Abstract: A clock signal generator and a clock signal generating method are provided. The clock signal generator is adapted for a test machine. The clock signal generator includes a first oscillator, a second oscillator, a delay value generator, and an output clock signal generator. The first oscillator and the second oscillator are activated alternatively. The first oscillator generates a first clock signal with a first frequency according to a delay value. The second oscillator generates a second clock signal with a second frequency according to the delay value, where phases of the first clock signal and the second clock signal are different. The delay value generator detects a pulse width of a reference pulse signal to generate the delay value. The output clock signal generator combines the first clock signal and the second clock signal to generate an output clock signal.

Abstract: An odd harmonic generation device is provided. The odd harmonic generation device includes an even harmonic generation unit and a mixer. In this context, the even harmonic generation unit is configured to generate two even harmonic signals on the basis of a fundamental signal. In addition to this, the mixer is configured to mix the fundamental signal with the two even harmonic signals to generate a desired odd harmonic signal.

Abstract: A method of frequency doubling includes receiving a first clock that has a fifty percent duty cycle and is a two-phase clock having a first phase and a second phase; outputting a second clock using a multiplexer by selecting one of the first phase and the second phase of the first clock in accordance with a third clock; delaying the second clock into a fourth clock using a recirculating delay circuit; and using a divide-by-two circuit to output the third clock in accordance with the fourth clock.

Abstract: A system and method for fast converging gain calibration for phase lock loops (PLL) are herein disclosed. According to one embodiment, a method includes receiving, with a voltage generation circuit, an input value representing a difference between a sampled voltage and a reference voltage, and adjusting, with the voltage generation circuit, the reference voltage by generating a voltage output based on the difference represented by the input value.

Abstract: A frequency doubler includes a multiplexer, a digitally controlled delay circuit, a divide-by-two circuit, a duty cycle detector, and a controller. The multiplexer receives a first clock and output a second clock in accordance with a third clock, in which the first clock has a fifty percent duty cycle and is a two-phase clock having a first phase and a second phase. The digitally controlled delay circuit receives the second clock and outputs a fourth clock in accordance with a digital word. The divide-by-two circuit receives the fourth clock and outputs the third clock. The duty cycle detector receives the second clock and outputs a logical signal in accordance with a comparison of a duty cycle of the second clock with a target duty cycle value. The controller outputs the digital word in accordance with the logical signal.

Abstract: A device is disclosed that includes a semiconductor substrate, a bottom electrode disposed on a first surface of the semiconductor substrate, an insulating layer disposed on a second surface that is opposite to the first surface, of the semiconductor substrate, a current-to-voltage converter, a first electrode and a second electrode that are separate from each other and disposed on the insulating layer. The first electrode is configured to be applied with an input signal, and the second electrode is configured to output an output current signal that is associated with the input signal, the input signal is configured to have a voltage level that is variable, and the output current signal is configured to have a peak current value and a valley current value. The current-to-voltage converter is configured to receive the output current signal to generate an output voltage signal.

Abstract: A system and method for fast converging reference clock duty cycle correction for a digital to time converter (DTC) based analog fractional-N phase-locked loop (PLL) are herein disclosed. According to one embodiment, an electronic circuit includes a clock doubler, a comparator that outputs a value representing a difference between a voltage at a voltage-to-current (Gm) circuit and a reference voltage that is adjusted to compensate for an offset of the comparator, and a duty cycle calibration circuit that receives the value output from the comparator and adjusts a duty cycle of the PLL by extracting an error from the value output from the comparator and delaying a clock edge of the duty cycle according to the extracted error.

Abstract: A clock generation circuit, which generates an output clock using an external clock as a target clock, includes a circuit arranged to change the output clock to high level in synchronization with an up edge of the target clock, circuits arranged to generate first and second ramp voltages with a period of interval between neighboring up edges of the target clock, and a circuit arranged to hold a comparison voltage corresponding to a second ramp voltage when an up edge of the target clock occurs. The level of the output clock is changed from high level to low level based on a comparison result between the first ramp voltage and the comparison voltage.

Abstract: A system and method for fast converging gain calibration for phase lock loops (PLL) are herein disclosed. According to one embodiment, a method includes receiving, with a voltage generation circuit, an input value representing a difference between a sampled voltage and a reference voltage, and adjusting, with the voltage generation circuit, the reference voltage by generating a voltage output based on the difference represented by the input value.

