# US 2018/0027314 A1 · Ultra high-speed photonics based radio frequency switching > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0027314 A1 - Document ID: US20180027314A1 - Status: Published application - Kind: A1 - Application number: 15/553,705 - Filed: 2016-02-26 - Published: 2018-01-25 - Earliest claimed: 2015-02-27 - Assignees: University of Georgia Research Foundation, Inc. - Applicants: University of Georgia Research Foundation, Inc. - Inventors: MABLE P. FOK; JIA GE - Web page: https://patentgrep.com/patent/US20180027314A1 ## CPC - H04Q 11/0005: {Switch and router aspects} - G02B 6/2938: {for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM} - G02B 6/29389: {Bandpass filtering, e.g. 1x1 device rejecting or passing certain wavelengths (G02B6/2938 takes precedence)} - H04B 10/2941: {using an equalising unit, e.g. a filter (H04B10/296 takes precedence)} - H04B 2210/006: Devices for generating or processing an RF signal by optical means - H04Q 2011/0035: {using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical} - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04B: TRANSMISSION ## Abstract Various examples are provided for radio frequency (RF) switching. In one example, a RF switch includes a dual-drive Mach-Zehnder modulator (DDMZM) that can generate a single-sideband (SSB) signal by modulating an input RF signal onto an optical carrier; a tunable phase modulator incorporated loop mirror filter (PM-LMF) that can optically notch filter the SSB signal in response to a control signal; and a photodetector (PD) that can generate a RF output signal based upon the SSB signal. In another example, a method includes modulating an input RF signal onto an optical carrier to generate a SSB signal; notch filtering the SSB signal by a tunable PM-LMF in response to a control signal; and generating a RF output signal based upon the SSB signal. ## Claims ### Claim 1 A radio frequency (RF) switch, comprising: a dual-drive Mach-Zehnder modulator (DDMZM) configured to generate a single-sideband (SSB) signal by modulating an input RF signal onto an optical carrier; a tunable phase modulator incorporated loop mirror filter (PM-LMF) configured to optically notch filter the SSB signal in response to a control signal; and a photodetector (PD) configured to generate a RF output signal based upon the SSB signal. ### Claim 2 (depends on 1) The RF switch of claim 1, wherein the control signal comprises a switching period that is less than a nanosecond and a rise-time/fall-time of about 100 picoseconds or less. ### Claim 3 (depends on 2) The RF switch of claim 2, wherein a switching speed of the RF switch is less than 200 picoseconds. ### Claim 4 (depends on 3) The RF switch of claim 3, wherein the switching speed is less than 100 picoseconds. ### Claim 5 (depends on 1) The RF switch of claim 1, wherein the input RF signal comprises a signal at a predefined frequency, and wherein the tunable PM-LMF is configured to turn on or off the signal at the predefined frequency in response to the control signal. ### Claim 6 (depends on 5) The RF switch of claim 5, wherein the tunable PM-LMF turns on or off the signal at the predefined frequency based upon a voltage level of the control signal. ### Claim 7 (depends on 1) The RF switch of claim 1, wherein the input RF signal comprises a first signal at a first predefined frequency and a second signal at a second predefined frequency, and wherein the tunable PM-LMF is configured to switch between the first signal and the second signal in response to the control signal. ### Claim 8 (depends on 7) The RF switch of claim 7, wherein the tunable PM-LMF switches between the first signal and the second signal based upon a voltage level of the control signal. ### Claim 9 (depends on 1) The RF switch of claim 1, wherein the SSB signal is launched into the tunable PM-LMF via an optical coupler. ### Claim 10 (depends on 9) The RF switch of claim 9, comprising an optical amplifier configured to amplify the SSB signal prior to launching into the tunable PM-LMF. ### Claim 11 (depends on 1) The RF switch of claim 1, wherein the PM-LMF comprises a polarization maintaining fiber (PMF), a polarization controller (PC), and a phase modulator (PM) configured to control operation of the PM-LMF based upon the control signal. ### Claim 12 (depends on 11) The RF switch of claim 11, wherein switching of the PM-LMF is based upon a Pockels electro-optic effect produced in the PM in response to the control signal. ### Claim 13 (depends on 1) The RF switch of claim 1, wherein the input RF signal is modulated onto the optical carrier by the DDMZM via a 90-degree hybrid coupler. ### Claim 14 A method, comprising: modulating an input radio frequency (RF) signal onto an optical carrier to generate a single-sideband (SSB) signal; notch filtering the SSB signal by a tunable phase modulator incorporated loop mirror filter (PM-LMF) in response to a control signal; and generating a RF output signal based upon the SSB signal. ### Claim 15 (depends on 14) The method of claim 14, wherein the PM-LMF switches between notch filtering at a first frequency and notch filtering at a second frequency in response to the control signal. ### Claim 16 (depends on 15) The method of claim 15, wherein the PM-LMF switches the RF output signal between the first frequency and the second frequency in response to the control signal. ### Claim 17 (depends on 16) The method of claim 16, wherein the input RF signal comprises a signal at the first frequency and no signal at the second frequency. ### Claim 18 (depends on 14) The method of claim 14, wherein the notch filtering of the SSB signal is based upon birefringence in a phase modulator (PM) of the PM-LMF and a polarization maintaining fiber (PMF). ### Claim 19 (depends on 18) The method of claim 18, wherein tuning of the notch filtering is based upon an electro-optic Pockels effect produced in the PM in response to the control signal. ### Claim 20 (depends on 14) The method of claim 14, wherein the control signal comprises a switching period that is less than a nanosecond and a rise-time/fall-time of about 100 picoseconds or less.