Abstract: A patch antenna structure includes a metal substrate, a feeding patch connected to the metal substrate, and a first feeding line disposed on the feeding patch, a first feeding point and a second feeding line connected in the first feeding line, and a second feeding point connected in the second feeding line, the first feeding line and the second feeding line intersect at a node. A length of the first feeding line between the node and the first feeding point and a length of the second feeding line between the node to the second feeding point are set equal. A switching component for changing the relative phase between the first feeding point and the second feeding point is provided in the first feeding line and/or in the second feeding line.

Abstract: Aspects of the subject disclosure may include, for example, polarization adaptation in panel MIMO antennas to improve isolation between downlink beams so as to reduce or minimize beam interference, which improves antenna performance and/or reduces antenna size requirements. Other embodiments are disclosed.

Abstract: Provided is an object shape detection apparatus that can detect the shape of a raised or depressed portion on the surface of an object. In accordance with a comparison result obtained by a reflection intensity comparator with regard to intensity of a horizontally polarized wave component and a vertically polarized wave component of a reflected wave, the object shape determiner detects the shape of the raised portion and the shape of the depressed portion of a detection target object. The object locator detects the position of the raised portion and the position of the depressed portion of the detection target object by measuring the distance to the raised portion and the distance to the depressed portion of the detection target object detected by the object shape determiner.

Abstract: A method for testing radio frequency performance of a wireless device is provided. Power level reporting information of a device under test is obtained. A propagation matrix is obtained based on the power level reporting information. An inverse matrix is obtained based on the propagation matrix to form a virtual cable between an output port of an instrument and a receiver port of the device under test. A throughput test signal is transmitted through the virtual cable to perform a performance test on the device under test and to obtain a test result of the radio frequency performance.

Abstract: A tunable narrow-linewidth photo-generated microwave source based on polarization control includes a high-reflectivity fiber grating, a high-gain fiber, a low-reflectivity polarization-maintaining fiber grating, a stress adjusting device, a single-mode semiconductor pump laser, an optical wavelength division multiplexer, a polarization beam splitter, a polarization controller, an optical coupler, and a photoelectric detector. Birefringence distribution in the low-reflectivity polarization-maintaining fiber grating is controlled by adjusting a stress magnitude of the stress adjusting device to the low-reflectivity polarization fiber grating, thereby controlling a laser frequency working in different polarization modes in a resonant cavity, and a tunable narrow-linewidth photo-generated microwave source is generated by a beat-frequency technology using a dual-wavelength narrow-linewidth laser with variable frequency intervals.

Abstract: A device includes a modem having a first feed port and a second feed port. A first planar dual-polarized sub-array has a first beamwidth and includes a first orthogonally polarized element communicatively coupled to the first feed port and a second orthogonally polarized element communicatively coupled to the second feed port. A second planar dual-polarized sub-array has a second beamwidth and includes a third orthogonally polarized element communicatively coupled to the second feed port and a fourth orthogonally polarized element communicatively coupled to the first feed port. The first dual-polarized sub-array and the second planar dual-polarized sub-array generate a collective beamwidth that exceeds the first beamwidth and the second beamwidth.

Abstract: A transceiver circuit that includes multi-port antenna and transmitter and receiver circuit may transmit and receive polarized electromagnetic waves. The polarization of transmitted electromagnetic waves may be determined by adjusting gain and phase differences between multiple circuit paths in the transmitter circuit. In a similar fashion, the gain and phase of circuit paths in the receiver circuit may be adjusted to accommodate different polarizations of received electromagnetic waves.

Abstract: Apparatus for dual-band antenna and communications tower comprising such apparatus are provided. The apparatus comprises a first part (202) comprising first and second propagation paths configured to selectively propagate signals of a first frequency with either a first polarization state or a second polarization state, a transition part (204) rotatable between first and second transition positions to selectively propagate signals of a second frequency along the second signal path with the first polarisation state when in the first transition position and with the second polarisation state when in the second transition position and a rotator part rotatable between first and second rotator positions. Wherein, the rotator part is configured to orientate the polarisation of signals in the second signal path in order to couple the second signal path to an interface, and allow propagation of signals in the first signal path in either the first or second rotator positions.

