Abstract: A DC-DC converter is provided with a control circuit 6 which comprises a drive signal generator 11 for producing on-off signals to a control terminal of a MOS-FET 3 in synchronization with pulse signals VOSC from an oscillator 10; an intermittent controller 12 for producing a control signal VC1 to drive signal generator 11 in response to the level of detection signal from an output voltage detector 5 to convert MOS-FET 3 to the intermittent operation during the light load period; and a power control circuit 16 for ceasing power supply VCC to oscillator 10 in response to control signal VC1 from intermittent controller 12 to stop production of pulse signal VOSC from oscillator 10 for the cessation term of MOS-FET 3 during the intermittent operation.

Abstract: A method for operation of a converter circuit is specified, wherein the converter circuit has a converter unit with a multiplicity of drivable power semiconductor switches and an LCL filter which is connected to each phase connection of the converter unit, in which method the drivable power semiconductor switches are driven by means of a drive signal which is formed from reference voltages. The reference voltages are formed by subtraction of damping voltages from reference-phase connection voltages, with the damping voltages being formed from filter capacitance currents, weighted with a variable damping factor of the LCL filter. An apparatus for carrying out the method is also specified.

Abstract: An analog, duty cycle replicating frequency converter extracts duty cycle information from an input, pulse width modulated signal and generates an output pulse width modulated signal of the same duty cycle at a different frequency without regard to the frequency of the input signal. It uses bipolar transistor based circuitry, adaptable to an application specific integrated circuit, to derive voltages representing the on-time and period durations of the input signal, convert these voltages to currents representing the logarithms thereof, generate a voltage representing the difference between the currents, exponentially convert the voltage to a current representing the duty cycle and control an oscillator to generate an output pulse width modulated signal at a predetermined frequency with the duty cycle of the input signal.

Abstract: It is an object of this invention to provide an AC adaptor capable of achieving downsizing and cost reduction, and having both a constant-voltage/constant-current control function necessary for battery charge, and an optimum current control function for driving of a low-power-consumption electronic apparatus. This AC adaptor includes a first constant-current control device which performs first constant-current control for charging a battery, a second constant-current control device which performs second constant-current control for supplying an electric current necessary to drive an electronic apparatus, and a voltage detecting device which detects the voltage drop of a DC output. If the output voltage becomes lower than a preset value, the second constant-current control for supplying the electric current necessary to drive the electronic apparatus is performed.

Abstract: A control system and a method of using the same for an electric machine having a random number generating module generating a random number ranging from a first value to a second value, a multiplying module multiplying the random number and a sample rate to generate an random delay value; and a delay limiter module limiting the random delay value as a function of speed of the electric machine and generating a limited delay value.

Abstract: A boost control module operates semiconductor switches of a boost converter circuit in an avalanche mode to precharge a boost output capacitor. The boost control module comprises a switching module that complementarily transitions a first semiconductor switch and a second semiconductor switch between ON and OFF states when a current does not exceed a maximum current threshold. The switching module transitions the first semiconductor switch and the second semiconductor switch to the OFF state when the current exceeds the maximum current threshold. The switching module maintains the first semiconductor switch and the second semiconductor switch in the OFF state until at least one of the inductor current is less than or equal to a minimum current threshold.

Abstract: The present invention comprises systems and methods for electrical power regulation and distribution. In an embodiment, a system includes a modulator coupled to the source that receives an unregulated output waveform and is operable to produce a first composite waveform, and a mixing unit that is operable to generate a second composite waveform by introducing a frequency modulated component into the first composite waveform. A demodulator is coupled to the mixing unit that demodulates the second composite waveform to generate a third composite waveform. A filter network is coupled to the demodulator that is configured to select a desired spectral portion of the third composite waveform.

Abstract: AC-to-AC power conversion systems and methods are presented, in which a small number of asymmetrical power switching devices are used to convert input AC power to output AC power of constant or variable frequency.

Abstract: A combination controller incorporates features of a classic controller and a state space controller to function as a hybrid controller unit. The PID portion of the classic controller regulates the steady state error and is separated from the pulse width modulated constant frequency signal generator that also comprises part of the classic controller. The PID portion is coupled with a state space controller such that the output of the PID controller, i.e., the steady state error correction, is input to the state space controller. The state space controller further receives as input variables a reference sinusoidal signal, the load current, the current across a pre-load filter capacitor, and the output voltage. From these inputs, the state space controller employs principles of differential calculus to generate a transient error correction that is fed to a PWM signal generator for generating a sinusoidal output voltage signal with both steady state and transient error correction.

