1. (Global System for Mobile communication)
GSM
(Global System for Mobile communication)

2. GSM Frequency Allocation Table
Band Tx Fc Rx BW
GSM 850
824 ~ 849
836.5
869 ~ 894
881.5
25M
GSM 900
Phase 1
890 ~ 915
902.5
935 ~ 960
947.5
Phase 2(EGSM)
880 ~ 915
897.5
925 ~ 960
942.5
35M
DCS 1800
1710 ~ 1785
1747.5
1805 ~ 1880
1842.5
75M
PCS 1900
1850 ~ 1910
1880
1930 ~ 1990
1960
60M
Dual Band
Triple Band
GSM 900
Tx Rx
DCS 1800
Tx Rx
PCS 1900
Tx Rx
MHz

3. GSM Frequency & Frame structure
MHz
124 channels (200 kHz)
downlink
- BW = 25MHz
- Channel space =200KHz
- Channel No = /20000
= 125 Chnnel
- 8 user share 200KHz
- 200 KHz time period = 4.615ms
ms/8user = 577us
- One user occupies CH for 577us
frequency
MHz
124 channels (200 kHz)
uplink
higher GSM frame structures
time
GSM TDMA frame 1 2 3 4 5 6 7 8
4.615 ms
GSM time-slot (normal burst)
guard
space
guard
space
tail
user data S
Training S
user data
tail
3 bits
57 bits 1
26 bits 1
57 bits 3
546.5 µs
577 µs

4. Advanced Material On TECHnology
ASM & FEM
Advanced Material On TECHnology

5. Miniaturization demand of mobile phone is increasing
What is ASM, FEM?
Miniaturization demand of mobile phone is increasing
Handset components ( Passive : Active = 75% : 25% )
To achieve multifuncion and miniaturizaion , handset need smaller module
Switching and filtering could be easily integrated into one module
ASM (Antenna Switch Module)
Because using TDMA to share time for 577us in 200KHz , GSM phone can use switch module.
A few ceramic duplexer and filter can implement same function of ASM, but using ASM is cheaper than duplexer.
ASM enable small sized multifunctional mobile phone
ASM function
- Diplexer function ( Divide the frequency band of GSM900 and DCS1800)
- Duplexer function ( Divide Tx, Rx signal for each GSM900 and DCS1800)
- Tx LPF function (Tx LPF for each GSM900 and DCS1800)
FEM (Front End Module)
> In addition to ASM, FEM includes Rx SAW filter
> With integrating SAW to ASM, it is easier to make phone small size.
> SAW filter function : In-band Rx signal can pass through with SAW filter

6. Mobile handset block diagram
GSM 900 Rx
DCS1800 Rx
GSM 900 Tx
DCS1800 Tx

7. Amotech ASM, FEM feature
Very low Insertion Loss in TX, RX.
- We guarantee TX I/L under -0.8dB of ASM.
- We have good Output of Power through ASM from PAM.
Very Stable and Flat Ripple in TX Bandwidth.
- We keep Power Level stable among Low, Middle, High level.
Good Attenuation in 2f0,3f0.
- We give better Harmonics in 2f0, and 3f0.
Better Stabilization on ESD Testing.
- We produce FEM embedded with Varistor.
Good TX and RX Isolation.
Perfect Engineering Support and Competitive Pricing

8. Amotech product line up
AMOTECH’S LTCC modules of ASM & FEM, ranging from 4532 dual band to 6750 triple band which have stable electrical characters, can keep mobile phone function good in TX,RX .
6750 : AMFT
5440 : AMFT
6750 : AMFD
5440 : AMAT
5440 : AMAD
4532 : AMAD
Dual Band ASM
Dual Band FEM
Triple Band FEM
Triple Band ASM

9. Market trend > Current main size (5440, 4532 for Dual ASM)
6750 →5440 → 4532 → 3216
Main size
for current market
(5440, 4532)
6.7mm
5.0mm
4.0mm
3.2mm
5.4mm
1.6mm
4.5mm
3.2mm
> Current main size (5440, 4532 for Dual ASM)
> Big trends are FEM will replace ASM.
> ASM + SAW is more expensive than FEM
> But, many engineers still like to use ASM, due to incredibility of FEM.
> SAMSUNG use ASM, 50% , and FEM, 50% for their GSM phone.
> Market situation is different depending on each country and mobile manufacturer.

10. DIPLEXER, DIODE, LPF, SAW, VARISTOR
Components of ASM,FEM
DIPLEXER, DIODE, LPF, SAW, VARISTOR
Dual ASM
Dual FEM
Dual FEM with varisotr
Diplexer 1EA
Diode Switch 2EA
LPF 2EA
Diplexer 1EA
Diode Switch 2EA
LPF 2EA
SAW Filter 2EA
Diplexer 1EA
Diode Switch 2EA
LPF 2EA
SAW Filter 2EA
Varistor 1EA~4EA

11. Block Diagram
Dual band ASM
Dual band FEM
Triple band ASM

12. Ex) Dual band ASM Dimension Pin Layout Terminal No. Terminal Name ①
DCS-Rx ②
VC2 ③
DCS-Tx ④
GND ⑤
EGSM-Tx ⑥ ⑦
ANT ⑧ ⑨
EGSM-Rx ⑩
VC1 ⑪ ⑫

13. Ex) Dual band ASM Control Voltage & Current Test Circuit
MIN
TYP
MAX
2.5
2.7
2.9
Mode
VC1
VC2
Current
ANT → EGSM Rx 0V
< 0.1mA
ANT → DCS Rx
EGSM Tx → ANT
2.7 V
10mA
DCS Tx → ANT
Test Circuit

14. Ex) Dual band ASM Electrical specification GSM 900 DCS1800 mode
Parameter
unit
Min
Max Rx
Frequency Range
MHz
925
960
1805
1880
Insertion Loss
at 25℃ dB
0.85 max
1.00 max
at -30~+85℃
1.10 max
Return Loss
15.0 min Tx
880
915
1710
1785
1.30 max.
1.40 max.
Attenuation
2 X fgt
30.0 min
25.0 min
3 X fgt
Isolation
Tx - Rx
20.0 min.
12.0 min
Current Consumption mA
10.0 max.
Permissible input Power
dBm
+35.0 peak
+33.0 peak
Electrical specification

15. Ex) Dual band ASM
S11,S21 graph
GSM Rx
GSM Tx
DCS Rx
DCS Tx

16. Ex) Dual band ASM
Smith chart
GSM Tx
GSM Rx
DCS Tx
DCS Rx