公开(公告)号：JP2002164824A

公开(公告)日：2002-06-07

申请号：JP2000357341

申请日：2000-11-24

Applicant: TOA CORP

Inventor： TOMORI JIYUNJI ,  YOSHIKAWA SUSUMU

IPC: H04B1/10 ,  H04B7/08 ,  H04B7/26

Abstract: PROBLEM TO BE SOLVED: To prevent generation of noise by operating squelch function at the time of antenna-switch on a diversity receiver using antenna-switching receiving method. SOLUTION: In this diversity receiver, a control part 8 turns on a switch circuit 11 just before an antenna 1 made valid through switching by a switch circuit 2. By this operation, a squelch control circuit 9 turns an output of a squelch switch 5 on-state compulsorily, where the on-state of the output is maintained for a prescribed time by the time constant of a smoothing capacitor 94 which constitutes the squelch control circuit 9. Consequently, even if the receiving condition by the switched antenna 1 is bad, the squelch switch 5 becomes the off-state of the output and the so-called squelch function will not operate by means of that the switch circuit 2 switches over as the original antenna 1 is valid again in the prescribed time. Therefore, it can be prevented to output a noise of peculiar sound 'puttyu' by operating the squelch function.

公开(公告)号：JP2001102983A

公开(公告)日：2001-04-13

申请号：JP27954399

申请日：1999-09-30

Applicant: TOA CORP

Inventor： YOSHIKAWA SUSUMU ,  TOMORI JIYUNJI

IPC: H04B7/26 ,  H04B7/15

Abstract: PROBLEM TO BE SOLVED: To securely set a channel of a radio communication system. SOLUTION: Of the radio communication system which has plural devices and at least one repeater while each slave device is equipped with a means for following a channel setting procedure each time transmission is started, the slave device is equipped with a transmitting means S4 for transmitting a radio wave of 1st frequency only momentarily each time transmission is started, a receiving means S5 for receiving a radio wave of 2nd frequency sent by the repeater in response to the radio wave of the 1st frequency, and a means S6 which starts a telephone call integral time timer in response to the receiving means.

公开(公告)号：JP2001103535A

公开(公告)日：2001-04-13

申请号：JP27789899

申请日：1999-09-30

Applicant: TOA CORP

Inventor： YOSHIKAWA SUSUMU ,  TOMORI JIYUNJI

IPC: H04B17/40 ,  H04B7/26 ,  H04W16/26 ,  H04W84/08 ,  H04Q7/28 ,  H04B17/02

Abstract: PROBLEM TO BE SOLVED: To provide a radio communication system that can continue relaying when a radio wave arrived after interruption of a radio wave over a prescribed period is not a radio wave for a channel setting procedure. SOLUTION: A repeater discriminates whether or not a radio wave received after interruption of a radio wave from a slave set over a prescribed period is a radio wave for a channel setting procedure and continues the relaying when the repeater discriminates that the radio wave is not the radio wave for the channel setting procedure. Thus, the repeater is provided with a 1st discrimination means S4 that discriminates whether or not the radio wave from the slave set is interrupted over a prescribed period, a 2nd discrimination means S7 that discriminates whether or not the radio wave received after the interruption of the radio wave is the radio wave for the channel setting procedure in response to the result of the 1st discrimination means, and a speech continuing means S5 that continues the relaying in response to the 2nd discrimination means.

公开(公告)号：JPH10107533A

公开(公告)日：1998-04-24

申请号：JP28189896

申请日：1996-10-02

Applicant: TOA CORP

Inventor： TOMORI JIYUNJI

IPC: H01Q1/38 ,  H01Q9/18 ,  H01Q9/26 ,  H01Q9/42

Abstract: PROBLEM TO BE SOLVED: To reduce the whole length of the antenna made of a printed circuit board. SOLUTION: An antenna that is nearly equivalent to a modified Brown antenna where a ground line is set lower so as to be set along with a coaxial cable is formed on a printed circuit board 1. Furthermore, a feed line pattern 11 and outer conductor patterns 12 on the printed circuit board 1 correspond respectively to an inner conductor and an outer conductor of a coaxial cable of a Brown antenna, and ground patterns 13 and an antenna element pattern 15 correspond respectively to an earth line (ground side element) and a vertical conductor (HOT side element) of the Brown antenna. Since the ground patterns 13 are placed close to the outer conductor patterns 12, a propagation speed of a radio wave is reduced resulting in causing a reduced wavelength. Thus, the ground patterns 13 are decreased.

公开(公告)号：JP2002319880A

公开(公告)日：2002-10-31

申请号：JP2001120815

申请日：2001-04-19

Applicant: TOA CORP

Inventor： TOMORI JIYUNJI ,  YOSHIKAWA SUSUMU

IPC: H04B7/08

Abstract: PROBLEM TO BE SOLVED: To provide a diversity receiver adopting an antenna switching system that suppresses a noise caused at antenna switching. SOLUTION: When an antenna switching circuit 2 selects a valid antenna 1, a control section 6 uses a changeover switch circuit 7 to sequentially switch a supply destination of a detection output of a detection section 4 to a low pass filter circuit 8, a low pass filter circuit 9, and the low pass filter circuit 8 in this order and finally to a loudspeaker 5. Thus, a missing (discontinuous) part of a detection output caused when any antenna 1 is invalidated can be unsharpened at antenna switching, that is, can be interpolated. Thus, production of a noise caused by the discontinuity can be suppressed.

公开(公告)号：JP2001298386A

公开(公告)日：2001-10-26

申请号：JP2000109902

申请日：2000-04-11

Applicant: TOA CORP

Inventor： SHIBATA TOSHIKAZU ,  TOMORI JIYUNJI

IPC: H04B7/08

Abstract: PROBLEM TO BE SOLVED: To reduce the effect of noise at the time of switching antennas in a receiver of an antenna switching diversity system. SOLUTION: A control part 5 supplies a switch control signal to a switching circuit 2 in accordance with the receiving state of a receiving part 3. In the circuit 2, by supplying the switch control signal, each of PiN diodes 21 and 22 is turned on/off, and the switch operation of respective antennas 1, 1 are accordingly conducted. Noise is sometimes outputted from the receiving part 3 because neither of the antennas 1 is momentarily connected to the receiving part 3 when the switch operation of the antennas 1, 1 is preformed. However, it is possible to reduce the level of the noise by using PiN diodes having small isolation in an on mode as the respective PiN diodes 21 and 22.