Abstract: A novel architecture of high-power four-quadrant hybrid power modules based on high-current trench gate IGBTs and arrays of low-current wide-bandgap diodes is conceived. The distributed physical layout of high power density wide-bandgap devices improves the cooling inside a fully-sealed module case, thus avoiding excessive internal heat flux build up and high PN junction temperature, and benefiting the converter's reliability and efficiency. The design of multiple-in-one hybrid integrated AC-switch module at high power ratings is enabled by using hybrid AC switch cells and aluminum nitride substrate structure.

Abstract: A method and arrangement for charging an intermediate circuit of a frequency converter, the intermediate circuit of the frequency converter comprising one or more capacitors, and the frequency converter having means for charging the intermediate circuit, the means comprising a rectifier bridge, a direct current choke, a direct-current transformer, a zero diode, and a semiconductor switch and a control circuit arranged to control the switch. The method comprises the steps of defining in advance high and low current limits, controlling the semi-conductor switch alternately to conductive and non-conductive states depending on the magnitude of a charging current, and stopping the controlling of the semiconductor switch when the charging current remains below the high current limit.

Abstract: A method and an apparatus for compensating reactive power and/or harmonic currents in an alternating-current network by means of a frequency converter (1) feeding an alternating-current load (3), which frequency converter has a mains bridge (10) and at least one load bridge (11), said bridges being provided with controllable semiconductor switches. In the method, the reactive power and/or harmonic currents in the alternating-current network are measured, the load of the mains bridge of the frequency converter is measured, and the reactive power and/or harmonic currents in the alternating-current network are compensated by means of the frequency converter when the mains bridge is running at less than full capacity or has no load.

Abstract: A method of commutation of current by separately controlled in each direction bi-directional switches of a matrix converter (MC) with at least three input phases, which allows to provide a safe step-by-step commutation of the current by MC switches without using information of the load current polarity and of the exact relation of mains voltages at the moment of step-by-step commutations beginning. It is suggested variants of implementing the proposed invention in the three phase-to-three phase MC with a space vector modulation (SVM) which provides the synthesis of space vectors of the output voltage and input current of zero and non-zero stationary vectors during each SVM cycle, with dividing the mains voltage period into six intervals with boundaries being determined by moments of input phase voltage polarity changing.

Abstract: A voltage protection circuit for a terminal of an electronic device, for example the TIP and RING lines of a linecard, is provided. The voltage protection circuit comprises a protection element, a first terminal of which is coupled to the terminal of the electronic device, a second terminal of which is coupled to a ground potential and a control terminal of which is coupled to a reference voltage element, the protection element having a low resistance between its first and second terminals when the control terminal is in a first state and a higher resistance between its first and second terminals when the control terminal is in a second state, the reference voltage element being further coupled to a reference voltage and being adapted such that the state of the control terminal depends on an applied voltage at the first terminal and the reference voltage.

Abstract: Three phase input voltage systems and three phase output voltage systems connected between a first rail and a second rail. Each of the three phase input voltage system includes an interruptible power transistor. Two series connected reverse diodes are connected in parallel with the interruptible power transistor. The phase input voltage system is connected with a node of the series connected reverse diodes.

Abstract: In one embodiment, a method for use with a power transfer device is characterized by shifting a control signal with a waveform having a randomly variable period; and switching said power transfer device with a resultant shifted control signal. In addition to the foregoing, other method embodiments are described in the claims, drawings, and text forming a part of the present application. In one or more various embodiments, related systems include but are not limited to circuitry and/or programming for effecting the foregoing-referenced method embodiments; the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect the foregoing-referenced method embodiments depending upon the design choices of the system designer. In addition to the foregoing, other system embodiments are described in the claims, drawings, and text forming a part of the present application.

Abstract: A method is provided for implementing a three-phase pulse-width-modulated alternating current voltage regulator including six four-quadrant switches, wherein each four-quadrant switch includes two two-quadrant switches. Three series branches, each series branch including one four-quadrant switch, and three shunt branches, each shunt branch including one four-quadrant switch, are provided. To obtain a desired converter state, the two-quadrant switches in the series and shunt branches are turned on or off in a predetermined sequence.

