Antennas forCell-Phones
Mokwon UniversityYong Heui CHO( 조용희 )
First Cell-Phone
Dr. Martin Cooper in Motorola
2
Thin phone: 7.1 [mm]
Motorola RAZR
Trend in Cell-Phone Develop-ment Volume and weight
3Volume [cc]
Weig
ht
[g]
Retractable Antenna
An antenna that you can retract Basically a dipole antenna with top
loading (looks like a hat)
4
$2 when you try to buy
$0.1 when you are a company
←amazon.com
Stubby Antenna
When you open a cap, you can see a helical antenna. (looks like a spring)
You don’t have to retract. → It is convenient for users.
What is stubby anyway?
5←shutterstock.com
Ceramic Helical Antenna
High permittivity → Small antenna size
6
Intenna
Internal antenna: The antenna is in a phone. You can’t see it.
A phone case is strongly related to an intenna.
7
Intenna for 3G Phone
8
A metal pattern is served as an an-tenna.
Triple-Band Antenna
Intenna: internal antenna Resonance: 900, 1600, 1900 [MHz]
9
←empire.de
PIFA
Planar Inverted F Antenna
10
Radiator Signal Input
CoaxialCable
Original From
PIFA
Integrated PIFA
PIFA for Notebook
11
PIFA for Cell-Phone
12
←antenova.com
Current Distributions
13
←empire.de
Antenna for Galaxy Nexus
Can you point where the intenna is now?
14
Impedance Matching for Phone
Chip capacitors and inductors are used to matching the antenna and circuit.
15 ←ham-radio.com
Apple’s Antennagate Death grip: when you touch a certain
part of an iPhone 4, your call may be dropped.
Stainless steel frame as multi-band an-tennas
16
Effect of Our Body to Phone Our body is a ground plane for a
phone. That means our body affects the phone seriously.
17
SAR Measurement
SAR: Specific Absorption Rate Your brain can absorb EM power. The
SAR measures how much power your head does.
18 ←nearfield.org
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