Showing papers by "Leimeng Zhuang published in 2010"

Novel Ring Resonator-Based Integrated Photonic Beamformer for Broadband Phased Array Receive Antennas—Part I: Design and Performance Analysis

Abstract: A novel optical beamformer concept is introduced that can be used for seamless control of the reception angle in broadband wireless receivers employing a large phased array antenna (PAA). The core of this beamformer is an optical beamforming network (OBFN), using ring resonator-based broadband delays, and coherent optical combining. The electro-optical conversion is performed by means of single-sideband suppressed carrier modulation, employing a common laser, Mach-Zehnder modulators, and a common optical sideband filter after the OBFN. The unmodulated laser signal is then re-injected in order to perform balanced coherent optical detection, for the opto-electrical conversion. This scheme minimizes the requirements on the complexity of the OBFN, and has potential for compact realization by means of full integration on chip. The impact of the optical beamformer concept on the performance of the full receiver system is analyzed, by modeling the combination of the PAA and the beamformer as an equivalent two-port RF system. The results are illustrated by a numerical example of a PAA receiver for satellite TV reception, showing that - when properly designed - the beamformer hardly affects the sensitivity of the receiver.

Novel Ring Resonator-Based Integrated Photonic Beamformer for Broadband Phased Array Receive Antennas—Part II: Experimental Prototype

Abstract: An experimental prototype is presented that illustrates the implementation aspects and feasibility of the novel ring resonator-based optical beamformer concept that has been developed and analyzed in Part I of this paper . This concept can be used for seamless control of the reception angle in broadband wireless receivers employing a large phased array antenna (PAA). The design, fabrication, and characterization of a dedicated chip are described, in which an 8 × 1 optical beamforming network, an optical sideband filter for single-sideband suppressed carrier modulation, and a carrier re-insertion coupler for balanced optical detection are integrated. The chip was designed for satellite television reception using a broadband PAA, and was realized in a low-loss, CMOS-compatible optical waveguide technology. Tuning is performed thermo-optically, with a switching time of 1 ms. Group delay response and power response measurements show the correct operation of the OBFN and OSBF, respectively. Measurements on a complete beamformer prototype (including the electro-optical and opto-electrical conversions) demonstrate an optical sideband suppression of 25 dB, RF-to-RF delay generation up to 0.63 ns with a phase accuracy better than ?/10 radians, and coherent combining of four RF input signals, all in a frequency range of 1-2 GHz.