Abstract

This work presents the design of compact multimode patch antennas for application in medium-size MIMO terminals combining spatial and radiation-pattern diversity. This design was inspired by previous work, which proposed the use of patch antennas providing two services at two frequency bands that required different radiation patterns. These precedents are briefly reviewed, before extending the concept of the dual-pattern two-frequency case to one in which diversity is demanded at a single frequency. A design with three modes at a single frequency is also accomplished. Some prototypes have been manufactured and measured. An example of the advantages of using these multimode antennas in terms of spectral efficiency in MIMO systems is also included. The key aspect of this work is the use of short-circuited ring patch (SCRP) antennas.