摘要:
A feedforward amplifier combines an input signal delayed by a delay circuit with an output signal by a combiner; down-converts the output of the combiner to a low frequency by a frequency converter; extracts a distortion component from the output of the frequency converter; measures the distortion component by a power detector; and controls a second vector regulator of a distortion canceling loop by a controller such that the distortion component measured becomes minimum.
摘要:
A feedforward amplifier which includes a distortion detector, a distortion eliminator, an error power extractor, a first level detector and a first controller. The error power extractor extracts output error power due to variations in the distortion eliminator by combining the output signal from the distortion eliminator with the signal from a first linear signal path in the distortion detector in opposite phases. The first level detector detects the output error power extracted by the error power extractor, and the first controller controls a first variable attenuator and a first phase shifter which are interposed in the distortion eliminator such that the output error power is maintained at zero. This can solve a problem of a conventional feedforward amplifier in that the power level of the pilot signal must be increased to heighten the detection sensitivity of the pilot signal because the detection level of the pilot signal becomes minimum at an optimum operation point, and that the increasing power of the pilot signal degrades the communication quality of a system employing the conventional feedforward amplifier.
摘要:
The invention relates to a curable fluorine-containing copolymer prepared by copolymerizing a monomer mixture. This monomer mixture is in an amount of 100 mol % in total and includes (a) 10-60 mol % of a first polymerizable monomer that is one of hexafluoroisobutene and hexafluoroacetone, each of which has one hexafluoroisopropylidene group; (b) 10-70 mol % of a fatty acid vinyl ester that is represented by a general formula of CH.sub.2 .dbd.CH--OC (.dbd.O) --R.sup.1 where R.sup.1 is one of an alkyl group and --(CH.sub.2).sub.m --R.sup.2 --(CH.sub.2).sub.n --H where R.sup.2 is one of a cycloalkylene group and a divalent aromatic group, and m and n are respectively integers each ranging from 0 to 12, the alkyl group having a carbon atom number of from 1 to 22 and an optional branched chain, each of the cycloalkylene group and the divalent aromatic group having an optional substituent; (c) 1-60 mol % of a second polymerizable monomer that has a cross-linkable functional group and a polymerizable double bond, the cross-linkable functional group being one selected from the group consisting of hydroxyl group, carboxyl group, hydrolyzable organosilyl groups, epoxy groups, .beta.-ketoester groups; and (d) 0-20 mol %, of a third polymerizable monomer that is different from the first and second monomers and the fatty acid vinyl ester and is free of a cross-linkable functional group. A coated film prepared by the application of a varnish containing the fluorine-containing copolymer is superior in water repellency and stain resistance.
摘要:
A vibration eliminating apparatus for eliminating vibration suspends a floor board from an installation floor. A supporting electromagnet is provided on the installation floor in order to suspend a magnetic member fixed to the floor board by a magnetic force. The magnetic member is provided with a thin magnetic pole through a non-magnetic member, and a control electromagnet having a yoke located in proximity to the thin magnetic pole is provided to control a horizontal position of the floor board. A vibration detector is provided to detect vibration of the floor board, and a vibration monitor is used to decide whether or not vibration detected by the vibration detector is within an allowable range of a machine mounted on the floor board and output an operation enable signal only when vibration is within the allowable range.
摘要:
This invention relates to an air bag inflation gas generator to feed combustion gas for inflation of air bags such as air bags for absorbing collision shocks, life jackets, rafts, and escape chutes. When the generator is exposed to a high temperature environment such as fire and a temperature of a second end plate rises, heat of the second end plate is transmitted to an ignition agent via a heat sensing means, the ignition agent is ignited at a temperature thoroughly lower than the firing temperature of gas generating agents, and the gas generating agents burn.
摘要:
An electroconductive magnetic carrier which is composed of carrier particles, each of the carrier particles comprising a basic particle in which magnetic particles with an average particle diameter of 0.05 to 1.0 .mu.m are dispersed in a binder resin, and electroconductive finely-divided particles with an average particle diameter of 0.5 .mu.m or less which are fixed on the surface of said basic particle to form a carrier particle with an average particle diameter of 5 to 100 .mu.m; a developer which is composed of the above electroconductive magnetic carrier and an electrically insulating toner; and an image formation method of forming toner images on a photoconductor by using this developer are described.
摘要:
An electroconductive magnetic carrier which is composed of basic particles, each of the basic particles comprising a binder resin and a magnetic material dispersed in the binder resin, and an electroconductive layer formed on the surface of the basic particle, a developer which is composed of the above electroconductive magnetic carrier and (b) an electrically insulating toner, and an image formation method of forming toner images on a photoconductor by using this developer are described.
摘要:
A linear amplifier includes a variable attenuator and a phase shifter for modifying the amplitude and phase of an input signal to compensate for amplitude and phase distortion caused by non-linear characteristics of a high-powered amplifier utilized in a microwave band communications system. An amplitude comparator and a phase comparator compare the amplitudes and phases of input and output signals of the linear amplifier circuit to develop control signals for controlling the operation of the variable attenuator and phase shifter. The elimination of digital signal processing circuitry allows increased speed of operation that is essential for use in the microwave bands.
摘要:
In a modulation system using an amplitude and a phase of a carrier wave as information such as a QPSK system, a modulation device modifies an input signal series to compensate the nonlinear characteristics of an amplifier located at a later stage, and provides a carrier wave modulated by the modified signal series to the amplifier. A first arithmetic circuit obtains an amplitude and a phase of an input signal by calculation. A ROM is set with correction data corresponding to the calculated amplitude so as to compensate the nonlinearity of the amplifier. A modification value generating circuit and a RAM output an amount of compensation so as to further modify the correction data according to part of an output signal from the amplifier to compensate amplifier characteristic changes due to temperature variations and the like. A second arithmetic circuit provides a signal series produced from the modified amplitude and phase to a quadrature modulator.
摘要:
A distributed FET amplifier comprising an array of FET elements each having a gate terminal, a drain terminal and a source terminal. The gate terminals of the adjacent FET elements are connected by a first inductor, and the drain terminals of the adjacent FET elements are connected by a second inductor. Between the source terminals of each of the FET elements and the ground is connected a parallel circuit comprising a capacitor having a capacitance greater than the gate-source capacitance of the FET element and an impedance element connected in parallel to the capacitor for grounding the direct current. A bias voltage supply circuit for supplying a bias voltage to such as distributed amplifier is also disclosed.