Abstract: A system and method for fast converging reference clock duty cycle correction for a digital to time converter (DTC) based analog fractional-N phase-locked loop (PLL) are herein disclosed. According to one embodiment, an electronic circuit includes a clock doubler, a comparator that outputs a value representing a difference between a voltage at a voltage-to-current (Gm) circuit and a reference voltage that is adjusted to compensate for an offset of the comparator, and a duty cycle calibration circuit that receives the value output from the comparator and adjusts a duty cycle of the PLL by extracting an error from the value output from the comparator and delaying a clock edge of the duty cycle according to the extracted error.

Abstract: The disclosed embodiments relate to the design of a high-speed frequency doubler circuit. During operation, the circuit uses a transformer-based balun to convert a single-ended input signal into a differential signal, wherein the transformer-based balun includes a transformer with a primary coil, which receives the single-ended input signal, and a secondary coil, which produces the differential signal. The transformer also includes a central compensation capacitor coupled between a center tap of the secondary coil and ground, wherein the central compensation capacitor acts to suppress common-mode components in the differential signal. Next, the circuit uses a pseudo-differential amplifier to convert the differential signal into a single-ended output signal, which has double the frequency of the single-ended input signal.

Abstract: A digital modulating device includes an oscillator that generates an oscillation signal, and a frequency doubling modulator that includes: a single-ended to differential converter converting the oscillation signal into two periodic signals; two inductors respectively receiving the periodic signals and respectively providing two input signals; a switching circuit; and two amplifier circuits. When the switching circuit operates in a first state, the amplifier circuits respectively amplify the input signals to respectively generate two amplified signals that are combined into a combined signal at a common node thereof. When the switching circuit operates in a second state, the amplifier circuits do not perform amplification.

Abstract: Apparatuses and methods for phase interpolating clock signals and for providing duty cycle corrected clock signals are described. An example apparatus includes a clock generator circuit configured to provide first and second clock signals responsive to an input clock signal. A duty phase interpolator circuit may be coupled to the clock generator circuit and configured to provide a first and second duty cycle corrected interpolated clock signals. A duty cycle adjuster circuit may be coupled to the duty phase interpolator circuit and configured to receive the first and second duty cycle corrected interpolated clock signals and provide a duty cycle corrected clock signal responsive thereto. A duty cycle detector may be coupled to the duty cycle adjuster circuit and configured to detect duty cycle error of the duty cycle corrected clock signal and provide the adjustment signals to correct the duty cycle error.

Abstract: A semiconductor apparatus that can detect the amplitude level of harmonics is provided. A semiconductor apparatus includes a common mode detector circuit that detects alternating current (AC) signals in a common mode, and a detector circuit that detects the amplitude level of an even-order harmonic output from the common mode detector circuit. The common mode detector circuit combines the AC signals being differential signals in common mode, thereby cancelling out odd-order harmonics to obtain direct current and even-order harmonics. The detector circuit detects the amplitude level of the even-order harmonics from a signal obtained by the common mode detection, and outputs the detected amplitude level.

Abstract: A clock doubler includes a first NAND gate having a first input for receiving a clock input signal and a second input, a second NAND gate having a first input and a second input for receiving a complement of the clock input signal, an output NAND gate having a first and second inputs coupled to outputs of the first and second NAND gates, respectively, and an output for providing a clock output signal, an inverter chain having an input for receiving the clock input signal and responsive to first and second control signals to selectively provide a first true output to the first input of the second NAND gate, and a second complementary output to the second input of the first NAND gate, and a control signal generation circuit providing the first and second control signals in response to the outputs of the first and second NAND gates.

Abstract: The present invention provides a frequency multiplier apparatus. The frequency multiplier apparatus includes an injection-locked frequency multiplier and a frequency-to-control signal converter. The injection-locked frequency multiplier outputs an output signal having a first frequency in response to an input signal having a first basic frequency. The frequency-to-control signal converter provides a first control signal to the injection-locked frequency multiplier in response to the input signal. The injection-locked frequency multiplier adjusts the first frequency to a second frequency in response to a change of the first control signal when the first basic frequency is changed to a second basic frequency.

Abstract: A clock doubler circuit includes a filtering circuit. The filtering circuit includes a first input to receive a first clock signal, a first output to provide a second clock signal, and a second output to provide a third clock signal. The third clock signal is a complementary signal to the second clock signal. The first clock signal, the second clock signal, and the third clock signal are at a first clock frequency. The second clock signal is a low pass filtered version of the first clock signal. The clock doubler circuit includes a frequency doubling circuit. The frequency doubling circuit includes a first input to receive the second clock signal and a second input to receive the third clock signal. The frequency doubling circuit includes an output node. The output node provides a fourth clock signal at a second clock frequency that is twice the first clock frequency.

