Abstract: Only a first radio station is equipped with a local oscillation signal source. A signal transmitted to a second radio station includes local oscilaation signal components used to up-convert a modulated intermediate frequency band signal in addition to intermediate frequency band signal components. The second radio station that receives the signal from the first radio station extracts and regenerate the local oscillation signal used at the first radio station using a local oscillation signal regenerator. The extracted and regenerated local oscillation signal is used to down-convert modulated radio signal components to the intermediate frequency band and simultaneously up-convert to the radio frequency band the modulated intermediate frequency band signal to be transmitted to the first radio station.

Abstract: A transmitter shown in FIG. 3 inputs to a mixer 36 an IF band modulation signal generated from transmission data and a frequency hopping signal obtained by a hopping synthesizer 38 controlled by a hopping pattern generator 37, thereby obtaining a frequency hopping radio signal to be transmitted. In a receiver shown in FIG. 4, a received signal is amplified and an unnecessary wave is removed from the signal, and the resultant signal is input to a mixer 44. The mixer 44 receives an output signal of a hopping synthesizer 47 controlled by a signal obtained by adding a fixed frequency offset signal to the hopping pattern generator 45. A signal downconverted to a first IF band without frequency hopping corresponding to the offset signal with a radio frequency band signal maintaining the relative spectrum relationship appears in the output of the mixer 44.

Abstract: A reference local oscillation signal transmission station 1 radiates a reference local oscillation signal to a service zone. A portion of the signal received by each radio slave station terminal 2 is branched and fed to an injection locked oscillator 6. As a result, a local oscillation signal which is synchronized with the reference local oscillation signal is obtained. In the slave station terminal 2, the thus-obtained local oscillation signal is fed to a transmission frequency converter (mixer) 7 and a reception frequency converter (mixer) 8. An IF band transmission modulated signal is fed to the mixer 7 for frequency conversion to a radio frequency band, and the thus-obtained radio-frequency modulated signal is transmitted. Meanwhile, a received radio-frequency modulated signal is fed to the mixer 8 for down conversion, and the thus-obtained signal is fed to an IF band demodulator 10 so as to restore an information signal.

Abstract: A transmitter 1 transmits from a transmission antenna 7 a mixture signal containing a radio-frequency (RF)-band modulated signal, and a portion of power of a local oscillation signal used for frequency conversion. Meanwhile, a receiver 8 detects the transmitted signal by means of a reception antenna-detection section 9. In the reception antenna-detection section 9, a plurality of base unit reception circuits 11 are disposed. Each base unit reception circuit 11 includes a planar printed antenna 12 such as a patch antenna, an amplifier circuit 13 formed on a very small planar circuit by means of an MMIC technique, and a mixer circuit 14 serving as a square-law detector. Respective outputs of the base unit reception circuits 11 are power-mixed and fed to the IF signal demodulation section. The IF signal demodulation section 10 demodulate reception data.

Abstract: In a radio communication apparatus and method, on the transmitting side, an input signal is modulated in an intermediate frequency band to produce a modulated intermediate frequency band signal, a local oscillation signal is used to up-convert the modulated intermediate frequency band signal to a modulated radio frequency band signal, and the local oscillation signal and the modulated radio frequency band signal are simultaneously transmitted as a radio signal, and, on the receiving side, the radio signal from the transmitter is received, the received signal is down-converted by multiplying the local oscillation signal component and the modulated radio frequency band signal component contained in the received signal to generate a multiplication component and thereby produce a modulated intermediate frequency band signal, and the modulated intermediate frequency band signal is demodulated.

Abstract: The present invention provides a radio communication device, a transmitter and a receiver capable of handling a plurality of signal waves. A radio communication device has a millimeter-wave transmitter (15) and a millimeter-wave receiver (29). Millimeter-wave transmitter (15) includes a multiplexing circuit (1), a millimeter-wave up-converter (4) and an antenna (3), and the millimeter-receiver includes an antenna (31), a millimeter-wave down-converter (32) and an output processing circuit (45). The signal waves dedicated to the user are modulated by a modulation circuit (121 to 124) so as to be allocated between the ground broadcast waves and satellite broadcast waves. The frequencies are multiplexed in an intermediate frequency band, after that, the multiplexed frequencies are converted into a millimeter-wave band and the resultant is transmitted. On the reception side, the multiplexed waves are down-converted, separated to signal waves and demodulated.

Abstract: This invention includes a wireless transmitter comprising an IF-signal generator that modulates input signals into those of an intermediate frequency band, signal distributors that distribute signals from the IF-signal generator, and a plurality of signal-transmission units that convert the signals distributed by the signal distributors into those of a radio frequency band, and then transmit the converted radio signals. The invention also includes a wireless receiver that receives the radio-frequency-band modulated signals and restores the signals of the intermediate frequency band. In this way, effective diversity is realized and signal interruptions are prevented. In addition, a handy, low-cost wireless communications system is provided.

Abstract: Only a first radio station is equipped with a local oscillation signal source. A signal transmitted to a second radio station includes local oscilaation signal components used to up-convert a modulated intermediate frequency band signal in addition to intermediate frequency band signal components. The second radio station that receives the signal from the first radio station extracts and regenerated the local oscillation signal used at the first radio station using a local oscillation signal regenerator. The extracted and regenerated local oscillation signal is used to down-convert modulated radio signal components to the intermediate frequency band and simultaneously up-convert to the radio frequency band the modulated intermediate frequency band signal to be transmitted to the first radio station.