Telecommunications – Receiver or analog modulated signal frequency converter – With wave collector
Reexamination Certificate
2000-07-20
2004-03-30
Chin, Vivian (Department: 2682)
Telecommunications
Receiver or analog modulated signal frequency converter
With wave collector
C455S552100, C455S553100, C455S078000, C455S080000, C455S277100
Reexamination Certificate
active
06714773
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a simple portable phone built-in portable phone. More particularly, the present invention relates to a simple portable phone built-in portable phone in which degradation of a transmission and reception characteristic can be prevented in antenna switching.
2. Description of the Related Art
A “multiple radio terminal” is known in which a simple portable phone (PHS) is built-in a portable phone (PDC). The multiple radio terminal has a diversity antenna structure which uses a PDC and PHS transmitting and receiving common antenna (hereinafter, to be also referred to as a “PDC/PHS common antenna”) and a PDC receive-only built-in antenna. An antenna switching integrated circuit is arranged between a PDC transmitting and receiving section and a PHS transmitting and receiving section.
FIG. 1
is a diagram showing a structure example of the PDC/PHS multiple radio terminal of this type. The PDC/PHS multiple radio terminal is composed of a PDC/PHS common antenna
402
and a PDC built-in antenna
401
as the antenna structure. Also, the PDC/PHS multiple radio terminal is composed of an external terminal
408
and an external terminal
405
as the external input-output terminals. Moreover, the PDC/PHS multiple radio terminal is composed of a PDC receiving section
406
, a PDC transmitting section
407
and a PHS transmitting and receiving section
409
as the transmission and reception structure.
The PDC/PHS common antenna
402
is connected with the PHS transmitting and receiving section
409
through a PDC/PHS common filter
404
. Also, the PDC/PHS common antenna
402
is connected with the PDC receiving section
406
and the PDC
15
transmitting section
407
through the PDC/PHS common filter
404
and an antenna switching circuit (ANT SW IC)
403
. Also, the external terminals
408
and
405
are connected with the PDC receiving section
406
and the PDC transmitting section
407
through the antenna switching circuit
403
. The PHS transmitting and receiving section
409
, the PDC receiving section
406
and the PDC transmitting section
407
are connected with a control unit
410
. Also, the antenna switching circuit
403
is composed of a plurality of switches SW
1
403
A to SW
7
403
G. Each the switches
403
A to
403
G is set to the ON/OFF state in response to a control signal from the control unit
410
. Thus, the switching control between the antenna and the transmitting and receiving section is carried out.
In such a PDC/PHS multiple radio terminal, an intermittent receiving operation is carried out in the reception wait condition, to eliminate a problem in each signaling system, especially, in case of use on high-speed movement in an area, and in case of use in a underground town area. Also, in such a multiple radio terminal, in the reception wait condition, each operation is not controlled finely, and the PDC side and the PHS side are controlled independently to operate asynchronously. This is because simplification of the circuit structure design and power consumption.
In the PDC/PHS multiple radio terminal as mentioned above, there is a case where the PHS side receives using the PDC/PHS common antenna during the reception in which the PDC side uses a built-in antenna. In this case, the conventional antenna switching circuit disconnects the PDC/PHS common antenna from the PDC receiving section. Therefore, the input/output impedance on PDC side of the PDC/PHS common filter becomes unstable. As a result, the matching condition shifts so that the characteristic of the PDC/PHS common filter becomes worse, resulting in degradation of the transmission and reception characteristic on the PHS side. Therefore, especially, the following problem occurs.
The reception on the PHS side can not be carried out normally at an intermittent reception timing of the PHS side, in the state that the PDC side receives by use of the built-in antenna. As a result, there is a possibility that the synchronization of the reception timing on the PHS side goes out. Also, when the synchronization of the reception timing on the PHS side goes out, the operation to establish the synchronization of the reception timing once again becomes necessary on the PHS side to switch from the intermittent receiving operation to the continuation receiving operation for receiving the terminating call. As a result, the problem is caused that the power consumption increases further with the continuation receiving operation for such synchronous establishment.
In conjunction with the above description, a portable terminal is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 5-167566). In this reference, the portable terminal is composed of an antenna (1), a receiving section (2), a data clock generating section (3), a first detection notifying section (4), a majority determining section (5), a second detection notifying section (6), and a central processing unit (7). The central processing unit (7) controls the receiving section (2) to stop based on a notice from the first detection notifying section (4) and the receiving section by a notice from the second detection notifying section (6). In this way, when a majority is determined before all data are received, a receiving circuit is stopped without reception of a remainder serial data. When the head of the following data format is detected, the receiving circuit is controlled to start an operation. Thus, low power consumption is realized.
Also, a diversity control method is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 5-183475). In this reference, in each of n-system base station receiving sections (31, 3N), after a desired signal is extracted from an SD reception signal, the received electric field intensity levels of the desired signals are detected and compared with each other (317). A diversity switching control signal is generated based on the comparing result. A receiving switch section (318) is driven in response to the diversity switching control signal to take out a demodulation signal of the desired signal of a system which has a higher received electric field intensity level. A base station includes n-system base station transmitting section (21, 2N) in addition to the n-system base station receiving sections (31, 3N). A transmission SD antenna is provided for the base station. A base station transmitting section transmits a transmission signal to a mobile station using the transmission SD antenna switched based on the diversity switching control signal from the base station receiving section.
Also, a mobile radio apparatus is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 5-316018). In this reference, a control data is transmitted from a base station. The control data is received by a receiving circuit (2) via an antenna (1) in a reception waiting state, is demodulated by a digital data demodulating circuit (4), is subjected to a majority determining process by a majority determining circuit (5), and is analyzed by a microprocessor (6). Also, the control data is converted into a digital data by an A/D converter (3). The microprocessor (6) determines the reception electric field intensity of the digital data and determines the number of words to be received within the control data to be repeatedly transmitted. The microprocessor (6) receives only the words of a predetermined number and controls the power source to the receiving circuit to be cut for a time from the head of the remaining words to the next sync signal.
Also, a personal handy phone is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 8-116301). In this reference, the power supply to a transmitting circuit (3) is turned off and an antenna switch (2) is set to the receiving circuit (5), in a reception waiting mode. A timer circuit (7) is connected to a call identifying circuit (6) and the receiving circuit (5) by a control line (18) to control the power to be intermittently supplied to them. When the mobile phone is called from a base station during the
Chin Vivian
Dickstein Shapiro Morin & Oshinsky LLP.
NEC Corporation
Yun Eugene
LandOfFree
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