公开(公告)号：JPH0927710A

公开(公告)日：1997-01-28

申请号：JP17530895

申请日：1995-07-12

Applicant: NEC CORP

Inventor： KURAMOTO AKIO ,  TANABE KOSUKE

IPC: H01Q21/08 ,  H01Q11/08 ,  H01Q21/24

Abstract: PROBLEM TO BE SOLVED: To obtain an excellent axis ratio and reduce variation in the electric field level of a radiation pattern in a circumferential direction. SOLUTION: A linear coaxial cable 1 and a linear coaxial cable 2 which is shorter than the coaxial cable 1 are arranged adjacently to each other so that their lower ends are aligned. Helical conductors 3 and 4 are wound spirally around only the upper part of the coaxial cable and helical conductors 5 and 6 are wound spirally around the lower part of the coaxial cable 1 and the coaxial cable 2. A straight line A passing the upper start points of the helical conductors 3 and 4 and a straight line B passing the upper start points of the helical conductors 5 and 6 are arranged having an about 90 deg. angle of rotation. Consequently, a circular polarized wave which is extremely excellent in axis ratio is obtained as a radiation pattern obtained by putting radiation electric fields of the helical conductors 3 and 4 and helical conductors 5 and 6 together.

公开(公告)号：JPH05152844A

公开(公告)日：1993-06-18

申请号：JP31495791

申请日：1991-11-28

Applicant: NEC CORP

Inventor： KURAMOTO AKIO

IPC: H01Q1/50 ,  H01Q9/26 ,  H01Q23/00 ,  H03F3/191

Abstract: PURPOSE:To suppress the characteristic deterioration in the entire antenna by reducing a feeder loss when the antenna is used as an array. CONSTITUTION:In the antenna such as a folded dipole antenna 1 having two feeding points 2, 3 connected electrically, it is featured that transmission and reception transistors(TRs) 4, 5 are connected to the feeding points 2, 3. Thus, when the feeder is in use, no deterioration in noise temperature is caused at the reception and excess production of heat at transmission is avoided, and the necessity of strong power resistance of circuits on the way of large power passing is not required.

公开(公告)号：JPH04351002A

公开(公告)日：1992-12-04

申请号：JP12421391

申请日：1991-05-29

Applicant: NEC CORP

Inventor： KURAMOTO AKIO

IPC: H01Q3/26 ,  H01Q9/16 ,  H01Q23/00

Abstract: PURPOSE:To change a direction of a radiation pattern within a horizontal plane of the antenna by providing two gamma matching circuits which are selected through the application of a bias voltage to four diodes to the system. CONSTITUTION:The antenna is provided with a main conductor rod 2 whose length is 1/2 wavelength to the center position of which an outer conductor 1 of a coaxial feeder is connected, 1st and 2nd conductor rods 6, 7 in total two arranged in parallel with a slight distance from the main conductor rod 2 and arranged symmetrically to the left and right from the center position of the main conductor rod 2, and 1st and 2nd diodes 4, 5 in total two connecting to each one terminal of the 1st and 2nd conductor rods 6, 7 with different polarity from the center conductor of the coaxial feeder, and also 3rd and 4th diodes 8, 9 arranged between each other terminal of the 1st and 2nd conductor rods 6, 7 and the main conductor rod 2 in the same polarity as that of the 1st and 2nd diodes 4, 5 respectively.

公开(公告)号：JPH04111602A

公开(公告)日：1992-04-13

申请号：JP22973490

申请日：1990-08-31

Applicant: NEC CORP

Inventor： KURAMOTO AKIO

IPC: H01Q9/27 ,  H01Q11/04 ,  H01Q11/08

Abstract: PURPOSE:To easily change the exciting phase of a radiation electric field by connecting a 1st and 2nd conductors to a spiral conductor and a center conductor with 1st and 2nd diodes directed opposite polarity to each other respectively and changing over the direction of a DC bias current. CONSTITUTION:When a high frequency signal is supplied to a coaxial center conductor of a coaxial feeder 10 while a negative DC bias current is supplied to the coaxial center conductor of the coaxial feeder 10, the DC bias current flows to ground via a coil 11 through 2nd diodes 8, 9 conducted. Thus, the high frequency power passes through the center conductor 3 and a doglegged conductor 5 and radiates from a spiral conductor 2. Thus, whether the high frequency current passes through a line conductor 4 being a 1st conductor or the doglegged conductor 5 being a 2nd conductor is changed over by changing the polarity of the DC bias current, in which the radiation angle of the conductors 4, 5 differs from each other. This results in a start point of radio wave radiation is selected at a point (a) or (b) thereby varying the exciting phase of the radiation electric field by an angle theta deg..

公开(公告)号：JPH03242006A

公开(公告)日：1991-10-29

申请号：JP4010490

申请日：1990-02-20

Applicant: NEC CORP

Inventor： KURAMOTO AKIO

IPC: H01Q3/30 ,  H01P1/17 ,  H01P1/185 ,  H01Q21/24

Abstract: PURPOSE:To execute beam scanning at a high speed by adopting simple constitution for a circularly polarized wave generating part of a primary radiator comprising a microstrip line with a light weight. CONSTITUTION:The antenna consists of antenna units 1-4 each arranged on four faces at the outside of a square waveguide 5. Each of the four antenna units 1-4 consists of a dipole 6, a phase shifter 7, a phase adjustment part 8 and a short needle 9, and the difference from the four antenna units 1-4 depends on the difference from the length of the microstrip line at the phase adjustment part 8, that is, lengths la, lb in the case of the antenna units 1, 2 respectively. Since the primary radiator part of the reflecting mirror antenna is simplified in this way, high speed beam scanning is attained.

公开(公告)号：JPH02132903A

公开(公告)日：1990-05-22

申请号：JP28623288

申请日：1988-11-12

Applicant: NEC CORP

Inventor： KURAMOTO AKIO

IPC: H01Q11/04 ,  H01Q11/08

Abstract: PURPOSE:To obtain single directivity, and in addition, to improve gain, and to make VSWR into a wide band by providing the lower part of a spiral conductor with a metallic reflecting plate, and in addition, providing the central end of the conductor with a matching circuit consisting of a coaxial central conductor and a coaxial outer conductor. CONSTITUTION:The spiral conductor 2 made by winding one conductor is formed on a printed board 1, and the metallic reflecting plate 3 formed into a box shape is arranged on the lower side of the board 1 so as to support the circumferential part of the board 1. Besides, a hole 3a is opened in the central position of the bottom surface of the reflecting plate 3, and the base end of the coaxial central conductor 4 whose tip end is connected to the central end of the conductor 2 is positioned in said hole. Further, the cylindrical coaxial outer conductor 5 whose tip end is opened is arranged around the hole 3a so as to surround the conductor 4. Here, both lengthes of the conductors 4,5 are made into 1/4wavelength, and the diameters of them are determined respectively so that the impedance matching of an antenna is attained. Through this constitution, since the reflecting plate 3 is box-shaped and has the metallic wall on its side, mutual association with a neighboring antenna at the time of multielement arrangement can be intercepted, and an upward sharp beam can be generated, and the high gain can be obtained.