Abstract: There are provided a variable inductor with little degradation in quality factor, and an oscillator and a communication system using the variable inductor. An inductance controller comprising a reactance device with a variable device value, such as, for example, a variable capacitor, is connected to a secondary inductor, magnetically coupled to a primary inductor through mutual inductance. The inductance controller is provided with an inductance control terminal for receiving a control signal for controlling capacitance of the variable capacitor. Inductance of the primary inductor is varied by varying the capacitance by the control signal.

Abstract: Provided is a colpitts quadrature voltage controlled oscillator capable of obtaining quadrature orthogonal signals using a quadrature combination between a base and a collector of each transistor, without using an additional circuit such as a coupled transistor, a coupled transformer, a multiphase RC filter, etc. Accordingly, since nonlinearity, increased phase noise, a decrease in the Q-factor of an LC resonator, and increased power consumption can be avoided, a colpitts quadrature voltage controlled oscillator that has low phase noise, low electric power consumption, and a compact size can be implemented.

Abstract: A voltage-controlled oscillator comprises an inductor and a group of variable capacitance elements forming a resonance circuit. The group of variable capacitance elements includes first and second variable capacitance elements connectable in parallel and having mutually different absolute values of a ratio of control-voltage sensitivity to capacitance. The first and second variable capacitance elements both have a first end supplied with a control voltage for controlling resonance frequency of the resonance circuit and have a second end selectively connected to the inductor by a band selection signal for deciding a band in which the resonance frequency exists.

Abstract: An inductor circuit includes a pair of inductors connected in parallel with each other and a switch for turning on and off electric power to one of the pair of inductors. The inductance of the inductor circuit can be varied and the quality factor Q can be improved. Further, RF circuits employing the inductor circuit can generate an intended operating frequency.

Abstract: One embodiment relates to a circuit for active loss compensation. The circuit includes a parallel inductor-capacitive (LC) tank circuit having a first single-ended output. A first adjustable capacitor, which includes a first terminal and a second terminal, is coupled to the first single-ended output. The circuit also includes a first pair of transistors having sources coupled to a first common node. One transistor of the first pair of transistors has a drain coupled to the first single-ended output and the other transistor of the first pair of transistors has a gate coupled to the second terminal of the first adjustable capacitor. Other embodiments are also disclosed.

Abstract: A single-ended-to-differential mixer includes a differential input circuit having a single-ended input. The differential input circuit is responsive to a single-ended input signal to generate first and second signals. The single-ended-to-differential mixer includes a passive tank circuit in communication between a reference voltage and the differential input circuit. The single-ended-to-differential mixer includes a mixer circuit in communication with the differential input circuit and responsive to the first and second signals and a second input signal to generate a differential mixer output signal.

Abstract: The EMI-free planar inductor is the core technology of the green technology. The EMI-free planar inductor adopts the structure of the closed magnetic field flux IC inductor (CMFFICI). All the magnetic field is confined in a small volume. The magnetic field is parallel to the surface of the chip. The EMI-free planar inductor makes the on-chip LC tank having very high Q and saves a lot of energy. Combining with the gain-boost-Q technology, it makes the high performance clock chip being comparable to the xtalchip. The xtalchip is the inductor being replaced with the crystal in the gain-boost Q resonator. Furthermore, the EMI-free planar inductor makes the highest power efficiency boost-buck converter and the on-chip spinning motor. It makes the PC laser TV projector being implementable.

Abstract: In various embodiments, the invention provides a clock generator and/or a timing and frequency reference comprising an LC oscillator with a frequency controller to control and provide a stable resonant frequency. Such stability is provided over variations in a selected parameter such as temperature and fabrication process variations. The various apparatus embodiments include a sensor to provide a signal in response to at least one parameter of a plurality of parameters; and a frequency controller to modify the resonant frequency in response to the second signal. In exemplary embodiments, the sensor is implemented as a current source responsive to temperature fluctuations, and the frequency controller is implemented as a plurality of controlled reactance modules which are selectively couplable to the oscillator or to one or more control voltages. The controlled reactance modules may include fixed or variable capacitances or inductances, and may be binary weighted.

