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LG Electronics Inc.
1.2 Description of RX Part Circuit
The main function of Diplexer is to prohibit the other band signals from flowing into the one band circuit and vice
versa. RF designer can use common tri-band antenna regardless of frequency band (800, 1575 and 1900 MHz). The
specification of VX9700 Diplexer is described below:
Cellular
PCS
Frequency Range
824 – 894 MHz
1850 – 1990 MHz
Insertion Loss to
Common
0.5 dB Max
(At +25 deg)
0.6 dB Max
(At +25 deg)
Isolation
18 dB Min
(to PCS)
18 dB Min
(to Cellular)
Temperature Range
-30 to +85 deg
1.2.2 Duplexer (DP1, DP2)
The duplexer consists of the RX bandpass filter (BPF) and the TX BPF which has the function of separating TX and
RX signals in the full duplex system for using the common antenna. The TX part BPF is used to suppress noises and
spurious out of the TX frequency band. The RX BPF is used to receive only RX signal coming from the antenna,
which is usually called preselector. It’s main function is to limit the bandwidth of spectrum reaching the LNA and
mixer, attenuate receiver spurious response and suppress local oscillator energy. As a result frequency sensitivity and
selectivity of mobile phone increase. The specification of VX9700 duplexer described below ;
z
PCS duplexer:
54dB (1850~1910MHz)
45dB (1930~1990MHz)
52dB min
(1850~1910MHz)
43dB min (1930~1990MHz)
Attenuation
9.5dB min
9.5dB min
Return Loss
3.0dB max
3.5dB max
Insertion Loss
1930~1990 MHz
1850~1910 MHz
Pass Band
TX to RX (min)
RX
TX
z
Cellular duplexer
56dB (824~849MHz)
47dB (869~894MHz)
54dB min (824~849MHz)
46dB min (869~894MHz)
Attenuation
9dB min
10dB min
Return Loss
2.6dB max
2.1B max
Insertion Loss
869~894 MHz
824~849 MHz
Pass Band
TX to RX (min)
RX
TX
Z3X-BOX.COM
Summary of Contents for VX9700
Page 26: ... 25 132 LG Electronics Inc VX9700 28 Powering Down Restart Z 3 X B O X C O M ...
Page 59: ... 58 132 LG Electronics Inc VX9700 Waveform Waveform F106 pin2 DP2 pin2 Z 3 X B O X C O M ...
Page 154: ...CON104 Z 3 X B O X C O M ...
Page 156: ...Z 3 X B O X C O M ...
Page 159: ...CON809 SW101 SW102 Z 3 X B O X C O M ...
Page 160: ...CON808 Z 3 X B O X C O M ...
Page 162: ...CON809 SW104 Z 3 X B O X C O M ...
Page 163: ...CON808 Z 3 X B O X C O M ...
Page 165: ...SW1 CON2 Z 3 X B O X C O M ...
Page 166: ...CON1 Z 3 X B O X C O M ...
Page 167: ... 15 132 LG Electronics Inc VX9700 Appendix 3 Part List VX9700 Part List Z 3 X B O X C O M ...
Page 168: ... 16 132 LG Electronics Inc VX9700 Appendix 4 Components Layout Z 3 X B O X C O M ...
Page 174: ...Z 3 X B O X C O M ...