- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373994 > ADL5387ACPZ-WP1 (Analog Devices, Inc.) 50 MHz to 2 GHz Quadrature Demodulator PDF資料下載
參數(shù)資料
| 型號： | ADL5387ACPZ-WP1 |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | 50 MHz to 2 GHz Quadrature Demodulator |
| 中文描述： | 50兆赫至2千兆赫正交解調(diào)器 |
| 文件頁數(shù)： | 18/28頁 |
| 文件大小： | 648K |
| 代理商： | ADL5387ACPZ-WP1 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁當前第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
ADL5387
Rev. 0 | Page 18 of 28
0
0°
0°
SIN
ω
LO
t
COS
ω
LO
t
ω
IF
ω
IF
ω
LSB
ω
USB
–
ω
IF
0
+
ω
IF
0
+
ω
IF
0
+
ω
IF
–
ω
IF
0
+
ω
IF
ω
LO
–90°
+90°
Figure 54. Illustration of the Image Problem
LOW IF IMAGE REJECTION
The image rejection ratio is the ratio of the intermediate
frequency (IF) signal level produced by the desired input
frequency to that produced by the image frequency. The image
rejection ratio is expressed in decibels. Appropriate image
rejection is critical because the image power can be much
higher than that of the desired signal, thereby plaguing the
down conversion process. Figure 54 illustrates the image
problem. If the upper sideband (lower sideband) is the desired
band, a 90° shift to the Q channel (I channel) cancels the image
at the lower sideband (upper sideband).
Figure 55 shows the excellent image rejection capabilities of the
ADL5387 for low IF applications, such as CDMA2000. The
ADL5387 exhibits image rejection greater than 45 dB over the
broad frequency range for an IF = 1.23 MHz.
0
–70
–60
–50
–40
–30
–20
–10
50
250
450
650
RF INPUT FREQUENCY (MHz)
850
1050 1250 1450 1650 1850
I
0
Figure 55. Image Rejection vs.
RF Input Frequency for a CDMA2000 Signal, IF = 1.23 MHz
EXAMPLE BASEBAND INTERFACE
In most direct conversion receiver designs, it is desirable to
select a wanted carrier within a specified band. The desired
channel can be demodulated by tuning the LO to the appropriate
carrier frequency. If the desired RF band contains multiple
carriers of interest, the adjacent carriers would also be down
converted to a lower IF frequency. These adjacent carriers can
be problematic if they are large relative to the wanted carrier as
they can overdrive the baseband signal detection circuitry. As a
result, it is often necessary to insert a filter to provide sufficient
rejection of the adjacent carriers.
It is necessary to consider the overall source and load impedance
presented by the ADL5387 and ADC input to design the filter
network. The differential baseband output impedance of the
ADL5387 is 50 Ω. The ADL5387 is designed to drive a high
impedance ADC input. It may be desirable to terminate the
ADC input down to lower impedance by using a terminating
resistor, such as 500 Ω. The terminating resistor helps to better
define the input impedance at the ADC input. The order and
type of filter network depends on the desired high frequency
rejection required, pass-band ripple, and group delay. Filter
design tables provide outlines for various filter types and orders,
illustrating the normalized inductor and capacitor values for a
1 Hz cutoff frequency and 1 Ω load. After scaling the normalized
prototype element values by the actual desired cut-off frequency
and load impedance, the series reactance elements are halved to
realize the final balanced filter network component values.
相關PDF資料 |
PDF描述 |
|---|---|
| ADL5387-EVALZ1 | 50 MHz to 2 GHz Quadrature Demodulator |
| ADL5390-EVAL | RF/IF Vector Multiplier |
| ADL5390ACPZ-REEL71 | RF/IF Vector Multiplier |
| ADL5390ACPZ-WP1 | RF/IF Vector Multiplier |
| ADL5390 | RF/IF Vector Multiplier |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ADL5387-EVALZ | 功能描述:BOARD EVAL FOR ADL5387 RoHS:是 類別:RF/IF 和 RFID >> RF 評估和開發(fā)套件，板 系列:- 標準包裝:1 系列:- 類型:GPS 接收器 頻率:1575MHz 適用于相關產(chǎn)品:- 已供物品:模塊 其它名稱:SER3796 |
| ADL5387-EVALZ1 | 制造商:AD 制造商全稱:Analog Devices 功能描述:50 MHz to 2 GHz Quadrature Demodulator |
| ADL5390 | 制造商:AD 制造商全稱:Analog Devices 功能描述:400 MHz to 6 GHz Broadband Quadrature Modulator |
| ADL5390ACPZ | 制造商:Analog Devices 功能描述:RF/IF VECTOR MLTPLR 24LFCSP - Tape and Reel 制造商:Analog Devices 功能描述:RF VECTOR MULTIPLIER 2.3GHZ SMD 制造商:Analog Devices 功能描述:RF Vector Multiplier,wideband,ADL5390 |
| ADL5390ACPZ-REEL7 | 功能描述:IC MULTIPLIER VECTOR 24LFCSP RoHS:是 類別:RF/IF 和 RFID >> RF 其它 IC 和模塊 系列:- 標準包裝:100 系列:* |
發(fā)布緊急采購，3分鐘左右您將得到回復。