TRACKING SYSTEM WITH BEAM SWITCHING ANTENNA

    公开(公告)号:CA1298402C

    公开(公告)日:1992-03-31

    申请号:CA568066

    申请日:1988-05-30

    Applicant: NEC CORP

    Abstract: In a tracking system of a stationary satellite, a phased array is used for an antenna mounted on an automobile. The phased array antenna has a sharp beam which is switched between two different directions in azimuth. The antenna beam is switched between the two directions periodically by control of phase constants in a feeding circuit of the antenna and comparison is made in strength between signals received before and after the beam switching to obtain an error signal as an azimuth error signal. Then, the antenna is mechanically moved in azimuth according to the azimuth error signal until the azimuth error signal becomes zero. In a case the antenna beam is also switched between two directions in elevation, the antenna beam is switched in elevation during an interval between successive two times of the beam switching operation in azimuth and detects a difference in strength of signals received before and after the switching in elevation to thereby produce the difference as an elevation error signal. The antenna is mechanically moved in elevation according to the elevation error signal until the elevation error signal becomes zero.

    ANTENNA DEVICE CAPABLE OF REDUCING A PHASE NOISE

    公开(公告)号:CA1321640C

    公开(公告)日:1993-08-24

    申请号:CA587856

    申请日:1989-01-10

    Applicant: NEC CORP

    Abstract: In an antenna device comprising an antenna block which can electrically control a direction of a radio wave transmitted or received by the antenna device, a phase shift unit is connected to the antenna block to phase shift an external electric signal or an internal electric signal given to or from the antenna device. The phase shift unit has variable and discrete phase shifts switched from one to another in response to a control signal supplied from a controller and supplies a phase shifted external signal to the antenna block or a phase shifted internal signal to an external device. The antenna block comprises a plurality of antenna elements and a plurality of phase shifters which are connected to the antenna elements to send the phase shifted external signal to the respective antenna elements or to send the internal electric signal to the phase shift unit.

    PARABOLIC ANTENNA THAWING DEVICE
    5.
    发明专利

    公开(公告)号:JPH0918211A

    公开(公告)日:1997-01-17

    申请号:JP16101095

    申请日:1995-06-27

    Applicant: NEC CORP

    Inventor: YAMANE TOSHINOBU

    Abstract: PURPOSE: To provide a parabolic antenna thawing device which can reduce its power consumption while keeping effectively the performance of an antenna reflector even at a low temperature. CONSTITUTION: This device includes a heater part 4 that is provided on the back side of a parabolic antenna 2, an open air sensor 6 and a snow sensor 8 which are prepared around the antenna 2, and a heater control part 10 which turns on the part 4 when the sensor 8 senses the snow. The part 10 has a 1st heater control function which turns off the part 4 when the sensor 6 detects the temperature lower than a prescribed level and a 2nd heater control function which turns on the part 4 when the open air rises up to a prescribed temperature from the temperature lower than a prescribed set level and then turns off the part 4 after the rapse of a prescribed time.

    PHASE SYNCHRONIZING RECEIVER
    6.
    发明专利

    公开(公告)号:JPH04120914A

    公开(公告)日:1992-04-21

    申请号:JP24216790

    申请日:1990-09-12

    Applicant: NEC CORP

    Inventor: YAMANE TOSHINOBU

    Abstract: PURPOSE:To easily obtain resynchronism by sweeping in a fine range even when the frequency of a received signal is deviated by generating the control voltage of a phase synchronizing loop based on the output frequency of a voltage controlled oscillator just before missing the received signal stored in a memory when the received signal is missed, and sweeping the voltage. CONSTITUTION:When the received signal is interrupted after the phase locked loop is temporarily locked, a microprocessor 9 controls a voltage controlled oscillator 4 through the output of a D/A converter 10 so as to be coincident with the count value of a counter 7 obtained before the received signal is interrupted, and the resynchronism is obtained by a little sweeping around the frequency. Thus, even when the frequency of the received signal is deviated or an oscillation frequency is deviated to the control voltage of the voltage controlled oscillator 4, the resynchronism can be easily obtained by sweeping within a fine range based on the oscillation frequency of the voltage controlled oscillator 4 to be held in a memory 8 just before the received signal is interrupted.

