Figure 2-4. Intermodulation products occurring at a receiver.

TM 11-490-5

Figure 2-4. Intermodulation products occurring at a receiver.

production and transmission of 7th order intermodulation

3. Intermodulation products may also occur in a

products which could interfere with a 50-MHz link is

link transmitter as a result of the mixing of signals from

shown in figure 2-5. Interfering signals entering the link

two interfering transmitters in the final stage of the link

transmitter antenna are mixed in the final stage and

transmitter. Intermodulation products are generated in

retransmitted as 7th order intermodulation product

the final stage according to the' same equation

signals according to the following relationship:

presented for receiver intermodulation products. The

transmitted signal consists not only of the desired signal,

fI = 4fa - 3fb

properly modulated, but the intermodulation products

= 4(51.2) - 3(51.6) MHz

also at the desired signal frequency (or, at least, within

= 204.8 - 154.8 MHz

the RF bandwidth of the link receiver).

The

= 50.0 MHz

intermodulation product signals will contain vestiges of

the interfering signal modulations which will be heard as

Therefore, fI = f0 = 50.0 MHz.

noise at the link receiver. An example of the

2-7