摘要:
Disclosed are circuits and methods for increasing an output frequency of an inductance-capacitance (LC) oscillator. In some embodiments, the LC oscillator can be implemented as a voltage-controlled oscillator (VCO) having differential outputs. When the VCO is implemented on a die, wirebond connections from the outputs to a ground results in an effective inductance that impacts a maximum frequency associated with the VCO. An electrical connection such as a wirebond between the differential outputs yields a reduction in the effective inductance thereby increasing the maximum frequency. In some embodiments, the wirebond between the differential outputs can be configured so that its contribution to mutual inductance is reduced or substantially nil.
摘要:
An oscillator, comprising: a pair of transistors to which source terminals are interconnected and to which drain and gate terminals are coupled by a positive feedback loop comprising an oscillator tank, wherein the source terminals of the transistors are connected to a current source configured to control physical parameters of the oscillator.
摘要:
Resistor bias circuitry is included in components of an XTAL oscillator system to reduce 1/f noise. An XTAL oscillator includes a resistor bias circuit attached to the XTAL core. A common mode feedback OP amp connected to the XTAL core also includes a resistor bias circuit. An XTAL oscillator chain includes an XTAL core, common mode feedback OP amp, common mode logic buffer (CML BF), and differential to CMOS converter (D2C) each with resistor bias circuitry.
摘要:
The present invention provides an improved frequency doubling circuit, with adjustable phase offset. Briefly, rather than using the traditional equations cos (2ωt)=cos 2(ωt)−sin 2(ωt) and sin(2ωt)=2 sin(ωt)cos(ωt), the quadrature output signals are generated utilizing mixers, each having two input signals, separated in phase by the same offset. This minimizes the effects of the non-linearities introduced by the mixer, which therefore reduces amplitude mismatch between the quadrature signals. Also, the phase offset of the quadrature output signals can be tuned and calibrated using a phase shifting circuit. This phase shifting circuit realizes a tuning range of approximately 5° in programmable steps. This combination of circuits can be used to minimize the amplitude mismatch and phase errors, thereby reducing the amplitude of and interference caused by transmission of the image frequency to the receivers input.
摘要:
When a signal of a double frequency is generated from the original signal, conventionally a 90-degree phase-shift circuit is necessary to suppress an output of a DC component and efficiently obtain a double wave. According to the present invention, an equal RF signal is inputted to input terminals and an output is matched with a frequency as high as that of the original frequency in a Gillbert cell double-balanced mixer, so that a doubled output is obtained with no DC offset. According to the circuit configuration of the present invention, it is possible to provide a circuit readily performing integration and to efficiently output only a double frequency merely by inputting a simple differential signal without the need for the original signal which has been phase controlled. Further, a DC short circuit in the resonance circuit makes it possible to eliminate a DC offset voltage in an output.
摘要:
Disclosed are circuits and methods for increasing an output frequency of an inductance-capacitance (LC) oscillator. In some embodiments, the LC oscillator can be implemented as a voltage-controlled oscillator (VCO) having differential outputs. When the VCO is implemented on a die, wirebond connections from the outputs to a ground results in an effective inductance that impacts a maximum frequency associated with the VCO. An electrical connection such as a wirebond between the differential outputs yields a reduction in the effective inductance thereby increasing the maximum frequency. In some embodiments, the wirebond between the differential outputs can be configured so that its contribution to mutual inductance is reduced or substantially nil.
摘要:
A circuit includes: first and second output terminals; a reference resonator coupled between the first and second output terminals; a cross-coupled oscillation unit coupled to the first and second output terminals; a first MOSFET diode coupled to the cross-coupled oscillation unit, the first MOSFET diode including a first transistor, a first resistor coupled between gate and drain terminals of the first transistor, and a first capacitor; a second MOSFET diode coupled to the cross-coupled oscillation unit, the second MOSFET diode including a second transistor, a second resistor coupled between gate and drain terminals of the second transistor, and a second capacitor cross coupled between the drain terminal of the second transistor and the gate terminal of the first transistor, wherein the first capacitor is cross coupled between the drain terminal of the first transistor and the gate terminal of the second transistor.
摘要:
Disclosed are circuits and methods for increasing an output frequency of an inductance-capacitance (LC) oscillator. In some embodiments, the LC oscillator can be implemented as a voltage-controlled oscillator (VCO) having differential outputs. When the VCO is implemented on a die, wirebond connections from the outputs to a ground results in an effective inductance that impacts a maximum frequency associated with the VCO. An electrical connection such as a wirebond between the differential outputs yields a reduction in the effective inductance thereby increasing the maximum frequency. In some embodiments, the wirebond between the differential outputs can be configured so that its contribution to mutual inductance is reduced or substantially nil.
摘要:
When a signal of a double frequency is generated from the original signal, conventionally a 90-degree phase-shift circuit is necessary to suppress an output of a DC component and efficiently obtain a double wave. According to the present invention, an equal RF signal is inputted to input terminals and an output is matched with a frequency as high as that of the original frequency in a Gillbert cell double-balanced mixer, so that a doubled output is obtained with no DC offset. According to the circuit configuration of the present invention, it is possible to provide a circuit readily performing integration and to efficiently output only a double frequency merely by inputting a simple differential signal without the need for the original signal which has been phase controlled. Further, a DC short circuit in the resonance circuit makes it possible to eliminate a DC offset voltage in an output.
摘要:
Device of the phase-locked loop type for demodulating a frequency-modulated signal. Device for frequency demodulation, using a phase-locked loop. According to the invention, for linearizing the variation of the frequency of a local oscillator (11) as a function of its control signal (Vb), a variable capacitance (Cv) is formed by an electronic module (20) which supplies the equivalent of a capacitance whose variation as a function of the control voltage (Vb) has a linearity deviation which is established for compensating the linearity deviation of the frequency of the oscillator as a function of the value of the capacitance (Cv).