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$\,\times\,$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 $\pi/10$ radians, and coherent combining of four RF input signals, all in a frequency range of 1–2 GHz.
© 2009 IEEE
Leimeng Zhuang, Chris G. H. Roeloffzen, Arjan Meijerink, Maurizio Burla, David A. I. Marpaung, Arne Leinse, Marcel Hoekman, René G. Heideman, and Wim van Etten, "Novel Ring Resonator-Based Integrated Photonic Beamformer for Broadband Phased Array Receive Antennas—Part II: Experimental Prototype," J. Lightwave Technol. 28, 19-31 (2010)