Abstract: A radio communication device includes: a local oscillator; an amplifier amplifying an output signal of the local oscillator and outputting a local oscillation frequency and a harmonic wave component thereof; and a harmonic mixer receiving an output signal of the amplifier and an information signal, and generating an up-converted signal of the information signal with the harmonic wave component based on the local oscillation frequency, while allowing the harmonic wave component to pass through.

Abstract: Transmitter and receiver for wireless communications with improved accuracy and stability in radio frequency control. A transmitter mixes an information-carrying signal (first signal) and a non-modulated wave signal (second signal) with a carrier signal, thereby producing a first and second radio frequency signals for radio wave transmission. A receiver mixes those two radio frequency signals to extract the original information signal. While the received radio frequency signals contain some frequency fluctuations and phase noises that have been introduced at the sending end, such unstable components ?f will cancel out at the receiving end.

Abstract: A patch antenna is disclosed that includes a dielectric substrate, a substantially rectangular radiation element formed of a conductive material on the dielectric substrate; and a feeder line connected to a feeding point for feeding to the radiation element. The feeding point has an impedance matching the impedance of the feeder line.

Abstract: A patch antenna is disclosed that includes a dielectric substrate, a substantially rectangular radiation element formed of a conductive material on the dielectric substrate; and a feeder line connected to a feeding point for feeding to the radiation element. The feeding point has an impedance matching the impedance of the feeder line.

Abstract: A harmonic mixer comprising an anti-parallel diode having two diodes connected in parallel in reverse directions between first and second ends, the first end receiving a local oscillation signal, and the second end receiving an information signal and a DC bias, an output signal of the harmonic mixer being available at the second end. With the capabilities of the anti-parallel diode, it is possible to realize the radio communication with the use of a high frequency range at least 30 GHz at a low cost and with a simple configuration of the harmonic mixer and the radio communication device having the same, although it is considered hard to generate the stable local oscillation frequency for the radio communication of at least 30 GHz.

Abstract: A radio communication device includes: a local oscillator; an amplifier amplifying an output signal of the local oscillator and outputting a local oscillation frequency and a harmonic wave component thereof; and a harmonic mixer receiving an output signal of the amplifier and an information signal, and generating an up-converted signal of the information signal with the harmonic wave component based on the local oscillation frequency, while allowing the harmonic wave component to pass through.

Abstract: A dielectric member 27 with a thickness of from 0.1&lgr; to 2&lgr; is disposed opposite to a patch plane 17 of a patch antenna 10A apart from the patch plane 17 by a distance of from 0.1&lgr;0 to 2&lgr;0, where &lgr;0 and &lgr; are the wavelengths of a radiated radio wave in free space and in the dielectric member, respectively. The dielectric constant of the dielectric member 27 may be lower in an outer portion thereof than a middle portion thereof. When the antenna is incorporated into the communication module, the dielectric member 27 is attached to the cover of the communication module.

Abstract: Transmitter and receiver for wireless communications with improved accuracy and stability in radio frequency control. A transmitter mixes an information-carrying signal (first signal) and a non-modulated wave signal (second signal) with a carrier signal, thereby producing a first and second radio frequency signals for radio wave transmission. A receiver mixes those two radio frequency signals to extract the original information signal. While the received radio frequency signals contain some frequency fluctuations and phase noises that have been introduced at the sending end, such unstable components &Dgr;f will cancel out at the receiving end.

Abstract: A dielectric member 27 with a thickness of from 0.l&lgr; to 2&lgr; is disposed opposite to a patch plane 17 of a patch antenna 10A apart from the patch plane 17 by a distance of from 0.1&lgr;0 to 2&lgr;0, where &lgr;0 and &lgr; are the wavelengths of a radiated radio wave in free space and in the dielectric member, respectively. The dielectric constant of the dielectric member 27 may be lower in an outer portion thereof than a middle portion thereof. When the antenna is incorporated into the communication module, the dielectric member 27 is attached to the cover of the communication module.

Abstract: A semiconductor module having a built-in antenna element for use in a system of a band of millimeter-waves or quasi-millimeter-waves comprises a substrate, an antenna element, a semiconductor integrated circuit, and a hermetically sealing portion. The antenna element is mounted on one side of the substrate. The semiconductor integrated circuit is also formed on the same side of the substrate as of the antenna element. The semiconductor integrated circuit includes at least either of a transmitter signal processing circuit composed mainly of an amplifier circuit and a frequency converter circuit for processing a signal which is exploited in the system of the band of millimeter-waves or quasi-millimeter-waves and transmitted to the antenna element, and a receiver signal processing circuit composed mainly of an amplifier circuit and a frequency converter circuit for processing a signal which is received by the antenna element and exploited in the system of the band of millimeter-waves or quasi-millimeter-waves.

Abstract: A semiconductor module having a compact antenna element capable of providing desired directivity therein has been disclosed. When an electromagnetic-wave radiation window has the capability of a lens, directivity can be set arbitrarily. For improving directivity, a convergent lens for converging millimeter waves or quasi millimeter waves is employed. For impairing directivity, a divergent lens is employed. In the case of the convergent lens, a direction in which radio waves are radiated or received by the antenna element can be set by deviating the center axis of the lens from the center of the antenna element.

Abstract: A high-speed heterojunction transistor includes a first region for controlling current, and a second region for receiving carriers which have passed the first region. An energy level difference between a lowermost valley of energy and an upper valley of energy in the conduction band of a semiconductor material constituting the second region is greater than that of a semiconductor material constituting the first region.

Abstract: A field effect transistor includes a semiconductor substrate, first and second semiconductor layers formed on the semiconductor substrate, and third semiconductor layers located between the first and second semiconductor layers. The third semiconductor layers have a forbidden band width narrower than those in the first and second semiconductor layers and form a quantum well. The third semiconductor layers include a doping layer such as planar-doping or high doping, and a channel is formed in the third semiconductor layers along the quantum well. The electrons supplied from the doped layer are confined by the quantum well and form a quasi-two-dimensional electron gas.

Abstract: A package for an integrated circuit having conductor patterns which can be connected to an external circuit to connect the integrated circuit to the external circuit. The package includes a dielectric plate which is provided on one end face with a grounding conductor. The conductor patterns are provided on the opposite end face of the dielectric plate. The dielectric plate is provided with conductor poles which are located between the conductor patterns and which extend through the thickness of the dielectric plate to be connected to the grounding conductor.

Abstract: A microwave monolithic integrated circuit (MMIC) device includes a transistor and a capacitor respectively formed on the same semiconductor substrate. The transistor has at least one high resistivity semiconductor layer which forms a heterojunction with an activating layer or the semiconductor substrate. The capacitor has a dielectric layer formed by the high resistivity semiconductor layer of the transistor.