No abstract

Acquisition of ultra-wideband signals by array antennas requires frequency-invariant radiation characteristics over the bandwidth of the signal in order to minimize distortions. In this study, a new synthesis technique of array antennas for radiating nanosecond pulse signals is presented. In this technique, all frequency-dependent radiation characteristics of the antenna array are considered and compensated through the utilization of frequency adaptive element excitations and the implementation of a complex array factor. Simulation results are presented for an equally-spaced linear array of wire dipoles designed based on the proposed method as an example to demonstrate the synthesis approach.

A novel perturbing methodology using asymmetrical defected ground structure (DGS) is proposed for a circularly polarized Figure 10 Measured and simulated VSWR for the modified antenna design of Figure 7(b). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com]

No abstract

A comprehensive synthesis method for ultra-wideband arrays, taking into consideration array total pattern, phase of the total radiated field, element field, element input impedance, and inter-element mutual coupling, is presented. Using the proposed method, we can achieve a desired total radiation pattern, while compensating for frequency variations of the element radiation characteristics and the inter-element mutual coupling.