Compact RDMS
TM
Telemetry Receiver
25
Quasonix, Inc.
6 IF
Module
The receiver’s integrated IF filter module, shown in Figure 8, includes eight (8) SAW filters, ranging in bandwidth
from 250 kHz to 40 MHz in approximately one octave steps. The standard eight filters are 250 kHz, 500 kHz, 1
MHz, 2 MHz, 4.5 MHz, 10 MHz, 20 MHz, and 40 MHz. These filters serve as anti-aliasing filters ahead of the A/D
converter in the demodulator itself. In addition, they can provide an added measure of adjacent channel interference
rejection. The measured responses of the eight filters are shown in Figure 9 and Figure 10 (note the change of
horizontal scale between the two figures).
Six additional filters are available allowing for a total of 14. The optional filters are 70 kHz, 1.4 MHz, 3 MHz, 6
MHz, 14 MHz, and 28 MHz. The measured responses of the optional filters are shown in Figure 11 and Figure 12.
Contact Quasonix for information about the optional filters.
Based on the receiver’s high level of integration, the proper IF filter is automatically selected based on the current
mode and bit rate settings of the demodulator. Although manual filter selection is available, it is not recommended.
Figure 8: 70 MHz IF Module in 2” x 3” Chassis
The IF module attaches directly to the demod modules.