5G BEAMFORMING DESIGN MADE EASY

Passive components Planar-Printed Antennas Antennas & Radomes
By Nesrine Selmi | 03/09/2021

WHAT IS 5G BEAMFORMING? 

In wireless communication, antennas radiate signals in all directions. Beamforming is simply a wireless technique that concentrates signals towards one specific receiving device.  That’s a big deal. It makes direct connection faster, more focused, sharper, and more reliable. But how to achieve that? Use Multiple Input Multiple Output (MIMO) antennas. 


MIMO 

In addition to high gain, MIMO antennas enable the 5G beamforming. The mathematics behind the way MIMO enable the beamforming is rather complex.  But in a nutshell, by controlling the magnitude and phase of each antenna, the beam gets formed in the desired direction without the need the boost broadcast power.   

 

HFWorks  

5G uses frequencies beyond 28 GHz which makes the design of MIMO challenging and expensive.  By using HFWorks, you can virtually build your MIMO, play with various combinations of magnitude and phase to study the effects on the resulting beam. In addition, you can also virtually obtain all the antennas parameters, including, gain, directivity, radiation pattern, SWR, etc.  Moreover, HFWorks is fully integrated, i.e. plugin, in SolidWorks, the #1 3D CAD platform.  As a result. HFWorks makes 5G beamforming design easy and affordable.  


AN EXAMPLE


Single two-port microstrip patch antenna 


HFWorks is used to model a single-patch antenna fed by two ports is shown above.  An impedance transformer is added to improve the impedance characteristics. The width wt of the impedance transformer is varied to study the effects on the antenna characteristics.  


S-parameters of the single two-port patch antenna for different wt 


The S11 graphs clearly shows that the largest bandwidth is obtained when wt = 0.05 mm. In addition, the insertion loss |S21| < -20 dB for all cases. 

After selecting the proper single antenna, or the so called the unit cell, and studying its performance, an antenna array is created.


Series-fed 2×2 patch antenna array 


The S-parameters of the array show a good matching around 28 GHz with an isolation between the ports better than 20db.  


Simulated S-parameters of the 2×2 array antenna 


Because of the symmetry, only the phase of one port is adjusted to study the beam-scanning capability of the 2×2 array antenna. When all ports phases are equal to zero degree, a maximum gain of 13.2 dB (θ=0º) is realized. To scan the beam, at each time a phase of one port is adjusted and the rest are zero. As shown below, by varying the phase of the antennas, the beam is shaped, i.e. Beam-formed differently.  


3-D radiation Patterns of the 2×2 array antenna 


 

SUMMARY AND TAKEAWAYS 

Beamforming is the backbone of 5G networks.  Multiple Input Multiple Output antennas make the beamforming a reality by playing on the magnitude and phase of the individual antennas constituting the array. Because 5G networks operate at mm wave frequencies, MIMO design is both challenging and expensive.  HFWorks makes such tasks easy and affordable.