An antenna arrangement comprises a patch conductor (102) supported substantially parallel to a ground plane (104). The patch conductor includes first (106) and second (108) connection points, and further incorporates a slot (202) between the first and second points. The antenna can be operated in a first mode when the second connection point is connected to ground and in a second mode when the second connection point is open circuit. By connection of a variable impedance (514), for example a variable inductor, between the second connection point and the ground plane, operation of the arrangement at frequencies between the operating frequencies of the first and second modes is enabled.