CN114844567A - Photon-assisted millimeter wave and laser hybrid communication transmitter - Google Patents

Abstract

The invention discloses a photon-assisted millimeter wave and laser mixed communication transmitter, which belongs to the technical field of microwave photonics and is characterized in that an optical frequency comb is used for generating two beams of frequency coherent light, wherein one beam of light is divided into two beams of light through a first polarization maintaining coupler after being subjected to modulated light signals obtained by a light intensity modulator, one of the two beams of light is divided by the first polarization maintaining coupler and is sent to a laser antenna through an optical amplifier to be radiated and output, the other beam of light is combined with unmodulated light signals generated by the optical frequency comb at a second polarization maintaining coupler, and optical heterodyne is performed through a photoelectric detector to generate millimeter wave radio frequency signals which are radiated and output through a millimeter wave antenna. The invention utilizes the optical frequency comb to generate a multi-carrier light beam, one path is used as a laser signal, the other path generates a millimeter wave radio frequency signal through optical heterodyne, the laser signal and the millimeter wave signal are respectively transmitted through the laser antenna and the millimeter wave antenna which are integrated by the same aperture, and the mixed communication function of millimeter waves and laser is realized through a set of system.

Description

Photon-assisted millimeter wave and laser hybrid communication transmitter

Technical Field

The invention belongs to the technical field of microwave photonics, and particularly relates to a photon-assisted millimeter wave and laser mixed communication transmitter.

Background

With the gradual exhaustion of the frequency spectrum resources of the microwave frequency band, the development of the communication frequency to a higher frequency band is promoted, and the millimeter wave frequency band and the laser have broadband frequency spectrum resources of several GHz to dozens of GHz, which is an important development direction of the future wireless communication. The bandwidth resources of millimeter wave communication and laser communication are rich, the communication capacity is large, the transmitted beam is narrow, the safety is higher, the range of the existing interference frequency band is exceeded, and the anti-electromagnetic interference performance is strong. The advantages of broadband, high reliability, high safety and the like of millimeter wave communication and laser communication enable the millimeter wave communication and the laser communication to have wide military and civil potentials. However, millimeter wave communication has large rain attenuation, and the communication performance is obviously reduced in a meteorological environment with large rainfall or water vapor; laser communication is susceptible to atmospheric turbulence and is difficult to traverse clouds, smoke, fog, and the like. The requirement of all-weather communication is difficult to guarantee by separate millimeter wave communication and laser communication.

Disclosure of Invention

Aiming at the defects or improvement requirements in the prior art, the invention provides a photon-assisted millimeter wave and laser hybrid communication transmitter, solves the problems of signal generation, modulation and transmission in millimeter wave and laser hybrid communication, and can be applied to scenes with higher requirements on communication bandwidth and all-weather communication.

In order to achieve the above object, the present invention provides a photon assisted millimeter wave and laser hybrid communication transmitter, comprising: the device comprises an optical frequency comb, a light intensity modulator, two polarization maintaining optical couplers, an optical amplifier, an optical fiber, a photoelectric detector, a radio frequency power amplifier, a laser antenna and a millimeter wave antenna;

two beams of coherent light with frequencies fc and fc-fs are generated by using an optical frequency comb, wherein one beam of light with the frequency fc modulates a baseband signal onto fc through a light intensity modulator to form a modulated light signal, the modulated light signal is divided into two beams of light through a first polarization maintaining coupler, one path of the modulated light signal branched by the first polarization maintaining coupler is sent to a laser antenna through an optical amplifier and is output by radiation through an optical fiber, the other path of the modulated light signal is combined with an unmodulated light signal with the frequency fc-fs generated by the optical frequency comb at a second polarization maintaining coupler, optical heterodyne is performed through a photoelectric detector to generate a millimeter wave radio frequency signal with the frequency fs, and the millimeter wave radio frequency signal is output by radiation through a millimeter wave antenna after passing through a radio frequency power amplifier.

In some optional embodiments, the optical-frequency comb comprises: the device comprises a fixed wavelength laser, a radio frequency source, a radio frequency power divider, a radio frequency phase shifter, a light intensity modulator, a light phase modulator and a light filter;

A radio frequency source generates a radio frequency single tone signal with the frequency fo, the radio frequency single tone signal is divided into two paths of radio frequency signals by a radio frequency power divider, one path of radio frequency signal passes through a light intensity modulator, and the other path of radio frequency signal passes through a light phase modulator after being subjected to phase shifting by a radio frequency phase shifter;

the optical wave beam with the frequency fc generated by the fixed wavelength laser sequentially passes through the light intensity modulator and the optical phase modulator, then generates a plurality of optical carriers with two paths of radio frequency signals, and selects the optical carrier with the required wavelength after the generated plurality of optical carriers pass through the optical filter.

