The antenna port feed to the T/R channel usually passes through a ferrite circulator, often with a ferrite isolator
to protect the power amplifier, or occasionally with a high power T/R switch that can terminate the receive path with a load during the transmit pulse cycle.
Solbach, "A New Finline Ferrite Isolator
for Integrated Millimeter-wave Circuits," IEEE Transactions on Microwave Theory and Techniques, Vol.
To reduce interaction between the mixer and the input filter/antenna system, a ferrite isolator is commonly employed in the RF input path as well.
The front-end LNA provides buffering between the antenna and diplexer filters and the mixer itself, which allows for the removal of the ferrite isolator.
Products include specialized filters, combiners, tower mounted amplifiers, Passive Intermodulation (PIM) test solutions, radio link diplexers, ferrite isolators
, circulators and in-building DAS interface solutions.
In particular, he addresses engineers designing magnetic-based and dielectric-based components like ferrite isolators
and circulators, dielectric based filters, and antennas and radomes where there are significant specialist materials requirements.
The reason is not only the "inter-modulation distortion effect," or "rusty bolt effect" which is caused by metal-metal junctions or magnetic materials, such as ferrite isolators
These drop-in ferrite isolators
cover WiMAX frequency bands of 3.
The design also includes two dual-stage ferrite isolators
that offer -50 dB of antenna-to-TX isolation.