Radio-Frequency Communication Using Higher Order Gaussian Beams

Abstract

Recent explosive growth in the number of wireless devices and demand for portable information content has led to the need for modern wireless systems with higher bandwidth to support faster data rates. It is necessary to move to higher frequency bands to increase the channel capacity. It is important to develop new methods to increase channel capacity for applications, including short range chip-to-chip wireless links. One approach to increasing capacity that has been explored in optics and at radio frequency (RF) is mode-division-multiplexing (MDM) of multiple orthogonal electromagnetic beams.

This dissertation focuses on developing radio-frequency communication using higher order modes of Gaussian beams, specifically Hermite-Gaussian (HG) and Laguerre-Gaussian (LG). First, a physical phase plate was designed and fabricated to transform plane waves to Hermite-Gaussian beams. The phase plate is designed for an HG11 mode, working at E-band from 71 to 76 GHz. Second, an HG11 beam is formed using four inset-fed microstrip patch elements arranged with a microstrip corporate feeding network at the same frequency. The physical phase plate and the patch antenna array were both simulated using ANSYS HFSS. Radiation pattern measurements were taken on an NSI 700S-360 spherical near-field system at from 71 to 76 GHz with an Agilent vector network analyzer (VNA). Third, LG beams were generated with spiral phase plates (SPP) from 71 to 76 GHz. Then a dual-channel E-band communication link using commercial impulse radios was demonstrated with two LG beams over 2 meters range. LG OAM beams at E-band were also generated by a circular patch array and then a wireless communication link was built using the array to demonstrate twisting a wave with patches and untwisting it with a SPP. Also included is a demonstration of horn antennas manufactured by 3D printing with low cost metallic paint for X-band and Ka-band frequencies. This work advances wireless communication using advanced hardware techniques.