SY3-EMC, 30 - 200 MHz, 2500 Watts, Tuned Yagi

30-200 MHz @ 200 V/m

Prior to the introduction of MIL-STD-461F, it was possible to perform RF susceptibility tests using currently available antennas on 30-200 MHz. MIL-STD-461F was introduced to address the deficiencies of previous RF susceptibility standards and thus made it extremely difficult and expensive to achieve successful testing using existing antenna technologies. Because the SY3-EMC Yagi is a high-Q, adjustable antenna that has very high efficiency, a wide beam width, and excellent harmonic rejection, it enables susceptibility testing to the specifications of now MIL-STD-461G and RS-103.

SY3-EMC PRINCIPLE OF OPERATION

The SY3-EMC is a tunable antenna system that allows precise control of all the element lengths. This provides very broad frequency coverage with a single antenna while maintaining ideal performance characteristics. This technology is especially useful in the case of Yagi antennas because they are essentially single-frequency devices. The ability to automatically adjust the antenna also allows operation in less-than-ideal locations, such as EMI chambers, where room effects seriously detune antennas in the 30 MHz to 100 MHz range. The basic antenna element consists of two reels of perforated copper-beryllium strip that are driven by a microprocessor-controlled stepper motor, which enables very precise control of the copper-beryllium element. Power is delivered to each of the copper-beryllium conductors via a specially designed mechanical brush that is rated for 2.5 kW with a 100% duty cycle. The SY3-EMC Yagi incorporates a patented fold-back technique that reduces the size of the antenna by 40% while decreasing gain by only 0.3 dB. This unique element design also keeps the high voltages at the tips away from structural surfaces, thus minimizing E-field pattern distortion and maintaining a very high return loss.

Auto-Tuned, Turnkey System – Introducing the OptimizIR-EMC AI

The OptimizIR AI is a tunable antenna system that precisely adjusts each antenna element to the optimum length for any given frequency, covering both horizontal and vertical polarizations. This mechanical tuning mitigates performance loss often seen in fixed-length dipole antennas (Yagis, Log-Periodics, and Biconicals) as they move away from their resonant frequency. The antenna’s unique design includes a microprocessor-driven stepper motor to control reels of copper-beryllium strip conductors, delivering power through a robust mechanical brush. A patented fold-back method reduces the antenna’s size by 40% with minimal gain reduction while also keeping high-voltage tips away from surfaces—thus preserving a high return loss. This approach delivers reliable, high-efficiency performance even in challenging test environments like EMI chambers.