Abstract: A method for confusing the electronic signature of a signal transmitted by a radar, includes the generation by the radar of at least one pulse, wherein the method comprises a step of modulation, in the pulse, of the polarization of the transmitted signal, according to two orthogonal or opposite polarizations, the modulation of the polarization being performed according to a predetermined modulation code.

Abstract: A radar apparatus according to the present disclosure includes: a transmission unit configured to transmit radio waves; a reception unit including a first receiver configured to receive a first reflected radio wave and a second receiver configured to receive a second reflected radio wave, the first reflected radio wave and the second reflected radio wave having different polarization characteristics from each other and being included in reflected radio waves that are the radio waves reflected by a detection target; and a control unit configured to control operations of the transmission unit and the reception unit, and configured to identify the detection target on the basis of the operation of the transmission unit, a first reception level at the first receiver, and a second reception level at the second receiver.

Abstract: According to one configuration, a wireless communication system includes antenna hardware, radio communication hardware, and a controller. The controller defines wireless sectors of coverage and configures them dynamically depending on network conditions. The radio communication hardware is coupled to the antenna hardware. The antenna hardware includes multiple antenna elements to wirelessly communicate in a network environment. During operation, the controller generates configuration settings to control a configuration of the radio communication hardware and the antenna hardware. The controller applies the configuration settings to the radio communication hardware to define corresponding wireless coverage provided by one or more software defined sectors in multiple base stations in a network environment. The one or more instantiated base stations (as indicated by the configuration settings) provide multiple communication devices in the network environment access to a remote network such as the Internet.

Abstract: A millimeter or mm-wave system includes transmission of a millimeter wave (mm-wave) radar signal by a transmitter to an object. The transmitted mm-wave radar signal may include at least two signal orientations, and in response to each signal orientation, the object reflects corresponding signal reflections. The signal reflections are detected and a determination is made as to location of the object.

Abstract: An antenna device includes: an antenna configured to radiate a radio wave; a substrate at which the antenna is provided; and a cover which covers the substrate from a radiation surface side of the antenna, the cover is a dielectric material, a maximum distance between the cover and the substrate in a normal direction to the substrate is smaller than ½ of a free space wavelength of the radio wave, and a thickness of the cover is smaller than ½ of an effective wavelength of the radio wave in the cover.

Abstract: A method is provided for determining a road condition by using a radar system having transmitter and receiving units for transmitting and receiving radar waves having two different polarizations and providing transmit and receive signals indicating an intensity of the transmitted and received radar waves. Co-polarized backscattering coefficients and at least one cross-polarized backscattering coefficient are determined based on the transmit and receive signals. If the cross-polarized backscattering coefficient is greater than or equal to a threshold, the road condition is determined based on a ratio of the co-polarized backscattering coefficients and based on a difference of one of the co-polarized backscattering coefficients and the cross-polarized backscattering coefficient. If the cross-polarized backscattering coefficient is smaller than the threshold, the road condition is determined based on the ratio and a difference of the co-polarized backscattering coefficients.

Abstract: A TRP selects two UEs that have potential for MU-MIMO transmission, and the TRP then measures signal and interference for each panel in both UEs based on UL beam management for a set of one or more candidate TRP beams. Based on the measurements, the TRP determines if multi-user transmission (i.e., co-scheduling of the two UEs) is possible.

Abstract: An electronic device that uses an arbitrary transmit polarization is described. This electronic device includes: a first antenna having a first predefined polarization; and a second antenna having a second predefined polarization, where the second predefined polarization is different from the first predefined polarization. During operation, an interface circuit in the electronic device selectively transmits, from the first antenna, first wireless signals corresponding to the packet or the frame. Moreover, the interface circuit selectively transmits, from the second antenna, second wireless signals corresponding to the packet or the frame, where the second wireless signals have a same magnitude as the first wireless signals, and the second wireless signals are transmitted from the second antenna concurrently (or at the same time) as the first wireless signals are transmitted from the first antenna. Note that the interface circuit may dynamically modify the transmit polarization during the communication.

