95results about How to "Avoid insertion loss" patented technology

The invention discloses a high-different frequency isolation broadband double-frequency base station antenna array, which comprises at least one high-frequency antenna unit, a low-frequency antenna unit and a floor board, wherein when one high-frequency antenna unit exists, the high-frequency antenna unit is placed at one side of the floor board, when multiple high-frequency antenna units exist, the high-frequency antenna units are placed at two sides of the floor board respectively, each high-frequency antenna unit comprises multiple oscillator arms and a Balun, the oscillator arms are connected through a distributed inductor, and feeding is carried out through the Balun; the low-frequency antenna unit is placed in the middle of the floor board and comprises multiple oscillator arms and a Balun, the oscillator arms are connected through a distributed capacitor, feeding is carried out through the Balun, the Balun is provided with a feeder line and an H-type microstrip branch, and the H-type microstrip branch is connected with the feeder line. In a condition of not cascading filters, high isolation in a condition in which the distance between the different-frequency antenna units is small and the floor board is small can be realized, insertion loss of a filter is avoided, a stable pattern in a broadband is realized, and due to a decoupling structure, the volume of an antenna unit is not added extraly.

The SAW element 11 comprises a serial arm 17 formed between an input terminal 15 and an output terminal 16, two serial arm side SAW resonators 20 located in the serial arm 17, at least three parallel arms 19 connected between the serial arm 17 and a reference potential terminal 18, and parallel arm side SAW resonator 21 located in the parallel arms 19, respectively. Each of these parallel arm side SAW resonators 21 has an anti-resonant frequency corresponding with the predetermined resonant frequency of each serial arm side SAW resonator 20. Further, at least one parallel arm side SAW resonator 21 has a resonant frequency different from those of the other parallel arm side SAW resonators 21. Thereby, not only insertion loss can be prevented from being deteriorated but also an attenuation characteristic of the SAW element 11 can be readily varied.

The invention discloses a multicore optical fiber connector which comprises a plug assembly and a socket assembly. The plug assembly is formed by an insulation casing and a plurality of plug inserting core assemblies, wherein each plug inserting core assembly comprises a ceramic inserting core seat, a spring, a spring blocking unit, a ceramic inserting core and a ceramic sleeve. The socket assembly is formed by an insulation casing and a socket inserting core assembly. The multicore optical fiber connector is characterized in that an outer spring is sleeved outside each plug inserting core assembly in the plug assembly, the front end of the plug inserting core assembly is provided with a plug front outer casing, the front end of the plug front outer casing is sleeved outside each ceramic sleeve, the tail end of the plug front outer casing is connected with each spring blocking unit, the outer edges of the spring blocking unit and the plug front outer casing are provided with annular protrusions respectively, and the outer spring is arranged between the two annular protrusions. According to the multicore optical fiber connector, the outer spring is sleeved outside each plug inserting core assembly so that axial and radial floating between the plug front outer casings and internal parts can be achieved, and insertion loss and return loss are avoided.

The invention discloses a semi-distributed passive variable attenuator. The semi-distributed passive variable attenuator comprises a 0-7dB distributed attenuation module, an 8dB attenuation module, a 16dB attenuation module and an input control conversion module. A switch field effect transistor adopting the structure that a body end is connected with a source electrode, a switch field effect transistor provided with a channel parallel connection resistor structure and a switch field effect transistor of a stacked structure are used as control switches. The semi-distributed passive variable attenuator is controlled by a five-digit figure signal to operate independently. Coplanar waveguide transmission lines are used for matching adjacent attenuation modules and matching 50-omega input impedance and 50-omega output impedance. The operating frequency range of the semi-distributed passive variable attenuator is 0-50 GHz, wherein the semi-distributed passive variable attenuator can realize 32 states of low-loss low-phase shift signal amplitude attenuation by stepping with the length of 1dB in the attenuation range of 0-31dB. The semi-distributed passive variable attenuator has the advantages of being low in loss and additional phase shift, high in degree of linearity, wide in operation frequency band, simple in circuit structure, and applicable to a radio frequency / microwave system processing high-power signals.

