Luneberg Lens Offers Wide Scan With Multiple Pencil Beams

Dec. 11, 2007
Recently, there has been a resurgence in research interest in spherical Luneberg and homogeneous lens antennas for launching multiple pencil beams. With these approaches, all of the generated beams are almost identical because of the inherent ...

Recently, there has been a resurgence in research interest in spherical Luneberg and homogeneous lens antennas for launching multiple pencil beams. With these approaches, all of the generated beams are almost identical because of the inherent symmetry of the structure. The result is very wide scan coverage of up to 180 deg. To specifically target millimeter-wave multi-fan-beam applications, a two dimensional (2D) Luneberg lens was recently proposed by Xidong Wu of Photonic Systems (Billerica, MA) and Jean-Jacques Laurin from the Poly-Grames Research Center at Ecole Polytechnique (Montreal, Canada). This lens is based on a partially-filled parallel plate technique.

A low-cost polymer material was chosen for its ease of matching and low loss tangent. The approach results in the presence of a thick air region at the edge of the parallel plates, which permits the insertion and fine positioning of the feeding element. The feeding element is a tapered slot antenna (TSA), which is oriented to favor the excitation of the TE10 mode between the parallel plates.

The researchers present a detailed design of the 2D Luneberg lens operating at 30 GHz. A combined ray-optics/diffraction method is used to obtain the system's radiation pattern. Results are compared with the predictions of a timedomain numerical solver. For this prototype, 3- dB E- and H-plane beamwidths of 6.6 and 54 deg., respectively, were obtained. The sidelobe level in the E-plane was -17.7 dBc. The measurement results demonstrate broadband characteristics with radiation efficiencies between 43 and 72 percent over the tested frequency band of 26.5 to 37 GHz. See "Fan-Beam Millimeter- Wave antenna Design Based on the Cylindrical Luneberg Lens," IEEE Transactions on Antennas and Propagation, Aug. 2007, p. 2147.

About the Author

Nancy Friedrich | RF Product Marketing Manager for Aerospace Defense, Keysight Technologies

Nancy Friedrich is RF Product Marketing Manager for Aerospace Defense at Keysight Technologies. Nancy Friedrich started a career in engineering media about two decades ago with a stint editing copy and writing news for Electronic Design. A few years later, she began writing full time as technology editor at Wireless Systems Design. In 2005, Nancy was named editor-in-chief of Microwaves & RF, a position she held (along with other positions as group content head) until 2018. Nancy then moved to a position at UBM, where she was editor-in-chief of Design News and content director for tradeshows including DesignCon, ESC, and the Smart Manufacturing shows.

Sponsored Recommendations