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New Signal Chain Resources from Texas Instruments:

Apple Feels Antenna Angst As Form Trumps Function

Date Posted: July 20, 2010 12:00 AM
Author: Lou Frenzel

In trying to plot different antenna patterns, I found it difficult to get reasonable results because just being near the receiver or transmitter antenna disturbed the signal strength and plot. That’s why commercial antenna tests are run in shielded rooms with lots of isolation and remote metering of results. Close proximity to an antenna is bad, so you can imagine what full contact will do to the signal.

The whole antenna situation with cell phones is a massive challenge to designers. There are multiple antennas in all cell phones these days, usually two for quad-band phones, with one for the Bluetooth, one for the Wi-Fi, and another for the GPS. Being jammed in there close together means that all these antennas influence each other, lowering the efficiency of all of them. Just wait until we get Long-Term Evolution (LTE) multiple-input multiple-output (MIMO) in the handset. It’s on the way. It will only be 2x1 MIMO, but even that will cause additional problems.

Antennas are basically nothing more than little bent pieces of metal. But lots of thought, math, testing, and experimentation go into making them work. And you have to have a good antenna. They are the transducer to the “ether” that makes wireless work. Antenna design is truly a black art, despite the good modeling tools available today. Smart phones have really put the pressure on designers dealing with both the antenna and packaging.

The lesson here is to listen closely to your RF/antenna guy. Now you know why that “fields” course that you had in EE school, where you tried to learn Maxwell’s equations, was important.

The iPhone is probably the best smart phone out there. I’ve had two of them. My 3GS is so good I don’t really need an iPhone 4, which is easy to criticize. Apple has done a remarkable design job over all. Any RF product, especially one this complex, is going to have some issues. It’s hard to be perfect in any design. But this antenna problem could have been averted.

I can’t wait to see what Apple does with the iPhone 5 antenna. An aluminum foil hat would be good.

Related Content:

antenna problems | Apple | iPhone 4 | RF antenna design
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  • jtruchsess
    2 years ago
    Jul 22, 2010

    What a load of bollocks. My iPhone 4 has great reception, better than that of my iPhone 3G. I can press directly on the area in question with very little signal loss, and with the bumper case it's a non-issue. All internal-antenna cellphones are affected to some extent by body proximity; Apple is being pilloried by sour-grapes types due to their massive success. The columnists comment "In the Apple tradition, style and physical design are everything" is completely gratuitous and unfair. Yes, Apple has brilliant I.D., but their products are also the most functional in the industry.

  • jtruchsess
    2 years ago
    Jul 22, 2010

    What a load of bollocks. My iPhone 4 has great reception, better than that of my iPhone 3G. I can press directly on the area in question with very little signal loss, and with the bumper case it's a non-issue. All internal-antenna cellphones are affected to some extent by body proximity; Apple is being pilloried by sour-grapes types due to their massive success. The columnists comment "In the Apple tradition, style and physical design are everything" is completely gratuitous and unfair. Yes, Apple has brilliant I.D., but their products are also the most functional in the industry.

  • jtruchsess
    2 years ago
    Jul 22, 2010

    What a load of bollocks. My iPhone 4 has great reception, better than that of my iPhone 3G. I can press directly on the area in question with very little signal loss, and with the bumper case it's a non-issue. All internal-antenna cellphones are affected to some extent by body proximity; Apple is being pilloried by sour-grapes types due to their massive success. The columnists comment "In the Apple tradition, style and physical design are everything" is completely gratuitous and unfair. Yes, Apple has brilliant I.D., but their products are also the most functional in the industry.

  • jtruchsess
    2 years ago
    Jul 22, 2010

    What a load of bollocks. My iPhone 4 has great reception, better than that of my iPhone 3G. I can press directly on the area in question with very little signal loss, and with the bumper case it's a non-issue. All internal-antenna cellphones are affected to some extent by body proximity; Apple is being pilloried by sour-grapes types due to their massive success. The columnists comment "In the Apple tradition, style and physical design are everything" is completely gratuitous and unfair. Yes, Apple has brilliant I.D., but their products are also the most functional in the industry.

  • jtruchsess
    2 years ago
    Jul 22, 2010

    What a load of bollocks. My iPhone 4 has great reception, better than that of my iPhone 3G. I can press directly on the area in question with very little signal loss, and with the bumper case it's a non-issue. All internal-antenna cellphones are affected to some extent by body proximity; Apple is being pilloried by sour-grapes types due to their massive success. The columnists comment "In the Apple tradition, style and physical design are everything" is completely gratuitous and unfair. Yes, Apple has brilliant I.D., but their products are also the most functional in the industry.

  • jta@probesci.com
    2 years ago
    Jul 21, 2010

    Holding the antenna - or holding the box containing the antenna has similar effects - what is not clear from the hype is what is the intended counterpoise of the antenna, if an unbalanced design; or if a balanced design, how is balance maintained in the different operational scenarios - no hands, hands, pockets, etc. The only requirement for radiation (physics 1) is that charge separation be observable in the far field, and that the charge be moving. I suspect its time for Apple to utilize diversity - two or more antennas assigned to the same communication task - if one is nulled, perhaps the others won't be.

  • jta@probesci.com
    2 years ago
    Jul 21, 2010

    Holding the antenna - or holding the box containing the antenna has similar effects - what is not clear from the hype is what is the intended counterpoise of the antenna, if an unbalanced design; or if a balanced design, how is balance maintained in the different operational scenarios - no hands, hands, pockets, etc. The only requirement for radiation (physics 1) is that charge separation be observable in the far field, and that the charge be moving. I suspect its time for Apple to utilize diversity - two or more antennas assigned to the same communication task - if one is nulled, perhaps the others won't be.

  • jta@probesci.com
    2 years ago
    Jul 21, 2010

    Holding the antenna - or holding the box containing the antenna has similar effects - what is not clear from the hype is what is the intended counterpoise of the antenna, if an unbalanced design; or if a balanced design, how is balance maintained in the different operational scenarios - no hands, hands, pockets, etc. The only requirement for radiation (physics 1) is that charge separation be observable in the far field, and that the charge be moving. I suspect its time for Apple to utilize diversity - two or more antennas assigned to the same communication task - if one is nulled, perhaps the others won't be.

  • jta@probesci.com
    2 years ago
    Jul 21, 2010

    Holding the antenna - or holding the box containing the antenna has similar effects - what is not clear from the hype is what is the intended counterpoise of the antenna, if an unbalanced design; or if a balanced design, how is balance maintained in the different operational scenarios - no hands, hands, pockets, etc. The only requirement for radiation (physics 1) is that charge separation be observable in the far field, and that the charge be moving. I suspect its time for Apple to utilize diversity - two or more antennas assigned to the same communication task - if one is nulled, perhaps the others won't be.

  • jta@probesci.com
    2 years ago
    Jul 21, 2010

    Holding the antenna - or holding the box containing the antenna has similar effects - what is not clear from the hype is what is the intended counterpoise of the antenna, if an unbalanced design; or if a balanced design, how is balance maintained in the different operational scenarios - no hands, hands, pockets, etc. The only requirement for radiation (physics 1) is that charge separation be observable in the far field, and that the charge be moving. I suspect its time for Apple to utilize diversity - two or more antennas assigned to the same communication task - if one is nulled, perhaps the others won't be.