The invention discloses an antenna device, a control method for the same and an electronic device. The antenna device comprises a first antenna unit, a second antenna, a frequency band control unit, and a switch unit; the first antenna unit can transmit a first antenna signal including multiple frequency bands; the multiple frequency bands comprise a first frequency band and a second frequency band; the frequency of the second frequency band is different from that of the first frequency band; the second antenna unit can transmit a second antenna signal and the frequency band of the second antenna signal comprises the first frequency band; the frequency band control unit is connected to the first antenna unit and transmits the signal of the second frequency in the first antenna signal between the first antenna unit and a signal transceiver corresponding to the second frequency band; and the switch unit is used for connecting at least one of the frequency band control unit and the second antenna unit to a signal transceiver corresponding to the first frequency band for transmitting the signal of the first frequency band. The antenna device, the control method and the electronic device can avoid insertion loss of a switch unit on transmission paths of part of the antenna signals and improve signal quality of part of the antenna signals.

The invention discloses an ROF (radio over fiber) system based on a dual-modulator parallel structure, and relates to the fields of microwave photons, fiber-optical communications and the like. In order to overcome the technical difficulties in generating downlink high-frequency doubling MMWs (millimeter waves) and underclocking the uplink high-frequency signals in an existing ROF system, a structure that a first dual-pole Mach- Zehnder modulator is connected with a second dual-pole Mach-Zehnder modulator (30 and 31) in parallel is adopted to generate multi-frequency harmonic components. A first OFBG (optical fiber Bragg gratings) (60) and a second OFBG (61) as well as a first circulator (50) and a second circulator (51) are utilized to select frequencies; and a first photoelectric detector (40), a second photoelectric detector (41), a third photoelectric detector (42), a fourth photoelectric detector (43) and a fifth photoelectric detector (44) are utilized to generate downlink quadruple-frequency MMWs and signals of after uplink signal underclocking. The frequency of the output signals of a sinusoidal signal generator (21) are within the range from 1GHz to 30GHz, MMW signals within the range from 4GHz to 120GHz can be generated, and the signals for the underclocking of the uplink signals can be provided. A first mixer (80) and a second mixer (81) are used for mixing the uplink high-frequency signals with the underclocked signals so as to reduce frequencies of uplink signals.

The invention belongs to the technical field of distributed optical fiber sensing. The invention provides a Brillouin optical time domain reflector modulated by the physical random number, aiming at the compromise between the spatial resolution, the signal-to-noise ratio, and the measurement precision of the Brillouin optical time domain reflector in the prior art. The Brillouin optical time domain reflector comprises a first DFB laser emitting module, a second DFB laser emitting module, a first optical fiber coupler, a pulse optical amplifier, a second optical fiber coupler, a polarization controller, a gain switch modulator, a physical random number generating module, a DWDM dense type wavelength division multiplexer, a sensing optical fiber, an optical fiber circulator, a continuous optical amplifier, an optical filter, a third optical fiber coupler, a scrambler, a photodetector, a mixer, a microwave adjustable frequency source, an electric amplifier, an electric filter, an A / D conversion module, and a host computer. The invention can monitor the strain magnitude and location of the sensing optical fiber along the line in real time with high precision under the premise of ensuring spatial resolution.

A polarization switching / variable directivity antenna according to the present invention includes a radiation conductor plate 12 on a front face, and a ground conductor plate 14 on a rear face, of a dielectric substrate 11. At least one directivity switching element and at least two polarization switching elements are provided within the ground conductor plate 14 on the rear face. The directivity switching element includes a first slot which is formed by a removing a loop-like portion from the ground conductor plate 14 and at least two directivity switching switches (22a to 22d). Each polarization switching element includes a first slot which is formed by removing a loop-like portion from the ground conductor plate 14 and at least one polarization switching switch (23a to 23d). Switching of a maximum gain direction of radiation directivity of the antenna is realized through control of the directivity switching switches 22a to 22d, and switching of the rotation direction of a circularly polarized wave which is emitted from the antenna is realized through control of the polarization switching switches 23a to 23d.

The application discloses terminal equipment. The terminal equipment comprises a first antenna, a second antenna, a first channel electrically connected with the first antenna, and a second channel electrically connected with the second antenna; the first channel comprises at least two first transmitting branches, at least two first transmitting branches are used for sending a carrier signal for realizing carrier aggregation through the first antenna; the second channel comprises a receiving branch electrically connected with the second antenna and a receiving filter electrically connected with the receiving branch, wherein the receiving branch is used for receiving a carrier aggregation signal through the second antenna, and the receiving filter is used for filtering the carrier aggregation signal, thereby obtaining the carrier signal for realizing the carrier aggregation.

