Mechanically Reconfigurable, Dual-Band Slot Dipole Antennas

Mechanically reconfigurable dual-band slot dipole antennas with wide tuning ranges are developed in this communication. The dual-band operation is achieved by inserting parallel slots with different lengths and the tuning is realized by incorporating a dual rack and pinion mechanism to slide parasitic patches to vary the slot lengths and the frequency of operation of each band. To demonstrate the proposed approach, two frequency-tunable antennas are prototyped. The first design uses two motors to tune the frequency band ratio between 1 and 2.6. The second design uses one motor to maintain a constant frequency band ratio of 2 over the tuning range of 2-3 GHz for the lower band and 4-6 GHz for the upper band. Both designs show minimal variation in gain, polarization, and radiation pattern over the tuning range.