User's Manual

EXHIBIT 2 PAGE 8 OF 17
TX RX Systems Inc. Manual 7-9257 (version 1) 11/03/00 Page 8
can also occur giving weaker signals than
desired.
e) Signal booster model with excessive gain. In
systems that have an existing signal booster, it
is sometimes assumed that an identical unit
should be installed when expanding the system
to provide extended coverage. In most cases, a
signal booster with far less gain than the first is
required.
f) Improper installation or application of signal
splitters or directional couplers in the signal dis-
tribution system. This is usually the cause of too
low a signal level but deserves mentioning here.
Signal splitting needs to be done with constant
impedance signal splitters so that the proper
power splitting ratios and VSWR are main-
tained. Using tee connectors by themselves is
inviting trouble. Directional couplers must be
connected with regard to their directionality and
coupling levels or improper system signal levels
may result.
Procedure for Measuring Input Signal Levels
1) Set a spectrum analyzer for the center fre-
quency of the system (930.5 MHz).
2) Set the analyzers sweep width so that the entire
passband frequency range can be observed.
3) The analyzers input attenuator should be set to
observe input signal levels from approximately -
80 dBm to 0 dBm.
4) Connect the analyzer to the section of the sig-
nal distribution system that is going to serve as
the input (see figure 3).
5) Record the power level (in dBm) of all carriers in
the passband frequency range that are signifi-
cantly greater than the noise floor displayed on
the analyzer.
6) To find the total power being applied the calcu-
lations listed below must be performed. The
conversion chart at the rear of the manual can
be used. Here are the steps:
a) Convert all values in dBm to Watts
b) Total the power for all carriers in Watts
c) Convert the total power in Watts to dBm
Example: suppose we have a signal booster with a
maximum gain of 70 dB. After checking the input
signal levels, it was determined that there are three
signals that are significantly greater than the noise
floor displayed on the analyzer. These signals have
strengths of -45 dBm, -43 dBm and -41 dBm.
S p e c t r u m A n a l y z e r
R a d i o 1
R a d i o 2
S I G N A L D I S T R I B U T I O N S Y S T E M
Figure 3: Typical test equipment setup for measuring input signal levels.