The invention relates to a multiple-quantum well waveguide butt-coupling method comprising the following steps of: A, carrying out primary epitaxy on a substrate to obtain a multiple-quantum well structure; B, after a dielectric film is deposited, carrying out mask photoetching, and removing a waveguide part of a first region requiring secondary epitaxy by using a three-step etching method; C, placing an epitaxial wafer into metal organic chemical vapor deposition equipment for high-temperature treatment; and D, carrying out secondary epitaxial growth to obtain a second multiple-quantum well structure. By using the method, an attractive interface etching appearance can be achieved, cavities caused during growth can be avoided, the butting quality can be effectively improved, the coupling loss can be reduced, and good repeatability can be obtained. The multiple-quantum well waveguide butt-coupling method can be used for manufacture and batch production of various photoelectronic integrated chips.

The invention discloses a linear-cavity active Q-switching all-fiber laser. The laser is characterized in that a linear cavity is provided, the output tail of a pumping semiconductor laser is connected with the pumping input port of a fiber beam combiner; the fiber output port of the fiber beam combiner is connected with a high-reflectivity fiber bragg grating; the other terminal of the high-reflectivity fiber bragg grating is welded with gain fibers together; the other terminal of the gain fibers is welded with a low-reflectivity fiber bragg grating formed on polarization-preserving fiber; an adjustable piezoelectric element signal drive circuit is used for driving a piezoelectric element to press fiber in the cavity periodically to modulate the polarization direction of light; the other terminal of the low-reflectivity fiber bragg grating is connected with the input terminal of a fiber isolator; and the output fiber is connected with the output terminal of the fiber isolator. The laser provided by the invention has the advantages of little insertion loss, simplified structure, high repeating frequency of laser pulses, low cost and easiness in industrialization. Large-diameter core double-cladding gain fibers can be used in the laser cavity, so that high-energy high-power laser pulses can be obtained conveniently.

The invention provides a graphene electro-optical modulator and a preparation method thereof. The graphene electro-optical modulator is in a plate capacitor structure and comprises an optical substrate, a bottom graphene layer, an insulating layer and a top graphene layer, and the optical substrate, the bottom graphene layer, the insulating layer and the top graphene layer are arranged sequentially from bottom to top. The top graphene layer and the bottom graphene layer are in mutual insulation through the insulating layer, the top graphene layer is above the bottom graphene layer, and an external modulation voltage is applied to the bottom graphene layer and the top graphene layer. The graphene electro-optical modulator is an active Q modulation device independent of a waveguide structure on the basis of a graphene electro-optical modulation technology; modulation depth is changed by amplitude variation of the external periodic voltage, and light modulation depth requirements of different laser parameters can be met; after the graphene electro-optical modulator is inserted into a laser, high-pulse-energy controllable-repetition-rate pulse laser output can be achieved. Therefore, the graphene electro-optical modulator has a promising market prospect.

The invention discloses an optical fiber and a fiber laser. The optical fiber comprises an outer cladding, a protective layer and a fiber core; the fiber core is formed by a rare earth-doped active fiber core body and n pure quartz pumping fiber core bodies, wherein the rare earth-doped active fiber core body is provided with a pure quartz inner cladding, and the n is greater than or equal to 1; each pumping fiber core body and the active fiber core body are mutually contacted but not fused together, wherein the spread length of a contact site is greater than or equal to one tenth of the perimeter of the pumping fiber core body so that light can be coupled from the pumping fiber core body to the active fiber core body in a one-way mode. The fiber laser comprises the optical fiber, a resonant cavity and a semiconductor laser body, wherein a high-reflective optical grating and a low-reflective optical grating are etched in the two ends of the active fiber core body respectively and service as the resonant cavity together; the pumping fiber core bodies are connected with the semiconductor laser body in a fusion welding mode. The optical fiber can reduce the number of fusion welding points to the maximum extent and effectively improve pumping light absorption efficiency, thereby realizing heat dissipation inside the fiber laser and improving output quality of the fiber laser; since cerium is used, the fiber laser also has the advantages of resistance to photon darkening and radiation.

The invention belongs to the technical field of integrated circuits, and in particular relates to a four-channel phased array transceiver with phase control and applied to a 5G millimeter wave base station. The four-channel phased array transceiver monolithic is integrated with a four-channel transmitter and a four-channel receiver, and mainly comprises a transmission antenna, a power amplifier with phase control, a frequency mixer in a transmission path, a receiving antenna, a low-noise amplifier with phase control and a frequency mixer in a receiving path. Phase shifting is achieved by usingan interstage matching network of the low-noise amplifier and the power amplifier, so that the high area overhead and insertion loss of the traditional passive phase shifter are avoided; meanwhile, the phased array transceiver monolithic is integrated with the four-channel transmitter and the four-channel receiver, so that the area of the whole transceiver chip is greatly reduced. Therefore, compared with the traditional transceiver framework, the four-channel phased array transceiver has the advantages of small area and high link gain.