Abstract: Frequency multipliers include a pair of transistors each connected to a common impedance through a respective collector impedance formed from a transmission line. Each transmission line has a length between about one quarter and about one eighth of a wavelength of an input signal frequency and is tuned to produce a large impedance at a collector of the respective transistor at the input signal frequency. The output frequency between the collector impedances and the common impedance is an even integer multiple of the input frequency.

Abstract: A frequency multiplier circuit includes a first signal input terminal, a second signal input terminal, an output terminal, a power source terminal, a ground terminal, a main control circuit which is connected to the first signal input terminal, the second signal input terminal, the power source terminal and the ground terminal, a reference circuit which is connected to the power source terminal and the ground terminal, and a frequency synthesis circuit which is connected to the main control circuit, the reference circuit, the output terminal, the power source terminal and the ground terminal.

Abstract: Exemplary embodiments are related to a clock doubler. A device may include a duty cycle correction circuit configured to receive an input clock signal and convey a corrected clock signal. The duty cycle correction circuit may include a first circuit to convey an output voltage during a first cycle of the input clock signal and correct a current mismatch of the first circuit during a second cycle of the input clock signal. The duty cycle correction circuit may also include a second circuit to convey the output voltage during the second cycle and correct a current mismatch of the second circuit during the first cycle. Further, the device may include a clock generator for receiving the corrected clock signal and generating an output clock.

Abstract: A dual-edge triggered variable frequency divider for use in digital frequency synthesis is disclosed. The variable frequency divider utilizes a multiphase clock and a logic unit, including both positive and negative edge triggered unit delay elements connected in parallel. The variable frequency divider generates a clock pulse from a signal source that corresponds to an input value from a logic unit, generates a next input value by the logic unit based on the input value and a frequency control word, and transmits the next input value from the logic unit to the signal source in response to the clock pulse. The multiphase clock is configured to generate the clock signal in response to the falling edge of the first pulse of the clock signal.

Abstract: A frequency doubling device suitable to generate an output terminal voltage oscillating at a differential frequency double the frequency of the input differential voltage, includes a first differential pair of P-type transistors and a second differential pair of N-type transistors controlled by the differential input voltage, as well as an LC oscillator including a LC resonant dipole through which the absorbed current is forced by two differential pairs of transistors.

Abstract: A high frequency divider involves a plurality of differential latches. Each latch includes a pair of cross-coupled P-channel transistors and a variable resistance element. The latch is controlled to have a lower output resistance at high operating frequencies by setting a multi-bit digital control value supplied to the variable resistance element. Controlling the latch to have a reduced output resistance at high frequencies allows the 3 dB bandwidth of the latch to be maintained over a wide operating frequency range. The variable resistance element is disposed between the two differential output nodes of the latch such that appreciable DC bias current does not flow across the variable resistance element. As a consequence, good output signal voltage swing is maintained at high frequencies, and divider current consumption does not increase appreciably at high frequencies as compared to output signal swing degradation and current consumption increases in a conventional differential latch divider.

Abstract: A clock multiplier circuit includes a clock generator, a delay element, a logic gate, and a duty cycle correction circuit. The clock generator generates a clock signal. The delay element generates a delayed clock signal in response to the clock signal. The logic gate generates a frequency-multiplied clock signal in response to the clock signal and the delayed clock signal. The duty cycle correction circuit generates an adjustment signal based at least in part on the frequency-multiplied clock signal. The clock generator adjusts a duty cycle of the clock signal in response to the adjustment signal.

Abstract: In accordance with an embodiment, a frequency doubling circuit includes a differential transistor pair coupled to an input port of the frequency doubling circuit, a first differential cascode stage having an input coupled to an output of the differential transistor pair, a plurality of first impedance elements coupled between the output of the differential transistor pair and the input of the first differential cascode stage, and an output combining network coupled between the first differential cascode stage and an output port of the frequency doubling circuit.

Abstract: Frequency multipliers include a pair of transistors each connected to a common impedance through a respective collector impedance formed from a transmission line. Each transmission line has a length between about one quarter and about one eighth of a wavelength of an input signal frequency and is tuned to produce a large impedance at a collector of the respective transistor at the input signal frequency. The output frequency between the collector impedances and the common impedance is an even integer multiple of the input frequency.