Abstract: An oscillator device includes a resonator including a coil and a capacitor connected to the coil in parallel; and an oscillator connected to the resonator. Electric waves are emitted from the coil to at least one receiving antenna of the receiver while the oscillator device changes position and direction over time. The coil has an outer diameter and a total length which is approximately the same as the outer diameter.

Abstract: A method and apparatus for real time clock brownout detection. A low power real time clock (RTC) operates continuously to keep time in a global positioning system (GPS) receiver while some receiver components are powered down. In various embodiments, a brownout detector circuit detects a loss of RTC clock cycles. If a loss of RTC clock cycles exceeds a predetermined threshold such that the RTC is not reliable for GPS navigation, an RTC status signal so indicates.

Abstract: System and method for increasing the frequency tuning range of a RF/microwave LC oscillator. A preferred embodiment comprises a voltage controlled oscillator (VCO) configured to generate an output signal at a frequency that is dependent upon a magnitude of an input voltage level and an effective inductance of an inductive load and a variable inductor coupled to the VCO. The variable inductor comprises a primary inductor coupled to the VCO to produce a magnetic field based upon a current flowing through the primary inductor and a secondary inductor magnetically coupled to the primary inductor, the secondary inductor to affect the magnitude of the effective inductance of the primary inductor.

Abstract: Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank.

Abstract: A capacitance switching element includes first and second capacitors connected in series by transistors. The gates of the transistors are biased by a first signal through one set of resistors, and the sources and drains are biased by a second signal through a second set of resistors. The signals are level-shifted and may be complimentary. To turn the element ON, the first signal may be set to VDD and the second signal may be set to zero. To turn the element OFF, the first signal may be set to a multiple of VDD/2 and the second signal may be set to the multiple plus one of VDD/2. When the element is used in an oscillator tuning circuit, the voltage stress on the transistors is reduced and the transistors may be fabricated with thin oxide. The oscillator may be used in a transceiver of a cellular access terminal.

Abstract: A tail-tank coupling technique combines two complementary differential LC-VCOs to form a quadrature LC-VCO. The technique reduces phase noise by providing additional energy storage for noise redistribution and by cancelling noise injected by transistors when they operate in the triode region. The resulting noise factor is close to the theoretical minimum 1+?, similar to a differential LC-VCO driven by an ideal noiseless current source. However, its figure-of-merit is higher, due to the absence of voltage head-room being consumed by a current source. The optimal ratio of tail-tank capacitor to main-tank capacitor for minimizing phase noise is approximately 0.5. The method can be extended to combine any even number of LC tanks resonating at fo and 2fo to form an integrated oscillator producing quadrature phase at frequency fosc and differential output at 2fosc.

Abstract: An oscillation circuit induces a first inverter, a second inverter, a first inductive load, a second inductive load and a capacitive load. A first inverter and a second inverter receive a first signal and a second signal, and invert the first and the second signal to output a first inverted signal and a second inverted signal respectively. An output end of the first inverter is electrically connected to a first inductive load, and an output end of the second inverter is electrically connected to a second inductive load. Further, a capacitive load is electrically connected to the output end of the first inverter and the output end of the second inverter, so as to receive the first and the second inverted signal respectively. The capacitance of the capacitive load changes with a control signal.

Abstract: The present invention provides a voltage-controlled oscillator operating from microwave frequencies to millimeter wave frequencies, which is capable of outputting a large power with an output impedance thereof being set up to a predetermined level at low power consumption, and a communication device using the same.

Abstract: A phase locked loop, voltage controlled oscillator, and phase-frequency detector are provided. The phase locked loop comprises a phase-frequency detector (PFD), a loop filter (LF), a voltage controlled oscillator (VCO), and a 3-stage frequency divider. The PFD receives a reference signal and a feedback signal to determine phase and frequency errors. The LF), coupled to the phase-frequency detector, filters the phase and frequency errors to generate a control voltage. The VCO, coupled to the loop filter, generates a VCO output signal according to the control voltage. The 3-stage frequency divider, coupled to the voltage controlled oscillator, divides the frequency of the VCO output signal 3 times to generate the feedback signal.