The invention discloses an optical fiber mode revolver, a full-fiber mode multiplexer and a demultiplexer. The optical fiber mode revolver comprises two inner cores which are symmetrically distributed, and the distances between the fiber core of the optical fiber and the two inner cores are preset distances; the angle between the connection line between the inner cores and the optical axis of the guided mode is the preset angle; the refractive index of the fiber core and the refractive indexes of two inner cores are different; the length of the optical fiber mode revolver is the beat length of two propagation constants of two guided modes which realize the mode conversion. Because the two inner cores are symmetrically arranged on two sides of the fiber core of the optical fiber, the refractive index of the inner core is different from that of the fiber core, and the incident guided mode can be rotated for 90 degrees. As a result, the mode conversion can be realized on the basis of the optical fiber, and the reusing of the mode can be realized. Besides, the mode revolver is based on the optical fiber, which prevents the insertion loss and effectively improves the performance of the communication system.

The invention discloses a broadband circularly polarized filtering array antenna with sequential rotary feeding. A circularly polarized antenna unit is realized by cutting opposite angles of a squarepatch and introducing degenerate mode separation; then, opening resonance rings of different sizes are etched on the surface of the patch, and gain zero points are introduced to the two sides of a working frequency band respectively to achieve good out-of-band rejection; and the 2 * 2 circularly polarized antenna array with the relative bandwidth of 43.14%, the axial ratio bandwidth of 1.71% and the highest gain of 14.64 dBi is realized by adding parasitic patches, forming T-shaped grooves and adopting a strip line probe mixed feed structure and a sequential rotary feed technology.

Provided is an optical transceiver module having a dual band pass WDM coupler embedded therein, wherein the dual band pass WDM coupler provides pass bands for selectively passing a transmission signal output from an optical transmitting unit, and an optical signal having a specific wavelength received by an optical receiving unit among optical signals input through a common port. According to the present invention, a size and cross-talk of the optical transceiver module may be reduced, and the optical transceiver module may be used as a video transceiver in an optical subscriber network according to an ITU-RG.983.3 standard.

The invention discloses a fundamental frequency light seed injected narrow linewidth inner cavity Raman laser. A laser gain medium absorbs pumping light to form population inversion so as to generate laser gain, and thus 1064nm fundamental frequency laser oscillation formed under positive feedback effect of a laser resonant cavity composed of a resonant cavity reflecting mirror, a resonant cavity folded mirror and an output mirror; a fundamental frequency light seed source emits 1064nm single frequency seed light which enters the laser resonant cavity after passing through the isolator and being focused by a seed light coupling lens and reflected by a beam splitter; the single frequency seed light is effectively coupled into the laser resonant cavity to achieve seed injection; when 1064 fundamental frequency laser passes through a laser gain medium and a Raman gain medium, Raman gain is generated, when the Raman gain is larger than loss of the Stokes resonant cavity composed of the resonant cavity reflecting mirror, the resonant cavity folded mirror and the output mirror, stimulated Raman scattering occurs, and stable 1176nm Stokes light oscillation is formed in the Stokes resonant cavity.

The invention discloses a flat-gain broadband neodymium glass amplifier based on birefringence filtering. The flat-gain broadband neodymium glass amplifier comprises a polarization controller, a birefringence filtering spectrum equalizer and a neodymium glass amplifier. The polarization controller is composed of a quarter wave plate and a half-wave plate which are successively arranged in an optical path. The birefringence filtering spectrum equalizer is composed of a polarizer, a phase delayer and a polarization analyzer, wherein the polarizer, the phase delayer and the polarization analyzer are successively arranged in the optical path. The polarization passing direction of the polarizer is same with that of the polarization analyzer. The phase delayer is fixed on a rotating adjusting frame. The neodymium glass amplifier comprises neodymium glass and a pumping light source. According to the flat-gain broadband neodymium glass amplifier, the neodymium glass broadband laser amplifier with the flat gain is constructed based on the birefringence filtering spectrum equalizer and the neodymium glass amplifier. Particularly, spectrum transmittance is adjusted by means of birefringence spectrum filtering technology; counter compensation is performed on the gain spectrum of a traditional neodymium glass amplifier; and finally a flat gain spectral line in a relatively wide spectrum range is realized.

