A UHF Deployable Log Periodic Dipole Antenna: Concept, Design, and Experiment

A deployable log periodic dipole antenna (DLPDA) is proposed. The antenna consists of pairs of collapsible steel tape springs (as the dipoles), a novel stretchable zigzag double-sided parallel stripline (ZDPS) (as the boom), and a coplanar waveguide on one side of the parallel striplines to guide the electromagnetic wave from the backend to the frontend. As a result, the proposed antenna becomes foldable and can be stored in a small volume prior to deployment. A design guideline for the DLPDA is given based on the simplified circuit model. Furthermore, the ZDPS, which is found as a slow wave structure, has been studied. The empirical equations are derived to obtain its characteristic impedance and propagation constant, which are the key parameters for the design guideline. One prototype of the DLPDA has been fabricated and tested. The deployment mechanism of the prototype has been successfully demonstrated using compressed air in a lab. The prototype has a stowed volume of <; 2000 cm
³
, which is only 2% of the volume in fully deployed state.