摘要:
The semiconductor integrated circuit includes an inverting amplifier that generates an oscillation signal with an input connected to the first terminal and an output connected to the second terminal, the inverting amplifier fluctuating in gain in response to a gain control signal. The semiconductor integrated circuit includes a waveform shaping circuit that shapes a waveform of the oscillation signal and outputs a clock signal to a clock signal output terminal. The semiconductor integrated circuit includes an edge detecting circuit that detects an edge of the clock signal and outputs the gain control signal at a time of the edge.
摘要:
A negative resistance generator includes first and second terminals; first and second inductors connected in series between the terminals; and a semiconductor amplifying device having a first control electrode connected to the first terminal and a first active electrode connected to the second terminal and a second active electrode connected to the junction of the inductors. When employed in an active filter resonator a first variable capacitor is interconnected with the inductors for setting the resonant frequency of the resonator. The resonators may be combined in an active filter with a transmission line where each of the resonators is interconnected to the line by decreasing resistance from the input to the output in order to balance the rf currents to which the resonators are subjected. An improved dual loop active filter control system is achieved by using a master oscillator that employs a resonator that is matched to the active filter resonator in the filter and servoing the frequency and Q-factor controls so that the drive signals are compensated for temperature drifts, manufacturing tolerances, and other problems while a buffer amplifier is used between the master oscillator and the frequency and gain control loops for isolating the master oscillator reference circuit from the loading of the loops and from the perturbation introduced by the frequency reference signal; a frequency shifting circuit in the frequency control loop permits the reference signal to be shifted to a lower or higher frequency than that of the master oscillator.
摘要:
The invention relates to an ultra-high frequency oscillator (11-14 GHz) having a plurality of transistors, stabilized on at least one of their electrodes by a microstrip line coupled to a dielectric resonator. The oscillator according to the invention groups the transistors on the periphery of an insulating substrate, which centrally supports a single dielectric resonator common to all the transistors. The microstrip lines have two end portions, which are not coupled and are parallel to the field lines of the resonator, and a coupled central portion, perpendicular to the field lines. The transistors and microstrip lines are coplanar. The output is by a coaxial cable at the center of the substrate or by a microstrip line coplanar to the substrate.
摘要:
In a tunable UHF transistor oscillator with a frequency determining resonating LC circuit reduction of the harmonic to fundamental ratio is obtained through the use of an output circuit consisting of an output resistor connected in parallel with a resistor voltage divider a part of which is used as a damping resistor for a second controllable tuned circuit comprising an inductor with a larger inductance than that of the frequency determining circuit and the same capacitance and a non linear circuit between the control voltage source and the adjustable capacitor of said second circuit. The output is taken across the second tuned circuit. Coupling between the transistor and the frequency determining circuit is low.
摘要:
The invention relates to electrical oscillators arranged to oscillate so as to produce a substantially sinusoidal output signal. The said oscillator includes a general impedance transvertor circuit arrangement having two differential amplifiers connected only to a plurality of resistive and capacitive impedance elements and arranged to simulate a tuned circuit with sufficient feedback to maintain oscillation within the tuned circuit. The transvertor circuit is an active device in the form of an impedance invertor circuit or a convertor circuit.
摘要:
A high-Q active notch filter includes only one operational amplifier employing resistive positive feedback and reactive negative feedback. The positive feedback resistance can be selectively changed to convert the notch filter to an oscillator operating at the notch frequency.
摘要:
A voltage controlled oscillator operable on two widely separated frequency bands, such as 900 MHz and 1.8 GHz for example. The voltage controlled oscillator includes two negative resistance generators (32, 34) which share a common tunable tank circuit (26) and a common impedance matched combiner circuit (28) which provides the RF output (36). The VCO uses only one varactor (30) to tune both frequency bands. Separate negative resistance generators (32, 34) are used to provide optimum frequency selectivity within each frequency band.
摘要:
A Colpitts-type oscillator circuit suitable for use with electronic identification systems is disclosed. The oscillator circuit utilizes a pair of transistors coupled together with a feedback loop that includes a parallel LC circuit such that the output amplitude can be as high as a factor of 20 times the supply voltage or more while maintaining a high Q, low distortion output. The oscillator circuit is a modified Colpitts oscillator that includes a NPN transistor and a PNP transistor coupled together and a Colpitts type feedback loop containing a parallel LC circuit. The capacitance of the parallel LC circuit consists of at least two capacitors in series forming a capacitive divider which provides a low impedance feedback via the base of the NPN transistor into the emitter of the PNP transistor. The collector of the PNP transistor taps into the inductor of the parallel LC circuit such that the inductor is driven to resonance.
摘要:
A low phase noise, high frequency low voltage integrated circuit oscillator has a minimum number of live pins. It includes a three transistor current mirror defining a voltage node and a current node with an emitter follower transistor coupled between the voltage node and the current node. An output is taken from the emitter follower transistor and a tuned circuit is coupled to the voltage node. A pair of power supply pins are provided for power application to the integrated circuit and one live pin is coupled to the voltage node. A tuning circuit for affecting capacitance changes for varying the frequency of the oscillator is connectable to the voltage node. In some versions of the oscillator that use a separate crystal, additional pins are needed.
摘要:
A voltage-controlled oscillator capable of very high ratios of modulation to oscillation frequency is disclosed embodying a resonant circuit with an inductance and two tuning diodes connected with opposite polarity in series across the inductance, a cross-coupled feedback amplifier circuit with two matched MMIC inverting amplifiers capacitively cross-coupled to the resonant circuit for driving the resonant circuit into oscillation at its resonant frequency to produce an output carrier wave, and a transmission line resonator connected to the resonant circuit between the tuning diodes to couple a wide band frequency modulating voltage thereto for modulating the output carrier wave.