Abstract: When a power supply switch is turned on and an RF signal and an LO signal are input to a bipolar transistor, a mixed signal of both signals is output as an IF signal. When the power supply switch is turned off, the bipolar transistor operates as two diodes connected between a base terminal and an emitter terminal and between the base terminal and a collector terminal. When the IF signal and the LO signal are input, the input signals are mixed with each other by the diodes and the RF signal is output. Accordingly, one frequency conversion has a plus conversion gain and when bidirectional frequency conversion is performed by the use of one frequency converter, an external circuit such as a signal path switching switch is not necessary.

Abstract: A variable matching circuit includes a variable capacitance circuit formed of a capacitor coupled to varactor diode and provided between terminals, and a resonator-type circuit includes a plurality of inductors and a variable capacitance circuit formed of a capacitor and a varactor diode. The inductors and the variable capacitance circuit are coupled in parallel together. The resonator-type circuit is connected in shunt with the terminal. The foregoing structure forms an L-type matching circuit. The bias of the varactor diodes can be thus varied, and plural values of the inductance of the resonator-type circuit can be switched over with a FET. The variable matching circuit can electrically control an impedance conversion available for wider ranges of frequency bandwidths.

Abstract: A wireless communication apparatus for performing wireless communication with another communication apparatus comprises: a contact sensor 101 operable to detect physical contact with the another communication apparatus; a short-range communication unit 102 operable to transmit management information required for a session of the wireless communication to the another communication apparatus, using a short-range communication method different from a method of the wireless communication; and a control unit 106 operable to cause the short-range communication unit 102 to transmit the management information in response to a detection of the physical contact by the contact sensor 101, and start the session with the another communication apparatus after the management information is transmitted.

Abstract: There are provided a plurality of systems of reconfigurable radio processing unit (102) whose function and performance can be modified. A control unit (104) collects quality information on the communication link in communication methods received at respective radio processing systems (102a, 102b). According to this, the control unit (104) selects an optimal communication method and transmission mode from a plurality of communication methods and transmission modes (for example, diversity transmission between a plurality of systems, diversity transmission by a single communication method, and MIMO channel multiplex transmission). By modifying configurations of the reconfigurable radio processing unit (102) according to the selected communication method and transmission mode, it is possible to communicate at a desired transmission mode. Thus, it is possible to perform an optimal transmission to the communication link according to the quality condition and other request condition.

Abstract: A transmitting method and a transmitter apparatus, which need no manual adjustment, are disclosed. A delay amount is automatically adjusted such that an out-of-band distortion component of a transmission signal is minimized, and a correct timing is produced by the method and the apparatus. In this transmitter apparatus, a first delay adjusts a control timing over a voltage that controls a power amplifier, and a distributor distributes an output from the power amplifier in order to feedback parts of the output. A distortion adjusting units calculating a distortion component of the transmission signal by using the signal fed back by the distributor, and adjusts automatically a delay amount of the first delay so as to minimize the distortion component. This structure allows eliminating manual adjustment, and obtaining high power-efficiency with fewer distortions.

Abstract: A modulation apparatus which can be applied to the conventional analog PLL modulation system without using an enormous reference table, enables a phase distortion to be compensated accurately without requiring timing control with high accuracy, and can be applied to communication systems that do not perform amplitude modulation. In this apparatus, a signal generation section (101) generates a baseband phase signal. A phase distortion compensation section (102) obtains a phase distortion by multiplying a magnitude of a frequency change at predetermined time or magnitude of phase change between adjacent data of the baseband phase signal by a parameter specific to the apparatus, and thereby compensates the baseband phase signal for the phase distortion. A storage section (103) stores the parameter and calculation equation. A modulation section (105) modulates a frequency converted signal input from a frequency conversion section (104) using the baseband phase signal to generate a modulated signal.

