Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras

Method and Opto-electronic apparatus for determining frequency of intercepted signal using sub-Nyquist sampling

Categories for this Invention

Category: Information & Communication Technologies (ICT) /Photonics

Industry: Semiconductor & Electronics Manufacturing, Integrated devices.

Applications: Wireless Communication Devices, Telecommunication Infrastructure,

Market: The global Opto electronic apparatus market size is estimated at USD 1.64 trillion in 2024, and is expected to reach USD 2.25 trillion by 2029, growing at a CAGR of 6.5% during the forecast period (2024-2029).

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Problem Statement

  • In general, instantaneous frequency measurement (IFM) always has been a critical technology for  efficient broadband spectrum sensing.
  • IFM initially Started as analog and later it transforms to digital instantaneous frequency measurement (DIFM) systems.
  • DIFM further develops to high-speed sample-and-hold circuits, analog-to-digital converters (ADCs), and FFT processors and  aided to start the compressed sensing technologies called as sub-Nyquist sampling based frequency discriminators.
  • Compressive sensing methods (such as sub-Nyquist sampling) require low frequency and low complex hardware, enabling miniaturization.
  • Photonic-assisted microwave measurement techniques offer distinct advantages such as wide spectrum coverage, low frequency dependent loss, and immunity to electromagnetic interference.
  • Optical sub-Nyquist sampling using mode locked lasers (MLLs) offer very low jitter performance and ability to process the signal at baseband frequencies.
  • Thus there is a need for alternative technology for better results.

Technology

  • An Opto-electronic apparatus for determining a frequency of an intercepted signal using sub-Nyquist sampling, the Opto-electronic apparatus comprises
  • An Optical sampler for providing an Optical signal;
  • Optical delay lines  for interleaving the Optical signal in each Optical delay line.
  • A electro-Optic modulators  for obtaining a Optically sampled versions of the intercepted signal using a corresponding interleaved Optical signal from each Optical delay lines based on the sub-Nyquist sampling, wherein the intercepted signal is a radio frequency (RF) signal.
  • A Opto-electric converters  for converting each  Optically sampled versions of the intercepted signal into electrical domain
  • A frequency estimator for determining a frequency of the intercepted signal using each Optically sampled versions of the intercepted signal in the electrical domain based on a location in the left window or the right window.
  • A single optical sampler is used and parallel optical delay lines are provided to multiply the repetition rate of a pulsed optical signal which is then modulated with an intercepted signal to determine a center frequency of the intercepted signal.

Key Features / Value Proposition

  • A novel frequency measurement device based on  optical sub-sampling.
  • A novel sub-Nyquist based photonic instantaneous frequency measurement .
  • The intercepted signal is a radio frequency (RF) signal.
  • The optical sampler is a Mode Locked Laser (MLL) of 2 GHz repetition rate.
  • Electro-optic modulators is Mach Zehnder Modulator (MZM).
  • The optical signal of the intercepted signal is direct copy for  odd fold and mirrored copy for even fold.
  • Interleaving of the optical signal doubles a frequency of the optical signal at each of the optical delay line and Incorporation of  the parallel channels was made in a single integrated optic chip.
  • Highly stable and cost effective .

Applications:

  • ESM systems, Radar, surveillance, telecommunications, vehicular communication.

Questions about this Technology?

Contact For Licensing

sm-marketing@imail.iitm.ac.in
ipoffice2@iitm.ac.in

Research Lab

Prof. Deepa Venkitesh

Department of Electrical Engineering

Intellectual Property

  • IITM IDF Ref. 2204

  • Patent No: IN 531779

Technology Readiness Level

TRL – 4

Technology validated in lab scale.

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