Background: Patch antennas are composed of the substrate material with patch and
ground plane on both sides of the substrate. The dimensions and performance characteristics of the
antenna are highly influenced by choice of the appropriate substrate depending upon the value of
their dielectric constant. Generally, low index substrate materials are used to design the patch antenna,
but there are also some of the applications, which require the implementation of patch antenna
design on high index substrates like silicon and gallium arsenide.
Objective: The objective of this article was to review the design of antennas developed on high index
substrate and the problems associated with the use of these materials as a substrate. Also, main
challenges and solutions have been discussed to improve the performance characteristics while using
the high index substrates.
Methods: This review article is divided into various sections, including the solution of the problems
associated with the high index substrates in the form of the micro-machining process. Along with
this, types of micro-machining and its applications have been discussed in detail.
Results: This review article investigates the various patch antennas designed with micro-machining
technology and also discusses the impact of the micro-machining process on the performance parameters
of the patch antennas designed on high index substrates.
Conclusion: By using the micro-machining process, the performance of the patch antenna improves
drastically, but fabrication and tolerances at such minute structures are very tedious task for the antenna