Specifications

SIM7028 Hardware Design V1.00
www.simcom.com 34 / 48
5.2 LTE Antenna Design Guide
Users should connect antennas to SIM7028 antenna pads through micro-strip line or other types of RF
trace and the trace impedance must be controlled in 50
Ω
. It recommends that the total insertion loss
between the antenna pads and antennas should meet the following requirements:
Table 19: Trace loss
Frequency
Loss
700MHz-960MHz
<0.5dB
1710MHz-2170MHz
<0.9dB
2300MHz-2650MHz
<1.2dB
To facilitate the antenna tuning and certification test, a RF connector and an antenna matching circuit
should be added. The following figure is the recommended circuit.
Figure 17: Antenna matching circuit (MAIN_ANT)
In above figure, the components R1, C1, C2 and R2 are used for antenna matching, the values of
components can only be achieved after the antenna tuning and usually provided by antenna vendor. By
13
<-108.2
14
<-108.2
17
<-108.2
18
<-108.2
19
<-108.2
20
<-108.2
25
<-108.2
26
<-108.2
28
<-108.2
66
<-108.2
70
<-108.2
85
<-108.2