Abstract: An antenna element (1) includes, a film (10) of dielectric material having thereon a radiating antenna element (14) that radiates at a first order harmonic frequency within a desired first frequency band, a conducting capacitive load element (90) and the radiating antenna element (14) being capacitively coupled across a thickness of the film (10) at a second order harmonic frequency, to tune a radiated second order harmonic frequency to correspond with a desired second frequency band, thereby providing a dual band antenna element (1).

Abstract: A compact antenna for circular polarization comprises a substrate of a dielectric material which is formed on its bottom surface with a ground plane and on its top surface with four planar rectangular patches of an electrically conductive material. The four patches are mounted in a coplanar relation on the top surface of the substrate, and arranged along four sides of a square pattern with the length of each patch angled at 90.degree. with respect to the length of the two adjacent patches. Each of the four patches is short-circuited to the ground plane at a shorting point located at a corner of the square pattern. A 90.degree. hybrid circuit is connected to directly feed only the two adjacent patches with a phase difference of 90.degree. to thereby define these two patches as active antenna elements which are fed with 0.degree. and 90.degree. signals, respectively.