Energy Patterns of UWB Antenna Arrays With Scan Capability

A beam scanning technique is developed with a time delay for ultrawideband (UWB) arrays. In addition, we give a formulation for the time domain array factor for UWB antenna arrays. An UWB comb taper slot antenna array with large element spacing and impulse excitation is studied and four-element UWB linear array systems with element spacings of 2.5, 8.5, and 18 cm in the broadside direction and 20 degree scanning are implemented. The voltage response, spectrum response, energy pattern and energy gain for from simulation and measurement are in good agreement. The periodic grating lobes of the UWB antenna array do not occur in the energy pattern, even if the element spacing and scan angle are large. Simulation and measurement results for the energy pattern and voltage response in various directions are studied to validate the theory of an UWB antenna array with scan capability. The measured peak energy gain of arrays in the broadside direction and 20 degree beam scanning with element spacings of 8.5 and 18 cm are 10.79/10.78 dBi and 9.53/9.06 dBi, respectively.