Abstract: Methods for frequency multiplying include receiving a signal having an input frequency at a frequency multiplier comprising a pair of transistors; and selecting a harmonic in the signal by connecting the transistors to a common impedance through a respective collector impedance, wherein an output frequency at the harmonic between the collector impedances and the common impedance is an even integer multiple of an input frequency.

Abstract: There is provided a drive device capable of driving a capacitive load with efficiency and with low power consumption while keeping quality input reproducibility for output signal. A switching drive circuit 10f repeatedly performs operations in the order of VCP charging phase PH_VCP_CH, VCP discharging phase PH_VCP_dCH, VCN charging phase PH_VCN_CH, and VCN discharging phase PH_VCN_dCH. A switching amplifier 10 allows a charging phase per cycle for an input signal VIN that is a reference for operation to be either a phase in which the slope of the input signal VIN is positive from a reference voltage REFL or greater until a maximum voltage, or a phase in which the slope of the input signal VIN is negative from a reference voltage REFH or less until a minimum voltage.

Abstract: One embodiment relates to an integrated circuit which includes a transmitter buffer circuit, a duty cycle distortion (DCD) detector, correction logic, and a duty cycle adjuster. The DCD detector is configured to selectively couple to the serial output of the transmitter buffer circuit. The correction logic is configured to generate control signals based on the output of the DCD detector. The duty cycle adjuster is configured to adjust a duty cycle of the serial input signal based on the control signals. Another embodiment relates to a method of correcting duty cycle distortion in a transmitter. Other embodiments and features are also disclosed.

Abstract: There is provided a high resolution circuit for converting a capacitance-to-time deviation including a capacitance deviation detecting unit generating two detection signals having a phase difference corresponding to variations of capacitance of an micro electro mechanical system (MEMS) sensor; a capacitance deviation amplifying unit dividing frequencies of the two detection signals to amplify the phase difference corresponding to the capacitance deviation; and a time signal generating unit generating a time signal having a pulse width corresponding to the amplified phase difference.

Abstract: A sub-harmonic mixer includes a first transistor having a source and a drain and a second transistor having a source connected to the source of the first transistor and a drain connected to the drain of the first transistor. A mixing transistor is configured to be biased in a linear operating region. The mixing transistor includes a drain coupled to the sources of the first transistor and the second transistor. The mixing transistor has its drain driven by a signal at twice a local oscillator (LO) frequency and its gate driven by a radio frequency (RF) signal while the mixing transistor is biased in the linear region such that a process of frequency doubling and mixing are performed simultaneously.

Abstract: According to one embodiment, there is provided a DLL circuit including a delay chain, a plurality of phase comparators, and a controller. The plurality of phase comparators receive the reference clocks individually and receive respectively the clocks from the delay elements in mutually different stages, among the delay elements of the plurality of stages. The controller simultaneously receives comparison results of the plurality of phase comparators, determines the number of stages that generate the clock of which a phase is synchronized with a phase of the reference clock from among the delay elements of the plurality of stages, and selects the number of output stages from among the delay elements of the plurality of stages based on the determined number of stages so that a delay clock having a demanded delay amount with respect to the reference clock is output.

Abstract: Here, an apparatus is provided. The apparatus comprises a first supply rail, a second supply rail, a first ambipolar transistor (which is coupled to the first supply rail at its drain and which receives a reference voltage at its gate), a second ambipolar transistor (which is coupled to the first supply rail at its drain and which receives an input signal at its gate), a current source (which is coupled between the sources of the first and second ambipolar transistors and the second supply rail), and an output circuit (which is coupled to drain of the first ambipolar transistor). In operation, the output circuit provides an output signal having a frequency that is about twice the frequency of the input signal.

Abstract: One embodiment relates to an integrated circuit which includes a transmitter buffer circuit, a duty cycle distortion (DCD) detector, correction logic, and a duty cycle adjuster. The DCD detector is configured to selectively couple to the serial output of the transmitter buffer circuit. The correction logic is configured to generate control signals based on the output of the DCD detector. The duty cycle adjuster is configured to adjust a duty cycle of the serial input signal based on the control signals. Another embodiment relates to a method of correcting duty cycle distortion in a transmitter. Other embodiments and features are also disclosed.

Abstract: A millimeter-wave wideband frequency doubler stage for use in a distributed frequency doubler includes: a differential input pair of transistors, each transistor having respective gate, drain and source terminals, wherein the source terminals are coupled together to a first power supply node and the drain terminals are coupled together at a first node to a second power supply node; first and second pairs of bandpass gate lines coupled to the gate terminals of the transistors; and a pair of bandpass drain lines coupled to the drain terminals of the transistors.

