Noise Figure Characterization of the Hyperspectral Microwave Photonic Instrument (HyMPI)

This work demonstrates the noise performance of the photonic back end of a hyperspectral microwave-photonic spectrometer aimed at augmenting the remote sensing capability from space, with a focus on the Earth’s planetary boundary layer (PBL). Using a distributed-feedback (DFB) laser and an electro-optical phase modulator, a 40 GHz spectrum is upconverted into the optical domain and sent to a 10-channel photonic integrated serial array waveguide grating (SAWG) where the spectra are separated into 4 GHz channels. Spectral content of each channel is downconverted to baseband using a second DFB laser and measured using an electrical spectrum analyzer (ESA) at a resolution of 8 MHz. Measured results of the end-to-end system Noise Figure (NF) for all channels agree with the theoretical analysis and demonstrate the suitability of microwave photonics for atmospheric studies.