Abstract: Disclosed is a small, lightweight antenna having a relatively high gain, particularly suited for use with a portable radio device such as a bidirectional pager. In an exemplary embodiment, the antenna includes a loaded monopole radiator and a ground radiator. The loaded monopole radiator includes first and second conductors on a printed circuit substrate, where the first conductor has a given length oriented in a horizontal direction. The second conductor has a meander line shape and is oriented in a vertical direction. The ground radiator includes separately a first ground and a second ground at a lower portion of the printed circuit substrate, where the first and second grounds are symmetrical with respect to the second conductor.