Abstract: The present invention is provides a method and apparatus for routing a data packet in a network. For each nearby device capable of routing the packet toward a further destination, an associated cost or utility is determined. The device with lowest cost or highest utility is selected and the packet is forwarded toward same. The selecting may use a comparator tree. The cost or utility may be associated with forwarding the data packet from the candidate device toward the further destination. The cost or utility may be based on a distance from candidate device to the further destination, and may be determined using a Haversine function or approximation thereof, or by computing an inner product of a first vector and a second vector originating at a center of Earth, the first vector directed toward the candidate device, the second vector directed toward the further destination.

Abstract: A phased array antenna includes multiple antenna elements where each antenna element is an antenna apparatus that includes an antenna integrated with a filter. Each antenna apparatus includes a plurality of resonators where at least some of the resonators are each enclosed in a metal cavity and at least one resonator is exposed to free space to form a radiator element. Each antenna apparatus has a filter transfer function that is at least partially determined by dimensions of the radiator element and the position of the radiator element within the antenna apparatus. The scan volume of the phased array antenna is dependent on at least one physical dimension of the filter of the antenna apparatus.

Abstract: A method for wireless communication in a reflective environment includes (a) receiving first wireless signals at a first antenna assembly at least partially via a first reflective environment, (b) generating a first electrical signal from a first antenna element of the first antenna assembly in response to the first wireless signals, the first antenna element having a first polarization, (c) generating a second electrical signal from a second antenna element of the first antenna assembly in response to the first wireless signals, the second antenna element having a second polarization different from the first polarization, (d) shifting phase of at least one of the first electrical signal and the second electrical signal, and (e) after shifting phase, combining at least the first electrical signal and the second electrical signal to generate a combined electrical signal.

Abstract: An omni-directional antenna module includes a plurality of vertically and horizontally polarized antenna elements arranged to provide 360° coverage around an antenna, and to eliminate nulls below the antenna. The antenna elements are arranged in parallel with respective orthogonal axes of a three-dimensional Cartesian coordinate system, with the centers of the antenna elements being arranged collinearly along the vertical or “Z” axis so that the radiation patterns of the individual orthogonally polarized dipoles do not interfere.

Abstract: The disclosure provides for a system for communication with a client device. The system includes a first transmitter configured to transmit a first signal and a second transmitter configured to transmit a second signal. The first signal is configured for a first communication band, and the second signal is configured for a second communication band different from the first communication band. The system also includes a hybrid coupler configured to split the first or second signal to a first part and a second part. In addition, the system also includes a first antenna configured to transmit the first part, and a second antenna configured to transmit the second part. The second antenna is oriented perpendicularly relative to an orientation of the first antenna.

Abstract: Apparatus and methods for monitoring interference in radio communication systems are provided. In certain embodiments, an interference monitor system for a ground terminal detects for interference based on a sum of the power levels of orthogonal polarizations of detected interference, thereby allowing the total and average peak interference power levels to be obtained independent of interference polarization. Further, the interference can be divided into frequency bins over the received signal bandwidth(s), thereby facilitating measurement of interference spectral characteristics. Multiple interference monitors can be included to detect interference over the full angular range over which potential interference has access as well as to determine an angular direction of the interference.

Abstract: Disclosed herein is a new type of fully-connected, hybrid beamforming transceiver architecture. The transceiver described herein is bi-directional and can be configured as a transmit beamformer or a receive beamformer. A method and apparatus are described that allows the beamformer to operate in “carrier aggregated” mode, where communication channels in multiple disparate frequency bands can be simultaneously accessed.

Abstract: A multiband waveguide feed network includes multiple transmit (TX) magic tees, multiple receive (RX)-reject waveguide filters configured to reject RX frequencies, and multiple branch-line couplers configured to couple the plurality of RX-reject waveguide filters to the plurality of TX magic tees. The multiband waveguide feed network includes a quadrature junction coupler configured to couple the plurality of RX-reject waveguide filters to an antenna port. The multiband waveguide feed network is configured to be fabricated in four pieces with three split planes, and the multiband waveguide feed network is circularly polarized.