Abstract: A signal generator for coupling to a concealed conductor including a first oscillator configured to generate a first waveform having a first frequency, a first terminal coupled to the first oscillator through a first band pass filter configured to pass signals of the first frequency, a second oscillator configured to generate a second waveform having a second frequency, and a second terminal coupled to the second oscillator through a second band pass filter configured to pass signals of the second frequency.

Abstract: A divider has a clock generation circuit which combines a first trigger clock and a second trigger clock having a first phase difference, so as to generate a third clock having pulse edges corresponding to pulse edges of the first trigger clock and the second trigger clock; an output dividing circuit which divides the frequency of the third clock in half so as to generate a first differential output clock and a second differential output clock having a duty ratio corresponding to the first phase difference; and a phase correction circuit which detects a phase of the first output clock or the second output clock at a timing of the pulse edge of the first trigger clock or the second trigger clock, so as to generate a phase correction signal for resetting the output dividing circuit when the detected phase is not a normal phase.

Abstract: A frequency multiplier circuit, comprising a first stage including a first differential pair of amplifier elements having respective current conduction paths connected in parallel between first and second nodes and respective control terminals connected to receive input signals of opposite polarity at an input frequency in the radio frequency range, the first and second nodes being connected to respective bias voltage supply terminals through first and second impedances respectively so that current flowing differentially in the current conduction paths of the first differential pair of amplifier elements produces a voltage difference across the first and second nodes at a frequency which contains a harmonic of the input frequency, and a second stage including a second differential pair of amplifier elements coupled at the harmonic of the input frequency with the first and second nodes to amplify differentially the voltage difference and produce an output signal at the harmonic of the input frequency.

Abstract: A frequency doubler comprises: a non-overlapping signal generation circuit configured to receive a first signal and a first control signal and generate a first and second non-overlapping signals, each of the first and second non-overlapping signals has a frequency of the first signal, an average of a duty cycle of the first non-overlapping signal and a duty cycle of the second non-overlapping signal is determined by the first control signal; a combination circuit configured to receive and combine the two non-overlapping signals to generate a frequency-doubled signal.

Abstract: A frequency doubler receiving an in-phase oscillating signal and an inverse oscillating signal and generating an output signal oscillating at a multiplied frequency, accordingly. The frequency doubler has a first transistor, a second transistor, a first inductor and a second inductor. A first terminal of the first transistor and a first terminal of the second transistor are at a common voltage. The frequency doubler receives the in-phase oscillating signal and the inverse oscillating signal via control terminals of the first and second transistors. The first and second inductors couple a second terminal of the first transistor and a second terminal of the second transistor to an output terminal of the frequency doubler, respectively. The first and second inductors may be separate inductance devices or, in another case, be implemented by a symmetric inductor.

Abstract: The present invention provides a method for identifying a specific number of communicating points having relatively smallest accumulated path values from a plurality of transmitting points for a receiving point in a communication system. The method includes steps of: (a) defining a first coordination of each of the plurality of transmitting points and the receiving point on a complex plane; (b) transferring the first coordination of the receiving point to a second coordination thereof, in which the second coordination of the receiving point is near an origin of the complex plane; and (c) identifying the specific number of transmitting points having relatively smallest accumulated path values based on the second coordination of the receiving point.

Abstract: Techniques for generating quadrature signals from a local oscillator signal, wherein the generated quadrature signals have a frequency half of the local oscillator frequency. In an exemplary embodiment, two oscillators, e.g., injection locked oscillators, are provided, each oscillator having a load, a cross-coupled transistor pair, an integrating capacitor, and current injection transistors. A differential pair is coupled to the leads of each of the integrating capacitors, and the drains of the differential pair are coupled to the outputs of the other oscillator to help increase the slew rate of the output voltages of the other oscillator. The inputs to the differential pair may be first amplified to improve the gain of the differential pair. In another exemplary embodiment, the power consumption of the differential pair may be reduced by operating them in a discontinuous mode, e.g., by coupling the source voltages of the differential pair to corresponding delayed versions of the drain voltages.

Abstract: A frequency doubler comprises: a non-overlapping signal generation circuit configured to receive a first signal and a first control signal and generate a first and second non-overlapping signals, each of the first and second non-overlapping signals has a frequency of the first signal, an average of a duty cycle of the first non-overlapping signal and a duty cycle of the second non-overlapping signal is determined by the first control signal; a combination circuit configured to receive and combine the two non-overlapping signals to generate a frequency-doubled signal.

