A synthesizer of the present invention includes a synthesizer section that generates an oscillation signal based on a reference oscillation signal output from a MEMS resonator and inputs the oscillation signal to a frequency converter; and a control section that adjusts a frequency of the oscillation signal output from the synthesizer section. In frequency adjustment by the control section, when a frequency adjustment unit of the synthesizer section is defined as predetermined value F in which quality of an output signal from the frequency converter is a quality limit threshold value, frequency adjustment unit Δfcont of the synthesizer section is within predetermined value F.

Synthesizer and reception device using the same

An odd number of inverter circuits are connected with each other so as to form a ring. A first current-control element is provided between an oscillation signal line which is used for connecting adjacent inverter circuits and a power-source-potential point, a current flowing through the first current-control element varying by a first control signal. A second current-control element is provided between the oscillation signal line and a ground point, a current flowing through the second current-control element varying by a second control signal.

Voltage-controlled oscillator including current control element

There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to double the effective frequency of a ceramic coaxial resonator is to couple each end of a resonator to a Colpitts oscillator, the oscillators being balanced and out-of-phase by 180°. During operation, the resonator is effectively divided in half with a virtual ground forming in the center. This allows a single resonator to operate as two resonators of half the original size. Hence, the oscillation frequency for each of these balanced oscillators is doubled when compared to the frequency of similar oscillators that have separate ceramic coaxial resonators of similar size. This technique expands the range of use for a ceramic coaxial resonator so that, if implemented within a push-push architecture and if used along side a subharmonically pumped mixer that allows for doubling of the local oscillator frequency, the maximum oscillation frequency is increased to 40 GHz. This frequency range allows ceramic coaxial resonators to be used for high frequency applications such as LMDS.

Coaxial resonator and oscillation circuits featuring coaxial resonators

The application relates to a calibration apparatus and calibration method for a tuneable resonator of a delta-sigma modulator of the continuous time, band pass type. The calibration apparatus comprises: a resonator driver capable of causing an oscillating behaviour in a resonator output signal, a reference signal source that provides a reference signal, a frequency detector that provides a frequency relation signal corresponding to the frequency relation between the resonator output signal and the reference signal, and a controller that controls the tuneable resonator in dependence from the frequency relation signal so as to reduce frequency deviation.

Apparatus and method for the calibration of delta-sigma modulators

An oscillator is described, comprising at least one transistor having a first terminal connected to a power supply voltage. The oscillator comprises at least one inductive element connected to a second terminal of the transistor and to a bias voltage and at least one capacitive element coupled between a third terminal of the transistor and ground. The oscillator further comprises means to collect the output signal of said oscillator on the second terminal of the transistor. The oscillator is of the millimeter wave type, i.e., both the inductive element and the capacitive element are sized such that the oscillation frequency is between 30 and 300 gigahertz.

Millimeter wave oscillator

A Colpitts oscillator has an integrated circuit. The integrated circuit includes a transistor having an equivalent large size, a bypass capacitor connected between a collector of the transistor and a ground, a first feedback capacitor connected between a base and an emitter of the transistor, a second feedback capacitor connected between the emitter of the transistor and the ground, and an emitter follower connected to the emitter of the transistor. In a package, a stray reactance and a bonding wire are designed so as to agree with an element value and a Q value which can be used as parts of a resonator. A surface elastic wave resonator disposed outside the integrated circuit is connected between the base of the transistor and the ground. The oscillator is voltage controlled by a variable capacitance diode connected in series with the resonator.

Voltage-controlled oscillator using a surface elastic wave resonator

In a PLL comprising a voltage controlled oscillator (VCO) equipped with a variable resonator, a frequency divider, a phase comparator, and an low pass filter (LPF), a variable resonator control signal generation section has the output voltage of the LPF as an input, detects a f/v sensitivity of the VCO, generates a variable resonator control signal, and controls a capacitance of the variable resonator by the variable resonator control signal. In a disclosed embodiment, when a voltage detection circuit having the output voltage of the LPF as an input detects a predetermined voltage, a data latch circuit transmits a variable resonator control signal based on the voltage detected by voltage detection circuit to variable resonator and performs a variable capacitance control. As a result, the f/v sensitivity of the VCO can be controlled to an optimal value even in the event of PLL configuration element variation or temperature changes.

Oscillation control apparatus

PURPOSE:To work out a solution about the lack of a low noise oscillation circuit constituted in the same chip with other high frequency circuits and secure isolation properties and constitute a low noise oscillator and a high frequency circuit in the same integrated circuit chip. CONSTITUTION:A die pad 3 on which a chip is loaded and ground terminals 4 and 5 to the outside are not interconnected where there are provided at least one first ground terminal 4 which is not connected to a bonding pad and a substrate frame 10 installed to an area near silicon bipolar integrated circuit by way of aluminum wiring 11 and at least one second ground terminal 5 is provided, which is connected with aluminum wiring 12. The isolation properties are secured by setting the size and structure of a transistor to be used.

Takayuki Shimazu

Papers

Voltage-controlled oscillator using a surface elastic wave resonator

Oscillation control apparatus

High frequency semiconductor integrated circuit