Back-to-back F semicircular antenna with frequency and pattern reconfigurability

A BTBF (back-to-back F) semicircular antenna with frequency and pattern reconfigurablity is presented. The reconfigurable antenna consists of a centre-fed patch encircled by four identical radiation BTBF elements. By controlling four pin diodes, the reconfigurable antenna works in three states, and produces a corporate frequency band of 2.51-2.76 GHz within two states, and a band of 3.01-3.23 GHz. The three states achieve three different patterns. Moreover, the BTBF semicircular antenna is achieved by half-cutting a BTBF circular antenna. As the circular antenna is highly symmetric, half of this structure basically keeps the original radiation characteristics. This half-cut method shrinks the original size by half and simplifies the construction. It provides a compact, low-profile, low-cost and reconfigurable method for wireless communication application.