TeraSys Technologies is creating a portfolio of unique products to combat RF co-site interference through removal of harmful spurious energy from communication systems. 

Our absorptive filter technology has all of the properties typically seen in a filter, such as good group delay in the passband, low loss in the passband, high rejection in the stopband, etc. The key difference lies in the reflection coefficient of the stopband.  A conventional, or reflective, filter rejects energy in the stopband by reflecting the energy back towards the source. Thus, the voltage standing wave ratio (VSWR) of a reflective filter’s stopband is very high. In contrast, an absorptive filter absorbs energy in the stopband and therefore reflects no energy back towards the source resulting in a low VSWR in both the stopband as well as the passband.

• Absorptive filters are immune to source and load impedance variations such as in the case of antennas in constantly changing environments

• Absorptive filters remove reflected energy thus preventing the generation of reverse intermodulation distortion products

• Absorptive band pass filters provide low passband loss, sharp rolloff, and deep stopband rejection

Our absorptive notch filters (RF Absorptive Filters, RAF^TM) can be installed at the output of interference-generating transmitters without reflecting power back to the transmitter.   CoSite receiver systems are thus protected from spurious transmitter emissions caused by reverse intermodulation distortion or high-power emissions in the receiver band.

Our absorptive bandpass filters in the RAF product line provide high stopband rejection, low loss in the passband, and tight transitions between passband and stopband. Transmission zeros can be added to improve rolloff even further without reducing stopband rejection.

Our absorptive multiplexers (Absorptive MultipleXer, AMX^TM) allow connections between CoSited radios transmitting and receiving through the same antenna. A powerful benefit of absorptive technology ensures system performance is immune and independent of source and load impedance variations such as in the case of antennas in constantly changing environments. Spurious passbands that would normally occur with shifting impedances are eliminated ensuring clean transmission and reception.

For standard products, we provide datasheets with specifications along with s-parameter files in touchstone format to allow you to simulate how our products can help solve your RF co-site interference requirements. 

If you don’t see exactly what you are looking for, contact us by email at sales@terasystechnologies.com or by phone at (808) 469-4251 and we will be happy to discuss your requirements and how we can tailor a solution for your needs.

Click here to download a copy of the TeraSys Technologies RF CoSite Interference white paper.