| Model |
Short description |
Band, MHz |
Price, EUR
|
| IMF8-1V-50S-R/2 |
Narrow bandwidth diam. 8", single isolator, 50 W "regular" |
140-174 |
 |
| IMF8-1V-50S-X/2 |
Narrow bandwidth diam. 8", single isolator, 50 W "extreme" |
140-174 |
|
| IMF8-1V-50D-R/2 |
Narrow bandwidth diam. 8", dual isolator, 50 W "regular" |
140-174 |
|
| IMF8-1V-50D-X/2 |
Narrow bandwidth diam. 8", dual isolator, 50 W "extreme" |
140-174 |
|
| IMF10-1V-50S-R/2 |
Narrow bandwidth diam. 10", single isolator, 50 W "regular" |
140-174 |
|
| IMF10-1V-50S-X/2 |
Narrow bandwidth diam. 10", single isolator, 50 W "extreme" |
140-174 |
|
| IMF10-1V-50D-R/2 |
Narrow bandwidth diam. 10", dual isolator, 50 W "regular" |
140-174 |
|
| IMF10-1V-50D-X/2 |
Narrow bandwidth diam. 10", dual isolator, 50 W "extereme" |
140-174 |
|
| IMF10-1V-125S-R/2 |
Narrow bandwidth diam. 10", single isolator, 125 W "regular" |
140-174 |
|
| IMF10-1V-125S-X/2 |
Narrow bandwidth diam. 10", single isolator, 125 W "extreme" |
140-174 |
|
| IMF10-1V-125D-R/2 |
Narrow bandwidth diam. 10", dual isolator, 125 W "regular" |
140-174 |
|
| IMF10-1V-125D-X/2 |
Narrow bandwidth diam. 10", dual isolator, 125 W "extreme" |
140-174 |
|
| IMF10-1V-300S |
Narrow bandwidth diam. 10", single isolator, 300 W |
140-174 |
|
| IMF10-1V-300D |
Narrow bandwidth diam. 10", dual isolator, 300 W |
140-174 |
|
Intermodualtion filters design
Ether condition in large cities degraded dramatically in the last years, mainly because of uncontrolled operation of high power transmitting equipment, especially one, emitting digital streams. What makes situation worse, is that such transmitters are concentrated on the top of highest buildings and masts of the city, usually.
As a result, intermodulation throbs, originating interference for other means of communication, appear, due to neighboring antennas signals penetration. Transmitters noise itself "covers" the whole frequency range within several kilometers distance. Reach of transmitters installed in the neighborhood reduces dramatically.
Our company have designed and now successfully sale special filtration systems, intermodulation filters, consisting of 8 or 10-inch coaxial cavity bandpass filter and single or double ferrite isolator (see fig. 1), designated to fight against such interference.
On the given figures gain-frequency characteristic of the both devices is depicted individually.
As you can see, their characteristics are opposite to one another. If bandpass filter signal attenuation is growing moving away from resonance frequency, then, on the contrary, isolator attenuation is growing moving to central frequency (reverse signal passing from antenna to transmitter is meant).
Thus, we have system, providing direct signal passage with minimal loss (not more than 1.8 dB), and limiting penetration of spurious signals (at 75 dB level) to output circuit completely.
Besides, filter characteristic enables to attenuate transmitter self-noise radiation according to its gain-frequency characteristic.
Decision on usage of double or single circulator depends directly on the distance to neighboring antennas. Transmitter combiner, enabling several transmitters to operate through common antenna, can be constructed using IMF8-1V-50D, also.
The ferrite isolators of Regular (R) class provide an operation of the intermodulations filters or transmitting link in temporal regime of exploitation with TX/RX =1:5, i.e. when the working load onto the transmitters of your system is not high.
The ferrite valves of Extreme (X) class are being applied in the case when repeaters operate with enhanced load (up to 100% of the cycle). These are more expansive and highly reliable products with the valves based upon the radiators (which do not allow the ferrites to become overheated) and for massive carrying out (external) loads.
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