background image

4 of 9

 

 

 
 

 

Your source for quality GNSS Networking 

(719) 561-9520

 

Solutions and Design Services, Now!

 

 

5/25/2007

 

       

Document number: 060-FSA-ABQ-AAS-AGZ

 

Rev.  001 

1.  Passive 
2.  Amplified 
3.  Amplified - High Isolation 

Passive Option: 

In the Passive Configuration, the RF input from the antenna bypasses the amplification stages 
and is passed directly to the input Wilkinson Splitter element.  This splitter element divides the 
RF signal evenly, resulting in 3dB (ideally) reduction in signal level at the output of each splitter.  
The signal is then split again, resulting in four outputs, each output being 6dB (ideally) below the 
input signal.  In reality, since the Wilkinson Splitter elements are realized with non-ideal 
components which have a finite Q, the signal reduction for each Wilkinson Splitter element is 
approximately 4dB, resulting in an overall signal reduction through the splitters of approximately 
8dB.  When other losses are accounted for, such as losses in the RF connectors and the “Bias-
T’s”, the overall signal reduction through the passive configuration is approximately 9dB. 

Amplified Option: 

In the Amplified Configuration, the RF signal from the input is applied to two RF gain stages 
prior to the Wilkinson Splitter elements.  The first of these amplification stages provides 
approximately 17dB of gain at a very low noise figure.  The second stage provides additional 
gain so as to ensure that the input port to any output port gain of the splitter is approximately 
21dB. 

Amplified – High Isolation Option: 

In the Amplified – High Isolation Configuration, resistive, 50 Ohm signal attenuators are added 
in the RF output paths to provide additional isolation between each RF port.  This configuration 
may be chosen if it is possible for spurious emissions from one GPS receiver on one port of the 
splitter to cause interference with GPS receivers connected to other output ports.  In the high 
isolation configuration the input port to any output port gain of the splitter is approximately 10dB. 

Termination of Unused Ports: 

Note that in the Passive and Amplified (NON-High Isolation) configuration, all ports must be 
terminated in 50 Ohms in order to ensure proper operation of the Wilkinson Splitter elements.  If 
all ports are not terminated properly, the S14WI input/output SWR and Gain/Loss may not meet 
specifications.   
 
In the Amplified-High Isolation configuration, the 50 Ohm signal attenuators provide substantial 
isolation from open circuits on unterminated output ports.  Consequently, RF outputs may be left 
unterminated without adversely affecting the operation of the S14WI. 
 

Bias-T’s: 

GPS RF signal splitters are unique relative to other generic RF signal splitters in that they 
typically operate in conjunction with an active GPS antenna (that is a GPS antenna that includes 
an integrated Low Noise Amplifier).  Consequently, a GPS RF signal splitter must have 
provisions for managing the DC voltages to the active GPS antenna.  These DC voltages are 
typically applied to the center conductor of the RF coaxial cable which runs from the antenna 

Содержание S14W

Страница 1: ...gnal splitter that can be configured to monitor the GPS antenna current and provide an alarm indication if the antenna is not operating according to spec The S14WI also features an optional antenna DC bias Pick Choose circuit which allows for the active antenna DC input to be applied to any or all of the RF outputs With this option one DC voltage will be chosen to power the antenna while the other...

Страница 2: ...al Block Diagram 3 Operational Description 3 RF Signal Processing System 3 Passive Option 4 Amplified Option 4 Amplified High Isolation Option 4 Termination of Unused Ports 4 Bias T s 4 Antenna DC Bias Select System 5 Active GPS Antenna Monitoring System 5 Surge Arrestor System 6 Connecting the S14WI 6 Performance Specifications 7 Certifications and Approvals 7 Part Number 8 Mechanical 9 ...

Страница 3: ...or System DC Switching Circuit S14WI GPS Signal Splitter RF In DC Out RF Out DC In RF Out DC In RF Out DC In RF Out DC In RF Choke RF Choke RF Choke RF Choke RF Choke DC Blk DC Blk DC Blk DC Blk DC Blk Pwr Supply Active or Passive Active GPS Antenna Monitoring System Figure 1 S14WI Functional Block Diagram Operational Description RF Signal Processing System The RF signal processing system consists...

Страница 4: ...t port gain of the splitter is approximately 21dB Amplified High Isolation Option In the Amplified High Isolation Configuration resistive 50 Ohm signal attenuators are added in the RF output paths to provide additional isolation between each RF port This configuration may be chosen if it is possible for spurious emissions from one GPS receiver on one port of the splitter to cause interference with...

Страница 5: ...uitry will be automatically switched through an RF choke to 200Ohm DC loads The DC voltages may be applied to any or all of the RF outputs however the DC Bias Select circuit will always select the DC voltage on the lowest numbered RF port that has a DC voltage applied to power the S14WI and the application s antenna If the chosen DC input were to be removed or fail the DC Bias Select circuit will ...

Страница 6: ...14WI will periodically every 60 seconds attempt to re connect DC power to the antenna If the antenna failure condition persists the S14WI will re enter the fault condition repeating this cycle until the fault condition is removed Surge Arrestor System The S14WI includes standard Gas Discharge Tubes and Transient Voltage Suppressors on each RF input output Furthermore provisions for high current gr...

Страница 7: ...18 20 mA Ant Thru Current 3 Max source DC current through device 250 mA IOC Range for Open Circuit Threshold 15 75 Antenna Monitor 4 ISC Range for Short Circuit Threshold 5 100 180 mA Surge Protection 8 20us 5 KA Notes 1 Note that for proper RF performance the S14WI must have all RF ports terminated into a 50Ohm coaxial cable system or a 50Ohm load 2 Custom gain option available 3 Maximum current ...

Страница 8: ...k Gain Option A Amplified Axx Custom Gain Blank Passive H Hi Isolation Pick Choose Option PC Add Pick Choose Blank Std Config Antenna Monitor Option AM Add Ant Monitor Blank Std Config Connector Options NM N Male NF N Female SM SMA Male SF SMA Female TM TNC Male TF TNC Female BM BNC Male BF BNC Female SB SMB Jack Female SC SMC Jack Female MX MCX Jack Female For help in creating the part number to ...

Страница 9: ...9 of 9 Your source for quality GNSS Networking 719 561 9520 Solutions and Design Services Now 5 25 2007 Document number 060 FSA ABQ AAS AGZ Rev 001 Mechanical ...

Отзывы: