NI AWR Design Environment
ELDIS Pardubice was established in July 1991 to provide complex radiolocation solutions for customers’ demanding requirements for in-air traffic control and air defense applications. The main activities of ELDIS are focused on developing and manufacturing radar technology and systems for air traffic control.
ELDIS Pardubice designer Vadim Zavodny was challenged with developing a new antenna array with omnidirectional far field. While the current ELDIS antenna design works correctly, the company wanted a new design that was omnidirectional.
Omnidirectional antennas are widely used for non-directional antennas because they radiate equally in all horizontal directions while the power radiated drops off with elevation angle -- so little radio energy is aimed into the sky or down toward the earth and wasted. Omnidirectional antennas are widely used for radio broadcasting antennas and in mobile devices that use radios such as cell phones, FM radios, walkie-talkies, wireless computer networks, cordless phones, and GPS. In addition, they are used for base stations that communicate with mobile radios, such as police and taxi dispatchers and aircraft communications.
The first challenge was to show a true antenna element that has an omnidirectional pattern at azimuth plane. The best choice was a dipole, which is axially oriented and produces an antenna element array at the vertical layout.
The second challenge was the feeding network, which was designed with an array of 10 elements. The feeding network for a 10-port antenna array, as well as each element, needs complex amplitude and phase because it must be built in a cosecant squared pattern.
The feeding network has the output for the antenna array on the left with a one-port input on the right. The final challenge was how to calculate the antenna vector.
To address each of these challenges, the designer used NI AWR Design Environment™ software, which enables calculation of the antenna factor based on the signal-feeding network. The visual basic (VBA) macro was created using NI AWR software scripting tools. The VBA macro allowed the designer to analyze the complex feeding network in NI AWR software with a time savings of greater than 30 percent.
The designer chose NI AWR Design Environment because the software offers good availability of microwave circuit libraries and strong and efficient optimization. With the VBA macro, the complex feeding network was analyzed more quickly. In addition, the designer noted that NI AWR software has good documentation and a collection of “how-to” videos and application notes.