm³ and requires only DC, synchronization inputs by MIPI or GPIO, and a self-learning calibration process. The ATM covers a very broad frequency range of 600 to 2700 MHz and has an insertion loss less than 0.6 dB for a 50 Ω load. The ATM fulfills all challenging requirements for placement in a mobile phone antenna system, such as low distortion products under mismatch conditions, high ruggedness (+34 dBm at a load VSWR circle of 12:1) and an ESD contact discharge level of 8 kV.