Abstract: Provided is a differential cascode voltage-controlled oscillator that can reduce a phase noise by the use of a quality factor enhancement technique with negative conductance and can mitigate a ground-caused noise effect by the use of a cascode connection technique. The differential cascode voltage-controlled oscillator includes an AC signal generator, and first through fourth cascode amplifiers. The AC signal generator generates an AC signal with a certain frequency according to a control voltage. The first cascode amplifier is connected in a cascode configuration, and amplifies the AC signal to output the resulting signal to a first output terminal. The second cascode amplifier is connected in a cascode configuration and connected to the first cascode amplifier in a cross-coupled configuration, to amplify the AC signal to output the resulting signal to a second output terminal.

Abstract: A variable simulated inductor comprises an integrator connected to receive the voltage across the input to the circuit. The output of the inductor is connected to a control terminal of a transconductor connected across the input of the circuit. The gain of the transconductor is electronically controllable in order to control the inductance of the circuit. An oscillator using a variable simulated inductor and a piezoelectric resonator connected in parallel is also provided.

Abstract: A circuit arrangement and signal processing device are disclosed. In one embodiment, the circuit arrangement includes a resonator circuit for generating an output signal from an input signal with a capacitance and with an inductance, with an input at which the input signal can be provided, and with an output at which the output signal can be provided. A control circuit is provided for open-loop or closed-loop control of a quality factor of the resonator circuit, the control circuit being configured to control the quality factor of the resonator circuit in an open-loop manner or in a closed-loop manner depending on a signal profile of the signal amplitude of the input signal and/or of the output signal.

Abstract: A circuit for generating chaotic signals implemented using heterojunction bipolar transistors (HBTs) and utilized in low probability intercept communications. The HBT chaotic circuit generates truly random analog signals in the GHz range that are non-repeating and deterministic and may not be replicated by preloading a predetermined sequence. A fully differential autonomous chaotic circuit outputs two pairs of chaotic signals to be used in a communication system. As it is impossible to generate identical chaotic signals at the transmitter and receiver sites, the receiver itself sends the chaotic signal to be used for encoding to the transmitter. The receiver includes a chaotic signal generator and digitizes, upconverts, and transmits the generated chaotic signal to the transmitter. The transmitter uses the received chaotic signal to code data to be transmitted. The receiver decodes the transmitted data that is encoded by the chaotic signal to retrieve the transmitted data.

Abstract: A voltage controlled oscillator (VCO) is provided that includes an output buffer having a first buffer stage including a first transistor and a second buffer stage including a second transistor. The first and second transistors are connected in a cascaded emitter follower buffer arrangement.

Abstract: A reference frequency control circuit comprising: a frequency voltage converting circuit configured to receive an oscillation signal from an oscillator circuit, and output an output voltage corresponding to a frequency of the oscillation signal, the oscillator circuit being a circuit configured to oscillate at a frequency corresponding to a level of an input signal; and a control circuit configured to control a level of the input signal so that the output voltage is at a predetermined level.

Abstract: An injection-locked frequency divider for dividing a frequency of an injection signal and obtaining a frequency divided signal is provided. The injection-locked frequency divider includes a signal injection unit and an oscillator. The signal injection unit includes a first input terminal and a second input terminal for receiving the injection signal. The received injection signal exhibits a phase difference of 180° between the first input terminal and the second input terminal. The oscillator includes an inductor unit and a variable capacitance unit. The injection-locked frequency divider is featured with a wide injection locking range, and can be realized with a low operation voltage, and therefore can be conveniently used in different kinds of hybrid ICs.

Abstract: A technique for reducing temperature sensitivity of an LC oscillator circuit includes a passive circuit coupled in parallel with a load capacitor. In at least one embodiment, an oscillator circuit is configured to generate a periodic signal having a free-running frequency. The oscillator circuit includes a first circuit portion including at least one inductor coupled in parallel with at least one load capacitor. The first circuit portion has an inductance-capacitance product that has a first temperature sensitivity. The oscillator circuit includes a passive circuit portion coupled in parallel with the first circuit portion. The passive circuit portion includes at least one resistor in series with at least one capacitor. The passive circuit portion has a second temperature sensitivity that opposes an effect of the first temperature sensitivity on the free-running frequency of the oscillator circuit, thereby reducing temperature sensitivity of the free-running frequency.

