SIST EN 60835-2-3:2002

SIST EN 60835-2-3:2002 is the Slovenian standard for measuring RF branching networks used in digital microwave radio transmission systems, especially in terrestrial radio-relay systems. It gives test methods for checking how these multi-port networks behave in the pass-band and stop-band, and how much unwanted coupling or intermodulation they create. Engineers, test labs, and equipment suppliers use it when they need repeatable measurements for specification, development, or type testing.

What does SIST EN 60835-2-3:2002 specify?

SIST EN 60835-2-3:2002 specifies methods of measurement for branching networks used in digital radio-relay systems. The document is organized into a scope, general considerations, measurement clauses for return loss, in-band characteristics, isolation, and multi-carrier intermodulation products, plus a block diagram and a port-combination table.

The document focuses on how to measure the network, not on product design values. In practice, that means the user gets a common test language for comparing equipment from different suppliers.

What are the key requirements of SIST EN 60835-2-3:2002?

SIST EN 60835-2-3:2002 treats a branching network as a multi-port network that connects several transmitters and receivers, operating at different frequencies, to a common antenna feeder. That definition matters because the measurements are built around the actual ports used in service: transmit, receive, and common antenna connection.

Clause 2 notes that the measurements are usually type tests because disconnecting many waveguide flanges is time-consuming. If the transmit and receive branching filters are built into the equipment and the Tn and Rn ports are not accessible, the document allows equivalent filters of the same type to be substituted in the test setup. In practice, this helps laboratories test realistic assemblies without redesigning the equipment.

Clause 3 calls for return-loss/frequency measurements within the pass-band of each port, with all other ports terminated by matched loads or by transmitters and receivers. This tells the reader to check how well each port matches over frequency, which affects reflections and system performance.

Clause 4 covers in-band characteristics. Insertion loss is measured between Tn and C, and between C and Rn, at the pass-band centre frequency. Amplitude/frequency characteristic is measured over both pass-band and stop-band, while group-delay/frequency characteristic is measured in the pass-band. These measurements show how much signal is lost, how the level varies across frequency, and whether timing distortion could affect digital transmission.

Clause 5 specifies isolation testing. A c.w. signal is applied at a specified level and at the centre frequency of the pass-band to each transmit or receive port in turn, and the unwanted signal is measured at all receive ports. This checks whether energy leaks into the wrong receiver paths, which can create interference.

Clause 6 covers multi-carrier intermodulation products. Two or three high-level transmit signals are applied, a calibrated spectrum analyser is used at a receive port, and the unwanted product level is read from the display. The method is aimed at nonlinear effects in joints, flanges, or circulators, so it helps identify interference that appears only when multiple carriers are present. The detailed equipment specification should state the applied frequencies and levels, the product frequencies and type, and the maximum permitted product level.

What terms does SIST EN 60835-2-3:2002 define?

• Branching network - A multi-port network that connects several transmitters and receivers at different frequencies to one antenna feeder.
• Pass-band - The frequency range where the port is intended to carry signals with acceptable transmission.
• Stop-band - The frequency range where transmission should be strongly rejected.
• Insertion loss - The signal reduction measured between the specified ports, such as Tn to C or C to Rn.
• Isolation - The unwanted signal transfer from one port to another, measured at receive ports under specified excitation.
• c.w. - Continuous wave, meaning a single-frequency test signal used for isolation measurements.
• Multi-carrier intermodulation products - Unwanted signals created by combinations of two or more transmit frequencies that fall into a receive pass-band.

Who uses SIST EN 60835-2-3:2002?

SIST EN 60835-2-3:2002 is used by manufacturers of digital microwave radio transmission equipment, especially RF branching assemblies and transmit-receive couplers. It is also used by test laboratories, radio-relay system engineers, and quality teams that need to verify loss, isolation, frequency response, and intermodulation behavior. Buyers and specifiers use it to define what measurements should be reported for branching networks before deployment or acceptance.

Which standards are used with SIST EN 60835-2-3:2002?

SIST EN 60835-2-3:2002 refers to two companion IEC publications:

• IEC 835-1-2:1992 - Provides measurement methods for basic characteristics common to terrestrial radio-relay systems and satellite earth stations.
• IEC 835-1-3:1992 - Provides measurement methods for transmission characteristics common to terrestrial radio-relay systems and satellite earth stations.

These referenced parts supply the measurement methods that this section relies on for return loss, insertion loss, amplitude/frequency behavior, group delay, and isolation.

What does the SIST EN 60835-2-3:2002 document contain?

SIST EN 60835-2-3:2002 contains a block diagram of an example RF branching network with transmit branching assembly, receive branching assembly, and transmit-receive coupler. It also includes Table 1, which shows which port combinations are used for return loss, forward characteristics, and isolation measurements. The clauses then describe the test setups and the reporting items needed for laboratory measurement and specification work.