Abstract: An apparatus comprises: a triaxial antenna including orthogonal x, y, and z linearly polarized elements to convert RF energy to x, y, and z RF signals; converters to convert the x, y, and z RF signals to x, y, and z complex signals, respectively; a polarization generator to rotate x, y, and z axes of the x, y, and z complex signals angularly responsive to angle signals, apply x, y, and z complex weights to the x, y, and z complex signals to produce x, y, and z controlled complex signals, respectively, and sum the x, y, and z controlled complex signals into a combined signal, such that the x, y, and z complex weights apply a polarization to the RF energy as manifested in the combined signal, and the angle signals rotate a plane of the polarization relative to the x, y, and z axes, without moving the triaxial antenna.

Abstract: A method for wireless communication in a reflective environment includes (a) receiving first wireless signals at a first antenna assembly at least partially via a first reflective environment, (b) generating a first electrical signal from a first antenna element of the first antenna assembly in response to the first wireless signals, the first antenna element having a first polarization, (c) generating a second electrical signal from a second antenna element of the first antenna assembly in response to the first wireless signals, the second antenna element having a second polarization different from the first polarization, (d) shifting phase of at least one of the first electrical signal and the second electrical signal, and (e) after shifting phase, combining at least the first electrical signal and the second electrical signal to generate a combined electrical signal.

Abstract: A mechanical architecture of a beam former comprises a plurality of elementary combination circuits and a support structure, the elementary combination circuits being independent of one another, each elementary combination circuit intended to form a beam, the support structure comprising two metal interface plates, respectively top and bottom, the two interface plates formed parallel to one another and spaced apart from one another, in a heightwise direction Z orthogonal to the two interface plates, the elementary combination circuits mounted in the space between the two interface plates and fixed at right angles to the two interface plates.

Abstract: An apparatus includes a package and a beam former circuit. The package may be configured to be mounted on an antenna array at a center of four antenna elements. The beam former circuit may (i) be disposed in the package, (ii) have a plurality of ports, (iii) be configured to generate a plurality of radio-frequency signals in the ports while in a transmit mode and (iv) be configured to receive the radio-frequency signals at the ports while in a receive mode. A plurality of ground bumps may be disposed between the beam former circuit and the package. The ground bumps may be positioned to bracket each port. Each ground bump may be electrically connected to a signal ground to create a radio-frequency shielding between neighboring ports.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE). The UE reports antenna capability information of the UE, the antenna capability information comprising identification information of each of one or more antenna subarrays and polarization information indicating at least one polarization supported by each of the one or more antenna subarrays. The UE further receives an indication to operate each of the one or more antenna subarrays with one or more of the at least one polarization and communicates according to the indication.

Abstract: A multi-line phase shifter of a multi-band mobile communication base station antenna includes: a multi-line phase shifting circuit for receiving an input signal of a first frequency band, and dividing and phase-shifting the input signal so as to correspond to a plurality of radiation elements; and a plurality of frequency combination/division circuits for receiving a plurality of signals divided and phase-shifted by the multi-line phase shifting circuit and a plurality of signals of a second frequency band which have been inputted by being divided and phase-shifted for a plurality of radiation elements by an external multi-line phase shifter, combining corresponding signals, and outputting the same to the plurality of radiation elements.

Abstract: Disclosed are a communication method, a terminal and a communication system, which are applied between a terminal and a base station in a line of sight communication environment. A first polarizing antenna having the same polarity as that of a second polarizing antenna of a base station is set on a terminal, wherein the first polarizing antenna includes a first antenna component and a second antenna component having different polarities; and a first signal and a second signal which are sent by the base station via the second polarizing antenna are received via the first polarizing antenna.

Abstract: Determining the physical location of wirelessly connected devices within a network can provide a number of security benefits. However, manually determining and configuring the physical location of each device within a system can be burdensome. To ease this burden, devices within a network are equipped with a location detection sensor that is capable of automatically determining a device's location in relation to other devices within the network. A location detection sensor (“sensor”) may include a light source, a light direction sensor, a rangefinder, and a radio or wireless network interface. Two location detection sensors can perform a location detection process to determine their relative locations to each other, such as the distance between them. As more sensors are added to a network, a sensor management system uses the relative locations determined by the sensors to map the sensors to a physical space layout.