Abstract: A semiconductor switch device for an AC power source comprises several first semiconductor elements and several second semiconductor elements connected in series with a plurality input AC sources of an AC power source, respectively. An end of each of the second semiconductor elements is electrically connected with each other. An output AC sources is formed between each first semiconductor element and its associated second semiconductor element, each output AC source being electrically connected to a load. A first reverse diode is connected in parallel with each first semiconductor element and a second reverse diode is connected in parallel with each second semiconductor element. A continuous closed circuit is formed by the load and one of the second semiconductor elements when the AC power source is cut off, thereby avoiding momentary over-voltage.

Abstract: An electronic method and apparatus are described for an isolated, universal input, power supply in the form of a single-ended resonant converter that utilizes capacitive energy storage versus magnetic energy storage, for converting an ac or DC input voltage to a variable voltage and current DC output or a variable ac output voltage, current, frequency, or phase. The preferred topology is a direct ac to ac, single-ended resonant converter using a single switch (4) and integrated magnetic element (1) with inherent near-unity power factor. Advantages of this method include a significant reduction in global energy consumption, simpler circuitry, substantially lower cost, higher efficiency, and longer operational life.

Abstract: A method and an apparatus for power factor correction for a non-ideal load, which is supplied from a mains power supply, by a compensation device which is electrically connected in parallel with the load and has a pulse converter with at least one capacitive store. A transfer function space vector is calculated as a function of a determined mains power supply voltage space vector, a mains power supply current space vector, a compensator current space vector and of an intermediate circuit voltage which is present on the capacitive store. As a result of which the pulse converter generates a compensator voltage space vector on the mains power supply side as a function of the intermediate circuit voltage. A compensator current space vector, that keeps the undesirable reactive current elements away from the mains power supply, is thus obtained via a coupling filter that is represented as a compensator inductance.

Abstract: A power converting apparatus and a power converting method for driving a high voltage AC motor at a variable speed. Conventional invertor systems cannot solve technical subjects such as energy conservation, resource conservation, miniaturization, efficiency promotion and voltage and current waveform distortion suppression for improvement in environment needed by the market, and cannot solve another technical subject of improvement in redundancy such that, upon failure, operation is performed with a normal part.

Abstract: An AC--AC multi-module matrix PWM converter includes one to a plurality of phase banks within which are provided architecturally identical basic circuit modules of single phase output AC--AC matrix converters. Each basic converter module includes three-phase AC inputs and two output terminals. The modules may then be interconnected in series or parallel with other modules within a phase bank to increase the output voltage or current respectively of the phase bank. The differential power module structure and the differential phase PWM modulation scheme increases the output voltage by 15.5% in comparison with 120.degree. phase modulation. Individually designed and tested phase banks can be further connected to a higher power symmetric three phase system or multiphase system for various AC load and AC motor controls. The modular structure permits standardization of the power electronics design and manufacture at system level.

Abstract: A high power AC--AC converter having integrated adaptive commutation control and a new modularity design based on standard per-phase floating AC power-building modules. The per-phase floating AC power building modules designed with high voltage throughput and optimal partitioning differential output architecture which is suitable for multi-phase multi-module high power electronic systems. Now integrated and smart AC power switch modules are provided to reduce the gate control complexity, minimize circuit connection terminals and simplify power bus structure.

Abstract: A matrix converter utilizes a bidirectional lateral insulated gate bipolar transistor (IGBT) including two gate electrodes. The IGBT can conduct in two directions. The matrix converter preferably is a three phase matrix converter including nine bidirectional IGBT switches. The IGBT switches are controlled by a control circuit which includes eighteen control lines, two for each IGBT. Additionally, the bidirectional IGBT can be used in a precharge circuit of a power inverter or in a dynamic brake associated with a motor controller.

Abstract: A batteryless, portable frequency divider, such as used in presence detection systems for article surveillance or as used for article-location determination, includes a series LC resonant circuit connected directed across a parallel LC resonant circuit. One circuit is resonant at a first frequency and the other circuit is resonant at a second frequency that is a plural-integer-divided quotient of the first frequency. In one class of embodiments, either or both of the series and parallel resonant circuits includes a variable capacitance element, such as a varactor, in which the capacitance varies in accordance with the voltage across the variable capacitance element. The variation of the capacitance of the variable capacitance element in response to variations in energy in the higher-frequency resonant circuit resulting from receipt electromagnetic radiation at the first frequency causes the lower-frequency resonant circuit to transmit electromagnetic radiation at the second frequency.