Abstract: In one embodiment, a multiple band oscillator system is disclosed which comprises a first oscillator having a first input, a resonating element, a first output, and a second output. In addition, the multiple band oscillator system also comprises a second oscillator having a second input, a third output, and a fourth output. The first oscillator has a first oscillator frequency and the second oscillator has a and second oscillator frequency. The multiple band oscillator system also contains a tuning capacitive element coupled to the first and second oscillators for determining the second oscillator frequency, and the first oscillator and the second oscillators are both capable of operating the resonating element.

Abstract: A technique includes selecting one out of a plurality of frequency bands and providing a voltage controlled oscillator to generate a mixing signal for the selected frequency band. The technique includes adjusting a frequency gain of the voltage controlled oscillator based on the selected frequency band.

Abstract: An integrated circuit package includes an inductance loop formed from a connection of lead wires and one or more input/output (I/O) package pins. In one embodiment, the inductance loop is formed from first and second wires which connect a first bonding pad on the integrated circuit chip to a first I/O pin of the package and a third and fourth wires which connect a second bonding pad on the chip to a second I/O pin of the package. To complete the inductor loop, the first and second I/O pins are connected by a third conductor between the pins. The third conductor may include one or more bonding wires and the I/O pins are preferably ones which are adjacent one another. However, the loop may be formed from non-adjacent connections of I/O pins based, for example, on loop-length requirements, space considerations, and/or other design or functional factors. In another embodiment, connection between the first and second I/O pins is established by making the I/O pins have a unitary construction.

Abstract: A crystal oscillator emulator integrated circuit comprises a first temperature sensor that senses a first temperature of the integrated circuit. Memory stores calibration parameters and selects at least one of the calibration parameters based on the first temperature. A semiconductor oscillator generates an output signal having a frequency that is based on the calibration parameters. A heater adjusts the first temperature to a predetermined temperature. A disabling circuit disables the heater after the calibration parameters are stored in the memory.

Abstract: A voltage controlled oscillator (VCO) includes a VCO unit having multiple VCO unit output terminals and an amplifier having multiple amplifier output terminals respectively connected to the VCO unit output terminals. The VCO unit generates first output signals having an oscillation frequency corresponding to a supply voltage. The amplifier amplifies a value obtained by performing n-th differentiation on a transconductance component of each first output signal (n being a natural number). Second output signals, corresponding to the first output signals, are output through the amplifier output terminals. Each second output signal includes the amplified value of the corresponding first output signal.

Abstract: Embodiments of the present invention include a common-gate amplifier having an input terminal and an output terminal, a transistor having a source, a drain, and a gate, four inductors, and two capacitors, and a negative amplification circuitry. The negative amplification circuitry has an input terminal to receive an RF signal. The negative amplification circuitry applies negative or zero amplification to the RF signal and outputs the negative or zero amplified signal on an output terminal. Alternative embodiments include a Colpitts differential oscillator, which includes two Colpitts single-ended oscillators. Each Colpitts single-ended oscillator includes a transistor. The source of the transistor in one Colpitts single-ended oscillator may be capacitively coupled to the gate of the transistor in the other Colpitts single-ended oscillator.

Abstract: A Method and an apparatus for distributing a clock signal are disclosed. The apparatus for distributing a clock signal includes a pair of flat plates, a variable inductor and a connection channel. The pair of flat plates includes a clock flat plate having at least one of clock signal extraction points and a reference flat plate arranged in parallel to the clock flat plate. The inductor is connected between the pair of flat plates, and the connection channel is configured to connect electrically the at least one of clock signal extraction points to an external circuit. The inductor may be adjusted to have an inductance for generating a resonance signal of a target frequency from the pair of flat plates.

Abstract: A voltage controlled oscillator includes a loop-shaped transmission line, an active circuit connected to a signal line, and a variable capacitor block connected to the signal line and having a plurality of variable capacitor units. Each variable capacitor unit includes a variable capacitor element, a control terminal for applying a control voltage to the variable capacitor element, and a reference voltage terminal for applying a reference voltage to the variable capacitor element. At least two variable capacitor units receive different reference voltages.

