Abstract: The voltage controlled oscillator comprises an oscillating system wherein two variable capacitors are alternately connected. The capacitances of these two capacitors vary respectively in the same direction as the voltage that is applied thereto and in the opposite direction. Replacing one variable capacitor by the other is performed automatically when the output frequency of the oscillator reaches a predetermined switching value. It is thus possible to divide an operating frequency band of the oscillator into at least two parts in which the frequency varies alternately in the same direction as the control voltage of the oscillator and in the opposite direction. Switchable fixed capacitors can be connected in the oscillating system, either when one variable capacitor is replaced by the other or by means of a command, to make the oscillator switch from one frequency band to a lower band.

Abstract: A local oscillating circuit includes an integrated circuit that has an oscillating transistor, protection diodes against electrostatic damage, and first and second terminals each being connected to a base and a collector of the oscillating transistor, cathodes of the protection diodes being respectively connected to the first and second terminals and anodes thereof being connected to a ground; and a resonating circuit that is provided outside the integrated circuit and is connected between the first and second terminals. A reverse-biasing voltage is applied to each of the cathodes of the protection diodes when VHF high-band signals are received while a voltage is not applied to each of the cathodes when VHF low-band signals are received.

Abstract: To present a variable capacity circuit and a control method of variable capacity capable of extending a variable capacity width of a variable capacity element to a maximum extent without increasing an element area of the variable capacity element or varying the level of control voltage, a variable capacity circuit 2 comprises a capacity value control circuit 11, varactors VA1 and VA2, and resistance elements R1 and R2. The capacity value control circuit 11 issues a variable output voltage CNTOUT depending on input control voltage VT, and controls the potentials at both ends of the varactors simultaneously. The output voltage CNTOUT is variably adjusted so as to have a negative correlation to the control voltage VT. Variable width of terminal voltage VD can be extended from a variable width SA1 to a variable width SA1a (range is +/?(Vcc1)). As a result, as shown in FIG. 5B, the changeable area of a varactor capacity value CV can be extended from a changeable area CA1 to a changeable area CA1a.

Abstract: A VCO circuit (20) has a coil (21) and, in parallel therewith, a constant capacitance (24) and adjustable capacitance elements (22, 23). A first capacitance element (22) is formed by one or more varactors whose capacitance can be adjusted by an analogue adjusting voltage (Vtune), while a second capacitance element (23) is formed by an arrangement comprising a plurality of capacitors which can be actuated by a digital bit word VCWD[N:1]. Digital calibration for the VCO (20) is performed by determining whether the present adjusting voltage is within a particular voltage range and, if this is not the case, the digital bit word being incremented or decremented by a bit value.

Abstract: Improved voltage controlled oscillator (VCO) circuits are disclosed. A symmetrical voltage controlled oscillator (VCO) system according to the embodiments of the present invention comprises a frequency tuning circuit containing one or more varactors for receiving a predetermined tuning signal and a frequency tuning bias signal for altering capacitances of the varactors, a modulation circuit coupled in parallel with the frequency tuning circuit containing one or more varactors for modulating one or more outputs, and a core circuit coupled in a parallel with the tuning circuit and the modulation circuit for providing an oscillation mechanism, wherein the core circuit has an inductance module coupled in a parallel fashion with the frequency tuning circuit and the modulation circuit, wherein circuit elements of the VCO system are symmetrically arranged for increasing oscillation efficiency thereof and the varactors are tuned to deliver the output at an output frequency.

Abstract: A phase synchronous multiple LC tank oscillator is described. A plurality of oscillator stages are configured to oscillate synchronously. The phase of each of the plurality of oscillator stages is substantially the same and the plurality of oscillators are inductively coupled.

Abstract: A source coupled differential complementary Colpitts oscillator is described, which enables a differential oscillation and also can improve phase noise performance by source-coupling a complementary Colpitts oscillator using an inductor. A differential complementary Colpitts oscillator includes: a plurality of complementary Colpitts oscillators and a source coupler which couples a source node of the plurality of complementary Colpitts oscillators, enables the Colpitts oscillators to differentially oscillate.

Abstract: A method of differentially controlling an LC voltage controlled oscillator (VCO) includes providing an LC-VCO comprising at least one inductor, measuring an inductor common voltage (CMV) output at a point along the at least one inductor, utilizing the measured inductor CMV as an input to a charge pump, and outputting from the charge pump a plurality of differential control voltages to control an output of the LC-VCO.

