JPH02218203A - Plane antenna for mobile radio communication - Google Patents

Abstract

PURPOSE:To execute energy density reception or polarized wave diversity antenna by coupled plane antennas by setting a notch antenna, which is a magnetic current antenna, in the disk part of an torus antenna which is a current antenna. CONSTITUTION:On the lower surface of the conductor disk in the torus antenna, since a current radially flows from a feeding pin 2 to the end part of the disk, there is no influence to the operation of the torus antenna even in case that a notch 9 is worked parallelly to the direction of the current. Since the electric length of the notch 9 is about 0.25 fold to a wavelength, the notch 9 can be set to a conductor disk 1 of the torus antenna, whose diameter is less than the half wavelength, by using a dielectric substrate 6. In excitation by a stripline, since the two notches are excited by a common mode in symmetrical positions to the center of the disk, the two notches execute operation equivalent with a half-wave slot antenna. A cross slot antenna is used as the notch antenna and it is set in a position spatially same as the torus antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combination antenna suitable for suppressing fading when used as a transmitting/receiving antenna for mobile communication.

FIG. 1(a) is a sectional view of a conventional circular antenna.

(b) shows a plan view, in which 1 is a conductor disk, 2 is a power supply pin, 3 is a short pin, 4 is a grounding plate, and 5 is a coaxial cable connector connected to the power supply pin. It is widely known that this antenna is a planar antenna suitable for mobile communications.

For example, K, Kanct, a, T, Kond
o, i(, Ando and, Goto, ”A
flush-nounted ant, enna
for novel communica Lio
ns,” IEEE, Proc, 8P-37
7-6, 1988゜.

This antenna is a low-height monopole antenna (feeding pin 2) on a ground plate 4, and a conductor disk 1 with a diameter of half a wavelength or less and a plurality of short pins 3 are installed for input impedance matching. It is sensitive to electric field components parallel to 2.

When using this type of antenna for mobile communication9
In order to reduce the effects of fading caused by surrounding obstacles, a spatial diversity method uses antennas with the same polarization at positions spatially shifted by 90 degrees and sequentially selects signals from antennas in good condition. Take advantage of. Spatial diversity has the disadvantage that the installation area becomes large because the two antennas are installed apart from each other.

Another method for reducing the effects of fading is to use a current antenna that is sensitive to the electric field and a magnetic field because there is a 90 degree phase difference between the electric field and magnetic field of the standing wave caused by surrounding obstacles with complex shapes. It is well known that energy density reception can be performed by combining magnetic current antennas that are sensitive to In addition, in such a combination antenna, depending on the combination of the current antenna and the magnetic current antenna, it is also possible to utilize the polarization diversity effect that takes advantage of the fact that vertical polarization and water polarization are independent of each other. As a typical combination antenna, there is a combination of a slot antenna and a monoball antenna, but since both antennas are installed in the same spatial position, the antenna becomes large.

The present invention provides a planar combination antenna by combining a circular plate of a planar annular antenna, which is a current antenna, with a notch antenna, which is a magnetic current antenna.

The implementation of the present invention will be explained in detail below with reference to the drawings.

Fig. 2(a) is a cross-sectional view of a circular antenna combined with a notch antenna, where 6 is a dielectric substrate processed with a notch antenna, 7 is a short pin with a feeder line installed inside to excite the notch antenna, and 8 is a This is a coaxial cable connector for powering the Notchi antenna.

(b) is a plan view of the upper surface of the dielectric substrate 6, 1o.

11 is an example of a strip line made of conductive foil that excites a plurality of notches 9 processed on the bottom surface, (C)
shows a plan view of the bottom surface of the dielectric substrate 6, in which the notch 9
is made by removing a portion of the conductor foil 12 from the dielectric substrate. Note that the notch 9 indicated by a broken line in FIG. 2(b)
．． The short pin 3.7 is installed on the lower surface of the dielectric substrate, and is drawn in the figure to show the positional relationship with the strip line on the upper surface.

The current on the lower surface of the conductor disk 1 of the circular antenna is fed to the feed pin 2
Since the current flows radially toward the end of the disk, machining the notch 9 parallel to the direction of the current will not affect the operation of the circular antenna.The length of the notch 9 is such that its electrical length is equal to the wavelength. Since it is approximately 0.25 times, by using the dielectric substrate 6, the conductor disk 1 of the circular antenna whose diameter is less than half a wavelength
It can be installed in In the strip line excitation shown in the example in Figure 2(b), two notches located symmetrically with respect to the center of the disk are excited in the same phase, so the two notches are equivalent to a half-wavelength slot antenna. take action. As shown in Figure 2(b), there are two sets of notches excited in the same phase.

The notch antenna is a cross slot antenna.

Since the cross slot is located at the same spatial location as the circular antenna, it operates in principle in the same way as a conventional combination antenna that combines a circular current antenna with a magnetic slot antenna. .

When the notch 9 is excited by the strip lines 10 and 11 as shown in FIG. 3, the two notches located symmetrically with respect to the center of the disk are excited in opposite phases, and the notch antenna and the circular antenna are activated. Although they are not in the same spatial position and cannot receive energy density reception, the Notchi antenna is a horizontally polarized antenna with its maximum radiation direction in the horizontal direction, so it performs polarization diversity together with the circular antenna, which is a vertically polarized antenna. becomes possible.

FIG. 4 is a plan view of the lower surface of a dielectric substrate in which notches 13 and 14 of different lengths are installed on the lower surface of the dielectric substrate as an embodiment of a circular antenna combining notch antennas. In this case, while having characteristics similar to those shown in FIG. 2, it is an effective structure for widening the band of the notch antenna.

As explained above, by using a dielectric substrate with a notch antenna installed on the conductor disk of a two-ring antenna, it is possible to perform energy density reception and polarization diversity while integrated with a planar ring antenna. The present invention is effective as an antenna for mobile communication.

[Brief explanation of the drawing]

FIG. 1(a) is a sectional view of a conventional circular antenna. 2(b) is a plan view, and FIG. 2(a) is a sectional view of a circular antenna combined with a notch antenna according to the present invention. (b) is a plan view of the top surface of the dielectric substrate 6, (C) is a plan view of the bottom surface, FIG. 3 is a row of notch excitation methods, and FIG. FIG. Explanation of symbols, 1... Conductor disk, 2... Power supply bottle, 3
...Short pin, 4...Grounding plate, 5, 8...Connector for excitation coaxial cable, 6...Dielectric substrate, 7.
...A short bin with a feeder line for excitation of the Notsuchi antenna installed inside. 9゜3゜14...notsuchi. 10゜1... Strip line for notch excitation. 12... Conductor foil. Figure 2 Figure 1 (a) (b) Figure 3 Figure 4

Claims (1)

[Claims] (1) In the disk part of the circular antenna, which is a current antenna,
A combination antenna characterized by installing a notch antenna, which is a magnetic current antenna.