Fig. 1. Schematic of the proposed single-pixel super-resolution technique.

Fig. 2. Experimental setup. (a) The schematic of the experimental setup. (b) A zoom view of the experimental setup. (c) The probe antenna. (d) The 2-bit reconfigurable transmissive metasurface. (e) The FPGA controller.

Fig. 3. Experimental estimation of the achieved resolution. (a)–(d) The optical images of the two-hole objects with the minimum distances of (a) 50 mm, (b) 40 mm, (c) 30 mm, and (d) 20 mm. (e)–(h) The simulated results without the space–time modulation (OR) and with the space–time modulation (SR). (i)–(l) The corresponding measured results without/with the space–time modulation. The blue circles indicate the ground-truth positions of the holes. (m)–(p) The intensities along the dotted lines of the third row. GT, ground truth; OR, original resolution; SR, super-resolution.

Fig. 4. Experimental results of multiple objects. (a₁)–(a₄) Optical images of more complex objects with (a₁) four holes, (a₂) seven holes, (a₃) eight holes, and (a₄) three strips. (b₁)–(b₄) The simulated results without the space–time modulation. (c₁)–(c₄) The simulated results with the space–time modulation. (d₁)–(d₄) The measured results without the space–time modulation. (e₁)–(e₄) The measured results with the space–time modulation. The circles in (b₁)–(e₄) indicate the ground-truth object positions. (f₁)–(f₄) The intensities along the dotted lines in (e₁)–(e₄).

Fig. 5. Schematic of the single-pixel imaging model.

Fig. 6. Flowchart of the phase retrieval procedure.

Fig. 7. (a) A radiation-source array. Each source has a signal channel. (b) The space–time modulated metasurface radiation source.

Fig. 8. Phase distributions of the VRS illumination patterns. The amplitude distributions are assumed to be unitary.

Fig. 9. Simulated phase distributions of MetaTX. MetaTX consists of 13×13 unit cells. Ti denote the ith time sequence. The set {−4,−3,−2,−1,0,1,2,3,4} denotes the harmonic indices, which correspond to the radiation sources in Fig. 7(b) from left to right, respectively.

Fig. 10. Simulated phase distributions of MetaTX after eliminating the spherical wave.

Fig. 11. Simulated amplitude distributions of MetaTX.