Transmitting and receiving arrangement for portable appliances.

(42) Date of commencement of the patent: 15.12.1990 (45) Date of issue: 12. 8.1991

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>EP-A 177 362 US 4584585 AT-PS 387117</td><td>SIEMENS AKTIENGESELLSCHAFT ÖSTERREICH</td>

<td>T.TAGA UK TSUNEKAWA, PERFORMANCE ANALYSIS OF A</td><td>A-1211 VIENNA (AT).</td>

<td>BUILT-IN PLANAR INVERTED F ANTENNA FOR 800 MTZ BAND</td><td></td>

<td rowspan="2">PORTABLE RADIO UNITS, IEEE TRANS., SELECTED AREAS IN COMMUN., VOL. SAC-5, NO.5, PP. 921-929, JUNE (1987)</td><td>(72) Inventor:</td>

<td>RASINGER JOSEF DIPL.ING. MÖDLING, LOWER AUSTRIA (AT). SCHOLTZ ARPAD LUDWIG DIPL.ING. DR. VIENNA (AT). BONEK ERNST DIPL.ING. DR. VIENNA (AT).</td>

(54) TRANSMISSION AND / OR RECEIVING DEVICE FOR PORTABLE DEVICES (57) An antenna for the transmitter and receiver of a portable radio (cordless telephone, mobile telephone, pager, telepoint device, etc.) consists essentially of two sheet metal angles (2, 3), which are arranged side by side. One of the two elements is energized by means of a coaxial feed line (4) with high frequency currents. The second sheet metal angle (3) is excited by radiation coupling with the first sheet metal angle (2). In a modified version both sheet metal angles (2,3) are fed, whereby a separate coupling of transmitter and receiver is possible. In the shield (1), the entire high-frequency, low-frequency and digital technology is housed. The shielding (1) also serves as an earth model for the antenna. The sheet metal angles (2, 3) are widened at their free ends in such a way that their spacing there is smaller than at the bending edge of the crest line. This results in hoQQ cross currents, which cause a small impedance.

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AT 393 054

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AT393 054B

The invention relates to a transmitting and / or receiving device for portable devices, consisting of a shield and an associated antenna, which is connected via at least one feed line to a transmitter output or receiver input, wherein the shield of metal and the antenna of two mutually in consists essentially parallel sheet metal angles

Such an arrangement is described in EP-A177 362 as a broadband antenna for portable radios. It consists of two angled resonators of different resonant frequency. Both resonators are fed from a common line via a branch in the manner of an inverted-F antenna. The antenna resonators act independently of each other and form no unit. Therefore, the efficiency is not particularly large. The distance between the parallel legs is constant

In US 4,584,585 an antenna with resonators of wire angles is described. A resonator is fed at the end and forms an inverted-L antenna. The second resonator is radiation coupled. Although this arrangement does not provide good efficiency, the antenna has a fixed impedance and is poorly adaptable. The shape of the active antenna resonator is relatively difficult to bend and, moreover, the base plate also has a step. The bandwidth is relatively low.

From AT-PS 387.117 is known to achieve by each two diagonally opposite metal pads a rotationally symmetric emission and reception characteristics. This arrangement is preferably used in the 900 MHz band of cordless telephones.

In addition, Inverted F antennas from T. Taga and K. Tsunekawa, Performance Analysis of a Built In Planar Inverted F Antenna for 800 MHz Band Portable Radio Units, IEEE Trans., Selected Areas in

Commun., Vol. SAC-5, no. 5, pp. 921-929, June (1987) known An adaptation of such antennas is done by varying the position of the feed point.

Dra invention is the object of improving the transmission and reception power of the antenna.

This is achieved according to claim 1 characterized in that only one bending angle is connected to the feed line that a coaxial feedthrough for the feed line and the feed line via a duplex filter with transmitter output and receiver input is connected and that for varying the input impedance of the antenna, the two sheet metal angle in the range Ends are so widened that dra distance between the plate angles in the end region is smaller than at dra kink edge of the apex line.

