Abstract:
Systems for controlling the frequency of the output signal of a controllable oscillator (202) in a frequency synthesizer (200) are provided. One such system comprises a controllable oscillator (202) and a frequency control circuit (208). The controllable oscillator (202) is configured to generate an output signal that has a predefined frequency. The controllable oscillator (202) is also configured with a plurality of operational states that are controlled by the frequency control circuit (208). Each operational state of the controllable oscillator (202) defines a distinct frequency for the output signal of the controllable oscillator (202). The frequency control circuit (208) receives the output signal of the controllable oscillator (202) and determines the distinct frequency for the output signal that best approximates the predefined frequency. The frequency control circuit (208) may also provide a control signal to the controllable oscillator (202) that is configured to change the controllable oscillator (202) to the operational state corresponding to the distinct frequency that best approximates the predefined frequency.
Abstract:
An injection locking oscillator (ILO) comprising a tank circuit having a digitally controlled capacitor bank, a cross-coupled differential transistor pair coupled to the tank circuit, at least one signal injection node, and at least one output node configured to provide an injection locked output signal; a digitally controlled injection-ratio circuit having an injection output coupled to the at least one signal injection node, configured to accept an input signal and to generate an adjustable injection signal applied to the at least one injection node; and, an ILO controller connected to the capacitor bank and the injection-ratio circuit configured to apply a control signal to the capacitor bank to adjust a resonant frequency of the tank circuit and to apply a control signal to the injection-ratio circuit to adjust a signal injection ratio.
Abstract:
The invention provides a piezoelectric oscillator including a semiconductor integrated circuit and a piezoelectric resonator, and also a voltage-controlled oscillator including a semiconductor integrated circuit, a piezoelectric resonator, and another electronic component, characterized in that the piezoelectric resonator having a case with cross-section of an elliptic or a track-like (combination of a rectangle and two semicircles) shape, the semiconductor integrated circuit, and the electronic component are molded with a resin into a very thin unit in the form of a surface mounting structure.
Abstract:
Systems for controlling the frequency of the output signal of a controllable oscillator (202) in a frequency synthesizer (200) are provided. One such system comprises a controllable oscillator (202) and a frequency control circuit (208). The controllable oscillator (202) is configured to generate an output signal that has a predefined frequency. The controllable oscillator (202) is also configured with a plurality of operational states that are controlled by the frequency control circuit (208). Each operational state of the controllable oscillator (202) defines a distinct frequency for the output signal of the controllable oscillator (202). The frequency control circuit (208) receives the output signal of the controllable oscillator (202) and determines the distinct frequency for the output signal that best approximates the predefined frequency. The frequency control circuit (208) may also provide a control signal to the controllable oscillator (202) that is configured to change the controllable oscillator (202) to the operational state corresponding to the distinct frequency that best approximates the predefined frequency.
Abstract:
The invention relates to a device for high-frequency and/or radio-frequency tuning. An object of the invention is to provide a new and improved approach for enabling an increased high-frequency and/or radio-frequency tuning range by a reduced complexity and board space even with regard to multiband and/or multistandard purposes, in particular suitable within the radio design for mobile communication systems and/or networks, preferably by simultaneously reducing the undesirable parasitic influences. The invention proposes a device for high-frequency and/or radio-frequency tuning comprising within one IC-package a first variable capacitor (C 1 ) and at least one second capacitor (C 2 ), each of the at least one second capacitor (C 2 ) being fixed or variable respectively, at least one signal path connected to the first variable capacitor (C 1 ) and providing at least one input and one output port (rf-port1, rf-port2) and at least one controllable switching means (S C2 ) for individually connecting and disconnecting at least one of the at least one second capacitor (C 2 ) into the signal path or from the signal path, in particular in parallel to the first variable capacitor (C 1 ).
Abstract:
Systems for controlling the frequency of the output signal of a controllable oscillator in a frequency synthesizer are provided. One such system comprises a controllable oscillator and a frequency control circuit. The controllable oscillator is configured to generate an output signal that has a predefined frequency. The controllable oscillator is also configured with a plurality of operational states that are controlled by the frequency control circuit. Each operational state of the controllable oscillator defines a distinct frequency for the output signal of the controllable oscillator. The frequency control circuit receives the output signal of the controllable oscillator and determines the distinct frequency for the output signal that best approximates the predefined frequency. The frequency control circuit may also provide a control signal to the controllable oscillator that is configured to change the controllable oscillator to the operational state corresponding to the distinct frequency that best approximates the predefined frequency.
Abstract:
The invention proposes a device for high-frequency and/or radio-frequency tuning comprising within one IC-package a first variable capacitor (C1) and at least one second capacitor (C2), each of the at least one second capacitor (C2) being fixed or variable respectively, at least one signal path connected to the first variable capacitor (C1) and providing at least one input and one output port (rf-port1, rf-port2) and at least one controllable switching means (SC2) for individually connecting and disconnecting at least one of the at least one second capacitor (C2) into the signal path or from the signal path, in particular in parallel to the first variable capacitor (C1).
Abstract:
A tuning circuit for a reference oscillator (200) including voltage variable capacitors (222, 224) in a back to back configuration and providing a control terminal for voltage controlled tuning of the reference oscillator (200). Also included in the tuning circuit is a modulation bias circuit for modulating the reference oscillator (200).
Abstract:
A resonator (50) is connected in circuit with a negative resistance element (Q3,Q4) for producing oscillation at a resonant frequency of the resonator (50). A digital phase shifter (58) is incorporated into the resonant frequency in accordance with an applied digital signal. The resonator (50) can be connected in series with the negative resistance element (Q3), in which case the phase shifter (58) is connected as either a short-circuit or an open-circuit transmission line. Alternatively, the resonator (50) can be connected in parallel with the negative resistance element (Q4) in a feedback loop. An analog phase shifter (84) can also be provided in the resonator (50') for continuously variably setting the resonant frequency over the tuning increments of the digital phase shifter (58).
Abstract:
A phase modulator includes a digital frequency word generator, an adder and a register arranged to generate recurrent digital sawtooth signals at a carrier rate. A second digital adder is coupled to receive the sawtooth signals and also receives digital information signals. The adder produces recurrent digital sawtooth signals phase-modulated by the information signal. A pair of adders receive the digital sawtooth signals and mutually sign-reversed digital information signals to produce a pair of oppositely phase-modulated constant-amplitude signals in a pair of channels. A sine memory is addressed by the phase-modulated digital sawtooth signals to produce phase-modulated sinusoidal-representative digital signals. The digital signals are then converted to analog signals. Since the two channels contain signals which are phase-modulated but not amplitude-modulated, the signals may be amplified by nonlinear amplifiers. An adder is coupled to the outputs of the two channels to sum together the two phase-modulated signals to produce an amplitude-modulated signal. Combinations of amplitude and phase modulation may be generated by a combined structure.