An Iterative Technique for the Synthesis of Active Antenna Oscillator Arrays

A design procedure for the synthesis of a coupled active antenna oscillator array is presented. Such an array is synthesized by deriving two sets of parameters: the radiators' positions and the oscillators' outputs. The outputs are used to excite the radiators. Minimization of the mean square error between the desired pattern and the resulting one is made. Synthesis starts from an initial array, which is perturbed iteratively by varying simultaneously the element excitations and positions. In the iteration, the first variation of the cost function is set equal to zero. The final array results from the last iteration, where the stopping criteria are met. The procedure designs simultaneously both the antenna and the attached coupled oscillator array providing viable solutions. The second by properly configuring the tuning parameters through the use of closed-form formulas. The resulting arrays are shown to comply with the desired pattern and the nonlinear dynamics thus proving the validity of our method

Simple, zero-feedback, collaborative beamforming for emergency radio

Collaborative beamforming among a set of distributed terminals is studied, assuming a) no specialized RF hardware for carrier frequency synchronization, and b) zero feedback from destination (either in the form of pilot signals or explicit messages). A solution is provided for conventional radios in relevant critical applications, such as emergency radio. The proposed scheme simply exploits lack of synchronization among distributed carriers, operating at the same nominal carrier frequency. It is shown that such beamforming is possible and its performance is analytically quantified.Greece. General Secretariat of Research and Technolog