Microlab’s low pass filters are designed to suppress harmonics and out of band noise and interference (by 55 dB and more), to improve signal quality in high power system applications and bench testing.
The design used is known as rod and bead and is constructed of alternate lengths of high and low impedance transmission lines tuned to provide the proper frequency reponse. The design ensures a low loss pass band response down to at least 40% of the cut-off frequency. In the stop band rejection of at least 55 dB occurs at 150% of cut-off and extends typically for several octaves. When compared to lumped element construction, the single piece rod and bead filter has far fewer solder joints, is better supported, and operates cooler with a better VSWR.
Microlab also offers a wide range of broad and narrowband diplexers and triplexers to meet the rigorous demands of the wireless market. The focus is to provide extremely broad bandwidths (they add Tetra to the wideband by adding 80-520 MHz band to 700-2700 MHz band), with minimum loss, low PIM and high isolation. The most suitable design technique for such requirements is often the suspended substrate which has low loss and has the cost benefit of being tuned by design. Such units have become a very important building block in the combining of multiple signals being distributed in DAS (Distributed Antenna Systems). Microlab also provides diplexers combining all wireless with WiMAX.