UC San Diego

The use of electronically steerable antennas for Satellite Communication (SATCOM) applications has been limited for many years to mostly defense systems. Those planar phased antenna arrays were not able to penetrate the commercial SATCOM market due to their high cost, complex design, low yield, low production numbers, and time-consuming calibration needed for each antenna unit. This dissertation aims to make affordable SATCOM planar phased arrays with high yield and minimal calibration available for the commercial market. The low-cost phased arrays are not only useful for SATCOM on-the-move (SOTM) terminals, but similar phased-arrays can be built for point-to-point communications and low-power radars.

This dissertation presents two affordable Ku-band dual-polarized receive-only (Rx) and transmit-only (Tx) phased-arrays with 256-elements. The phased antenna arrays can receive or transmit linear, rotated-linear, and circular polarization. Both designs archive state-of-the-art performance with wide-scan angles and high polarization purity. The array designs are based on a low-cost approach where beamformer chips are assembled on a printed circuit board (PCB) with dual-polarized antennas and an integrated Wilkinson combiner/divider network. An affordable and reliable PCB stack-up is developed for both designs and achieves a 100% yield. The two tile designs are scalable to allow large-scale phased-arrays construction with 1024 elements or higher. Also, one phased array can be calibrated, and then, the same calibration coefficients can be applied to different arrays, thereby significantly reducing the calibration time and cost of large-volume commercial arrays. The phased-arrays’ near-ideal performance, scalable compact size, low-profile, and ultra-lightweight make them ideal for affordable Ku-band SATCOM terminals.

Another critical parameter that determines the receive phased array size and, consequently, its cost is the required gain-to-noise-temperature (G/T). To maintain high G/T, a packaged low-noise amplifier (LNA) is needed near each antenna element. Therefore, this dissertation also demonstrates the designs of two stable packaged LNAs for a K-band SATCOM receive phased-array using two different technologies (SiGe and CMOS SOI). Both LNAs achieve state-of-the-art packaged performance in terms of gain, NF, and power consumption in both SiGe and CMOS processes. Additionally, a simplified simulation schematic is shown to provide an accurate representation of the packaging effects in a shorter time than the full 3D EM simulation model.

Finally, a K-band phased-array beamformer channel with a novel 8-bit phase shifter and low phase imbalance gain control using 45nm CMOS SOI technology is presented. The channel has a measured peak gain of 24.2 dB with 3-dB bandwidth of 16.4-19.8 GHz and 2.5 dB NF. The phase shifter has a high resolution of 8-bit with the RMS phase and amplitude error of <1.4° and < 0.3 dB, respectively. Also, the K-band channel offers a 37.2 dB gain tuning range with a fine 0.25 dB step and low phase imbalance due to the added correction capacitors. The achieved performances make this beamformer channel ideal for affordable and high-performance SATCOM K-band receive phased-array systems.