Abstract:
Oscillator having first frequency-determining elements provided for a first oscillation frequency. In order to provide an oscillator, particularly for use in video signal processing, which can be switched and tuned to at least two oscillation frequencies, at least a second frequency-determining element is provided which can be connected to the first frequency-determining element for adjusting the oscillator to a second oscillation frequency.
Abstract:
A switchable multi-frequency dielectric resonator oscillator that generates microwave energy at any of several available frequencies is disclosed. The oscillator includes a transistor that is operable for oscillation at a frequency determined by a feedback resonator connected to its control terminal, and switching means for selectively connecting any one of a plurality of feedback resonators to the control terminal of the transistor. The oscillation frequency of the oscillator is determined by the resonant frequency of whichever of the feedback resonators is connected to the control terminal of the transistor through the switching means. It is preferred to utilize dielectric resonators as the feedback resonators, a field effect transistor as the transistor, and PIN diodes as the switching means.
Abstract:
An oscillator circuit includes a terminal T1, a terminal T2, a variable capacitance element having one end connected to the terminal T1, and a capacitance value varying in accordance with a frequency control signal, a variable capacitance element having one end connected to the terminal T2, and a capacitance value varying in accordance with the frequency control signal, a load capacitance circuit connected to the terminal T1, and a load capacitance circuit connected to the terminal T2, and oscillates a resonator element at a frequency corresponding to the frequency control signal. The oscillator circuit is capable of adjusting the capacitance values of the load capacitance circuits, a reference voltage (the electrical potential of the terminal T1), and a reference voltage (the electrical potential of the terminal T2) in accordance with configuration information.
Abstract:
A voltage control oscillator capable of obtaining the desired output voltage by lowering the higher order harmonic level, is provided. Further, in the voltage control oscillator, a resonance circuit achieves the resonance by switching two different resonance frequencies. Moreover, inductors of a matching circuit are selectively used to change the inductance by turning on/turning off a diode of an impedance regulation circuit according to the respectively switched frequencies. Furthermore, the synthesized impedance with a matching capacitor is changed to achieve the matching with each of two frequencies.
Abstract:
A high stability digitally tuned L-band cavity oscillator employs PIN diode switching of the cavity resonant frequency to provide an output signal at any one of 16 discrete frequencies under the control of a four-wire digital input. An analog input is added to adjust the center-line frequency over a bandwidth at least as wide as the least significant incremental step to further provide for AFC and phase lock capability. A half-wave resonator cavity is used with a quarter-wave member notched at intervals along its length. A switching diode adapted to be coupled to a source of digital signals is coupled across each notch to digitally control the electrical characteristics of the resonator and its output frequency. A varactor provides the analog and fine tuning control.
Abstract:
6. Apparatus for pulse modulating a crystal oscillator comprising: A TRANSISTOR AMPLIFIER; A PLURALITY OF PARALLEL FEEDBACK PATHS CONNECTED TO SAID AMPLIFIER, EACH SAID FEEDBACK PATH INCLUDING A CRYSTAL HAVING A DIFFERENT RESONANT FREQUENCY; SWITCH MEANS ASSOCIATED WITH EACH OF SAID FEEDBACK PATHS, EACH SAID SWITCH MEANS NORMALLY OPEN TO DISCONNECT EACH OF SAID FEEDBACK PATHS FROM SAID AMPLIFIER; MEANS FOR APPLYING A PULSE MODULATING SIGNAL TO AT LEAST THE BASE ELECTRODE OF ONE TRANSISTOR FORMING ONE STAGE OF SAID AMPLIFIER TO RENDER IT CONDUCTIVE; GAIN CONTROL MEANS CONNECTED TO THE STAGE OF SAID AMPLIFIER TO WHICH SAID-PULSE MODULATING SIGNAL IS APPLIED FOR PROVIDING MAXIMUM GAIN IN SAID AMPLIFIER WHEN SAID AMPLIFIER IS FIRST RENDERED CONDUCTIVE AND FOR DECREASING THIS GAIN THEREAFTER; AND MEANS FOR APPLYING SUCCESSIVE SWITCHING SIGNALS TO SAID SWITCH MEANS, ONE AT A TIME, TO THEREBY CONNECT DIFFERENT ONES OF SAID FEEDBACK PATHS TO SAID AMPLIFIER, WHEREBY AN OUTPUT SIGNAL OF THE FREQUENCY OF THE CRYSTAL ASSOCIATED WITH THE CONNECTED FEEDBACK PATH IS GENERATED.
Abstract:
According to an embodiment, a receiver includes a voltage controlled oscillator, a frequency-to--digital converter and an input sensitivity controller. In the voltage controlled oscillator, input sensitivity relative to a baseband signal is controlled based on an input sensitivity control signal. The voltage controlled oscillator oscillates at a frequency controlled by a voltage of the baseband signal to generate an oscillation signal. . The frequency--to-digital converter performs frequency-to-digital conversion of the oscillation signal to generate a digital signal. The input sensitivity controller generates the input sensitivity control signal based on the digital signal.
Abstract:
Apparatus and methods are also disclosed related to an oscillator that includes a switching network configured to tune a resonant frequency of a resonant circuit. One such apparatus includes a switching network having a circuit element, such as a capacitor, that can be selectively coupled to the resonant circuit by a switch, such as a field effect transistor. For instance, the switch can electrically couple to circuit element to the resonant circuit when on and not electrically couple the circuit element to the resonant circuit when off. An active circuit can assert a high impedance on an intermediate node between the switch and the circuit element when the switch is off.