Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
2000-04-06
2004-11-23
Gelin, Jean (Department: 2681)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S556100, C455S083000, C455S103000, C455S552100
Reexamination Certificate
active
06823196
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication apparatus comprising a plurality of different radio transmitter sections, a method of controlling transmission operation of the communication apparatus, a computer readable medium on which a computer program of transmission operation control for the communication apparatus is stored and a communication system using the communication apparatus.
2. Description of the Related Art
Hitherto, a mobile communication apparatus for use in single systems contains one radio transmitter section and one radio receiving section. When radio transmitter sections and radio receiving sections in the technological levels of two different communication systems are stored simply in a single case in forming a mobile communication apparatus such as a portable telephone and a car telephone corresponding to the respective communication systems, mutual interference occurs due to leakage of electromagnetic waves among the different transmitter sections. Therefore, the respective transmitter sections must be shielded individually to prevent the mutual interference.
Further, although the respective transmitter sections are electrically connected and coupled in order to share an antenna, they generate unnecessary radio waves due to mutual modulation distortion caused by the coupling. Therefore, the unnecessary radio waves must be suppressed by inserting a non-reciprocal device such as an isolator and a circulator or by inserting a filtering device such as a duplexer on the wiring path connecting the transmitter sections.
However, the size and weight of the apparatus increase by enhancing the isolating performance of the parts such as the non-reciprocal device, filtering device and antenna switch. The size and weight of the apparatus also increase by enhancing the isolating performance to the shield. Therefore, they cannot be applied to a communication apparatus which requires portability such as a PDC (personal digital cellular telecommunication system)/PHS (personal handy-phone system) complex portable telephone.
Still more, it is not easy to realize sharing of the transmitter sections, or the transmitter sections for large power in particular, optimized for two communication systems having different frequency or modulating schemes because a technology must be developed for optimizing performance parameters of different indices. For instance, when a transmission power amplifier in a GSM (global system for mobile communication) scheme in which an envelope of transmission radio waves is constant is combined with a transmission power amplifier in a PDC scheme in which an envelope changes, an F-class operational amplifier in which no envelope is taken into account in case of only GSM must be combined with an AB-class operational amplifier in which an envelope is taken into account in case of only PDC to effectuate its efficiency in the same level with the amplifier of the respective systems. The efficiency of the amplifier determines the degree of power consumption and largely affects the usable speech time of a battery operation of the portable telephone. Therefore, the portable telephone which may be used for a long time as the user desires cannot be realized just by combining the amplifiers.
In Japanese Unexamined Patent Publication JP-A 10-336757 (1998) is disclosed a technology related to a mobile communication apparatus for implementing multi-modes communication among a plurality of autonomous communication systems and to a method for controlling the communication apparatus.
SUMMARY OF THE INVENTION
Hence it is an object of the invention to provide a communication apparatus capable of suppressing generation of unnecessary radiowaves due to mutual modulation distortion without increasing the size and weight of the communication apparatus and to provide a method of controlling transmission operation of the communication apparatus, a computer readable medium on which computer program of transmission operation control for the communication apparatus is stored and a communication system using the communication apparatus.
The invention provides a communication apparatus comprising a plurality of radio transmitter sections; and transmission control means for, when specific one of the plurality of radio transmitter sections is engaged in transmission, rejecting a transmission request which is made to another radio transmitter section of the plurality of radio transmitters which is not engaged in transmission.
According to the invention, the communication apparatus comprising the plurality of radio transmitter sections for different communication systems is constructed by individually shielding the radio transmitter section so that they do not interfere from each other in general. The radio transmitter sections are also electrically connected and coupled to share an antenna.
Although unnecessary radiowaves generated by mutual modulation distortion caused by the coupling have been suppressed by inserting a non-reciprocal device such as an isolator and a circulator or by inserting a filtering device such as a duplexer on a wiring route for connecting the radio transmitter sections, the size and weight of the communication apparatus have been increased by enhancing the isolation performance of the parts such as the non-reciprocal device, filtering device and antenna switch. Further, the size and weight of the apparatus increase by enhancing the isolation performance of the shield.
In the communication apparatus of the invention, a transmitting operation is controlled so as to reject the transmission request when the transmission request is made to another radio transmitter section when the specific radio transmitter section is engaged in transmission. Accordingly, the unnecessary radiowaves may be suppressed from being generated due to the mutual modulation distortion which is otherwise caused by the coupling of the respective radio transmitter sections without enhancing the isolation performance of the parts such as the non-reciprocal device, filtering device and antenna switch and without enhancing the isolation performance of the shield.
Accordingly, the quality of the transmitted radiowaves may be kept high without increasing the size and weight of the communication apparatus and the communication apparatus of the invention may be suitably used as a communication apparatus requiring portability in particular.
The invention provides a communication apparatus comprising a plurality of radio transmitter sections; and transmission control means for, when specific one among the plurality of radio transmitter sections is engaged in transmission, holding a transmission request which is made to another radio transmitter section thereamong which is not engaged in transmission, and validating the held transmission request when the transmission of the specific radio transmitter section ends.
According to the invention, the communication apparatus comprising the plurality of radio transmitter sections is constructed by individually shielding the radio transmitter section and electrically connecting the radio transmitter sections. Although unnecessary radiowaves generated by mutual modulation distortion caused by that have been suppressed by inserting the non-reciprocal device and the filtering device on the wiring route for connecting the radio transmitter sections, the size and weight of the communication apparatus have been increased by enhancing the isolation performance of those devices and shield.
In the communication apparatus of the invention, a transmitting operation is controlled so as to hold the transmission request once when the transmission request is made to the other radio transmitter section when the specific radio transmitter section is engaged in transmission and to validate the held transmission request again when the transmission of the specific radio transmitter section ends. Accordingly, the unnecessary radiowaves may be suppressed from being generated due to the mutual modulation distortion which i
Edo Kenji
Itoh Taizoh
Maemura Takashi
Moriwaki Yoshitsugu
Nakano Yoshiro
Gelin Jean
Nixon & Vanderhye P.C.
Ramos-Feliciano Eliseo
Sharp Kabushiki Kaisha
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