A Scalable 0.5-6 GHz $4\mathrm{x}4$ True Time Delay (TTD) Active Electronically Scanned Transmitter/Receiver Tile and Array

This paper presents scalable 16-element 0.1-8 GHz ultra-wideband transmit (Tx) and receive (Rx) tiles with true-time-delay (TTD) beam steering. A 7 -bit (8/16/32/64/128/256/512 picoseconds) time-delay is available on every element with 30 dB gain control. The Tx channel has an output power of 25–27 dBm, while the Rx channel has a noise figure (NF) of 2.7-3.5 dB. Two Tx tiles are integrated with a wideband antenna to build an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8\mathrm{x}4$</tex> -element active electronically scanned array (AESA) at 0.5-6 G Hz. The array scans to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 60^{\circ}$</tex> in the azimuth and elevation planes and transmits 50-59dBm EIRP at I-dB compression point at 1–6 GHz. Measurements are done without any calibration due to the symmetrical nature of the TTD unit cells, which greatly reduces the overall system cost. The AESA unit has an integrated power supply and 2048 beam memory positions for fast beam steering (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&lt; 2$</tex> microseconds). The AESA tile can be scaled in an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NxN}$</tex> format resulting in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$16\mathrm{x}16$</tex> -element or larger arrays.