Abstract: A complementary metal oxide semiconductor voltage controlled oscillator is provided. The voltage controlled oscillator includes an LC tank which is supplied with a power supply voltage, the LC tank oscillating at a certain frequency; a negative resistor including first and second N-channel metal oxide semiconductor field effect transistors (NMOS FETs) to sustain the oscillation of the LC tank; a direct current block to remove a direct current component from the power supply voltage; an alternating current block to apply an alternating current voltage to the gates of the first and second NMOS FETs; a first current mirror including third and fourth NMOS FETs and allowing a current to symmetrically flow in the voltage controlled oscillator, a drain and the gate of the third NMOS FET being connected to a reference voltage supply; and the reference voltage supply applying a direct current voltage to the first current mirror.

Abstract: A method, circuit, and/or system for controlling an amplitude and/or limiting or reducing the energy consumed by an LC voltage controlled oscillator (LCVCO). In one embodiment, an oscillator can include: (i) a bias circuit that can provide first and second bias signals; (ii) an oscillator core that can provide a periodic signal with a frequency related to the first bias signal and an amplitude, where the oscillator core can also provide a feedback signal; and (iii) a current/amplitude controller that can control the amplitude by dynamically dusting the first bias signal in response to the feedback signal. Embodiments of the present invention can advantageously provide a reliable and simplified design approach for amplitude control and substantial energy reduction in an oscillator, such as an LCVCO circuit or a Colpitts differential oscillator.

Abstract: A voltage-controlled oscillator for generating differential output is disclosed. The voltage-controlled oscillator comprises a Colpitts oscillator having a first inductor and a capacitive divider having at least two capacitors connected in series. A varactor is connected in series with the capacitive divider and to a reference voltage, and a second inductor is mutually coupled to the first inductor for providing the differential output. A second inductor is substantially centrally tapped and connected to the reference voltage for providing a substantially balanced output. The operating frequency of the voltage-controlled oscillator is dependent on an applicable potential difference across the varactor.

Abstract: A variable capacitance circuit capable of switching on and off a variable capacitance function, includes variable capacitance means formed such that variable capacitance elements whose capacitance values change according to a voltage value of a supplied capacitance control voltage are connected so as to be paired and a plurality pairs of variable capacitance elements are connected in parallel forming multiple stages; bias voltage generation means for generating bias voltages of different voltage values based on a constant voltage from a constant voltage source; and an on-off switch for the variable capacitance function, in which the variable capacitance function of the variable capacitance means is turned on by supplying the bias voltage to the variable capacitance element of each stage of the variable capacitance means and turned off by grounding the bias voltage of each voltage value.

Abstract: Methods and apparatus are disclosed for adjusting the frequency tuning range of an oscillator circuit. The oscillator circuit is comprised of at least two MOS devices; a first reactance connecting a drain electrode of a first MOS device to a gate electrode of a second MOS device and a second reactance connecting a drain electrode of the second MOS device to a gate electrode of the first MOS device; and a tank circuit connected to the source and drain electrodes. The first and second reactance may comprises a capacitor or a diode or a combination thereof. In addition, one or more resistors may optionally be connected between a gate electrode of at least one of the MOS device and a power source.

Abstract: Voltage controlled oscillator comprising a LC tank circuit (L, C, R) coupled to modulator means and characterized in that the modulator means are coupled to amplifier means via an adder for generating a quadrature periodical output signal having a frequency in a relative wide range, the frequency being controlled by a control signal (V.sub.T) provided to the modulator means.

Abstract: In accordance with certain described implementations, a voltage controlled oscillator (VCO) includes a VCO coarse tuning bank having multiple coarse tuning bank bits. Each coarse tuning bank bit has an associated bit capacitance. The bit capacitances of the coarse tuning bank bits may be selectively engaged using, for example, a single switching transistor for each coarse tuning bank bit.

Abstract: Improved voltage controlled oscillator circuits and phase-locked loop circuits are disclosed. For example, a voltage controlled oscillator circuit comprises a first linear amplifier, the first linear amplifier generating a coarse-tuning voltage from an input voltage, a second linear amplifier, the second linear amplifier generating a fine-tuning voltage from the input voltage, and a voltage controlled oscillator comprising a coarse-tuning input coupled to the first linear amplifier, a fine-tuning input coupled to the second linear amplifier, and a clock signal output, wherein a frequency of a signal on the clock signal output is changeable as a function of the input voltage. Such a voltage controlled oscillator circuit may be employed in a phase-locked loop circuit.

