JPH02107005A - Plane antenna - Google Patents

Abstract

PURPOSE:To obtain a beam tilt at high efficiency and at wide angle by respectively providing specific phase differences at serially-fed plural antenna elements, forming serial sub-array, further providing the specific phase differences, and feeding the plural serial sub-arrays in parallel. CONSTITUTION:A serial sub-array 2 is formed by respectively providing the integer times 360/N deg. in phase difference or the integer times 360(P+1/N) deg. in phase difference (P is integer) at antenna elements 11 to 1N. Further, the plural serial sub-arrays 2 are fed in parallel by a feeder line 3 by providing the same phase or the integer times 360 deg. in phase difference. Thus, since the design of phase regulation is limited to the serial sub-arrays 2, the beam tilt type antenna can be relatively easily designed, further the length of the feeder line can be made minimum, and the high antenna efficiency can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flat antenna used for satellite broadcast reception, microwave transmission, and receivers.

[Prior Art] A conventional beam tilt type planar antenna feeds power to a serial feed type antenna element formed by bending a microstrip line into a crank shape with a sequential phase difference.

However, the band is generally narrow, and the entire band of satellite broadcasting (3
00 to 400 MHz>, it was difficult to obtain a good gain.

In order to improve the band and efficiency, an antenna has been proposed in which the antenna element is composed of an annular slot and a batch element, and power is supplied to this using electromagnetic coupling.8 [Problems to be Solved by the Invention] However, since this antenna is fed in parallel, the number of elements is limited to 2'' (n = integer), and in order to design an antenna with a gain of 1 and an appropriate size, the length of the feed line must be slightly longer. As a result, there was a problem in that feed line loss increased and efficiency decreased.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a planar antenna that is capable of highly efficient beam tilt over a wide angle.

[Means for Solving the Problem] As shown in FIG. 1, the present invention provides a series sub-array 2 by providing N antenna elements 11 to 1 (N is an integer of 3 or more) fed in series. As shown in FIG. 2, power is supplied to the plurality of series sub-arrays 2 in parallel through a power supply line 3 with a phase difference of an integer multiple of 360 degrees.

[Function] By optimizing the number of antenna elements 11 that are fed in series, a planar antenna with an optimal gain and an optimal size can be realized, and the phase adjustment design can be applied to the series sub-array part. Because of this limitation, it is possible to improve the accuracy of adjustment, and as a result, the sidelobe pattern can be improved.

Furthermore, since power is fed to a plurality of series sub-arrays 2 at an integer multiple of 360 degrees or in the same phase, the length of the feed line 3 can be minimized and the antenna efficiency does not deteriorate.

[Example] The present invention will be explained below with reference to Examples.

In this example, a commercially available polyester film (5
A series sub-array 2 in which three antenna elements 1 are connected in series with a spacing of 16 mm, each having a phase difference of 120 degrees, using a printed board formed by laminating copper foil (18 um thick) on a substrate (0 um thick) using an existing method. Each feeder line 3 is in phase or 3
A pattern of 128 power supply lines connected at the shortest distance with a phase difference of 60 degrees is formed on the printed board by etching to form a power supply circuit. FIG. 3 shows a part of this power supply circuit, and the power supply lines 3 within the broken line frame in FIG. 3 correspond to the series subarrays 2.

The antenna element (radiating element) 1 is formed in a rectangular annular slot A of, for example, 15 mm x 1311 M as shown in FIG. A radiation circuit is formed by forming 3×128 patch elements B along with the power supply line 3 by etching on a printed board equivalent to the printed board described above.

Then, the printed board on which the power supply circuit was formed was laminated on a commercially available AI board (0.5 mm thick) with a spacer made of a 21-thick foamed plastic sheet interposed therebetween, and the printed board on which the power supply circuit was formed was further laminated with a spacer similar to the above spacer interposed therebetween. The desired planar antenna is completed by laminating printed boards with radiation circuits formed on them. At this time, power is fed between each antenna element 1 and the feed line 3 by an electromagnetic coupling, thereby widening the usable band.

When the planar antenna of this example manufactured in this manner was evaluated, a beam tilt type planar antenna of about 31 degrees was obtained, and its efficiency was also over 50%.

Furthermore, it was confirmed that a sidelobe level of 15 dB or more could be achieved, resulting in extremely good results.

In place of the antenna element (radiating element) 1 of the above embodiment, as shown in FIG. Similar effects were obtained even when a circular antenna element (radiating element) 1 consisting of a patch element B° was used.

Furthermore, even when the spacer was partially punched out in a lattice shape or a honeycomb shape, the same effect as in the above embodiment was obtained.

12 In this embodiment, instead of the feeding circuit of Embodiment 1, a series sub-array 2 is formed in which five series antenna elements 1 are each provided with a phase difference of 144 degrees, for example, 128 series sub-arrays 2 are formed. A power supply circuit is used in which the power supply line 3 is connected in the same phase or with a phase difference of an integral multiple of 360 degrees so that the length of the power supply line 3 is minimized. Of course, the arrangement of the radiation circuit is changed in accordance with the feeding circuit.

In this example, an antenna with a beam tilt of approximately 40 degrees was confirmed. And its efficiency is 40% or more at 300M
This was achieved with Hz.

In this example, instead of the printed board used in Example 1 above, a printed board made of 25us thick polyester laminated with 2On thick AI foil was used, and after etching the power supply circuit and the radiation circuit, the 251JIl was used. A thick polyester film and a printed board on which a feeding circuit and a radiation circuit are formed are laminated in a sandwich shape, ensuring antenna performance equivalent to that of Example 1, and weather resistance reliability of approximately 3.
I was able to improve it twice as much.

[Effects of the Invention] The present invention provides N antenna elements (N is an integer of 3 or more) fed in series with a phase difference of an integral multiple of degrees or a phase difference of an integral multiple of 360 (P + 1/N) degrees ( P is an integer) to form a series subarray, and power is fed in parallel to the plurality of series subarrays with the same phase or a phase difference of an integer multiple of 360 degrees, so the phase adjustment design is a part of the series subarray. This makes it relatively easy to design a beam tilt antenna, and the length of the feed line can be minimized, resulting in high antenna efficiency. By optimizing the number of antennas, an antenna of any size and gain can be realized.

[Brief explanation of the drawing]

FIG. 1 is a conceptual explanatory diagram of the series subarray of the present invention, FIG. 2 is a conceptual diagram of the present invention, FIG. 3 is a partially omitted configuration diagram of the radiation circuit of Embodiment 1 of the present invention, and FIG. 4 is the same as above. Fig. 5 is a block diagram of another example of the antenna element used in the above. 1 is an antenna element, 2 is a series subarray, 3 is a feed line,
A is an annular slot and B is a batch element. Agent Patent Attorney Ishi 1) Long Figure 7 1 ■: Antenna element 2 is a series subarray / l: Antenna element 2 is a series subarray

Claims (1)

[Claims] (1) A phase difference of an integer multiple of 360/N degrees or a phase difference of an integer multiple of 360 (P+1/N) degrees (P is an integer )
to form serial subarrays with in-phase or 360
A planar antenna characterized in that power is fed in parallel to the plurality of series sub-arrays with a phase difference of an integral multiple of degrees.