Abstract: In a multimode radio, as many frequency dividers as the number of radio systems become necessary and the circuit scale of a frequency dividing section becomes large. A frequency dividing section 22 is made up of a frequency divider 19 for dividing output of a local oscillator, a frequency divider 20 for dividing output of an in-phase local oscillation signal of the frequency divider 19, and a dummy circuit 21 connected to the output terminal of a quadrature local oscillation signal of the frequency divider 19. At the first frequency band operation time, output of the frequency divider 19 is used for modulation and demodulation and at the second frequency band operation time, output of the frequency divider 20 is used for modulation and demodulation.

Abstract: A radio communication system includes a base station of a radio communication system A, a base station of a radio communication system B operation in non-synchronized way with the base station, and a mobile station capable of communicating with both of the radio communication system A and the radio communication system B. The base station includes a radio unit for transmitting/receiving a radio wave to/from the mobile station and a system information estimation unit for estimating the system information on the radio communication system B and outputting the system estimation information. The radio unit of the base station reports the system estimation information on the base station to the mobile station. The mobile station receives the system estimation information on the base station in advance so as to perform effective switching without using a cabled connection from the radio communication system A to the radio communication system B via a relay device or the like.

Abstract: There are disclosed a transmission device and a reception device having a high secrecy making it difficult to wire tap by a third device. The transmission device includes a modulation section which can be modulated by a plurality of modulation methods and a transmission section which can transmit a radio signal by using a plurality of carrier frequencies. Moreover, the reception device includes a demodulation device which can demodulate by using a plurality of demodulation methods and a reception section which can receive a radio signal by using a plurality of carrier frequencies. The transmission communication method or the reception communication method is changed as the time elapses by changing the combination of the modulation method or demodulation method and the carrier frequency, thereby transmitting or receiving data.

Abstract: A transmitting method and a transmitter apparatus, which need no manual adjustment, are disclosed. A delay amount of a delay means is automatically adjusted such that an out-of-band distortion component of a transmission signal is minimized, and a correct timing is produced by the method and the apparatus. In this transmitter apparatus, a first delay means adjusts a control timing over a voltage that controls a power amplifying means, and a distributor distributes an output from the power amplifying means in order to feedback parts of the output. A distortion adjusting means calculates a distortion component of the transmission signal by using the signal fed back by the distributor, and adjusts automatically a delay amount of the first delay means so as to minimize the distortion component. This structure allows eliminating manual adjustment, and obtaining high power-efficiency with fewer distortions.

Abstract: A filter of microwave and millimetric bands with spurious characteristic controlled is disclosed. A filter circuit on a top surface of the substrate including resonators electromagnetically resonating and coupled at a resonance frequency at a microwave band and a millimeter wave band, for filtering an input signal from the connectors through the resonator and outputting the filtered signal through the connector. The filter circuit is contained in a metal box including a top plate confronting the top surface and the filter circuit, side walls, and a bottom plate. An inside surface of the top plate has a shape other than a flat plane to control the spurious characteristic, that is, a protrusion. The bottom plate of the metal box may be coalesced. The spurious characteristic may be controlled by a hollow portion in the top plate. The protruding portion may be provided to the side walls. The spurious frequency may be controlled by a dielectric plate in the space in the shielding.

Abstract: A dielectric filter includes a dielectric block having multiple through holes which are created in parallel and grooves which are created around the opening of the through holes. A conductor is formed inside the grooves and the through holes. The inside conductors and in-groove conductors are connected at the opening of the through hole surrounded with the groove. The inside conductors and an outside conductor are connected at a second end. The opening of the through hole is formed inside an open-circuit end of the dielectric block.

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A dielectric resonator is provided which includes a dielectric block, an inner conductor formed on an outer surface of the dielectric block, and another outer conductor formed on an outer surface of the dielectric block. The inner conductor is so geometrically modified as to change the characteristic impedance in a manner wherein the shape of either the inner conductor or the dielectric block is changed.

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).