mmWave Axial Choke Horn Antenna with Lens
Millimeter wave (mmWave) antennas operate in the band of frequencies where the wavelength is between 10mm and 1mm. The frequency range for mmWave application is thus constrained to be greater than 30 GHz, but less than 300 GHz. Various applications exist in this frequency range, incl. wide band telecommunication and imaging applications for security screening. The following example demonstrates how an antenna was designed for communication at 60 GHz.
Antenna Magus Synthesis
Antenna Magus (version 4.1) identified a wide variety of options associated with the keywords "millimeter wave" and upon further reading an axial-choke conical horn antenna with lens was identified as a good candidate for the intended application.
A design process was followed where only the operating frequency was specified (60 GHz) and Antenna Magus was relied upon to deliver a good design. The design details were exported to FEKO for further modelling and simulation experimentation.
Experimentation in FEKO concentrated on establishing whether the Antenna Magus design functioned as expected at 60 GHz and what the contribution of the lens is to the radiation characteristics of the antenna.
A review of the near fields in front of the horn and inside the lens and horn cavity reveals that the lens performs a focusing function. This qualitative evaluation is confirmed with 2D polar plots where the boresight gain as well as 3dB beam width can be measured and compared. These plots demonstrate that the antenna with the lens has roughly 2 dB better gain at boresight and 5° narrower 3 dB beam width in both the E- and H-planes.
|Focused with lens||Antenna only|
|Near field review of antenna|
|Far field gain review of antenna|
Antenna Magus and FEKO were used to design and evaluate a 30 GHz mmWave antenna for communication applications. It was demonstrated that the resulting axial choke horn antenna with lens performs as required and that the lens in the design focuses the main beam as opposed to the same design without the lens.