In this letter, a new hybrid technique to synthesize sparse linear arrays is proposed. This technique is based on the combination of two methods. As a first method, a deterministic synthesis algorithm is used to resolve the nonuniform amplitude excitations and the antenna element locations. Then, the second method is an iterative optimization scheme that computes the phase of the excitation currents. This approach is proven valid to properly match diverse beam patterns (narrow-beam, flat-top, and square-cosecant) with sparse linear arrays. Three numerical experiments are reported that show the performance of the proposed technique and compare it to other outstanding methods available in the literature.

This research paper deals with a innovative way to simplify the design of beam-forming networks (BFNs) for multibeam steerable antenna arrays based on coherently radiating periodic structures (CORPS) technology using the noniterative matrix pencil method (MPM). This design approach is based on the application of the MPM to linear arrays fed by CORPS-BFN configurations to further reduce the complexity of the beam-forming network. Two 2-beam design configurations of CORPS-BFN for a steerable linear array are analyzed and compared using this compressive method. Simulation results show the effectiveness and advantages of applying the MPM on BFNs based on CORPS exploiting the nonuniformity of the antenna elements. Furthermore, final results show that the integration of CORPS-BFN and MPM reduces the entire antenna system including the antenna array and the beam-forming network subsystem resulting in a substantial simplification in such systems.

With the arrival of 5G wireless communication systems, there has been increased interest in exploring higher frequency bands above 6 GHz, up to millimeter-wave frequencies. Radio wave propagation at these higher frequencies can suffer from substantial Doppler impairments. The linear dependency of Doppler shifts with carrier frequencies make them challenging to use in high-mobility 5G cellular scenarios. Therefore, the Doppler power spectrum (DPS) characteristics and radio channel coherence time (CT) of the received signals are of great importance for 5G wireless systems. In this way, this paper presents the effects of a narrow beam phased antenna array in reducing the DPS (due to user movement) and, simultaneously, increasing the coherence time (CT). Functional and complete descriptive assessments of beamwidths versus the DPS and CT, through different elements and geometries of the phased antenna array, are analyzed. Moreover, in terms of CT and the DPS, better performance on the 5G cellular scenarios was obtained.

In the above paper (ibid., vol. 61, no. 1, pp. 449-453, Jan. 2013), the mathematical formulation has an improper representation. Corrections are presented here.