Showing results: 31 - 33 of 33 items found.
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A.H.Systems, Inc.
For many years most standards called for the use of a half-wave dipole antenna set for frequencies above 80 MHz. However, to reduce test time, broadband antennas such as the biconical antenna and log periodic antennas began to be accepted. Broadband antennas, compared to half wave dipoles, reduce test time because the technician did not have to stop the test to adjust the dipole antenna for each frequency. A.H. Systems'' 7 models of Biconical Antennas operate efficiently over the frequency range of 20 MHz to 18 GHz. Suitable for FCC, MIL-STD, VDE, TEMPEST, and immunity testing, each Biconical antenna will provide reliable, repeatable measurements.
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Com-Power Corporation
A typical emi emission test is performed using broadband EMC antennas such as biconical, log periodics, Combilogs and horns. These antennas usually placed at 1, 3 or 10 meter distance as required by the test specification. These is considered far field measurements and the emission limits are given for the specific distance by the specification. During EMI compliance measurements, the emissions levels from products are compared with these limits. If the product exceeds these limits it is considered failing. These tests are typically conducted in a open area test site IOATS) or inside an anechoic chamber.
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Stacked LPDA -
Schwarzbeck Mess Elektronik
The stacked Logarithmic Periodic Dipole Antenna consists of two ordinary Log.-Per. structures. The excellent characteristics (flat gain over a large bandwidth, low SWR) of the ordinary Log.-Per. designs could be maintained using the stacked LP design. The stacked design helps to focus the directional pattern of the H-plane somewhat, resulting in a typical gain improvement of ca. 2-3 dB compared to an ordinary LPDA. This is especially important for immunity testing, where a maximum fieldstrength and a good field uniformity is required. The beamwidth in the E-plane and the H-plane are nearly identical, providing an optimised illumination of the EuT with minimised ground reflection influence. Further the STLP 9128 C has an excellent cross-polar rejection.
