Design and demonstration of 1-bit and 2-bit transmit-arrays at X-band frequencies

This article describes the design of planar transmit-arrays at 10 GHz with 1-bit and 2-bit phase quantization and specific unit-cell designs in each case. The influence of the main design parameters are investigated numerically. The measured directivity/gain values equal 26/23.6 dBi for the 1-bit design, and 23.7/14.3 dBi for the 2-bit design, respectively. In particular, the influence of the unit-cell size is highlighted. Both designs are built on a two-layer printed circuit board assembly and operate in linear polarization. Beam-steering characteristics up to ±30° are investigated and compared by tilting the feed source and by changing the phase distribution across the array.