Abstract: A DC to DC switch mode power supply for a service subscriber interface unit of a fiber optic network includes a source of DC primary power, a main DC to DC switched mode power supply connected to the source of DC primary power and including switching circuitry and rectifier circuitry for supplying DC operating power to the service subscriber interface unit including central office battery power to at least one subscriber loop connected thereto, and a ringing voltage DC to AC switched mode generator connected to the source of DC primary power and including switching circuitry and synchronous rectification circuitry for generating ringing ringing voltage approximating a sine wave supplied as a reference to the synchronous rectification circuitry. A Johnson counter and resistor capacitor network is preferably employed to convert a reference ringing square wave into a sine wave.

Abstract: A DC-to-AC electric power converting apparatus including an invertor circuit having a plurality of switching elements, a transformer connected to the invertor circuit, and a cyclo-converter circuit for converting the frequency of the output from the transformer. A carrier signal generator is provided for generating a carrier signal of a predetermined frequency.

Abstract: A universal phase-controlled reversible power converter having one transformer with multiple windings (i) couples a fixed d.c. voltage to an associated transformer winding through a fixed port having switches controlled for switching by fixed-phase signals, and (ii) couples any number of voltages having any waveform(s) whatsoever each to an associated transformer winding each through an associated variable port that has a filter with an inductor and controllable switches. Variable-phase switching control signals control the variable ports to produce any desired three-state demodulated waveform. A three-state demodulated waveform is filtered to present (i) a corresponding counter emf of any desired waveform to an input source or power, or (ii) any desired output waveform to a sink of power. Controllably producing the counter emf as a picture-of-the-line-input-voltage makes the load factor of the power converter, and all its loads, unity.

Abstract: An electrical circuit receives an alternating input signal and full-wave rectifies the alternating input signal. The rectified signal is then developed by the circuit into an output signal which has a frequency double the frequency of the alternating input signal. The doubled-frequency output signal is then output to a load. Alternatively, the circuit receives a direct current input signal, converts the direct current input signal into a periodically varying output signal, and outputs the periodically varying output signal to a load.

Abstract: A single-transistor frequency doubler uses an elliptical filter on the collector of the transistor to improve the bandwidth of the doubler. Bandwidths in excess of thirty five percent having relatively constant output power levels at frequencies over 200 MHz can be realized.

Abstract: A power conversion apparatus comprises an inverter for converting a voltage of a DC power source into AC power having a frequency higher than the commercial frequency, a transformer, fed by the inverter, for outputting AC power, which is adjusted at a desired voltage, a frequency converter, formed by two pairs of two gate turn-off thyristors (GTOs) connected in reverse-parallel, for converting the frequency of the AC power supplied from the transformer into the commercial frequency, and an energy regenerating device having capacitors for absorbing the energy of a spike voltage occurring due to a circuit inductance upon interruption of a current of each GTO of the frequency converter and a bridge circuit, formed by GTOs and diodes connected in reverse-paralel therewith, for switching over the direction of connecting the capacitors with a secondary winding of the transformer in accordance with the polarity of a voltage of the secondary winding in such a manner that the energy stored in the capacitors is regener

Abstract: In a direct AC to AC converter system the normal rectifier assistance functions are phase modulated by a 30.degree. lag and by a 30.degree. lead, and switching between lagging and leading function is effected at a high frequency according to a duty cycle: ##EQU1## and where .theta. is the electrical angle of the AC power supply, thereby insuring a sinusoidal input current in the system.

Abstract: A power source using high-frequency phase control possessing an ability to cause the transfer of electric power between a power source side and a load side to be made through a high-frequency transformer and to effect control of the output voltage by subjecting the power source side and the load side circuits to on-off control with a certain phase difference. This power source can be used as an uninterruptible power source, a device for controlled drive of a motor, a DC constant-voltage power source, or a constant-current device, for example.

