This high-speed, selective, nonlinear signal processor uses a mechanical wave-mixing matrix to synthesize multi-band frequencies, enabling a tremendous boost in the spectrum resources through accessing white bands in cm- and mm-wave spectrums. To accommodate the increasing number of wireless users and their explosive demand for higher communication data rates, emerging wireless systems, such as the 5G wireless network, target system-level transformation to exploit multi-band communication schemes over ultra- and super-high-frequency (UHF and SHF) regimes. Multi-band communication systems rely on spread-spectrum communication schemes that distribute wide-band signals among several distinct carrier-aggregated frequencies over an extended spectrum to accommodate enhanced communication data rates. Realization of spread-spectrum wide-band communication systems requires a phase-synchronous set of frequency references to serve as local oscillators at each carrier frequency and facilitate a coherent combination of data from multiple carriers without signal distortion. Such a reference set is currently realized through exploiting several standalone resonators, besides phase locked loop (PLL) based synthesizers, that impose additional burden on the integration, complexity, and power consumption of the systems. Furthermore, with the inevitable increase in the number of constituent sub-carriers and extension of communication bands into higher frequencies, beyond the UHF, the PLL-based synthesizer solutions are not efficient, due to the significant degradation in the phase-noise with increased output-to-input frequency ratios. Researchers at the University of Florida have developed a fully-mechanical synthesizer that employs nonlinear acoustic wave-mixing processes to realize a phase-synchronous frequency reference chain over multiple bands, without the need for PLLs. This device enables operation of multi-band 5G wireless communication systems in carrier-aggregation mode through using a single frequency reference, reducing the complexity and power consumption of the system.
High-frequency signal processing unit that synthesizes multiple frequencies throughout the entire UHF and SHF ranges for 5G multi-band telecommunications systems with ultra-low power consumption
This phononic signal processing system uses nonlinear acoustic wave propagation to synchronize signals of varying frequencies for efficient multi-band, carrier-aggregated communications systems. Waveguides that support certain vibration modes at desired frequency are cross-couple on geometrically engineered semiconductor and piezoelectric regions. These regions feature perforations that enhance the elastic anharmonicity of the material, allowing them to exhibit acoustic wave-mixing properties. The perforations also provide acoustic band-gap around specific frequencies, which isolates the local excitations from nonlinearly generated signals. Since the system employs mechanical wave-mixing to process signals, this frequency synthesizer is substantially immune to electromagnetic interference and frequency-pulling effects at ultra-high and super-high frequencies (UHF and SHF), thereby increasing the stability of frequency references in multi-band wireless systems in the cm- and mm-wave spectrums.