The invention discloses a highly integrated four-channel S-band transceiver module, comprising a receiving channel, a transmitting channel and an external interface, wherein the receiving channel comprises paired band branch I and Q receiving channels, and the transmitting channel comprises paired band branch I and Q transmitting channels. The two-port feeding of the transceiver module can effectively improve the circular polarization axis ratio of the antenna, and the transceiver channels are separated, which can improve the isolation of the transceiver, reduce the interference between channels and help to improve the communication capability of the system. Furthermore, the invention also discloses a phased array antenna with the high-integration four-channel S-frequency transceiver module, which can realize polarization adjustability by cooperating with a four-point feeding antenna unit, realizes polarization conversion and beam scanning of the phased array antenna through electroniccontrol phase shift and branch switching, effectively reduces the antenna port surface, and realizes miniaturization design.

A non-reciprocal circuit element includes first and second isolators of a high-pass type, each of the first and second isolators including a permanent magnet, a ferrite body to which a direct-current magnetic field is applied by the permanent magnet, and first and second center electrodes arranged on the ferrite body so as to cross each other in an insulated state. The first isolator has a passing frequency band that is higher than a passing frequency band of the second isolator. The first and second isolators include input portions that are electrically connected to define a single input port. A low pass filter is provided between the input port and the input portion of the second isolator.

The invention discloses a drive control circuit, a drive method, a circuit board and an air conditioner. The motor drive control circuit comprises a first power module, a second power module, a firstswitch group, a controller, a totem-pole PFC circuit and a step-down switch circuit, wherein the first power module and the second power module are connected to two sides of an open-winding motor, thecontroller is connected with the totem-pole PFC circuit to control the totem-pole PFC circuit to reach at least one of the following states: a diode rectification state, a low-frequency switching state and a high-frequency switching state; and a diode rectification mode and a low-frequency switching mode of the totem-pole PFC circuit are matched. The controller controls the step-down switch circuit to carry out step-down output, and provides a voltage suitable for low-frequency operation for the first power module, thereby obtaining a higher energy efficiency ratio in a low-frequency operation state of the open-winding motor, the operation efficiency of equipment at a low frequency is improved, and the energy-saving demands are met.

The invention relates to a radio frequency low-temperature low-noise amplifier system of thermoelectric refrigeration, belonging to the technical field of microwave communication. The system mainly comprises a sealing heat insulation cavity, a thermoelectric cooling assembly arranged in the cavity, a radio frequency low-temperature and low-noise amplifier, a temperature sensor, a heat dissipation assembly, a heat conduction assembly and an electric control assembly, wherein the radio frequency low-temperature and low-noise amplifier, the thermoelectric cooling assembly and the heat dissipation assembly are sequentially connected through the heat conduction assembly; the electric control assembly is respectively connected with the thermoelectric cooling assembly, the heat dissipation assembly and the radio frequency low-temperature and low-noise amplifier; the temperature sensor is arranged on one side of the heat dissipation assembly, which is close to the thermoelectric cooling assembly, and is connected with the electric control assembly; and the radio frequency input interface and the radio frequency output interface in two ends of the radio frequency low-temperature and low-noise amplifier are fixed in two end walls of the sealing heat insulation cavity. The radio frequency low-temperature low-noise amplifier system of thermoelectric refrigeration ensures vibration and water prevention and heat insulation when the low-temperature and low-noise radio frequency amplifier works in low-temperature, and meanwhile is capable of improving the sensitivity of the radio frequency receiving system.

The invention discloses an optical fiber mode locked laser. A Sagnac filter, which is arranged in a cavity of an optical fiber mode locked laser, is utilized as a frequency spectrum filtering element that is used for assisting mode locking and narrowing a pulse width. Because the filer is an all-fiber device, an insertion loss and an aligning difficulty can be avoided, wherein the insertion loss and the aligning difficulty are caused by introduction of a block device; and environmental stability and robustness of the optical fiber mode locked laser are enhanced; besides, a filtering bandwidth is easy to adjust and adjustment of the filtering bandwidth enables a spectral width and a pulse width of an output mode locked pulse to be effectively changed.

