Spruce Creek Microwave
Small Cell Multicoupler Specs
Pass band loss (Port 1-Port 2) 500MHz to 1350MHz ------ .5db MAX .25db typical
Pass band loss (Port 1-Port 2) 1700MHz to 3000MHz ------ .5db MAX .25db typical
Pass band return loss (Port 1-Port 2) 500MHz to 1350MHz------ 14 db MIN
Pass band return loss (Port 1-Port 2) 1700MHz to 3000MHz------ 14 db MIN
Stop band loss (Port 1-Port 2) 1575.42 MHz +/- 5MHz ----- 70 db Min.
Pass band loss (Port 1 to Port 3) 1575.42 MHz +/-10 MHZ .7 DB MAX .5DB Typical
Stop band loss (Port 1 to Port 3) 500MHz to 1350 MHz 70DBC min 80DBC typical
Stop band loss (Port 1 to Port 3) 1700MHz to 3000MHz 70DBC min 80DBC typical
Pass band return loss (Port 1-Port 3) Input/Output 14 DB Max. ( 1575.42 MHz +/-10).
DC block (Port 1 to Port 2) 40vdc > 10MEG
DC block (Port 3 to Port 1) 40vdc > 10MEG
MAX DC Current 200ma.
RF-DC Isolation >80DB Frequency Dependent
Temperature Operation -20 to 70 degrees C
Temperature Storage -40 to 85 degrees C
PIM min -153dbc
At the common port Broad band RF+GPS+DC will be coupled to the GPS filter Port # 3. Port # 2 is DC blocked and
contains RF in two bands – GPS that is notched to -70DBC 1575.42 +/- 10mhz. The DC bias will provide power to
the GPS preamp.
In order to meet the above requirements, a diplexer that incorporates a band pass filter that passes the GPS
frequencies and a notch filter that passes all other frequencies and rejects the GPS frequencies. Also included for
the provision of providing DC power to the remote GPS preamp, a low pass filter that isolates the DC from the cell,
PCS, and Wifi equipment that would be connected to the broad band port (port 1). A DC block will be used to
prevent DC on the broad band port just in case the equipment is not protected. As shown in the block diagram
(figure 2), the DC path can only flow from the common port to the GPS port. The overall design requirement is low
PIM (-153 DBC). PIM, by definition, is the nonlinearity of passive components. When power is applied to a system or
a component unwanted distortion products are produced that generate interfering signals to cause dropped calls
and limits the number of users on any given system.
All the components in the design must not contribute to Passive Intermodulation distortion. Any bimetal components
will contribute to this parameter. The connectors, DC Blocks, coils, capacitors, and plating can be contributors.
|2733 Spruce Creek BLVD
Port Orange, FL