The HL 562, which measures approximately 0.60 m x 1.65 m x 1.68 m, features a single-piece log-periodic array
in order to maximise mechanical stability and is calibrated prior to delivery using the three-antenna technique combined with tolerance analysis.
Yet, other studies for a log-periodic array
of narrow rectangular microstrip elements indicate that bandwidth at least as great as 50 percent can be achieved. However, this technique suffers from nearly all the disadvantages of the quasi-periodic technique.
Mayes, "Log-Periodic Array of Dual-Feed Microstrip Patch Antennas," IEEE Trans.
Mayes, "Coplanar Waveguide Dual-Feed Patch Elements and a Log-Periodic Array Thereof," Electromagnetics Lab.
This limitation can be overcome by using the concept of log-periodic arrays for the design of wideband printed antennas .
A critical point in the design of printed log-periodic arrays is the modeling of the feeding network .
Design procedures for Yagi-Uda and log-periodic arrays
, horns and microstrip patches are described, as well as techniques using the Schelkunoff, Fourier transform, Woodward-Lawson, Tschebyscheff and Taylor methods.