Amazon.com: Lintratek 70dB Cell Phone Signal Booster for House CDMA 850MHz PCS 1900MHz Dual Band Mobile Signal Amplifier Repeater Directional Antenna - Boost 3G 4G Voice & Data : Cell Phones &
pcb design - Ground plane for a GSM spring antenna with 4 layer PCB - Electrical Engineering Stack Exchange
Build Your Own Antenna: Double BiQuad sector antenna for PCS 1900 MHz / 3G / HSUPA / HSDPA / HSPA+ / LTE / 4G