An S-Band Multifunction Chip with a Simple Interface for Active Phased Array Base Station Antennas

Abstract

An S-band multifunction chip with a simple interface for an active phased array base station antenna for next-generation mobile communications is designed and fabricated using commercial 0.5-μm GaAs pHEMT technology. To reduce the cost of the module assembly and to reduce the number of chip interfaces for a compact transmit/receive module, a digital serial-to-parallel converter and an active bias circuit are integrated into the designed chip. The chip can be controlled and driven using only five interfaces. With 6-bit phase shifting and 6-bit attenuation, it provides a wideband performance employing a shunt-feedback technique for amplifiers. With a compact size of 16 mm2 (4 mm × 4 mm), the proposed chip exhibits a gain of 26 dB, a P1dB of 12 dBm, and a noise figure of 3.5 dB over a wide frequency range of 1.8 GHz to 3.2 GHz.