by Jeff Liebermann
Test of what happens when you place your hand over the antenna. Numbers are from the field test mode. Tests were performed in my office unless otherwise mentioned. When possible, the numbers were generated during a test call. An effort was made to run the test in low and weak signal locations as strong signal areas tend to not show as large a change.
The Two Fingers position was two fingers to the sides of the phone. If internal antenna, the Hand position was holding the phone in a manner covering the antenna location. If external, the whole hand covers the projecting antenna and the back of the radio.
| Mfg | Model | System | Two Fingers
(dBm) |
Hand
(dBm) |
Diff
(dB) |
Ant Type | Ant Location | Tester | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Blackberry | 8330 | VZW | -85 | -94 | 9 | Internal | JL | ||
| Blackberry | 8110 | AT&T | -92 | -99 | 7 | Internal | bottom | JL | |
| Blackberry | 8830 | VZW | -81 | -89 | 8 | Internal | JL | ||
| LG | vx8350R | VZW | -85 | -94 | 9 | Internal | JL | ||
| LG | vx5400 | VZW | -90 | -95 | 5 | Internal | top | JL | sick phone |
| LG | vx9100 | VZW | -82 | -90 | 8 | Internal | JL | phone open | |
| LG | vx8000 | VZW | -76 | -82 | 6 | External | telescoping | JL | |
| LG | vx8100 | VZW | -79 | -85 | 6 | External | radome | JL | |
| LG | vx8300 | VZW | -80 | -88 | 8 | External | radome | JL | |
| HTC | myTouch 3G | T-Mobile | -97 | -103 | 6 | Internal | bottom | JN | weak area |
| Motorola | RAZR V3c | VZW | -83 | -95 | 12 | Internal | bottom | JL | |
| Motorola | Droid X | VZW | -82 | -91 | 9 | Internal | bottom | TTV | |
| Motorola | E815 | VZW | -79 | -88 | 9 | External | telescoping | JL |
Compare these results with the -19.8dB and -24.6dB drop in signal levels observed with the iPhone 4. The Real Story on iPhone 4's Antenna
The worst phone I tested dropped the rx signal 16 times (-12dB). The iPhone 4 rx signal dropped 100 times (-20dB) to 288 times (-24.6dB) . That's a 6 to 18 times worse signal drop for the iPhone 4. Little wonder it drops calls. My guess(tm) is that something more than detuning the antenna is happening. I suspect that the receiver front end might be slightly regenerative, where touching the antenna kills the regeneration and the associated sensitivity.
Some of the phones tested.
Notes:
Email and questions:
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