Abstract: Inductor-capacitor (LC) oscillator circuits are formed of a conductive loaded resinbased material. The conductive loaded resin-based material comprises micron conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers in a base resin host. The ratio of the weight of the conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers to the weight of the base resin host is between about 0.20 and 0.40. The micron conductive powders are formed from nonmetals, such as carbon, graphite, that may also be metallic plated, or the like, or from metals such as stainless steel, nickel, copper, silver, that may also be metallic plated, or the like, or from a combination of nonmetal, plated, or in combination with, metal powders. The micron conductor fibers preferably are of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like.

Abstract: The present invention discloses an automatic page detector, to determine which page of a book is open. The automatic page detector uses a magnet and an inductor as a sensor. In the invention, there is a magnet at each page of the book and the locations of the magnets for different pages are different. There is an array of inductors just beneath the magnets when the book is closed. The inductors are connected to the feedback loop of a LC oscillator through analog switches. The proximity of a magnet to an inductor will change the frequency of the LC oscillator. Scanning the analog switches by a microprocessor and detecting the variation of frequency of the LC oscillator during each scanning time period, the status of each magnet will be detected and we can determine which page of a book is opened.

Abstract: A circuit arrangement for generating oscillations with a defined frequency includes an oscillator circuit (30, 32) for generating the oscillations and a dedamping circuit (18, 20) connected to the oscillator circuit for compensating any damping of the oscillator circuit. The dedamping or damping compensation by the dedamping circuit is accomplished with the aid of a rectifier circuit (60, 62). The dedamping circuit is a bridge circuit of CMOS field effect transistors (22, 24; 26, 28) which are controlled in their operation in closed loop fashion by respective rectifier circuit branches which are in turn connected to the oscillator circuit to provide a proportional closed loop control of the damping compensation.

Abstract: A VCO include a resonance tank circuit(A) and an amplification circuit(B) which oscillates and is amplified at a resonance frequency of the resonance tank circuit(A). The resonance tank circuit(A) is provided with a capacity band switching circuit(D) for varying an oscillation frequency band, and a current band switching circuit(E) for feeding an appropriate current, corresponding to each oscillation frequency band, to the amplification circuit(B). This allows expansion of the oscillation frequency variable range as well as realization of a favorable phase noise characteristic in a broad band by optimization of a current in each frequency band.

Abstract: A CMOS LC-tank oscillator includes a pair of symmetric inductors and a differential pair of transistors. The inductors have a first one of their terminals interconnected at a supply node to which a voltage supply is applied through a supply resistor and a second terminal connected to the drain of a respective one of the transistors. The transistors have their sources interconnected at a tail node which is connected to ground through a tail resistor. A current control loop controls a core current between the supply and tail nodes so as to keep a voltage drop across the tail resistor at a level determined by a reference voltage. The current control loop keeps the core current between the supply and tail nodes at the required level so that a resistor may replace the upstream supply voltage regulator and another resistor may replace the downstream bias regulator. Consequently, sources of noise injected into the LC-tank type oscillator are eliminated.

Abstract: The voltage controlled oscillator comprises an amplifier and an oscillating system comprising an inductor and a first and second variable capacitor connected in series, each having a capacitance varying according to its control voltage. The capacitance of one of the variable capacitors varies in the same direction as its control voltage and the capacitance of the other variable capacitor varies in the opposite direction to its control voltage. A capacitor having a fixed capacitance can be connected in series or in parallel with the first and second variable capacitors. The first and second variable capacitors are preferably formed by transistors, respectively of PMOS and NMOS type. An additional series of additional first and second variable capacitors can be connected in parallel with the first and second variable capacitors.

Abstract: A controlled oscillator circuit includes an amplifier including a first transistor coupled between a first node and a reference node, and a second transistor coupled between a second node and the reference node. The gate of first transistor and the gate of the second transistor may be cross-coupled. The oscillator may also include one or more variable capacitance circuits coupled between the first node and the second node, each including a first capacitor coupled between the first node and a third node, and a second capacitor coupled between the second node and a fourth node. Each variable capacitance circuit may also include a third, a fourth and a fifth transistor interconnected to selectively couple the first and second capacitors to the reference node. The third, fourth and fifth transistors may be low voltage transistors and the first and the second transistors may be high voltage transistors.