Abstract: A direct-to-home satellite outdoor unit may comprise a reflector, a support structure, circuitry, and an array of antenna elements mounted to the support structure such that energy of a plurality of satellite beams is reflected by the reflector onto the array where the energy is converted to a plurality of first signals. The circuitry may be operable to process the first signals to concurrently generate a plurality of second signals, each of the second signals corresponding to a respective one of the plurality of satellite beams. The circuitry may be operable to process one or more of the second signals for outputting content carried in the one or more of the second signals onto a link to an indoor unit.

Abstract: A wireless communication system includes a plurality of wireless devices that communicate with each other. Each of the wireless devices includes a transmission unit configured to transmit a carrier of a fixed strength with polarization waves thereof rotated to a different one of the wireless devices using two antennae spatially orthogonal to each other, a reception unit configured to receive a carrier transmitted from the transmission unit of the different wireless device, and a timing detection unit configured to detect a timing at which the polarization waves of the carrier received by the reception unit within a period of rotation indicates a maximum strength. The transmission unit performs transmission or reception of a specific information signal using the carrier based on the timing detected by the timing detection unit.

Abstract: In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are independently adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals of various polarizations are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements, with the transmitted beams having various polarizations. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously.

Abstract: Provided is a wireless communication system that achieves high-reliability communication between a transmitter and a receiver.

Abstract: An antenna assembly includes: a base; a first rod coupled to the base; an outer frame coupled to the first rod, the outer frame being rotatable around the first rod; a first antenna having a first end coupled to a first position of an inner surface of the curvy frame, and a second end coupled to a second position of the inner surface of the outer frame, the first antenna being rotatable around a pivot extending from the first position to the second position; and a second antenna having a first end coupled to a third position of the inner surface of the outer frame, and a second end exposed to an inner space surrounded by the outer frame.

Abstract: A method and system use the mutual coupling property of multiple antenna elements for measuring differences in propagation time among various signal paths involving antenna elements in a radio frequency transmit/receive system. The method and system alleviate the need for external test equipment by using the same hardware used in standard operation of the transmit/receive system for performing propagation time measurement through the generation, mutual coupling, and acquisition of a specially selected reference signal. In an embodiment involving calibration of various signal paths to realize matched propagation times, the signal energy returned through these various paths during standard system operation arrives for acquisition more closely coincident in time, increasing the instantaneous bandwidth of the system.

Abstract: A method (1100) for cross-polarization interference power suppression in dual-polarization radio communication systems includes: filtering (1101) a vertical polarization component (xV(n)) and a horizontal polarization component (xH(n)) of a received dual-polarization channel signal by a 2×2 channel weights matrix (507, 508); and determining (1102) the 2×2 channel weights matrix (507, 508) based on a minimum variance distortionless response criterion.

Abstract: A signal generator for producing periodic signals for a measuring apparatus of automation technology. The signals have sequential, discrete signal frequencies, which lie within a predetermined frequency range. A control- and/or computing unit, a clock signal producer are provided, wherein the clock signal producer provides a constant sampling frequency, which is greater than the maximum discrete signal frequency in the predetermined frequency range. A memory unit is provided, in which for each of the discrete signal frequencies the amplitude values of the corresponding periodic signals are stored or storable as a function of the sampling frequency. The control- and/or computing unit reads out the stored or storable amplitude values of the discrete frequencies successively with the sampling frequency of the clock from the memory unit and produces the periodic signals, or forwards for producing.

Abstract: Output from a plurality of radios is received at input ports of a combiner, combined and carried over a coaxial line to a receiver. A DC current is detected entering one of the input ports. The input port in which DC current was detected is assigned as a DC I/O port, and an identity of the assigned DC I/O port is wireless transmitted to the receiver. The receiver separates a DC current from the combined signals received over the coaxial transmission line. The receiver, based on the wireless transmitted identity of the assigned DC I/O port, routes separated DC current to a receiver I/O port corresponding to the identity of the assigned DC I/O port.

Abstract: There is proposed a method of in-flight transmission of data recorded by a black box of an aircraft (1), the method comprising the emission (600) by the aircraft (1) of a radioelectric beam (F1, F2) transporting said data according to a first directivity (D1) if at least one predetermined parameter does not indicate a critical state of the aircraft (1), and according to a second directivity (D2) different from the first directivity (D1) if the predetermined parameter indicates a critical state of the aircraft (1).