Abstract: An AC frequency conversion technique is disclosed using an H-switch toggled at irregular times to yield a chopped sinusoid output waveform of a given fundamental frequency. The irregular switching pattern is a departure from the classical cycloconverter frequency conversion approach. The H-switch is connected between a pair of power lines L1 and L1 and alternately switched between one and another ON state at any point in the AC cycle to yield any up-converted or down-converted output frequency of the chopped sinusoid output waveform. The output waveform has a positive half cycle during which the H-switch is in one ON state when L1 is positive with respect to L2 and is in the other ON state when L2 is positive with respect to L1. The output waveform has a negative half cycle during which the H-switch is in the one ON state when L1 is negative with respect to L2 and is in the other ON state when L2 is negative with respect to L1.

Abstract: An AC frequency conversion technique is provided by alternately switching between AC power lines at irregular times to yield a chopped sinusoid switched output waveform of given fundamental frequency. The technique does not rely on an input rectifier bridge nor on capacitive filtering to DC.

Abstract: A three-phase matrix converter including switches having snubber circuits associated thereto, is provided with a common voltage clamp capacitor for limiting the voltage applied to the snubber capacitor, and energy is accumulated in the clamp capacitor which is controllably dissipated, in particular by providing energy to auxiliary elements of the overall system.

Abstract: A current regulator for a variable frequency power supply includes a proportional plus integral circuit that produces a composite control output signal for each phase. To improve the performance of the current regulator at higher frequencies, the composite control output signal for each phase also inlcudes a cross coupled component which is produced by multiplying a d.c. signal proportional to frequency times an integrator output signal from another phase. The composite control signals are applied to a voltage source inverter which produces the output currents to a load.

Abstract: An electronic transformer comprising first and second switching converters for converting the positive and negative half periods, respectively, of an input alternating voltage into high frequency voltages, which are rectified to produce an output alternating voltage at the input voltage frequency. The converters are constructed as fly-back converters with the choke coils as well as the output and input capacitors combined into elements common to the two respective high frequency fly-back converters. First and second backward diodes are connected parallel to each switching transistors of the two fly-back converters and each converter includes an auxiliary switching transistor switching at the input frequency to change over the converters from one half period to the other of the input AC voltage.

Abstract: Odd harmonic generator includes two amplitude limiting amplifiers and a frequency selective signal combining network. Sinusoidal signal at frequency of chrominance subcarrier is applied to inputs of both amplifiers. The first amplifier provides signal comprising fundamental and odd harmonic frequency components. The second amplifier provides signal comprising a fundamental frequency component and odd harmonic frequency components that are comparatively much smaller than the odd harmonic frequency components of the first amplifier's output signal. Signals are combined so that fundamental frequency components offset. Output signal at third harmonic of chrominance subcarrier frequency is used as clock signal for CCD comb filter in a color TV receiver.

Abstract: In an AC current control system for controlling multi-phase AC currents supplied from a power converter to a load, the currents are detected and coordinate-transformed into orthogonal two-axis current values i.sub.d, i.sub.q in a rotating coordinate rotating at an angular frequency .omega., and then compared with the references. The deviations are used to determine two-axis voltage values e.sub.d *, e.sub.q *, which are coordinate-transformed into multi-phase voltage values determining the output voltages of the power converter. The system is characterized in that the voltage value e.sub.d * is determined not only from .DELTA.i.sub.d but also from the product of .omega. and .DELTA.i.sub.q, while the voltage value e.sub.q * is determined not only from .DELTA.i.sub.q but also from the product of .omega. and .DELTA.i.sub.d. This arrangement makes it possible to provide a voltage component corresponding to the voltage drop across the inductive component of the load which is 90.degree. in advance of the current.

Abstract: A direct AC to AC supply converter in which the control of the bidirectional switches connecting each conductor of a polyphase input supply to each conductor of an output supply is effected by a data processor, the operation of the program of which is synchronized by interrupt with the input supply. The data processor calculates for each output phase 2 values representing pulse widths out of a repeating sequence of 3 (for three phase input and output supplies) and pulse generators produce 3 abutting width modulated pulses in a constant period much shorter than the periods of the supplies. The interrupt operates a software phase locked loop. The pulse generators include an interlock circuit ensuring that the width modulated pulses do not overlap and an overload detector responsive to the turn-on times of the switches. A default logic circuit responsive to hardward or software failure makes the width modulated pulses of equal duration.

Abstract: Four switching elements are configured to reduce the voltage of either an alternating or a direct current electrical power source. The present circuit effectively operates like a variable autotransformer when used with a.c. input power. Additionally, when employed with a conventional resistive load, the present invention exhibits a power factor near unity.