Abstract: An LC circuit section and a negative resistance section are provided for an LC-VCO. A pair of output terminals are provided for the LC circuit section and an inductor is connected between the output terminals, and two variable capacitors are connected in series to each other parallelly with the inductor. Further, the LC circuit section is provided with a pair of capacitors and a pair of switches that are connected between the capacitors and a ground potential and consist of NMOS transistors. Moreover, a switch that consists of the NMOS transistor is connected between a node, which is between one capacitor and one switch, and a node, which is between the other capacitor and the other switch, and the two nodes are connected to each other when the switch is closed.

Abstract: Proposed is a device actuated by a transponder for the generation of a switch signal. The device is based on an oscillating circuit (10) with a capacitance (C1), an identification coil (L1) and an oscillator amplifier (12). Connected to the oscillating circuit (10) is a frequency observer (20) which evaluates the frequency (f1) tuned in the oscillating circuit (10) and which when finding a change emits a switch signal (S). A change of the frequency in the oscillating circuit (10) is effected by the approach of a transponder (60). The device permits a nearly loadless transponder identification.

Abstract: An oscillator includes a resonant circuit of at least one inductance device and at least one tunable capacitance. The tunable capacitance is implemented through diffusion capacitances of at least one current-carrying transistor. The tunable capacitance has a first differential amplifier having a first transistor and a second transistor and a second differential amplifier having a third transistor and a fourth transistor Electrical properties of the first transistor and second transistor are complementary to electrical properties of the third transistor and fourth transistor, and control connections of the first transistor and the third transistor are connected to one another. Control connections of the second transistor and the fourth transistor are connected to one another. Second current connections of the first transistor and the third transistor are connected to one another, and second current connections of the second transistor and the fourth transistor are connected to one another.

Abstract: A quadrature VCO comprises: a first delay cell including a first differential VCO coupled between a power supply and a first current source; and first and second coupling transistors that each include a first terminal, a second terminal coupled to the power supply, and a third terminal, and that vary a current flowing from the second terminal to the third terminal according to quadrature-phase signals applied to the first terminal; and a second delay cell including a second differential VCO coupled between a power supply and a second current source; and third and fourth coupling transistors that each include a first terminal, a second terminal coupled to the power, and a third terminal, and that vary a current flowing from the second terminal to the third terminal according to in-phase signals applied to the first terminal.

Abstract: A voltage-controlled oscillator circuit. A pair of inductors are coupled to a first power source. A pair of capacitors respectively coupled between a variable resistor and the pair of inductors in serial. A pair of first switches respectively coupled between the pair of capacitors and a second power source. The first switch of the pair has a first control gate coupled to a connection point of the other first switch and the corresponding capacitor.

Abstract: The disclosure relates to a sub-millimeter backward wave oscillator. More specifically, the disclosure relates to a miniature backward wave oscillator having a biplanar interdigital circuit. In one embodiment the interdigital circuit includes diamond and is coated with an electro-conductive material.

Abstract: A voltage controlled oscillator apparatus includes at least two voltage controlled oscillators, each of the voltage controlled oscillators being formed on a semiconductor substrate and having an LC-resonant circuit including a three-terminal inductor or a two-terminal inductor, and a continuously variable capacitor, and an amplifier including n-channel transistors or n-channel transistors and p-channel transistors. Two of the three-terminal or two-terminal inductors constructing the first and second voltage controlled oscillators have a coil shape formed with a wiring layer of an integrated circuit formed on the semiconductor substrate, and one of the three-terminal or two-terminal inductors has such a shape that its inductance value differs from that of the other of the three-terminal or two-terminal inductors, and is disposed in a region inside of the other of the three-terminal or two-terminal inductors with respect to its planar shape.

Abstract: An apparatus and method of oscillating a wideband frequency are disclosed. The apparatus includes: a frequency oscillating unit for oscillating a predetermined frequency; a phase-locked loop for comparing the oscillated frequency and a reference frequency by feed-backing the oscillated frequency from the frequency oscillating unit and fixing an oscillating frequency of the frequency oscillating unit; and a variable dividing unit for varying a division ratio to approach to a frequency band required by the oscillating frequency and dividing the oscillating frequency.

