The microwave photonic channelizer can convert the RF signal into the optical domain for transmission and procession, effectively avoiding the limitation of electronic bottleneck, and realizing the instantaneous reception of ultra-wideband signal or multi-frequency signals, which can be perfectly applied to radar system and electronic warfare. In this paper, a microwave photonic channelizer based on dual-output image-reject mixer is proposed, both the signal path and the local oscillator path are divided into three paths by using an optical coupler. An acousto-optic frequency shifter (AOFS) is used by the optical local oscillator to shift the frequency to the left and right and then enters the image rejection mixer with the signal path. Finally, a 6 GHz bandwidth RF signal is divided into six subchannels with a bandwidth of 1 GHz to achieve simultaneous reception. This scheme needs no optical frequency comb and doubles the channelization efficiency, the image rejection ratio of the sub-channels is about 22 dB, and the spurious-free dynamic range of the system can reach 103.2 dB• Hz 2∕3 .
Aimed at the uneven energy consumption and data redundancy problem of the long-distance ribbon wireless sensor network, a cluster topology control algorithm is proposed based on the topology of ribbon wireless sensor network. The algorithm optimizes the cluster head selection mechanism and effectively guarantees sensor nodes with more residual energy and less communication cost as a cluster head. In order to reduce the data burden that the cluster head forwards the other cluster heads, then the algorithm choose a node with much residual energy and low communication cost in the cluster nodes as data forwarding node. The simulation results show that the topology control algorithm suitable for ribbon wireless sensor networks significantly balances the energy consumption of the network and prolongs the network lifetime.
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