Abstract: A synchronous oscillator is provided to divide the frequency of an input signal by a noninteger number, the noninteger number being expressed as the ratio of two whole integers X/Y. The oscillator is tuned to the desired output frequency, whereby every Yth cycle of the output signal is synchronized by every Xth cycle of the input signal at the negative (and possibly positive) peak of the output signal, thereby effecting a simultaneous multiplication and division of the input frequency of Y and X respectively. A pulse forming network provides the input signal in the form of pulses, whereby synchronization is effected at precise points in time. Pulse width and amplitude are adjustable to vary the input signal energy.

Abstract: The input power factor of an AC to AC static power converter is continuously adjustable between a maximum leading or lagging phase angle, determined by the load power factor, through rapidly transferring between conventional and complementary unrestricted frequency changer operation with the proportion of each sub generator cycle interval dedicated to each mode of operation being selected to produce the desired input power factor. Since the input power factor affects generator excitation, the input power factor control can be used in a closed loop feedback control system to regulate generator voltage.

Abstract: When the input frequency is below a preselected value, an unrestricted frequency changer (UFC) is operated in the conventional manner by sequentially switching to more positive input phases while the fundamental component of the output waveform is positive going and to more negative input phases while it is negative going. Above the preselected input frequency, the UFC is operated in a complementary manner; that is, by switching to more negative input phases while the output waveform fundamental component is positive going and to more positive input phases when it is negative going. The switching instants occur in UFC operation when the reference waveform is equal in amplitude but opposite in slope to each waveform in a set of timing waveforms phase locked to the input waveforms. During complementary UFC operation, switching occurs when the reference waveform is not only equal in amplitude to the timing waveforms but also has a slope of the same sense.

Abstract: A circuit arrangement for converting electrical energy has a static frequency converter which operates with a considerably higher frequency than the frequency to be produced, the arrangement has a heavy-duty switch, a transmitter and a rectifier on the secondary side, and a master control circuit, a regulating circuit and an auxiliary static frequency converter. The heavy-duty switches on the primary side and on the secondary side are provided for the two current directions with one transformer winding of a common transformer, and are also provided with filter sections for the low frequency range and high frequency range auxiliary frequency converters. The arrangement also is provided with quadrant shift locks at the primary side and the secondary side which determine the mode of operation of the static frequency converter in conjunction with the master circuit and the regulating circuit, whereby the output flow direction can be selected or is determined by a monitoring circuit.

Abstract: A signal at a frequency f.sub.0 is coupled through matching circuitry to the input of a parametric frequency multiplier stage. Non-linearities in this stage generate harmonics of the frequency f.sub.0, including a desired harmonic k.times.f.sub.0, where k=2, 4, 6, 8... . Unique output coupling circuitry presents a high load impedance to the parametric multiplier at the frequency f.sub.0, thereby enhancing harmonic generation, and transforms the impedance to signals of frequency k.times.f.sub.0 at the multiplier stage output to a desired value. The output coupling circuit includes two series connected transmission lines which couple between the output of the parametric multiplier stage and the multiplier output. A third transmission line, having an electrical length of one quarter wavelength at frequency f.sub.0, is connected as an open circuit shunt stub to the multiplier output, thereby effectively producing a short circuit thereat at f.sub.0.

Abstract: An improved circuit utilized in an RF tuner or receiver for selecting and nverting an RF signal to an intermediate frequency with reduced injection power requirements.The circuit is utilized in the "front end" of a radio frequency receiver or tuning section, the purpose being to convert the received RF signal to an intermediate frequency. The improved circuit comprises and includes a diode sampling bridge coupled to an RF signal receiving source, such as an antenna, a local oscillator coupled across the bridge providing pulses for actuating and turning on particular diodes of the bridge for a relatively short length of time. The bridge output is coupled to a selecting transistor, which may include a crystal filter coupled to the emitter of the transistor. The pulsing signal across the diode bridge is relatively short in comparison with the received RF signal. When the diode sampling bridge is conducting, the RF signal is mixed and passed to the selecting transistor base.

Abstract: Series connected field-effect transistors (FET's) of complementary conductivity types are employed to mix two input signals. The transistors are biased in their linear operating region and operate as common source amplifiers for the signals to be mixed. The input signals are applied to the respective gate electrodes of the transistors and the output signal containing upper and lower sideband frequencies is available at the common drain connection of the transistors.