Abstract: A transistor voltage-controlled oscillator (VCO) and a frequency synthesizer having the transistor VCO are provided. The frequency synthesizer adopts a divide-by-five injection-locked frequency divider, which includes a five-stage inverter ring oscillating frequency dividing circuit for reducing the operating frequency of the oscillating signal from the VCO, thus decreasing power consumption due to counting operation of the frequency synthesizer. The transistor VCO includes three transistor switching capacitor sets connected in parallel to one another to form a parallel structure. The gates of the transistor switching capacitor sets are connected to respective operating voltage sources, so as to switch the status of the corresponding transistor switching capacitor set, which in turn adjusts the harmonic frequency generated by the VCO, thereby allowing the VCO to generate a corresponding operating frequency with enough bandwidth.

Abstract: A controllable oscillating system for generating a differential oscillating signal is disclosed. The controllable oscillating system includes an oscillating circuit and a current adjusting device. The oscillating circuit includes a controllable resonator, a cross-coupling driving device, and a current source. The cross-coupling driving device is coupled to the controllable resonator and utilized for driving the controllable resonator to generate the differential oscillating signal. The current source is coupled to the cross-coupling driving device and utilized for providing a first current. The current adjusting device is coupled to the cross-coupling driving device and utilized for adjusting currents passing through the cross-coupling driving device.

Abstract: A voltage-controlled oscillator (VCO) comprising a first circuit, a second circuit, a comparator circuit, and a control unit. The first circuit can determine an output common mode voltage associated with an output of the VCO. The second circuit can generate an upper control voltage limit and a lower control voltage limit associated with a control voltage received by the VCO based, at least in part, on the output common mode voltage. The comparator circuit can compare the control voltage to the upper and lower control voltage limits. The control unit can determine whether to change a switched capacitance associated with the VCO based, at least in part, on whether the control voltage is outside the upper and lower control voltage limits, thereby maintaining an optimal region of operation for the control voltage.

Abstract: An oscillation circuit and the method for operating the same.

Abstract: In a high frequency oscillator circuit including first and second field effect transistors, the first field effect transistor has a gate connected to a short-stub transmission line and a drain connected to an oscillation output terminal, and the second field effect transistor has a drain connected to a source of the first field effect transistor and a grounded source. The high frequency oscillator circuit oscillates by using a feedback circuit including the short-stub transmission line and the second field effect transistor. A feedback capacitor is further provided which is connected between a gate of the second field effect transistor and the drain of the first field effect transistor.

Abstract: An apparatus described herein is an LC tank circuit that may include a capacitance, a first inductance, and a second inductance. The first inductance and the second inductance may each be center tapped coils.

Abstract: A PLL includes an open-loop automatic frequency calibration circuit. The open-loop automatic frequency calibration circuit includes a frequency detector, first and second sinks, a comparator and a bank selector. The frequency detector generates an up-signal and a down-signal responding to a frequency difference between a first phase difference signal having a phase difference from a reference oscillation signal and the second phase difference signal having a phase difference from a frequency division oscillation signal. The first and second sinks discharge the first and second capacitors respectively responding to the up-signal and the down-signal. The comparator compares voltages of the first and second capacitors. The bank selector selects a bank according to binary search, selects an optimum bank among two banks lastly searched, and outputs a bank selection signal. The voltage-controlled oscillation changes frequency features thereof in response to the bank selection signal.

Abstract: An injection-locked frequency divider includes a signal injection circuit and colpitts VCO. The signal injection circuit is for injecting an injection signal. The colpitts VCO includes first and second transistors, first and second LC tank circuits and a cross-coupled transistor pair. The first terminals of the first and second transistors receive the injection signal. The first and second LC tank circuits are for determining resonance frequency of an oscillation signal of the colpitts VCO. The cross-coupled transistor pair includes third and fourth transistors. The control terminals of the third and fourth transistors are respectively coupled to first terminals of the fourth and third transistors. The first terminals of the third and fourth transistors are respectively coupled to a first terminal or control terminal of the first and second transistors for providing an equivalent negative resistance. The injection signal and oscillation signal are mixed in frequency to generate differential output signals.

