Journal of Lightwave Technology · 2016 · 77 citations · 18 references
EngineeringElectrical EngineeringMicrowave EngineeringOpticsPhotonicsIntegrated PhotonicsMicrowave MixersOptical Communication SystemsOptical ModulatorsPhotonic Integrated CircuitsReceiver SystemsImage RejectionMach-zehnder ModulatorsMicrowave Phase Shifter DesignMillimeter-wave ReceiversMixersNoise FloorOptical Phase ShiftersPhase Shifters
IRMs eliminate image‑frequency interference in microwave receivers, and achieving wideband operation requires precise 90° phase shifting and parallel mixing across a broad frequency range. The authors propose and demonstrate a photonic scheme that simultaneously provides wideband 90° phase shifting and parallel frequency mixing using a dual‑polarization dual‑drive Mach‑Zehnder modulator and an optical filter. A proof‑of‑concept experiment implements this scheme, employing the dual‑polarization dual‑drive MZM and optical filter to achieve the required phase shift and mixing. The resulting IRM achieves an image rejection ratio of ~60 dB over 10–40 GHz, with all unwanted mixing spurs suppressed below the noise floor.
Image-reject mixers (IRMs) play an important role in microwave and millimeter-wave receivers to eliminate the interference from the image frequency. The keys to realizing a wideband IRM are the precise 90° phase shifting and parallel frequency mixing within a large operational frequency range. In this paper, we propose and demonstrate a novel photonic scheme that can perform simultaneously wideband 90° phase shifting and parallel frequency mixing based on a dual-polarization dual-drive Mach-Zehnder modulator and an optical filter. An IRM is thus implemented. A proof-of-concept experiment is carried out. The experimental results show that the image rejection ratio of the proposed IRM reaches ~60 dB, when the RF and LO frequencies are tuned in a frequency range of 10-40 GHz. In addition, since the optical filter is employed to select only the two +first-order RF and LO sidebands, the unwanted mixing spurs are all suppressed below the noise floor.
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Shilong Pan, Dan Zhu, Shifeng Liu et al. · IEEE Microwave Magazine · 2015 · 166 citations
Engineering, Aerospace Engineering, Electrical Engineering +13