Abstract: In the case of a voltage-controlled LC oscillator (4), the effects of supply voltage fluctuations are reduced according to the invention, due to the fact that a stabilized voltage source (3) is assigned to the LC oscillator (4), which supplies the LC oscillator (4) with a stabilized voltage. This in particular is the case if the LC oscillator (4) is integrated together with other circuit components in a semiconductor and heavy noise or strong disturbances occur on supply voltage lines (1, 2). Advantageously, the stabilized voltage source (3) is formed by an operational amplifier (6), after which a driver transistor (5) is positioned, whereby the operational amplifier is subjected to a reference voltage (7).

Abstract: To provide a voltage controlled variable capacitor which can change a capacitance value thereof in a wide controlled voltage range and control the capacitance value easily with a high precision without complicating the circuit configuration thereof, and to provide a voltage controlled variable capacitor which can change a capacitance value thereof with a good linearity. The voltage controlled varactor is configured in a manner that varactors VCk, each formed by a series connection of a fixed capacitor Ck (k=1, 2, . . . , n) and a MOS transistor Mk of N channel type, are connected in parallel. The MOS transistors M1 to Mn are configured in a manner that gate widths W are same but gate lengths L1 to Ln are elongated sequentially (that is, L1<L2< . . . <Ln) so that the threshold voltages thereof are differentiated from one another.

Abstract: An LC oscillator (I) comprises a cross-coupled PMOS transistor pair (Ma, Mb) coupled to a pair of capacitors (Cva, Cvb) and a pair of inductances (La, Lb). To enhance the signal amplification of the oscillator, a pair of auxiliary transistor circuits (Qa, Qb; Na, Nb) is provided which are coupled between the drain and, preferably, the source of each PMOS transistor. The capacitors (Cva, Cvb) are preferably variable capacitors and the inductances (La, Lb) are preferably connected to ground to allow a enlarged tuning voltage range.

Abstract: In a configuration wherein an output signal from a differential oscillator is input into a differential buffer amplifier, an operating current for the differential oscillator including a resonator, which has a node at the midpoint of an inductor, and a pair of field-effect transistors for oscillation and an operating current for the differential buffer amplifier including a pair of bipolar transistors for amplification are made common. In order to obtain the common operating current, the current from the pair of bipolar transistors for amplification is fed from the midpoint of the inductor into the pair of field-effect transistors for oscillation.

Abstract: Disclosed are integrated circuits having multiple electromagnetically emissive devices, such as LC oscillators. The devices are formed on an integrated circuit substrate and are given different planar orientations from each other. Particular integrated circuit packages disclosed are “flip-chip” packages, in which solder bumps are provided on the integrated circuit substrate for flipping and mounting of the finished integrated circuit upon a printed circuit board or other substrate. The solder bumps provide conductive connections between the integrated circuit and the substrate. The orientations and positioning of the emissive devices are such that one or more of the solder bumps are interposed between neighboring emissive devices to act as an electromagnetic shield between them.

Abstract: The present invention achieves technical advantages as a high performance analog charge pumped phase locked loop (PLL)(10) with process and temperature compensation in closed loop bandwidth. The PLL reduces the variation in bandwidth and stability by making the product KVCO*ICP independent of process and temperature variation. The PLL achieves a higher performance than existing PLL architectures, achieving a high dynamic range up to at least 110 dB, such that a PWM class-D amplifier is realizable with this PLL. The PLL has a constant bandwidth and damping factor while using an analog charge pump (16).

Abstract: An oscillator circuit with an oscillator device. The oscillator device has a oscillator bias contact (Vcm). A bias source (Vbias) is connected to said oscillator contact with a source contact. The voltage source includes a varying bias source which in use provides a bias varying in time. The bias source may for example be a switched DC source which in use provides an output signal varying between a first level and a second level.

Abstract: A phase synchronous multiple LC tank oscillator includes a plurality of oscillator stages configured to oscillate synchronously. The phase of each of the plurality of oscillator stages is substantially the same.

Abstract: MEMS-based, computer system, clock generation and oscillator circuits and LC-tank apparatus for use therein are provided and which are fabricated using a CMOS-compatible process. A micromachined inductor (L) and a pair of varactors (C) are developed in metal layers on a silicon substrate to realize the high quality factor LC-tank apparatus. This micromachined LC-tank apparatus is incorporated with CMOS transistor circuitry in order to realize a digital, tunable, low phase jitter, and low power clock, or time base, for synchronous integrated circuits. The synthesized clock signal can be divided down with digital circuitry from several GHz to tens of MHZ—a systemic approach that substantially improves stability as compared to the state of the art. Advanced circuit design techniques have been utilized to minimize power consumption and mitigate transistor flicker noise upconversion, thus enhancing clock stability.

