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97
GHz.
f)
Set the channel power bandwidth:
Press [Ch BW] and set the channel power bandwidth with the figure keys. For CDMA signals, set to
1.23MHz.
g) Set the span of channel power.
Press [Span] and set the span of channel power with the figure keys. In this example, it sets to 2.5MHz.
NOTE:
The bandwidth of channel power represents a frequency width at which
the microwave analyzer displays the frequency span of power, while the
channel power span is the frequency range over which the microwave
analyzer sweeps. The channel power span should be set to be greater
than or equal to the channel power bandwidth. Otherwise, the microwave
analyzer will automatically set the channel bandwidth equal to the
channel power span. The ratio of channel power span to channel power
bandwidth remains constant. This ratio remains constant as the channel
power span changes. Changing the channel power bandwidth can
change this ratio. For example, when the channel power span is doubled,
the microwave analyzer will also increase the channel power bandwidth
by the same factor.
h)
Enable the
averaging
function:
Press [Avg Off On] and set the average number of times to 16 and turn on the averaging function.
When the channel power measurement function is turned on, the detection mode is automatically set to
the root mean square detection mode. The two vertical dashed lines displayed on the screen indicate the
bandwidth of the channel power. The measurement results are displayed at the bottom of the screen as
shown in Figure 5-24.
Figure 5-24 CMDA Signal Channel Power Measurement
3
GSM Channel Power Measurement
The Global System for Mobile Communications is a global specification for digital cellular
communications and three frequencies are allocated to GSM mobile communications: 850 MHz, 900
MHz, and 1,800 MHz. The GSM system uses Frequency Division Multiplexing (FDMA) and Time
Division Multiplexing (TDMA). There are approximately one hundred or more intervals with 200 kHz
carrier frequency (FDMA) in each frequency band, and each carrier frequency is divided into time slots to
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