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A Green's function to describe the time behavior of the locking phases in a circular planar array of mutually coupled microwave oscillators is proposed. Using this Green's function the dynamic behavior of the array can be described for any arbitrary free running frequency of elements of the oscillator array. Beam steering is realized via detuning the edge oscillators of the array from a reference frequency and the beam direction is controlled by the amount of detuning for each oscillator at the edge. Some detuning functions such as sinusoidal, triangular and rectangular ones have been applied and, the resulting array patterns are compared with one another. V C 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE 21:383-391, 2011.

Based on the properties of surface wave modes in dielectric slab waveguides, it is shown that the cutoff frequencies of the surface wave modes can be obtained from the zeroes of the reflection coefficient at wavenumbers close to the light line. Afterwards, a surface wave periodic structure is analyzed by the method of excitation of eigenmodes. By considering the field distribution of the surface wave modes of the open waveguide structure, the unit cells are loaded by appropriate metamaterial resonators. The metamaterial resonators introduce a new surface wave mode propagating at frequencies below their resonant frequency while the eigenmodes of the guided structure are not strongly affected. This method can be employed to obtain an arbitrary frequency band for near-field imaging applications.

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Abstract-Double-sided open periodic structures are analyzed using inhomogeneous plane wave scattering. The leaky and surface wave modes of several unit cells of different structures are computed using the poles of generalized reflection and transmission coefficients of inhomogeneous plane waves in the spectral domain. It is shown that the reflection and transmission coefficients of the zeroth order Floquet mode contain the poles of the Green's function of the complex stratified periodic structure. The properties of evanescent mode amplification as well as super resolution near field imaging in a wire medium are addressed. A balanced leaky wave antenna unit cell with double-sided radiation feature is introduced and it is shown that, in contrast to grounded structures, total absorption in lossless nonchiral double-sided open unit cells is not feasible as long as the behavior of the unit cell is well described by its fundamental mode.