Apparatus for testing mobile telephones

Abstract

A testing apparatus for testing mobile telephones includes an antenna coupler, a holder and a testing device. The antenna coupler includes a printed circuit board upon one side of which is formed a slot antenna operative in a first frequency range and a dipole antenna operative in a second frequency range. The holder secures a mobile telephone under test in proximity to the antenna coupler. A coupler formed on a second side of the printed circuit board selectively supplies signals received by one of the antenna elements to the testing device. The testing device measures transmission and reception characteristics of the mobile telephone under test, including transmission phase error, frequency error, power and spectrum, and bit error rate.

Description

[0001] This application is a continuation application of co-pending U.S. patent application Ser. No. 09 / 123,731, entitled "Antenna Coupler For Testing Mobile Telephone," filed Jul. 28, 1998. The disclosure of the foregoing patent application is incorporated herein by reference in its entirety.[0002] The invention relates to an antenna coupling device for testing mobile telephones. An antenna coupler is a component of a test structure for servicing and development of mobile telephones.[0003] When testing mobile telephones or mobiles, a plurality of properties or parameters are investigated, which can be loosely categorized as transmission and reception measurements. In transmission measurements for example, among other things a measurement of the phase error, of the frequency error, of the power and of the spectrum is carried out. In reception measurements bit error rates are measured. With respect to the technical background of tests of radio telephones, reference is made to chapter...

AI Technical Summary

Benefits of technology

[0008] Therefore the object underlying the present invention is to avoid the disadvantages of prior art, and in particular to provide a simply constructed antenna coupler which has a low coupling attenuation for the plurality of commercially available radio telephones.

[0013] More advantageously, the upper side of the printed circuit board, particularly its external area, consists of conductive material which is earthed. This provides a certain screening of external fields, without the necessity for a space-consuming box. Furthermore, access to the mobile during testing is ensured in this way.

[0016] According to a preferred embodiment of the invention the diplexer is formed on the underside of the printed circuit board, like the antenna elements in strip transmission line technology, so that an extremely cost-effective and compact structure can be produced.

[0017] In a further advantageous embodiment of the invention the underside of the printed circuit board is surrounded by a screening casing, in order to eliminate interfering influences from the environment.

Problems solved by technology

Consequently measurements are only possible in large screened chambers, which are lined with HF-absorbent materials.

In these a basic disadvantage that in order to use the test item the box must be opened and closed again.

Moreover, such a box is inconvenient, complex and expensive to manufacture.

In the first known type of transmission a disadvantage is that this is not suitable for test items with an antenna integrated in the casing or with an antenna too large for the coupling mechanism.

In the second type, positioning of the test item is imprecise, as the latter cannot be securely fixed.

Finally, in both known types of HF transmission the frequency range of the coupler is restricted to an undesirable degree by the structure, and the coupling attenuation for many test items is so high that the dynamics of the measuring appliance are not sufficient.

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