Abstract: A wireless communication unit (100) comprises a voltage controlled oscillator (123) having an active device (450) operably coupled to a first variable capacitance (425) to provide a variable capacitance value based on an applied steering line voltage, and a feedback network comprising a resonator (475), operably coupled to an output of the active device, for feeding power back to an input of the active device to sustain oscillations (123). Notably, a second variable capacitance is operably coupled to receive a control voltage from the steering line (405) and located between the resonator (475) and the active device (450).

Abstract: Disclosed is a quadrature VCO (voltage controlled oscillator) which comprises a first delay cell including a first switching transistor and a second switching transistor, the first delay cell outputting first and second in-phase signals with different phases; and a second delay cell including a third switching transistor and a fourth switching transistor, the second delay cell outputting first and second quadrature-phase signals with different phases. The first and second quadrature-phase signals are applied to back gates of the first and second switching transistors, and the first and second in-phase signals are applied to back gates of the fourth and third switching transistors.

Abstract: A radio frequency voltage controlled oscillator (RF VCO) includes a differential oscillator including two field effect transistors (FETs) in which an electric current flows laterally to a substrate and a current source including a bipolar transistor in which the electric current flows in a direction either perpendicular or lateral to the substrate from an emitter to a collector via a base. Therefore, 1/f noise is very small. Resultantly, the RF VCO using the bipolar junction transistor as the current source reduces the 1/f noise generated by the current source of a RF CMOS VCO and, ultimately, the phase noise of the VCO.

Abstract: A miniature resonating marker assembly that includes, in one embodiment, a ferromagnetic core, a wire coil disposed around the core, and a capacitor connected to the wire coil adjacent to the magnetic core. The core, coil, and capacitor form a signal element that, when energized, generates a magnetic field at a selected resonant frequency. The magnetic field has a magnetic center point positioned along at least one axis of the signal element. An inert encapsulation member encapsulates the signal element therein and defines a geometric shape of the resonating marker assembly. The geometric shape has a geometric center point substantially coincident with the magnetic center point along at least a first axis of the signal element. The shape and configuration of the assembly also provides for a miniature signal element specifically tuned to resonate at a selected frequency with a high quality factor.

Abstract: A tunable oscillator having a tuning voltage input includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. The first varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range.

Abstract: A voltage controlled oscillator amplitude control circuit has a voltage controlled oscillator circuit to output an oscillating signal having a controlled amplitude. It also has a control circuit to control the amplitude of the oscillating signal by providing a dominant pole, a filtering function, rectification, and a gain at a single node of the circuit.

Abstract: An integrated circuit (IC) with an oscillator and electrostatic discharge (ESD) protection in which the parasitic capacitance of the ESD protection circuitry is disassociated from the oscillator circuitry to minimize loading of the tank circuit thereby minimizing degradation of the tank circuit quality factor (Q).

Abstract: The invention relates to an oscillator circuit configuration comprising in an LC-parallel oscillatory circuit and a transistor as an amplifying element. A compensating winding is associated with the parallel oscillatory circuit whereby the collector voltage of the transistor is fed to said winding in order to compensate the effect of the parasitic collector capacity. Preferably, the collector current from the transistor is maintained constant be an amplifier.

Abstract: A voltage-controlled oscillator comprising a LC tank circuit coupled to a pair of transistors and crossed-coupled to a pair of emitter follower transistors each transistor having a collector, an emitter and a base, the voltage controlled oscillator being characterized in that a supply voltage applied to the collectors of the emitter follower transistors is substantially different from a supply voltage applied to the bases of the emitter follower transistors.

Abstract: A voltage controlled oscillator that can rapidly change frequencies over a wide range is disclosed. The voltage controlled oscillator has a transistor having a base, an emitter and a collector. An output port and a power supply port are connected to the collector. A high pass filter is connected between ground and the base of the transistor. A tuning element is connected between the high pass filter and ground. The tuning element includes a pair of varactor diodes. The varactor diodes have their cathodes connected together at a first node. A series combination of a resistor and inductor are connected between a tuning port and the first node. A capacitor is connected between the first node and the emitter.