A surface-mount crystal oscillator includes a crystal unit housing and an element housing which is provided on the base side of the crystal unit housing. A crystal blank is accommodated and hermetically sealed in the crystal unit housing. A concavity having an open side is formed in the element housing, and an IC chip is secured to the bottom surface of the concavity by means of face-down bonding. Notch portions or recess portions which are adjoining and connecting to the concavity and which are used for injecting fluid resin are formed in the frame portion at the periphery of the concavity. Fluid resin is injected to the bottom surface of the concavity by way of the notch portions and cured to form a protective resin layer of the IC chip.

Surface mount crystal oscillator

A high-frequency module includes a switch IC and a matching circuit. The high-frequency module includes a multilayer body. The switch IC and an inductor of the matching circuit are mounted on a top surface of the multilayer body. A top-surface land electrode on which a common terminal of the switch IC is mounted is connected to one end of a wiring conductor through a via-conductor. The other end of the wiring conductor is connected to a top-surface land electrode on which a terminal electrode at one end of the inductor is mounted, through a via-conductor. An end portion of the inductor on the side connected to the common terminal of the switch IC is disposed near the common terminal. Thus, the length of the wiring conductor is shortened and a parasitic capacitance is decreased.

High-frequency module

An on-vehicle communication device capable of suppressing a delay in providing information, avoiding congestion, and sufficiently securing transmission power, includes a communication controller to controls a transmission cycle and transmission power when data is transmitted from a transmitting/receiving device. The communication controller uses its own vehicle information and surrounding vehicle information to estimate a degree of risk and a safe distance of its own vehicle. The communication controller controls the transmission cycle of its own vehicle based on a communication channel utilization rate of its own vehicle, a communication channel utilization rate of a surrounding vehicle and the degree of risk of its own vehicle, and controls the transmission power of its own vehicle based on the communication channel utilization rate of its own vehicle, the communication channel utilization rate of the surrounding vehicle and the safe distance.

On-vehicle communication device

The present invention provides an apparatus providing plural wireless transceivers within a desired power budget and associated methods. A plurality of wireless communication modules, each having a lower-power state and a higher-power state are provided, drawing power from a common source. Arbitration is performed to control which of the plurality of wireless communication modules are in the higher-power state, thereby controlling total power delivered by the power source to the plurality of wireless communication modules.

Apparatus providing plural wireless transceivers within a desired power budget and associated method

An oscillator having improved frequency stability which includes an oscillator circuit and an SC-cut resonator connected with the oscillator circuit. The SC-cut resonator has a first turning point. A temperature compensation circuit is connected with the oscillator circuit. The temperature compensation circuit is adapted to adjust a reference frequency generated by the oscillator circuit according to a frequency response associated with a second turning point of an AT-cut resonator.

Apparatus and method of temperature compensating an ovenized oscillator

A PLL (Phase-Locked Loop)-controlled oscillator has a temperature-compensated crystal oscillator having a quartz crystal unit, an oscillating circuit connected to the crystal unit, and a temperature compensating mechanism for generating a temperature compensating voltage for compensating for frequency vs. temperature characteristics of the crystal unit, and a voltage-controlled oscillator having an LC oscillating circuit, for being controlled by a PLL using the temperature-compensated crystal oscillator as a reference signal source. The temperature-compensated crystal oscillator has circuit components except for the crystal unit, the circuit components and the voltage-controlled oscillator being integrated in a one-chip IC. The one-chip IC and the crystal unit are integrally combined with each other in the PLL-controlled oscillator.

PLL-controlled oscillator

A high-frequency wireless communication device is provided that is capable of enlarging the range of communication by enhancing reception sensitivity while avoiding mutual interference. The device comprises an antenna filter and a direct detection type reception mechanism connected to the antenna filter. A crystal filter is used as the antenna filter. A crystal chip constituting the crystal filter and an IC chip into which the reception mechanism is integrated are housed in a single modular container to configure a high-frequency wireless module.

Akaike Kazuo

Papers

PLL-controlled oscillator

High-frequency radio apparatus