Active antennas for emerging X-band RADAR applications

Active antennas traditionally employ T/R modules comprised of amplifiers, phase shifters and step attenuators. These modules are normally mounted in an orientation orthogonal to the plane of the array making the antenna bulky, heavy, and expensive to manufacture. In contrast highly integrated silicon ICs allow all electronic functions to be assembled on one side of a multilayer PCB within the lattice spacing driven by wavelength constraints. Placing planar radiating elements on the other side of this PCB allows for low cost and low weight active antennas. This paper describes two ICs developed for X-band radar applications. One of them is a highly integrated silicon IC designed in 0.13um BiCMOS technology used for beam forming and the other is a III-V IC that provides high output power for transmit function and low noise amplifier with appropriate limiting for the receive function. Both these ICs are sized such that they fit in required lattice spacing on one side of a multi-layer PCB.