GB2242316A

GB2242316A - Patch type microstrip antenna for receiving vertically and/or horizontally polarized waves

Info

Publication number: GB2242316A
Application number: GB9014524A
Authority: GB
Inventors: Yoshiji Koiso
Original assignee: Funai Electric Engineering Co Ltd
Current assignee: Funai Electric Engineering Co Ltd
Priority date: 1990-03-22
Filing date: 1990-06-29
Publication date: 1991-09-25
Anticipated expiration: 2010-06-29
Also published as: GB2242316B; JPH03120113U; GB9014524D0

Abstract

A patch type microstrip antenna in which vertically and/or horizontally polarized waves can be received, wherein a patch antenna is used instead of a feed horn. The antenna has a plurality of radiation elements (5a - 5d, Fig 2a) arranged on a base plate (4), and feeders (6, 7) of which one end is connected to the predetermined positions of each radiation element. Two output terminals (8, 9) are provided on the other end of the feeders so that vertically and horizontally polarized waves are outputted separately. Accordingly, changing over the received waves can be executed easier. The patch antenna can be mounted on the focal point (F, Fig 3) of a concave reflecting mirror antenna (20). <IMAGE>

Description

PATCH TYPE MICROSTRIP ANTENNA FOR RECEIVING VERTICALLY AND/OR HORIZONTALLY POLARIZED WAVES The present invention relates to a patch type microstrip antenna for receiving vertically ánd/or horizontally polarized waves in broadcasting via satellite. In conventional antennas for receiving satellite broadcast signal, there are a parabolic reflector antenna which makes use of the reflection of an electromagnetic wave and a plane antenna which receives the electromagnetic wave directly.

As shown in Fig. 3, the parabolic reflector antenna is so designed as to reflect the received wave with a reflection Xirror 20 and converge the wave on the focal point F. On the focal point F, a primary radiator 21 (hereinafter referred to as a feed horn) as shown in Fig. 4 is provided as a wave receiving device for receiving the converged electromagnetic wave, and the radiator 21 is faced to the forwarding direction of the electromagnetic wave.

The feed horn 21 has a polar rotor 22 for receiving either vertically or horizontally polarized wave selectably, and a converter 23 for converting frequency of a satellite broadcast signal. The polar rotor 22 has a probe antenna, and is so designed as to rotate by angle of 90 degrees the probe antenna (not shown) for linking with an electric field, and thereby to be able to receive the vertically or horizontally polarized wave selectably. The converter 23 changes the frequencies of the vertically and the horizontally polarized waves in satellite broadcast signal, then outputs signals to a satellite broadcast tuner.

In the plane antenna, the electromagnetic wave from the broadcasting satellite is received directly by a receiving element (radiation element). As a plane antenna, a patch microstrip antenna, a ring slot antenna and the like are conventionally known.

However, the performance of the conventional parabolic reflector antenna is determined by the feed horn 21 and the reflecting mirror 20, and the feed horn 21 is bulky. Then it is difficult to make the whole configuration of the antenna thin and simple. Also it is inconvenient to be necessary to rotate the probe antenna provided in the polar rotor 22 in order to change over the vertically and horizontally polarized waves as abovementioned. And in the case of the plane antenna, if the attitude of the plane antenna is fixed, only either of the vertically or horizontally polarized wave can be received.

The present invention is to solve the above-described problems associated with known antennas. An object of the present invention is to provide a patch type microstrip antenna for receiving vertically and/or horizontally polarized waves, wherein a patch antenna is used instead of a feed horn. Accordingly, the structure of the antenna becomes simple, and also the configuration becomes small. furt > .er, two output terminals for outputting vertically and horizontally polarized waves are provided so that an operation for changing over the received waves can be executed easily.

In order to achieve the abovementioned object, a patch type microstrip antenna according to the present invention comprises a plurality of radiation elements arranged on a base plate of an antenna, wherein the predetermined positions on every each edge of the radiation elements with which each axis of the perpendicular coordinate axis intersects are connected respectively by feeders, and the horizontally and vertically polarized waves can be led to the output terminals respectively.