Abstract: An oscillator includes a first oscillating portion that outputs a first oscillation signal having a first oscillation frequency through a first intermediate node to an output terminal, a mounting portion that includes an insulating layer and that mounts the first oscillating portion, a first line provided in the insulating layer and coupled between the first intermediate node and ground, a second line provided in the insulating layer and coupled between the first intermediate node and a power supply terminal, and a third line provided in the insulating layer and coupled between the first intermediate node and the output terminal.

Abstract: An nth-order oscillator system for providing a resonating signal, a method of generating a resonating signal and a communications system. In one embodiment, the nth-order oscillator system, n being greater than two, includes (1) an amplifier configured to provide an intermediate signal and (2) a feedback loop including an nth-order complex LC tank and configured to generate the resonating signal by feeding back a complex-filtered form of the intermediate signal to the amplifier.

Abstract: Provided is an apparatus having a variable capacitor circuit which is capable of obtaining a constant gain with respect to a whole control voltage by using a linear variable frequency characteristic for a variation of the control voltages, to thereby attain a wide variable frequency range. For this, a variable capacitor circuit includes a plurality of variable capacitors being connected in parallel with each other and having different capacitances with respect to an input control voltage, wherein the sum of the variable capacitances of the plurality of variable capacitors at a same voltage level of the control voltage varied within the whole control voltage range has linearity.

Abstract: An injection-locked frequency divider is provided. The injection-locked frequency divider includes an active inductor unit, a source injection unit, a first transistor and a second transistor. The injection-locked frequency divider generates a frequency-divided signal having a half frequency of the signal source. A locking frequency range of the injection-locked frequency divider is determined by a quality factor of a resonant cavity. A quality factor of the active inductor unit is lower than a conventional spiral inductor because the active inductor unit is composed of active elements. In the injection-locked frequency divider, the active inductor unit is used to instead of the conventional spiral inductor, so that the chip area can be reduced and the locking frequency range of the injection-locked frequency divider can be increased. Further, an induction value of the active inductor unit can be altered to change the locking frequency range of the injection-locked frequency divider.

Abstract: In general, in one aspect, the disclosure describes an apparatus that includes an inductive capacitive voltage controlled oscillator (LC VCO) to generate an output clock. A voltage to current converter is used to receive a forwarded clock and to inject the forwarded clock to the LC VCO. The output clock is a deskewed version of the forwarded clock.

Abstract: The present invention relates to an oscillator circuit having a resonant element, an active element, a feedback loop, and an additional loop comprising a phase shifting element.

Abstract: Provided is an oscillating apparatus that includes a plurality of variable frequency oscillators, each of which is provided in correspondence with a different oscillating band from one another; and a selection section that selects an oscillating signal that is from a variable frequency oscillator provided in correspondence with a designated oscillating band, from among the plurality of variable frequency oscillators, and outputs the selected oscillating signal, where the selection section includes a plurality of selectors connected in a tree structure, each selector outputting a selected one of inputted two or more oscillating signals, and each of the plurality of variable frequency oscillators is connected to a selector positioned at an end of the tree structure of the plurality of selectors.

Abstract: The voltage controlled oscillator (VCO) circuit comprises a tank circuit, a first tuning section comprising first capacitor elements wherein each one of the first capacitor elements is individually utilizable for the tank circuit, and a second tuning section comprising second capacitor elements wherein each one of the second capacitor elements is individually utilizable for the tank circuit and the capacitance of each one of the second capacitor elements is continuously adjustable in a predetermined capacitance range in dependence on a tuning voltage.

Abstract: A mixer comprises a differential input circuit that is configured to receive an input signal. The mixer comprises a tank circuit including a tuning capacitor arranged in parallel with an inductor. A resonant frequency of the inductor and tuning capacitor is substantially centered around a predetermined frequency of the input signal. The mixer comprises a mixer circuit that communicates with the differential input circuit and that is configured to receive first and second current signals and a second input signal. The mixer circuit is configured as a Gilbert cell double-balanced switching mixer for generating a differential mixer output signal as a product of the first and second current signals and the second input signal.