Ultra miniature UHF antenna with concurrent frequency and radiation pattern tunability

An ultra-miniature single access antenna has been designed, simulated and realized on FR4 substrate, covering the full UHF band with a second order radiation pattern diversity. The important antenna size reduction (sizes <;λ₀/34.6 at the lowest frequency) has been obtained by combining two technologies: 1- the twisted slot antenna and 2- the use of tunable components for both frequency and radiation pattern tuning.