According to the abovementioned structure, a satellite broadcast wave from a broadcasting satellite is received by a plurality of radiation elements on a base plate. Then, the received waves are separated into two components of vertically and horizontally polarized waves, which are led to the output terminals by the feeder respectively.

The separated electromagnetic waves are outputted from the output terminals to a satellite broadcast signal converter respectively1 in which either of the wave is selected and converted the frequency, then transmitted to the satellite broadcast tuner.

The present invention will be further explained hereinafter with reference to the following description of an exemplary embodiment and the accompanying drawings, in which: Fig. 1 is an outside view of patch type microstrip antenna for receiving vertically and/or horizontally polarized waves according to an embodiment of the present invention; Fig. 2 (a) is a top view of a patch section of the antenna; Fig. 2 (b) is a view showing positions where the edge of one radiation element intersects each axis of the perpendicular coordinate axis; Fig. 3 is a view showing that an electromagnetic wave is reflected by a reflecting mirror and converged on the focal point F; and Fig. 4 is a block diagram showing a feed horn (primary radiator) in a conventional parabolic reflector antenna.

An embodiment of the present invention will now be described with reference to the drawings. A patch type microstrip antenna according to the present invention may be used in combination with a reflecting mirror of a parabolic reflector antenna.

Fig. 1 shows an electromagnetic wave receiving device 1 for receiving an electromagnetic wave reflected by a reflecting mirror (indicated as numeral 20 in Fig. 3) of a parabolic reflector antenna. The wave receiving device 1 comprises a patch antenna 2 which receives electromagnetic waves from a broadcasting satellite and outputs vertically and horizontally polarized waves therefrom, and a satellite broadcast signal converter 3 in which the patch antenna 2 is attached on the surface thereof. The satellite broadcast signal converter 3 selects either of vertically or horizontally polarized wave in accordance with the receiving channel, then converts frequency thereof and outputs the signal in a connector terminal 3a.

Fig. 2 (a) shows the structure of the patch antenna 2. The patch antenna 2 is provided on a base plate 4 consisting of an insulating material, and has four receiving elements (hereinafter referred to as radiation elements) 5a, 5b, Sc and 5d (generically numbered 5) for receiving the electromagnetic waves, feeders (strip line) 6,7 for leading horizontally and vertically polarized waves and output terminals 8,9 for outputting horizontally and vertically polarized waves.

The radiation elements 5 are formed by printing and the like on the base plate 4. Each radiation element 5a,5b,5c and 5d is arranged likely to locate at each top point of a square respectively.

The feeder (strip line) 6 is provided so as to connect each position marked A, whereon one of the vertical edge of each radiation element 5 intersects with a horizontal axis (x) of the perpendicular coordinate axis, to a horizontally polarized wave output terminal 8. The feeder (strip line) 7 is provided' so as to connect each position marked B, whereon one of the horizontal edge of each radiation element 5 intersects with a vertical axis (y) of the perpendicular coordinate axis, to a vertically polarized wave output terminal 9. In other words, each of one end of the feeder 6,7 is connected to each radiation element respectively, and each of the other end is combined together respectively so as to form a horizontally polarized wave output and a vertically polarized wave output.

Each output terminal 8,9 is connected to the satellite broadcast signal converter 3. The base plate 4 of the patch antenna 2 is so attached on the outer surface of the satellite broadcast signal converter 3 that the surface of the radiation elements 5 faces to the outside. There is provided a grounding electrode plainly on the rear side face of the base plate 4.

Fig. 2 (b) is a view showing positions A and B described above. The patch antenna 2 of the wave receiving device 1 is attached on the focal point F of the parabolic reflector antenna in facing to a reflecting mirror 20 as shown in Fig.3.

Now, the procedure for leading the received electromagnetic wave to the satellite broadcast signal converter 3 will be described.

