Most third-generation (3G) mobile phone systems are based on CDMA technology, which puts new demands on test environments compared to TDMA systems. Measurements in CDMA systems require 80 dB of shielding because the mobile will attempt to lock onto the strongest base station. Without the RF Shield, the mobile would ignore the test signal and try to lock onto a local network.

In a CDMA system, for example WCDMA (UMTS), one of the worst-case shielding requirements arises when one mobile is in a max power test, and the other mobile is in a minimum power test. In this situation, one mobile is transmitting at +33 dBm, while the other is attempting to transmit -50 dBm. To properly isolate the two mobiles from each other, test stations will require at least 80 dB of isolation between them.

In addition, a receiver test close to the sensitivity level of the mobile receiver could severely affect test results. Testing the receiver via the antenna requires the phone to be isolated from a real base station by 80 dB. Without shielding, the mobile could receive the signal from a close-by network transmitter at –25 dBm while trying to detect a test signal at –104 dBm.

For service centres and manufacturing operations, the Willtek 4921 is the optimum solution because of its reliability, longevity and support in measurement precision. This has been verified through a series of endurance tests, and in line with military standard VG 95737, Electromagnetic Compatibility of Equipment – Part 15 Test Methods for Coupling and Shielding.

4916 Antenna Coupler

Next-Generation Antenna Coupler for All Mobile Phones

The Willtek 4916 Antenna Coupler is an essential extension to all mobile phone testers. The coupler supports extended frequency ranges for 3G mobile phone testing in addition to WLAN and Bluetooth. Using RF coupling, the 4916 allows non-wired connection mobile phone testing. The mobile phone antenna is also verified when the 4916 Antenna Coupler is used, resulting in a complete functional check of all mobile phone parts.

Lower Failure Rates and Shorter Repair Times
The new mechanical and RF design provides more accurate and sustainable measurements, resulting in less failures and shorter repair times. The 4916 is the first antenna coupler with a continuous bandwidth covering the important frequency bands for cellular wireless. Unique to other antenna couplers, the 4916 also provides a moving shuttle (U.S. patent pending) that allows you to move the mobile phone to the best out of five possible coupling positions. This means the coupling value is no longer impacted by the mobile’s size or its antenna position.

The 4916 can be delivered with four easily exchangeable shuttles; additional shuttles are available:

The standard shuttle allows you to move the mobile phone to the best out of five possible coupling positions in the vertical direction. This means the coupling value is no longer impacted by the mobile’s size or its antenna position.
The XY Shuttle further improves the measurement accuracy and repeatability by allowing to adjust the mobile’s position over the coupler in two dimensions.
The PDA Shuttle includes a universal cradle for PDAs or wider phones.
With the 1210 PCMCIA Data Card Testing Option, even wireless devices for notebook PCs can be tested.