Limiters are used to protect RF components against excessive incident power levels.The devices are designed and manufactured to meet stringent requirements, mechanically, electrically and environmentally. It is the specialty of Spectrum Elektrotechnik GmbH to design and manufacture devices to meet stringent specifications, electrically, mechanically and environmentally.



The power limiting circuit consists of a single PIN diode or several diodes, shunted across a transmission line, requiring a DC return in order to achieve proper limiting operation. Low input power passes with the minimum insertion loss of the circuit. Power levels, greater than the threshold level will cause greater insertion loss, resulting in leakage power that the output power of the device remains at constant level.



In radar applications a limiter is normally installed to protect the receiver against excessive power, caused by unwanted reflections from other nearby radars or objects that accidentally come close to the radar. For normal power levels the limiter will operate like the classic device. But even high power levels arrive, the limiter will act as a reflective unit, protecting the receiver by returning all the power that cannot be absorbed back into the line. To control the reflected power, usually a circulator is installed at the input of the limiter, directing the excessive power to a high power load where it will be absorbed.

High-power Limiter with SBY Connector

High-power Limiter, built on a modular basis, using the SBY Connector.



Spectrum Elektrotechnik GmbH offers mainly custom designed limiters, special components, using different or an even unique mechanical configuration, special frequency ranges than normally offered, higher power levels, etc. Spectrum Elektrotechnik GmbH is a very innovative company. It employs a strong and successful team of experienced engineers. They will always do their best to propose something that will perfectly fit the requirements.



Limiters have been designed and manufactured to serve multi octave bandwidths, from very low frequencies up to Ku band. Wide operating bandwidths usually apply for low power limiters. The higher the power level becomes, the narrower the bandwidth will be.



Most of the designs, Spectrum Elektrotechnik GmbH can offer, will be engineered exactly to the customer specifications, size and shape of the housing supplied with the necessary connector configuration, providing that the frequency range of the connectors do not limit the frequency range of the application. As Spectrum Elektrotechnik GmbH is manufacturing its own housings and its own connectors, almost every mechanical configuration needed and every connector style preferred may become reality.



VSWR is the ratio of the reflected signal and the incident signal. Every microwave component shows reflections and discontinuities within the circuit, as no design is perfect, and manufacturing tolerances do not allow perfect designs anyway.

Contact Details
Spectrum Elektrotechnik GmbH
Olschewskibogen 1
80935 Munich

Mailing address:
P.O. Box 450 533
80905 Munich

+49 (0)89 / 354 804-0
+49 (0)89 / 354 804-90