If you are like many recently licensed Amateur Radio operators your first purchase may well be a good Icom, Kenwood, Yaesu or other brand Handy-Talkie or HT two way radio. These are most frequently for the 2 meter and 70 centi-meter bands (144 and 440 MHz).
The antenna that comes with your radio is probably about 8 inches long and is a compromise between convenient length and performance.