Parametric Photonic Channelized RF Receiver
ABSTRACT A new class of photonic channelized radio-frequency (RF) receiver is proposed and demonstrated. The new device relies on generation of high fidelity signal copies by wavelength multicasting in a self-seeded, two-pump parametric mixer. Signal copying to widely spaced wavelengths enables channelization of the full RF bandwidth using a single periodic filter. The channelization uses freely tunable frequencies of newly generated copies and eliminates the need for construction of a dense, narrowband filter bank. The new concept is demonstrated by channelization of four subcarrier channels with 1-GHz spacing and greater than 20-dB extinction ratio between extracted channels.
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ABSTRACT: Noise properties of large-count spectral multicasting in a phase-insensitive parametric mixer were investigated. Scalable multicasting was achieved using two-tone continuous-wave seeded mixers capable of generating more than 20 frequency non-degenerate copies. The mixer was constructed using a multistage architecture to simultaneously manage high Figure-of-Merit frequency generation and suppress noise generation. The performance was characterized by measuring the conversion efficiency and noise figure of all signal copies. Minimum noise figure of 8.09dB was measured. Experimental findings confirm that noise of the multicasted signal does not grow linearly with copy count and that it can be suppressed below this limit.Optics Express 01/2013; 21(1):804-14. · 3.55 Impact Factor
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ABSTRACT: A photonic-assisted microwave channelizer with improved channel characteristics based on spectrum-controlled stimulated Brillouin scattering (SBS) is proposed and experimentally demonstrated. In the proposed system, lightwaves from a laser array are multiplexed and then split into two paths. In the upper path, the lightwaves are modulated by a microwave signal with its frequency to be measured. In the lower path, for each lightwave, the wavelength is shifted to a specific shorter wavelength via carrier- suppressed single-sideband modulation and the spectrum is then shaped. The wavelength-shifted and spectrum-shaped lightwaves are used to pump a single-mode fiber to trigger SBS. Thanks to the SBS effect, multiple gain channels at the wavelengths are generated. The channel profile of each channel, determined by the designed spectral shape of the pump source, is improved with a flat top and a reduced shape factor. The characteristics including the bandwidth, channel spacing, and channel profile can be controlled by adjusting the spectral shape of the pump source.Aproof-of-concept experiment is performed. A microwave channelizer with a shape factor less than 2, a tunable channel bandwidth of 40, 60, or 90 MHz, and a tunable channel spacing of 50, 70, or 80 MHz, is demonstrated.IEEE Transactions on Microwave Theory and Techniques 09/2013; 61(9):3470-3478. · 2.23 Impact Factor
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ABSTRACT: Noise performance of dual-pump, multi-sideband parametric mixer operated in phase-insensitive mode is investigated theoretically and experimentally. It is shown that, in case when a large number of multicasting idlers are generated, the noise performance is strictly dictated by the dispersion characteristics of the mixer. We find that the sideband noise performance is significantly degraded in anomalous dispersion region permitting nonlinear noise amplification. In contrast, in normal dispersion region, the noise performance converges to the level of four-sideband parametric process, rather than deteriorates with increased sideband creation. Low noise generation mandates precise dispersion-induced phase mismatch among pump and sideband waves in order to control the noise coupling. We measure the noise performance improvement for a many-sideband, multi-stage mixer by incorporating new design technique.Optics Express 07/2013; 21(15):17659-69. · 3.55 Impact Factor