A Lightweight Organic X-Band Active Receiving Phased Array With Integrated SiGe Amplifiers and Phase Shifters

Abstract

This paper presents for the first time an X-band antenna array with integrated silicon germanium low noise amplifiers (LNA) and 3-bit phase shifters (PS). LNAs and PSs were successfully integrated onto an 8 2 lightweight antenna utilizing a multilayer liquid crystal polymer (LCP) feed substrate laminated with a duroid antenna layer. A baseline passive 8 2 antenna is measured along with a SiGe integrated 8 2 receive antenna for comparison of results. The active antenna array weighs only 3.5 ounces and consumes 53 mW of dc power. Successful comparisons of the measured and simulated results verify a working phased array with a return loss better than 10 dB across the frequency band of 9.25 GHz-9.75 GHz. A comparison of radiation patterns for the 8 2 baseline antenna and the 8 2 SiGe integrated antenna show a 25 dB increase in gain (1 ). The SiGe integrated antenna demonstrated a predictable beam steering capability of 41 . Combined antenna and receiver performance yielded a merit of 9 1 dB K and noise figure of 5.6 dB.

Multilayer organic X-band antenna arrays using Wilkinson power dividers with embedded thin film resistors

“…These active devices will be wire-bonded to the bottom layer of the MLO substrate. Figure 10 shows the measured return loss obtained from a fabricated 8x2 array with integrated LNAs and phase-shifters [1]. Similar performance is expected from the fabricated 8x8 array with Wilkinson dividers.…”

“…Two 1-mil thick bond ply layers were used to complete the multilayer stackup. The RF distribution network was built on an embedded layer to allow room for integrated SiGe active devices such as LNAs, and phase-shifters on the bottom layer [1]. The antenna arrays were designed at a center frequency of 9.5 GHz with a bandwidth of 500 MHz.…”

“…Multilayer Organic (MLO) System on a Package (SOP) technology offers a low cost solution for this type of applications while providing excellent RF performance. Microstrip antenna phased arrays utilizing a substrate of Liquid Crystal Polymer (LCP) and RT/Duroid dielectric layers, and with integrated SiGe LNAs and phase-shifters, have been demonstrated in [1]. The radiating elements on these arrays were uniformly fed in parallel using an embedded microstrip feed network with reactive power dividers.…”

A lightweight, 64-element, organic phased array with integrated transmit-receive SiGe circuitry in the X band

“…In these implementations, a PS and an LNA within a single SiGe IC are used to drive individual [6] or several [7], [8] radiating elements in the array. The true benefit of these designs relies on the reduction of the NF of the system as it is significantly improved by placing the active circuitry closer to the radiating elements.…”

“…Further reductions in weight and footprint size have been achieved through vertical stack-ups of organic substrates such as liquid crystal polymer (LCP) and duroid [7]- [9]. Additionally, vertical stack-ups of organic materials give physical flexibility which permits the conformal mounting of the arrays without having to trade off future scalability of the system to a higher number of radiating elements.…”