A satellite broadcast wave from a broadcasting satellite is converged on the focal point F through the course shown as the solid line in Fig. 3. On the focal point F, the patch antenna 2 of the wave receiving device 1 is provided to receive the electromagnetic wave, wherein the wave is received by each radiation element 5 formed on the patch antenna 2. In each of the radiation element, when feeding is done from the position A on the x axis, the electric field between the position B on the y axis and the ground becomes zone. Therefore, the point B is not influenced by feeding from the position A.Accordingly, the horizontally polarized wave is transmitted from the horizontally polarized wave output terminal 8 to the satellite broadcast signal converter 3 through the feeder 6, and the vertically polarized wave is transmitted from the vertically polarized wave output terminal 9 to the satellite broadcast signal converter 3 through the feeder 7.

As abovementioned, the electromagnetic wave reflected by the reflecting mirror 20 of the parabolic reflector antenna is received at the patch antenna 2 of the wave receiving device 1, then transmitted to the satellite broadcast tuner through the satellite broadcast signal converter 3. Being selected a program by operating the satellite broadcast tuner, it can be seen on a television display.

The patch antenna 2 according to the present invention can be used for a wave receiving device as a plane antenna separately used.

As described above, according to the present invention, the predetermined positions where each edge of a plurality of radiation elements provided on the base plate of the antenna and each axis of the perpendicular coordinate axis intersect are connected respectively by the feeders, and the horizontally and vertically polarized waves can be led to the output terminals respectively. As a result, the horizontally or vertically polarized wave can be received selectably with ease and suitableness. Therefore, it can solve the problem of the conventional antenna that when it is set as a plane antenna, only either of the vertically or horizontally polarized wave can be received. Further, it can also solve the problem of the conventional parabolic reflector antenna that the received wave cannot be selected without rotating a probe antenna in a polar rotor.

Moreover, the configuration of the antenna becomes thin and the structure becomes simple, and at the same time, equivalent directivity and gain to the conventional field horn can be obtained.

Claims

1. Patch type microstrip antenna for receiving vertically and/or horizontally polarized waves comprising; a plurality of radiation elements arranged on a base plate of an antenna for receiving said waves, feeder for leading a vertically polarized wave, each of which one end is connected to each radiation element respectively on a predetermined position where a horizontal edge of the radiation element intersects with a vertical axis of the perpendicular coordinate axis , and each of the other end is combined together, feeder for leading a horizontally polarized wave, each of which one end is connected to each radiation element respectively on a predetermined position where a vertical edge of the radiation element intersects with a horizontal axis of the perpendicular coordinate axis, and each of the other end is combined together, an output terminal provided on the combined end of said vertically polarized wave feeder for outputting a vertically polarized wave, and an output terminal provided on the combined end of said horizontally polarized wave feeder for outputting a horizontally polarized wave.

2. Patch type microstrip antenna as claimed in claim 1, wherein the patch type antenna is used in combination of a reflecting mirror of a parabolic reflector antenna and arranged on a focal point of the parabolic reflector antenna.

3. An apparatus constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the Figures 1 and 2 (b) of the accompanying drawings.

4. An antenna system capable of receiving both vertically and horizontally polarised waves comprising a concave reflector antenna arranged for reflecting waves incident thereon to a focal region and a feeder antenna arranged at said focal region for receiving waves reflected thereto from said reflector antenna, said feeder antenna comprising a receiving element in the form of a conductive patch responsive both to horizontally and to vertically polarised waves, a first feeder conductor connected to said patch at a first position at which signals created by horizontally polarised waves may be fed from the patch, and a second feeder conductor connected to said patch at a second position at which signals created by vertically polarised waves may be fed from said patch.

5. An antenna system according to claim 4, wherein said feeder antenna comprises a plurality of said conductive patches and of said first and second feeder conductors, said feeder antenna further comprising a first output connected to each of said first feeder conductors and a second output connected to each of said second feeder conductors.

6. An antenna system according to claim 4 or 5, wherein the or each said patch is rectangular or square.