    INITIAL CATCH APPARATUS OF BEAM SCAN TRACING

    公开(公告)号:JPH01277784A

    公开(公告)日:1989-11-08

    申请号:JP10551688

    申请日:1988-04-30

    Applicant: NEC CORP

    Abstract: PURPOSE:To catch easily a wave source and further to prevent the false tracing due to a side lobe when a moving body goes out of a shield, by adding a reception intensity comparator to a beam scan tracing apparatus. CONSTITUTION:The level of a reception signal is detected by a reception intensity comparator 5, and when it lowers to a prescribed level or below, a signal (a) is outputted to give a command voltage to a servo amplifier 7 so as to rotate an antenna in one direction. By this operation, the antenna is rotated in one direction notwithstanding a level difference due to beam scanning. Accordingly, a reception level is restored when a moving body goes out of a shield and further when the antenna is directed to a wave source.

    BACK-UP POWER DIAGNOSIS CIRCUIT
    8.
    发明专利

    公开(公告)号:JPH01193914A

    公开(公告)日:1989-08-03

    申请号:JP1693988

    申请日:1988-01-29

    Applicant: NEC CORP

    Inventor: YAMANE TOSHINOBU

    Abstract: PURPOSE:To diagnose a back-up power circuit without using a complicated circuit by periodically operating a back-up power and checking the subsequent content of memory data. CONSTITUTION:When a central processing unit CPU 5 excites a relay 4a through an output port 6 and brakes a contact point 4b, a second volatile memory 3 operates by a back-up memory 7. When the back-up battery 7 is exhausted, storage data of the second volatile memory 3 is lost. The excitation of the relay 4a is removed, the second volatile memory 3 is operated by a normal-use power 1, and the content of a first volatile memory 2 which receives power supply only from the normal-use power is compared with that of the second volatile memory 3. When they are different, it is judged that an abnormality has occurred in the back-up power circuit, and an abnormality detection signal is outputted to a terminal 8. Thus, the consumption of the back-up power and the like can be diagnosed by a simple circuit.

    ANTENNA TRACKING RECEIVER
    9.
    发明专利

    公开(公告)号:JPS63163184A

    公开(公告)日:1988-07-06

    申请号:JP31573786

    申请日:1986-12-24

    Applicant: NEC CORP

    Inventor: YAMANE TOSHINOBU

    Abstract: PURPOSE:To perform an antenna tracking accurately, by providing a memory means into which phase difference information generated from a difference between transmission paths of sections of generating a fundamental mode signal and a high-order mode signal as received signals is stored as determined separately for several frequencies beforehand. CONSTITUTION:A signal received with an antenna 1 is supplied to a DELTA signal generating section 3 and a SIGMA signal generating section 4 separately through a feeder section 2 to produce DELTA signal in a high-order mode and a SIGMA signal in a fundamental mode. In this case, adjustment of a phase shift value in the SIGMAsignal is performed automatically based on a phase shift control data which is determined by arithmetic processing at an arithmetic control section 16 to execute the control of the phase shift value of a phase shifter 6. Then, a phase shift value for another frequency is calculated by interpolation based on several data preset as reference. This enables phase shift adjustment precisely to automatically make the phases of the DELTA and SIGMA signals match with a number of frequencies thereby performing an antenna tracking accurately.

    PHASE LOCKED LOOP RECEIVER
    10.
    发明专利

    公开(公告)号:JPH0563740A

    公开(公告)日:1993-03-12

    申请号:JP24032291

    申请日:1991-08-28

    Applicant: NEC CORP

    Inventor: YAMANE TOSHINOBU

    Abstract: PURPOSE:To acquire a desired frequency in response to a level of a carrier signal by outputting and storing a level of a voltage controlled oscillator at sweeping and controlling the sweeping with a microprocessor based on the level. CONSTITUTION:A A/D converter 10 generates a control voltage used to sweep a frequency of a voltage controlled oscillator 4, an A/D converter 14 outputs an output of a synchronization detector 5 to a microprocessor 9 and measures the level and stores it into a memory 8. The processor 9 outputs a signal to allow the converter 10 to sweep only the vicinity of the desired frequency based on a control voltage stored in the memory 8. The reception level is always monitored till the end of sweep at the start of sweep and the sweep continues while a maximum value of the reception level is being stored. In the range that a reception level gets higher than a reference value and then a succeeding reception level is smaller than the reference value, the reception maximum level for that time is stored in the memory 8. When the sweep is finished, the maximum reception level is sought and the vicinity is slightly swept.

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