Dra second sheet metal angle of the antenna is radiation coupled by the first excited and increases the bandwidth. Due to the small footprint, the arrangement is ideal for Moibilfunk applications

It is easy to manufacture and the entire high-frequency, low-frequency and digital electronics of a portable radio can be housed in the shield. This metal case also serves as an earth model for the antenna. By changing the attachment point of the feed line at the sheet metal angle and in that the two sheet metal angles are widened in the region of their ends to vary the input impedance of the antenna, the range of variation is particularly large. Therefore, in many applications

Adjustment networks between the antenna and transmitter output stage or transmission filter, as well as between antenna and receiver input or receive filter can be saved. The arrangement of the mutually parallel sheet-metal angles can also be described as a slot antenna, wherein the input impedance is variable within wide limits by the width and shape of the slot between the two resonators

The object can also be achieved according to claim 2 at each associated with a feed line sheet metal angle, that a coaxial feedthrough is present for each feed line and the feeders are connected via a respective transmit and receive filter to the transmitter output and receiver input and that for varying the input impedance of the antenna, the two sheet metal angles are widened in the region of their ends, that the distance between the sheet metal angles in the end region is smaller than at the bending edge of the crest line.

To the advantages of the arrangement according to claim 1, a partial decoupling of Sendraausgang and receiver input is achieved by feeding both sheet metal angles and the connection dra feeder lines with transmit and Empfangsfiltra. In addition, a separate optimization of transmitter and receiver adaptation is possible.

For the production of the metal parts in a single operation, it is advantageous that the shield and the sheet metal angle are punched out of a flat sheet and bent into the appropriate shape. But it is also possible that the sheet metal brackets are soldered to the shielding or connected to him well conductive.

The antenna can in principle be located over any side surface of the shielding housing. In experiments, however, it has proved to be advantageous that the plate angles at dra top or top surface of

Shielding are arranged. The sheet metal angles act as lambda / 4 resonators. Therefore, the bandwidth can be further increased by the fact that the length dra both sheet metal angle is unequal.

The invention will be explained in more detail with reference to two exemplary embodiments and drawings. Show it:

1 is a representation of the first embodiment,

Fig. 2 is a plan view of the antenna area and

Fig. 3 is a view of the second embodiment.

In the following embodiments, an antenna described in portable radios, such as

Cordless phones, mobile phones, pagers, telepoint devices etc. can be installed. As an internal antenna for a

-2AT393 054B digital cordless phone is set to the 1.7GHz band.

The construction of the first antenna is shown in FIG. 1 shown. On a shield case (1), the two acting as an antenna sheet metal angle (2, 3) are mounted on the top. The shield case (1) contains all the high-frequency, low-frequency and digital electronics of the cordless telephone handset. Apart from the shielding, the shielding housing (1) also fulfills the function of an earth simulation for the antenna. The top of the shielding (1) has proven to be a convenient place for the attachment of the antenna.

The shielding housing (1) (resp. Parts thereof) and the sheet metal angles (2,3) are punched out of a flat sheet metal and as shown in FIG. 1 shown bent. Connected to the first sheet-metal angle (2) is a feed line (4) which leads out of the interior of the shielding housing (1) via a coaxial feedthrough (5). The first sheet-metal angle (2) is thus the fed element of the antenna, the second sheet-metal angle (3) is radiation-coupled to the first sheet-metal angle (2). The feed line (4) is inside the shielding (1) via a duplex filter with a receiver input or Transmitter output connected.

FIG. 2 shows the attachment point of the feed line (4) at the first sheet metal angle (2). The location of this attachment point and the shape of the facing edges da Blechwinkel (2,3) makes it possible to vary the input impedance of the antenna over a large area. The sheet metal angles (2, 3) are widened towards the ends. This will create a matching network between the antenna and the transmitter output or Saved receiver input. The two sheet metal angles (2, 3) have a different length. Due to the resulting different resonant frequencies of the individual radiators results in a significant increase in bandwidth compared to a comparable, consisting of only a single sheet metal angle antenna.

An alternative possibility of combining transmitter and receiver with the antenna according to the invention is shown in FIG. 3 shown. The first sheet-metal angle (2) is connected to the first feed line (4), the second sheet-metal angle (3) to a second feed line (6). The feed lines (4,6) are led out via bushings (5). The transmitter output is connected via a transmission filter with the first sheet metal angle (2). Accordingly, the receiver input is connected via a reception filter with the second sheet metal angle (3). By this type of execution, a part of the required decoupling of transmitter output and receiver input causes the variation of input impedance by shaping the sheet metal angle (2,3) and variation of the attachment point of the feed lines (4,6) takes place as in the asten embodiment.