Serial‐fed linear frequency diverse arrays for obtaining direction of arrival (DOA) of frequency modulated continuous waveform (FMCW) sources with ambiguity reduction

Abstract

Possibility of exploiting serial‐fed linear arrays for obtaining the direction of arrival (DOA) of frequency modulated continuous waveform (FMCW) sources is discussed in this article. The angle of incident wave is assumed to be in the range, [−90°, 90°], with ambiguity reduction compared with the previous work. At first, the serial‐fed arrays are assumed as a transmitter with triangular FMCW sources, composing modified frequency diverse arrays. An explicit angle dependency is obtained on the separations between the maximums of the produced spatial power pattern in a design procedure. The approach is generalized for modified sawtooth frequency modulated continuous waveform (SFMCW) sources, which are combinations of two SFMCW sources with two different slopes of frequency shifts. In addition, a measurement setup is implied assuming the serial‐fed array as the receiver and an antenna with a known FMCW source and an unknown DOA as the transmitter. The DOA will be obtained from the separations between maxima of the received signals. Advantages of the proposed structure are the simplicity of antenna structure, ability of operation with narrowband antenna elements, and ambiguity reduction compared with the previous work.

Metrology and Measurement Systems

“…The non-contact harmonic detection of ferromagnetic materials defects is an electromagnetic NDT method based on the principle of FMCW [24]. Harmonic excitation signal combines the characteristics of lower and higher frequency electromagnetic wave which can improve the detection sensitivity and resolution and overcome the skin effect limitation.…”

Range‐angle beamforming with frequency diverse array radar using irregular superposed multicarrier approach for target indication

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Wideband linear microstrip array antenna with high efficiency and low side lobe level

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