Abstract: Systems and methods are presented for increasing throughput between mobile transmitters/receivers (e.g., between an Unmanned Aerial Vehicle and a ground station) using orthogonally polarized transmission channels. The system may first calibrate the receiver and transmitter antenna pairs using pilot signals and then may update look up tables for feedforward correction. The system may decouple and predict the cross polarization interference due to relative dynamic movement between the transmitter and the receiver. The system may perform a closed-loop suboptimal estimation to generate refined corrections by minimizing a difference between a training vector and a pilot-signal feedback. Cross-polarization discrimination between the transmission and reception antennas may then be Cancelled to improve signal to noise and interference ratio and performance of the system.

Abstract: Multi-band antenna systems for communication systems are disclosed. An antenna system includes at least one low band dipole radiating element for radiating RF energy in a low frequency range and at least one group or column of high band dipole radiating assemblies for radiating RF energy in a high frequency range. The low band dipole radiating element may be constructed to provide improved control beam width stability of the high band dipole radiating assemblies and improved cross-polarization performance in the low frequency range. The high band dipole radiating assemblies include high band dipole radiating elements and shrouds surrounding the high band dipole radiating elements. The shrouds are configured to improve the beam width stability and cross-polarization of the high band dipole radiating elements, improve isolation between the high band dipole radiating elements and to shift resonance of the high band dipole radiating assemblies below the low frequency range.

Abstract: The present invention relates to a communication node with at least one antenna arrangement having four first antenna devices with corresponding antenna port pairs. Each pair of antenna ports comprising a corresponding first antenna port for a first polarization and second antenna port for a second orthogonal polarization. A beamforming arrangement comprises four beam ports and is configured to apply beam weights to each one of the antenna ports. The present invention also relates to a corresponding method.

Abstract: A dielectric hollow antenna apparatus includes a hollow inside tapered rod (e.g., a waveguide) with a flat section and a cap. The antenna further includes a feed through section, a feed pin, and a metal flange. A low loss dielectric material fills the hollow rod that protrudes beyond the metal waveguide to form a radiating element. The radiating element is designed in such a way to maximize radiation and minimize reflections over the antenna bandwidth. The feed through section reduces internal reflection and the waveguide is designed to include a rectangular waveguide that support a propagation (TE01) mode and the waveguide then transitions to a circular waveguide that supports another propagation (TE11) mode. The antennas can be employed for radar level gauging and withstand high temperature and possesses a small diameter that permits the antenna to fit in small tank nozzles.

Abstract: A distance between at least one antenna of an interrogation system and a transponder, such as an RFID tag, is determined based on derivatives with respect to frequency of the phase and the signal strength of responses transmitted by the transponder and received at the at least one antenna. The derivatives of the phase and the signal strength facilitate compensating for sources of multipath interference. Determining changes in distance may further facilitate determining location, speed, or bearing of the transponder by the interrogation system.

Abstract: In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are independently adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals of various polarizations are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements, with the transmitted beams having various polarizations. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously.

Abstract: A reception apparatus includes a plurality of reception units each corresponding to a communication path among a plurality of communication paths, and a generation unit configured to, in a case where the plurality of reception units receives a first data unit and a second data unit, generate the first data unit at a first time corresponding to a time at which the plurality of reception units has completed reception of data forming the first data unit, and generate the second data unit at a second time corresponding to a time at which the plurality of reception units has completed reception of data forming the second data unit.

Abstract: A phase shift circuitry includes: a signal generation circuitry that receives an input signal, and outputs four signals different in phase from each other by 90 degrees based on the input signal, the four signals includes a first signal and a second signal; four variable amplifier circuitry that each includes a transistor, and amplify the four signals individually, with amplification factors based on control voltages supplied to gates of the transistors, the four variable amplifier circuitry include a first amplifier amplifies the first signal by a first control voltage and a second amplifier amplifies the second signal by a second control voltage; a synthetic circuitry that synthesizes output signals of the four variable amplifier circuitry, and outputs a synthesized signal; and a control circuitry supplies voltages, that are equal to or higher than the gate threshold value, to the first amplifier and the second amplifier.