RubySelecting the correct filters to provide the most optimal signal flow is crucial when designing for systems aboard ships and in buildings, tunnels and subways. The correct absorptive filter in both low and high pass eliminates instability, excess band ripples and false triggers on power detector circuitry due to reflected harmonics. This makes absorptive filters much more desirable than reflective filters which have several drawbacks.
Reflective filters bounce out of band signals back to their source and tend to excite non-linear behavior of the PA which results in more and higher modulation products. They also cause instability issues within the PA and the performance is very susceptible to temperature change. Selecting absorptive filters is a much better solution for broadband RF components for emerging RF amplifiers and antenna designs.
When selecting a brand of absorptive filters, be certain that you are selecting the latest technology which has been tested in house at rated power to ensure that the design is sound and the results will meet your desired specification. The most reliable manufacturers will have high power test labs on site to continually test new models and to create components to meet the exact specifications of your project. In addition, they will test their products under adverse conditions such as extreme heat and cold to ensure that the power handling and electrical specifications are met. Other testing which includes shock, vibration, salt spray, humidity and fungus tests can be requested but would most likely be performed at a third party testing facility.
Selecting the correct type of filters for your next project should include research about absorptive filters and their benefits over reflective filters. It is also crucial to research the manufacturers and their testing practices to ensure that you are getting nothing but the best products for your customers.
