MM-wave Phased Array Design Using Altair Feko
Due to the continued exponential growth and interest in millimeter-wave applications, a lot of attention has been put on beam steerable antennas. These types of antennas are identified as an attractive solution for 5G communication networks as they can enable beam switching or scanning to targeted users, while suppressing unwanted signals. To synthesize a sharper beam with required side lobe levels is called Beamforming. Beamforming is the application of multiple radiating elements transmitting the same signal at an identical wavelength and phase, which combine to create a single antenna with a longer, more targeted stream which is formed by reinforcing the waves in a specific direction. Beam steering is achieved by changing the phase of the input signal on all radiating elements. Phase shifting allows the signal to be targeted at a specific receiver. An antenna can employ radiating elements with a common frequency to steer a single beam in a specific direction. Different frequency beams can also be steered in different directions to serve different users.
Such an antenna array is also referred to as Phased Arrays. A phased array usually means an electronically scanned array which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas. In this blog, we focus on simulating linear phased arrays at 24Ghz using Altair Feko. For example purpose, we design a micro-strip patch array that has 10 elliptical elements placed linearly as shown in the image below. The spacing between each elements is lambda/2. The image below represents the simulated structure in Altair Feko.
To synthesize a beam of required side-lobe-level we compute antenna array excitations using Chebyshev distribution. This was implemented in Altair Compose. The compose script and model files are attached with this blog. The 3D radiation pattern is shown below. The resultant pattern with other steered beams of angle 15 degrees and 30 degrees are also shown on polar and cartesian plot.
The model (cfx) files for individual simulations and compose scripts are attached to this blog. For more details and questions, please reach out to Altair support.