Sprint AT&T T-Mobile Verizon Signal Booster Without External Antenna

Sprint, T-Mobile, Verizon Wireless and AT&T Wireless cell phone signal booster kits without external antenna make it possible to improve cellular reception in an apartment, condo, office building where outside antenna cannot be installed due to limited access to exterior of the structure. Browse building indoor phone booster kits as well as vehicle mobile amplifier kit that required no antenna on the top or roof of car, truck and RV. Window cell phone signal boosters work by capturing signal through a window using a directional window-mount antenna (also known as "donor" antenna), and amplifying it using the cellular amplifier base unit. Then the base unit broadcasts that signal wherever needed either through the built-in server antenna or separate interior server antenna(s).