Fig. 1. Coordinate definition for the calculation of electromagnetic field distribution.
Fig. 2. Arbitrary time delay feeding system employing tunable filters and chirped fiber grating; EOM: electro-optic modulator; PD: photodiode.
Fig. 3. Controllable area of the phased array antenna system.
Fig. 4. Description of the phased array antenna under numerical simulation system.
Fig. 5. Comparison of beam squinting characteristics between conventional phased array antenna and array antenna with true time delay lines.
Fig. 6. Required group delay for focusing at x = 5 [cm] and z = 15 [cm] in the case of the proposed array antenna employing true time optical delay lines.
Fig. 7. Required phase difference for focusing at x = 5 [cm] and z = 15 [cm] in the case of general phased array antenna.
Fig. 8. Comparison of the spot size of focal point with numerical aperture variation.
Fig. 10. Comparison of intensity profile while varying the space between antennas.
Fig. 11. Comparison of the lateral direction (x-axis) intensity profile of focal spot with varying the gap between antennas.
Fig. 9. Subwavelength focusing characteristics. (a) Lateral direction (x-axis) intensity profile of the focal spot with numerical aperture variation. (b) Spot size as a function of the numerical aperture.
Table 1. Simulation parameters for observing beam squinting caused by frequency detuning
Table 2. Simulation parameters for observing subwavelength focusing
Table 3. Simulation parameters for observing side lobes
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