Abstract: A millimeter-wave wideband frequency doubler stage for use in a distributed frequency doubler includes: a differential input pair of transistors, each transistor having respective gate, drain and source terminals, wherein the source terminals are coupled together to a first power supply node and the drain terminals are coupled together at a first node to a second power supply node; first and second pairs of bandpass gate lines coupled to the gate terminals of the transistors; and a pair of bandpass drain lines coupled to the drain terminals of the transistors.

Abstract: Aspects of a method and system for transmission and/or reception of signals up to EHF utilizing a delay circuit are provided. In this regard, a transceiver may comprise at least one delay circuit which may, in turn, comprise a plurality of delay elements and a variable capacitance. The delay circuit may be enabled to delay a first signal, via at least a portion of the delay elements and via the variable capacitance, to generate a second signal that is 90° phase shifted relative to said first signal. Additionally, the delay circuit may be enabled to mix the first signal with the second signal to generate a third signal that is twice a frequency of the first signal. The third signal may be utilized for up-conversion and/or down-conversion of signals to and/or from baseband, intermediate frequencies, and/or RF frequencies of up to EHF.

Abstract: An apparatus for generating a compensation signal for a power converter where the second harmonic ripple on the voltage bus is substantially removed from the compensation signal. The apparatus comprises a frequency-locked clock generator, a bus voltage data generator, a stack, and a compensation signal generator. The frequency-locked clock is coupled to the power converter voltage bus that contains harmonics of the AC line frequency. The clock generator frequency locks to the second harmonic of the AC line frequency and creates a system clock which is used for the synchronous operations throughout the apparatus. The bus-voltage data generator inputs a power converter scaled-bus voltage, generates bus-voltage data at a sampling rate which is determined by the coupled system clock. The output of the bus-voltage generator is input into a stack.

Abstract: A multiplier circuit, including: a transistor with gate, source and drain connections adapted to accept an input signal by the transistor gate; a reference voltage source providing a DC reference voltage to the transistor drain; an inductor connected between the drain and the reference voltage source; a resistor connected in parallel to the inductor between the transistor drain and the reference voltage source; a current source providing a DC current to the transistor source; two capacitors forming a voltage divider, with the first capacitor connecting between the gate and the source and the second capacitor connecting between the source and the ground in parallel to the current source; and wherein the multiplier circuit is adapted to accept an input signal and provide as output an amplified current signal with a frequency that is double that of the input signal.

Abstract: Aspects of a method and system for generation of signals up to extremely high frequency using a delay block are provided. In this regard, a first signal may be delayed, via at least a portion of a plurality of delay elements and via a variable capacitance, to generate a second signal that is 90° out of phase relative to the first signal. Additionally, the first signal and second signal may be mixed to generate a third signal, wherein a frequency of the third signal is twice a frequency of said first signal. The portion of the delay elements utilized for delaying the signal may be controlled via one or more switching elements. In this regard, one of the plurality of delay elements may be selected to output the second signal. Moreover, the portion of the delay elements utilized for delaying the signal may be programmably controlled.

Abstract: An output terminal 6 is provided at the connecting point 5 between the collector terminal of a transistor 1 and an open-ended stub 4 by connecting the open-ended stub 4 to the collector terminal of the transistor 1, the open-ended stub 4 having a line length equal to a quarter of the wavelength of a signal of frequency 2N·F0 or 2N times the oscillation frequency F0. In addition, an output terminal 9 is provided at a connecting point 8 located at a distance equal to a quarter of the wavelength of a signal of oscillation frequency F0 from the end of an open-ended stub 7 by connecting the open-ended stub 7 to the base terminal of the transistor 1, the open-ended stub 7 having a line length longer than a quarter of the wavelength of the signal of oscillation frequency F0.

Abstract: A frequency multiplier circuit, comprising a first stage including a first differential pair of amplifier elements having respective current conduction paths connected in parallel between first and second nodes and respective control terminals connected to receive input signals of opposite polarity at an input frequency in the radio frequency range, the first and second nodes being connected to respective bias voltage supply terminals through first and second impedances respectively so that current flowing differentially in the current conduction paths of the first differential pair of amplifier elements produces a voltage difference across the first and second nodes at a frequency which contains a harmonic of the input frequency, and a second stage including a second differential pair of amplifier elements coupled at the harmonic of the input frequency with the first and second nodes to amplify differentially the voltage difference and produce an output signal at the harmonic of the input frequency.