Product specifications
19
C
ONNECTORS
The following table details the connectors used by the Crescent Vector module. We
have also provided information on the mating connectors. Since your requirements
may be different, you are free to choose a different, compatible connector. The
antenna input impedance is 50 Ω.
Table 3-2. Crescent Vector Connectors.
Connector Crescent Vector SMT
Connector
Mating Connector
RF MCX, straight jack (female)
(Johnson: 133-3711-201)
MCX, straight plug (male)
(AMP: 1061015-1)
Interface 17 x 2 pin header plug
(male)
0.050” pitch
(Samtec: FTSH-117-01-L-
DV)
17 x 2, SMT header socket
(female)
0.050” pitch
(Samtec: FLE-117-01-G-DV)
C
RESCENT
V
ECTOR
M
OUNTING
There are two methods of mounting the Crescent Vector module. The first is the
most cost-effective method since it does not use cable assemblies to interface the
module to the integration. We recommend that you place an RF connector, header
connector, and mounting holes on your motherboard. The Crescent Vector then
mounts on stand-offs and the RF and header connector.
To accomplish this approach, you will, however need to be very contentious with the
GPS RF signals present on your motherboard. If you choose to use this method of
mounting the Crescent Vector, you will need to consider the correct standoff height
so that no flexural stress is placed on the Crescent Vector board mechanically when
fastening it down. The Crescent Vector Evaluation Motherboard, with its Johnson RF
connector and Samtec header socket, uses a standoff height of 0.3125” (there
should not be any washer between either the standoff and the Crescent module or
the standoff and the motherboard with this height unless accommodated for). If you
choose a different header connector, you may have to change the height of the
standoff.
The second method, at the expense of the cost of cable assemblies is to mount the
Crescent mechanically such that you can connect a ribbon power/data cable to the
module and an internal RF cable assembly. In addition to increased expense, there
is a reliability factor present with cable assemblies.
With the approach, it’s simple to accommodate a right angle MCX connector. If you
desire a right angle MCX connector for the first approach, in order to reduce the
complexity of your motherboard in having it not handle the RF signals, you will need
to use a ribbon cable and taller standoffs. This would provide you with clearance to
have a right angle cable-mount connector.
The mounting holes of the Crescent module have a standard inner diameter of
0.125”.