# US 8,543,009 B2 · Method and apparatus for synthesizing ultra-wide bandwidth waveforms > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,009 B2 - Document ID: US8543009B2 - Status: Granted - Kind: B2 - Application number: 12/960,085 - Filed: 2010-12-03 - Published: 2012-06-07 - Granted: 2013-09-24 - Earliest claimed: 2010-12-03 - Assignees: Raytheon Company - Applicants: Jean-Paul Bulot; Matthew J. Klotz - Inventors: Jean-Paul Bulot; Matthew J. Klotz - Web page: https://patentgrep.com/patent/US8543009B2 ## CPC - H04B 10/5165: {Carrier suppressed; Single sideband; Double sideband or vestigial} - H04B 10/25752: {Optical arrangements for wireless networks} - H04B 10/505: {using external modulation} - H04B 2210/006: Devices for generating or processing an RF signal by optical means - H04B: TRANSMISSION ## Abstract In accordance with various aspects of the disclosure, a method and apparatus is disclosed for increasing waveform bandwidth of an optical frequency waveform during optical double sideband suppressed carrier modulation. An optical modulator is configured to operate in double sideband, suppressed carrier modulation (DSB-SC) mode producing multiple optical sidebands and optical sideband harmonics. Proper selection of the appropriate optical harmonic via optical filter enables the synthesis of ultra-wideband single-sideband, suppressed carrier (SSB-SC) optical waveforms while simultaneously simplifying the radio frequency (RF) circuitry that generates the modulating radio frequency waveform. ## Claims ### Claim 1 A method of increasing waveform bandwidth of an optical waveform during double sideband suppressed carrier modulation, the method comprising: receiving a radio frequency waveform by a bandwidth multiplier; increasing a bandwidth of the received radio frequency waveform; providing the bandwidth increased radio frequency waveform to an optical modulator; and creating multiple optical harmonics of the radio frequency waveform during modulation of an optical carrier to produce a dual sideband suppressed carrier optical waveform, the sidebands having additional waveform bandwidth. ### Claim 2 (depends on 1) The method according to claim 1, wherein the optical modulator includes a Mach-Zehnder optical modulator. ### Claim 3 (depends on 2) The method according to claim 2, further comprising: biasing the Mach-Zehnder optical modulator by a direct current power source; and operating the Mach-Zehnder optical modulator in a dual sideband suppressed carrier mode. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: optically filtering the dual sideband suppressed carrier optical waveform to create a single sideband suppressed carrier waveform by an optical bandpass filter. ### Claim 5 (depends on 1) The method according to claim 1, wherein the bandwidth of the radio frequency waveform is increased by performing one or more bandwidth doubling operations by a radio frequency doubler prior to being modulated onto the optical carrier by the optical modulator. ### Claim 6 (depends on 1) The method according to claim 1, further comprising: providing one or more digital waveform samples into a digital to analog converter to produce the received radio frequency waveform. ### Claim 7 (depends on 4) The method according to claim 4, wherein the optical bandpass filter includes a Fiber Bragg Grating. ### Claim 8 (depends on 1) The method according to claim 1, wherein the bandwidth increased radio frequency waveform is provided to a radio-frequency input of the optical modulator. ### Claim 9 An apparatus for increasing waveform bandwidth of an optical frequency waveform during double sideband suppressed carrier modulation, the apparatus comprising: a bandwidth multiplier arranged to receive a radio frequency waveform and to increase a bandwidth of the received radio frequency waveform; and an optical modulator arranged to receive the bandwidth increased radio frequency waveform, wherein the optical modulator is arranged to create multiple optical harmonics of the radio frequency waveform during modulation of an optical carrier to produce a dual sideband suppressed carrier optical waveform, the sidebands having additional waveform bandwidth. ### Claim 10 (depends on 9) The apparatus according to claim 9, wherein the optical modulator includes a Mach-Zehnder optical modulator. ### Claim 11 (depends on 10) The apparatus according to claim 10, wherein the Mach-Zehnder optical modulator is arranged to be biased by a direct current power source and operated in a dual sideband suppressed carrier mode to create the multiple optical harmonics of the radio frequency waveform. ### Claim 12 (depends on 9) The apparatus according to claim 9, further comprising: an optical bandpass filter that is configured to filter the dual sideband suppressed carrier optical waveform and create a single sideband suppressed carrier waveform at an output thereof. ### Claim 13 (depends on 9) The apparatus according to claim 9, wherein the bandwidth of the radio frequency waveform is increased by performing one or more bandwidth doubling operations by a radio frequency doubler prior to being modulated onto the optical carrier by the optical modulator. ### Claim 14 (depends on 9) The apparatus according to claim 9, wherein the optical modulator includes a radio-frequency input arranged to receive the bandwidth increased radio frequency waveform. ### Claim 15 (depends on 12) The apparatus according to claim 12, wherein the optical bandpass filter includes a Fiber Bragg Grating. ### Claim 16 (depends on 13) The apparatus according to claim 13, wherein the optical modulator includes a Mach-Zehnder optical modulator.