Frankonia CIT-1000 Conducted Immunity Test System

MIL-STD-461G CS104 is a receiver front-end susceptibility requirement applicable from 30 Hz to 20 GHz for equipment and subsystems, such as communications receivers, RF amplifiers, transceivers, radar receivers, acoustic receivers, and electronic warfare receivers as specified in the individual procurement specification. For Navy ships and submarines, MIL-STD-461G CS104 is applicable for all receivers. The applicable frequencies are a function of the front-end design of the unit being evaluated.  The EUT shall not exhibit any undesired response beyond specified tolerances when subjected to the limit requirement provided in the individual procurement specification. MIL-STD-461G CS104 is used to determine the presence of spurious responses that may be caused by undesired signals at the EUT antenna input ports.   Procedures No test procedures are provided in the main body of this standard for this requirement. Because of the large variety of receiver designs being developed, the requirements for the specific operational characteristics of a receiver must be established before meaningful test procedures can be developed. Only general testing techniques are discussed in this appendix. Front-end rejection testing can be applied to a variety of receiving subsystems such as receivers, RF amplifiers, transceivers, and transponders. Several receiver front-end characteristics must be known for proper testing. These characteristics generally should be determined by the test. The maximum signal input that the receiver can tolerate without overload needs to be known to ensure that the test levels are reasonable. The bandpass characteristics of the receiver are important for determining frequencies near the receiver fundamental that will be excluded from testing. Requirements for this test are often expressed in terms of a relative degree of rejection by specifying the difference in level between a potentially interfering signal and the established

MIL-STD-461G CS114 applies from 10 kHz to 200 MHz for all interconnecting cables, including power cables. For EUTs intended to be installed on ships or submarines, an additional common mode limit of 77 dBμA applies from 4 kHz to 1 MHz on complete power cables (highs and returns - common mode test). MIL-STD-461G CS114 does not apply to coaxial cables to antenna ports of antenna-connected receivers except for surface ships and submarines.  MIL-STD-461G CS114 is used to verify the ability of the EUT to withstand RF signals coupled onto EUT associated cabling.   Test Equipment The test equipment shall be as follows: Measurement receivers Current injection probes (maximum and recommended minimum insertion loss shown in Figure CS114-2) Current probes Calibration fixture: coaxial transmission line with 50 ohm characteristic impedance, coaxial connections on both ends, and space for an injection probe around the center conductor. Directional couplers Signal generators Plotter Attenuators, 50 ohm Coaxial loads, 50 ohm Power amplifiers k. LISNs   Procedures The test procedures shall be as follows: a. Turn on the measurement equipment and allow sufficient time for stabilization. b. Calibration. Perform the following procedures using the calibration setup. (1) Set the signal generator to 10 kHz, unmodulated. (2) Increase the applied signal until measurement receiver A indicates the current level specified in the applicable limit exists in the center conductor of the calibration fixture. (3) Record the "forward power" to the injection probe indicated on measurement receiver B. (4) Scan the frequency band from 10 kHz to 200 MHz and record the forward power needed to maintain the required current amplitude. c. Verification. With the probes still in the calibration setup, configure the verification of the test system using Figure CS114-4. Conduct a scan as though this

Introduction IEC 61000-4-6 defines test procedures for the conducted immunity testing of electrical and electronic equipment to electromagnetic disturbances coming from intended RF transmitters in the 9 kHz to 80 MHz frequency range. Equipment that does not have at least one conducting cable that can couple equipment to the disturbing RF field is excluded from IEC 61000-4-6. The object of IEC 61000-4-6 is to establish a common reference for evaluating functional immunity when equipment is subjected to conducted disturbances. The source of the disturbance is an electromagnetic field coming from intended RF transmitters that may affect the cables connected to the equipment under test. IEC 61000-4-6 is necessary because untested cables can behave as passive receiving antenna networks and affect the performance of the equipment. Susceptible equipment is exposed to currents flowing through the equipment. Cable systems connected to the equipment are assumed to be in resonant mode, and as such are represented by coupling and decoupling devices having a common mode impedance of 150 Ω concerning the ground reference plane. When possible, the equipment is tested by connecting it between two 150 Ω common-mode impedance connections; one providing an RF source and the other providing a return path for the current. The test method in this standard subjects the EUT to a source of disturbance comprising electric and magnetic fields, which simulate those fields coming from intentional RF transmitters. Test Levels No tests are required for induced disturbances caused by electromagnetic fields coming from intentional RF transmitters in the 9 kHz – 150 kHz range.   Open Circuit Test Levels Frequency Range 150 kHz – 80 MHz Level U₀ dB (µV) U₀ (V) 1 120 1 2 130 3 3 140 10 Xᵃ Special Special *X is an open level *For testing