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 $8\mathrm{x}4$ -element active electronically scanned array (AESA) at 0.5-6 G Hz. The array scans to $\pm 60^{\circ}$ 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 ($< 2$ microseconds). The AESA tile can be scaled in an $\text{NxN}$ format resulting in $16\mathrm{x}16$ -element or larger arrays.

I. Introduction

Active electronically scanned array (AESA) have been used in many applications, but especially the ones used for wide-band communication systems (such as LTE or carrier aggregation waveforms) and for high resolution imaging favor ultra-wide bandwidth (such as 0.5-6 GHz) and wide scan angle (up to ). There are several antennas in literature which offer a decade bandwidth such as tapered-slot (Vivaldi), Balanced Antipodal Vivaldi Antenna (BAVA), spiral antennas and tightly-coupled dipoles [1]–[8].