On-Chip Instantaneous Microwave Frequency Measurement System based on a Waveguide Bragg Grating on Silicon

Abstract

We experimentally demonstrate an instantaneous frequency measurement system based on a 65 µm-long integrated Bragg grating filter. An amplitude comparison function based on its transmission and reflection responses allows identification of unknown RF frequencies above 30 GHz.

Low-error and broadband microwave frequency measurement in a silicon chip

“…The use of photonics for microwave IFM is attractive due to the possibility of pushing the frequency measurement range far beyond the capacity of electronicbased IFM systems [3,4]. Since its conception in 2006 [5], research into photonicbased IFM systems has progressed by various means [6,7,8,9,10], and has recently culminated with the demonstration of a number of on-chip IFM systems [11,12,13,14]. This trend towards integration is especially important for IFM receivers, where the IFM delay is directly related to the length of the path traveled by the light.…”

“…This limit was due to the trade-off between quality factor and free spectral range of the ring resonators employed by these prior demonstrations. A different technique made use of a highly compact onchip Bragg grating filter with promising results, but a relatively high 2% measurement error [14]. There are not many techniques that can simultaneously achieve wideband operation and low, sub-1% measurement error.…”