In some optional embodiments, the heterogeneous conformal integration of the laser antenna and the millimeter wave antenna forms a laser and millimeter wave common aperture integrated antenna.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

the microwave photonic technology is utilized to realize the mixed communication of millimeter waves and laser, the generation and modulation of millimeter wave signals and laser signals are realized through electro-optical conversion means such as optical frequency comb and optical heterodyne, and the spatial radiation of millimeter wave signals and laser signals is realized through the millimeter wave antenna and the laser antenna which are integrated in a common aperture. The advantages are complemented through seamless fusion of millimeter wave communication and laser communication, so that the requirements of future communication networks on communication bandwidth and all-weather reliability are met, and the problems of signal generation, modulation and emission in millimeter wave and laser mixed communication are solved. The method has the advantages of simple principle, simple and efficient scheme and high application value.

Drawings

Fig. 1 is a schematic diagram of a photon-assisted millimeter wave and laser hybrid communication transmitter according to an embodiment of the present invention, where OFC denotes an optical frequency comb, IM denotes an optical intensity modulator, PM-OC denotes a polarization maintaining optical coupler, EDFA denotes an optical amplifier, SSMF denotes an optical fiber, PD1 denotes a photodetector, PA denotes a radio frequency power amplifier, Baseband signal Tx denotes a Baseband signal, Integrated Tx-Antenna denotes a laser and millimeter wave common aperture Integrated Antenna;

fig. 2 is a schematic diagram of an optical frequency comb in cascade connection of an optical phase modulator and an optical intensity modulator according to an embodiment of the present invention, where CW denotes a fixed wavelength laser, RF denotes an RF source, PD2 denotes an RF power divider, PS denotes an RF phase shifter, IM denotes an optical intensity modulator, PM denotes an optical phase modulator, and TOF denotes an optical filter;

fig. 3 is a schematic diagram of a multi-wavelength carrier generated by an optical frequency comb according to an embodiment of the present invention, where fc is a laser center frequency, fo is a radio frequency source frequency, and fs is a millimeter wave radio frequency carrier frequency.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the present examples, "first", "second", etc. are used for distinguishing different objects, and are not used for describing a specific order or sequence.

The invention provides a photon-assisted millimeter wave and laser mixed communication transmitter, which comprises the main technologies of multi-carrier generation based on optical frequency comb, millimeter wave signal generation based on optical heterodyne, common aperture integration of a laser antenna and a millimeter wave antenna, and the like. The optical frequency comb is used for generating a multi-carrier light beam, one path of light beam is used as a laser signal, the other path of light beam generates a millimeter wave radio frequency signal through optical heterodyne, and the laser signal and the millimeter wave signal are transmitted through a laser antenna and a millimeter wave antenna which are integrated through a common aperture. A schematic diagram of a photon-assisted millimeter wave and laser hybrid communication transmitter is shown in fig. 1.

(1) Multi-wavelength generation based on optical frequency combs: the optical frequency comb is realized by cascading a phase modulator and an intensity modulator. A plurality of optical carriers are generated by utilizing a phase modulator, and the planarization of the multiple carriers is realized by a cascaded intensity modulator;

(2) millimeter wave signal generation based on optical heterodyne: one path of optical wavelength is used as signal light to realize baseband signal modulation through a modulator, the other path of optical wavelength is used as local oscillator optical signal, and the unmodulated local oscillator signal of the modulated optical signal is subjected to optical heterodyne on a photoelectric detector to generate a millimeter wave signal with required frequency;

(3) The laser antenna and the millimeter wave antenna are integrated in a common aperture mode: the laser lens antenna and the millimeter wave plane antenna are integrated in a heterogeneous conformal mode, and mixed emission of laser signals and millimeter wave signals is achieved.

