Try the MicroMag or DashMate antenna. I want an antenna that I can hide. The Mini Patch or Terk antenna is used by many of our customers that want to add an antenna but want to make it the least visible. You can connect most phones to an external antenna by using an installable hands free kit that comes with an external antenna adapter. You can also purchase an external antenna adapter that allows you to connect the antenna directly to your phone.
Some phones have an external antenna port.
Other phones require that you remove your fixed antenna and insert an external antenna adapter to that port. Still other phones have no way to connect an external antenna to it at all. One of the biggest obstructions to a strong signal is your head. Some people have had success with the RangeStar Clip On Antenna in 1900MHz digital areas and phones. Reception is poor inside my home or office.