Widening Frequency Envelope of an Antenna-Amplifier System With Coupling Structure

Although large coupling is traditionally avoided in antenna arrays, we show that coupling might offer an advantage. We present a coupling circuit enabling the study of coupling effects in a dipole antenna system without modifying amplifiers or radiating structures. Our experiments demonstrate that controlled coupling can significantly increase, even by 36%, the operation frequency envelope of the radio system. The finding suggests that mutual coupling between elements of an array might be beneficial, provided that weighted element feeding can be used for active impedance and beam reconfiguration.