As shown in fig. 1, first, an optical frequency comb OFC is used to generate two beams of coherent light with frequencies fc and fc-fs, wherein one optical beam with frequency fc is modulated by an intensity modulator IM onto a Baseband signal Baseband Tx to become a modulated optical signal, and the modulated optical signal is split into two beams of light by a first polarization maintaining coupler PM-OC. Then, one path of the branched modulated optical signals is sent to a laser antenna for radiation output through an optical signal amplifier EDFA, the other path of the modulated optical signals is combined with unmodulated optical signals with the frequency of fc-fs generated by an optical frequency comb at a second polarization maintaining coupler PM-OC, optical heterodyne is performed through a photoelectric detector PD1 to generate millimeter wave radio frequency signals with the frequency of fs, and the millimeter wave signals are radiated and output through a millimeter wave antenna. The invention utilizes microwave photon technology and realizes the generation and modulation of optical signals and radio frequency signals through a set of system. In addition, in the aspect of radiation output of laser signals and millimeter wave signals, the conformal design of the two antennas is realized by adopting heterogeneous integration of a millimeter wave plane antenna and a laser lens antenna.

The optical frequency comb is used for generating two coherent light beams, the design schematic diagram of the optical frequency comb is shown in figure 2, and the optical frequency comb is generated in a mode of cascading an optical phase modulator PM and an optical intensity modulator IM. The optical phase modulator PM can generate a plurality of optical carriers under the drive of a certain radio frequency signal, but the multi-carrier amplitude generated by the optical phase modulator itself is not flat, and a cascaded intensity modulator IM is needed to realize the flattening of the multi-carrier amplitude. The radio frequency source RF generates a radio frequency single tone signal with the frequency fo, the radio frequency single tone signal is divided into two paths of radio frequency signals by the radio frequency power divider PD2, one path of radio frequency signal passes through the intensity modulator IM, and the other path of radio frequency signal passes through the phase modulator PM after the phase shift of the radio frequency phase shifter PS. The optical beam with frequency fc generated by the laser CW and the two paths of input radio frequency signals generate a plurality of optical carriers through intensity modulation and phase modulation. The generated multiple optical carriers are shown in fig. 3, and optical carriers of a desired wavelength are selected after passing through an optical filter TOF. The scheme for generating the optical frequency comb by utilizing the cascade mode of optical phase modulation and optical intensity modulation has the advantages of simple structure, stable optical carrier frequency and high optical carrier signal-to-noise ratio.

It should be noted that, according to implementation needs, each step/component described in this application may be divided into more steps/components, or two or more steps/components or partial operations of steps/components may be combined into a new step/component, so as to achieve the purpose of the present invention, for example, different baseband signal modulation modes and different optical frequency comb generation modes are all specific implementations of the present invention.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (3)

1. A photon-assisted millimeter wave and laser hybrid communication transmitter, comprising: the device comprises an optical frequency comb, a light intensity modulator, two polarization maintaining optical couplers, an optical amplifier, an optical fiber, a photoelectric detector, a radio frequency power amplifier, a laser antenna and a millimeter wave antenna;

two beams of coherent light with frequencies fc and fc-fs are generated by using an optical frequency comb, wherein one beam of light with the frequency fc modulates a baseband signal onto fc through a light intensity modulator to form a modulated light signal, the modulated light signal is divided into two beams of light through a first polarization maintaining coupler, one path of the modulated light signal branched by the first polarization maintaining coupler is sent to a laser antenna through an optical amplifier and is output by radiation through an optical fiber, the other path of the modulated light signal is combined with an unmodulated light signal with the frequency fc-fs generated by the optical frequency comb at a second polarization maintaining coupler, optical heterodyne is performed through a photoelectric detector to generate a millimeter wave radio frequency signal with the frequency fs, and the millimeter wave radio frequency signal is output by radiation through a millimeter wave antenna after passing through a radio frequency power amplifier.

2. The photonic-assisted millimeter wave and laser hybrid communication transmitter of claim 1, wherein the optical frequency comb comprises: the device comprises a fixed wavelength laser, a radio frequency source, a radio frequency power divider, a radio frequency phase shifter, a light intensity modulator, a light phase modulator and a light filter;

the radio frequency source generates a radio frequency single tone signal with the frequency fo, the radio frequency single tone signal is divided into two paths of radio frequency signals by a radio frequency power divider, one path of radio frequency signal passes through a light intensity modulator, and the other path of radio frequency signal passes through a light phase modulator after being subjected to phase shifting by a radio frequency phase shifter;

the optical wave beam with the frequency fc generated by the fixed wavelength laser sequentially passes through the light intensity modulator and the optical phase modulator, then generates a plurality of optical carriers with two paths of radio frequency signals, and selects the optical carrier with the required wavelength after the generated plurality of optical carriers pass through the optical filter.

3. The photonic-assisted millimeter wave and laser hybrid communication transmitter of claim 1 or 2, wherein the heterogeneous conformal integration of the laser antenna and the millimeter wave antenna forms a laser and millimeter wave common aperture integrated antenna.

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