- 您现在的位置：买卖IC网 > PDF目录97935 > EVB3020A GSM Multiband RF Transceiver PDF资料下载
参数资料
| 型号： | EVB3020A |
| 英文描述： | GSM Multiband RF Transceiver |
| 中文描述： | 手机多频段射频收发器 |
| 文件页数： | 4/44页 |
| 文件大小： | 409K |
| 代理商： | EVB3020A |
第1页第2页第3页当前第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页
Advance Data Sheet
W3020 GSM Multiband RF Transceiver
December 1999
12
Lucent Technologies Inc.
IF/Baseband Amplifier
The IF amplifier is a balanced-input/balanced-output
type and is connected to a balanced SAW filter. It
consists of three gain stages: an IF amplifier and two
sections of baseband amplifiers. The gain can be
changed in steps of 32, 16, 8, and 4 dB. The base-
band also contains a level-shifter stage to drive an
A/D converter directly. The level-shifter stage has 21
dB of gain that can be switched off. The specifications
below are for the two modes of operation.
The gain of the IF section is programmed via the
three-wire serial bus.
The IF amplifier contains the 32 dB amplifier stage
and has a gain of either 0 or 32 dB. The IF amplifier is
followed by a quadrature mixer with a fixed gain of
4 dB. The first baseband amplifier (G3, G2, G6) after
the low-pass filter and demodulator has gains
selectable between 0, 4, 8, 12, 16, 20, 24, and 28 dB.
Using the other gain steps, the IF and baseband gain
can be varied by 64 dB in 4 dB steps. The second
baseband amplifier (G5, G1) has gains selectable
between 0, 4, 21, and 25 dB. The 21 dB gain step in
the second baseband amplifier section is not tested
and should therefore not be used. Figure 3 is a
diagram of the gain steps.
6
16/0
8/0
4/0
21/0
G4
G3
G2
G6*
G1
G5*
LPF1
LPF2
*Not tested.
4/0
32/0
Figure 3. IF Amplifier Gain Steps
The baseband amplifier section contains dc correction
circuitry that minimizes dc offsets at the I/Q outputs.
The low-pass filters in the baseband contain a self-
calibrating circuit for tuning of filter cut-off frequency.
The selectable gain settings are programmed via the
TR register as described in the Programming
Information section. Filter tuning and dc calibration
are also explained in that section.
To achieve the specified absolute gain accuracy, the
total gain should be calibrated at room temperature.
This would normally be part of the overall phone
calibration. Absolute gain accuracy measures the gain
change over a specified temperature range relative to
the room temperature measurement. In the GSM
system, this specification is dependent on all the RX
functional blocks and not solely on the IF strip. The
relative gain accuracy is a measure of the gain stage
accuracy over a 20 dB range (see Figure 4). Relative
gain accuracy is determined after calibration of the
32 dB amplifier.
Note:
=
Y
,
X
relative gain accuracy.
Figure 4. Actual Gain vs. Requested Gain
The input impedance of the IF strip will vary slightly
when the 32 dB amplifier is switched between the ON
and OFF states. We recommend that the IF strip be
matched with the 32 dB amplifier in the ON state to
provide the best match to the SAW filter when the
input level is at a minimum. The input matching
network can match the IF input directly to the SAW
filter or to 50
.
A matching network to 50
was chosen for the
evaluation board to allow for convenient laboratory
measurements. To keep the input impedance low and
minimize impedance variation between gain settings
of the IF stage, a resistor is shunt-connected between
the input terminals. The input network can then be
matched to the desired input impedance. (The
specified gain includes a resistor value of 500
.) For
testing purposes, the input has been matched to 50
,
and the gains of the IF/baseband amplifier are all
referred to a 50
matched input impedance. The I/Q
outputs are terminated in high-impedance loads. The
gains are voltage gains and include the voltage gain in
the impedance transformation of the input matching
network. The network is illustrated in Figure 5.
32/0
R1
500
1:1
INPUT
IMPEDANCE
50
IFIN PIN 34
Note: Balun is shown for testing purposes only.
W3020 G4 bit
IFIP PIN 35
Figure 5. IF Strip Balanced Input Matching
Network
ACTUAL = REQUESTED
REQUESTED GAIN (dB)
ACTUAL
GAIN (dB)
X
Y
ACTUAL GAIN
20 dB
相关PDF资料 |
PDF描述 |
|---|---|
| EVB3020A-IFBD | GSM Multiband RF Transceiver |
| EVB3030A | W3030 3 V Dual-Mode IF Cellular Receiver |
| EVB72001 | EVB72001 EValuation board for TH72001 |
| EVB72002 | EVB72002 EValuation Board for TH72002 |
| EVB72011 | EVB72011 EValuation Board for TH72011 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| EVB3020A-IFBD | 制造商:AGERE 制造商全称:AGERE 功能描述:GSM Multiband RF Transceiver |
| EVB3030A | 制造商:AGERE 制造商全称:AGERE 功能描述:W3030 3 V Dual-Mode IF Cellular Receiver |
| EVB-3250 | 功能描述:界面开发工具 Evaluation Board RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V |
| EVB32-M8L | 制造商:Leviton Manufacturing Co 功能描述: |
| EVB-3300 | 功能描述:界面开发工具 USB3300 Hi-Speed USB Phy Evaluation Board RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V |
发布紧急采购，3分钟左右您将得到回复。