The invention discloses a graphene-aided D-type superfine optical fiber structure, which relates to the technical field of optoelectronics. The graphene-aided D-type superfine optical fiber structure comprises a fiber core and a fiber core coating layer. The graphene-aided D-type superfine optical fiber structure is characterized in that the fiber core includes an exposed section directly exposed in the air and a non-exposed section coated in the fiber core coating layer; a support mechanism is arranged below the exposed section; the middle section of the exposed section is polished to form a D-type optical fiber section; the polished surface of the D-type optical fiber section is provided with a graphene layer contacting the D-type optical fiber section, and the width of the graphene layer is larger than the diameter of the fiber core; and the two ends of the graphene layer at the two axial sides of the fiber core are respectively provided with a first electrode and a second electrode which contact the graphene layer. The problem that the traditional graphene optical fiber cannot obtain the high nonlinear characteristics of graphene is solved, and the insertion loss and power consumption of the device are reduced.

The invention discloses an all fiber filter. The filter comprises: a 2*2 fiber coupler, possessing a first port and a second port which are located on one side and a third port and a fourth port which are located on the other side; a polarization maintaining fiber, two ends of which are respectively welded with passive fibers of the third port and the fourth port so as to form an annular optical path. The passive fiber between the third port and the polarization maintaining fiber coils into a fiber ring possessing a certain radius. The fiber ring is taken as a first polarization controller. During introducing a block device, insertion losses can be generated and alignment is difficult. Bu using the all fiber filter, the above problems can be solved. An all-fiber system is easy to be realized. Filtering bandwidth is easy to be adjusted so that the all fiber filter is suitable for occasions with various different performance requirements.

The embodiment of the invention provides a signal processing circuit, a mobile terminal and a signal processing method, the signal processing circuit comprises N+1 antennas, wherein at least a part ofthe N+1 antennas are distributed on a first side edge and a second side edge which are adjacent to each other of the mobile terminal; a radio frequency front-end module which comprises a signal receiving and transmitting end and N-1 signal receiving ends; a single-pole double-throw switch which comprises a first contact, a second contact and a third contact, wherein the signal receiving and transmitting end is connected with the first contact, and the second contact is connected with a first antenna arranged on the first side edge of the mobile terminal; an N-pole N-throw switch. When the mobile terminal is in a vertical screen state, a first contact and a second contact of the single-pole double-throw switch are connected; and when the mobile terminal is in a horizontal screen state, thefirst contact and the third contact of the single-pole double-throw switch are connected. According to the embodiment of the invention, the communication quality of the mobile terminal can be improved.

The invention provides a high-precision broadband numerical control attenuator, comprising a numerical control attenuator and a feedback compensation circuit. One end of the feedback compensation circuit is connected between an input end and an output end of the numerical control attenuator, and the other end is grounded. Feedback capacitances and / or feedback inductances corresponding to impedance values in the feedback compensation circuit are accessed to the numerical control attenuator according to band values of input signals of the numerical control attenuator and attenuation precision demands on different bands, thereby adjusting attenuation precision of selected bands. According to the attenuator, the attenuation precision of the corresponding bands of the input signals of the numerical control attenuator can be adjusted, electrical characteristics such as an insertion loss of the numerical control attenuator are influenced less, and the problems such as serious deterioration of the insertion loss, an input 1dB compression point, an input voltage standing wave coefficient and an output voltage standing wave coefficient are avoided.

The invention provides a communication control device, a method and a mobile terminal. The device comprises a determination module for determining the current network state; the transmitting module isconfigured to send a control command to the switch control module if the current network state satisfies a preset condition, so that the switch control module switches from the first path to the second path between the control signal input terminal and the signal output terminal of the switch control module. A bypass circuit is provided in the communication control device according to an embodiment of the present invention, Filter and Switch Control Module, after the determination module determines the current network state, if the sending module judges that the current network state satisfies the preset condition, the switch control module can connect the bypass circuit to the signal input terminal and the signal output terminal according to the received control command, and disconnectsthe circuit path of the filter in the communication control device, thereby avoiding the insertion loss of the filter and improving the network coverage of the communication device.

The invention relates to a multi-channel video optical transceiver system capable of realizing video output switching without an external matrix, which comprises an M-channel video optical transceiver sending end and an M-channel video optical transceiver receiving end. By adopting the system, video output at the receiving end of the multi-channel video optical transceiver system provided by the invention can be directly connected with equipment such as a large screen, a monitor and the like, thus saving expensive video matrix, significantly lowering fabrication cost of similar systems, and avoiding insertion loss of an analog video signal introduced by the video matrix; and output switching of the multi-channel video optical transceiver of the invention is carried out in a digital domain, thus being free from loss of a switching signal. Therefore, the multi-channel video optical transceiver system can avoid quality reduction of the analog video signal introduced by the video matrix.