William Baron

A Broadband High-Gain Bi-Layer LPDA for UHF Conformal Load-Bearing Antenna Structures (CLASs) Applications

A broadband high-gain bi-layer log-periodic dipole array (LPDA) is introduced for conformal load bearing antenna structures (CLASs) applications. Under the proposed scheme, the two layers of the LPDA are printed on two separate thin dielectric substrates which are substantially separated from each other. A meander line geometry is adapted to achieve size reduction for the array. The fabricated and tested array easily exceeds more than an octave of gain, pattern, and VSWR bandwidth.

A MEMS reconfigurable pixel microstrip patch antenna for conformal load bearing antenna structures (CLAS) concept

A four by four pixelated microstrip patch antenna is reconfigured in three frequencies using RF MEMS switches. The proposed antenna can be integrated within a physical structure under the CLAS concept which can replace bolt-on antennas. Structural testing of the antenna clearly demonstrates the structural robustness of this CLAS reconfigurable antenna.

Aperture coupled MEMS reconfigurable pixel patch antenna for conformal load bearing antenna structures (CLAS)

The study and design of an aperture coupled MEMS reconfigurable pixel patch antenna is proposed for operation under the CLAS concept. By activating and deactivating certain sections of a pixelated area the antenna is reconfigured in three frequency bands within 1-2 GHz. Simulation results show that the antenna bandwidth ranges from 5% to 25% and the peak realized gain is greater than 9 dBi.

A pixelated pattern reconfigurable Yagi-Uda array for conformal loadbearing antenna structure (CLAS)

A conformal pixelated pattern reconfigurable Yagi-Uda array is proposed. The array operates at around 2.5 GHz and can steer the beam in the 45 and -45 degree directions with the help of RF switches and a metal reflector placed 1 inch below the array surface.

A broadband VHF-UHF Yagi-Uda end-fire array

A broadband VHF-UHF end-fire Yagi-Uda array is proposed for possible air vehicle integration and operation within the 240-465 MHz frequency band. The array consists of a driven dipole, a reflecting dipole, and three directing dipoles. The broadband impedance, pattern, and gain responses are obtained by adding two parasitic metal strips adjacent to a fat driven strip dipole. The array has a peak gain greater than 7 dBi and Forward to Backward ratio (F/B) greater than 13 dB throughout most of the operating frequency band.

Conformal direct written antenna on structural composites

The experimental studies of a conformal direct written antenna is presented. Investigation results of transmission lines fabricated using direct writing are presented followed by array results. It is shown that a direct written array on structural composite operates at around 2 GHz and can direct its beams in the 45 and -45 degree directions with the help of a metal reflector placed 1 inch below the array surface. The array provides a peak gain of 7 dBi.

Superstrate configurations for a MEMS reconfigurable pixelated patch antenna for CLAS

The experimental and simulation studies of an aperture coupled reconfigurable pixelated patch antenna for CLAS applications is presented. The antenna active dimensions are reconfigured to attain a wide swath of bandwidths within the 1-2 GHz frequency range. Simulated return loss bandwidths are between 8%-26% while measured bandwidths are between 6%-24% when the antenna is reconfigured from low to high frequency bands.

Structural composite materials near a broadband Log-Periodic-Dipole-Array (LPDA)

This paper presents the effects of structural composite material loading on a broadband LPDA. The proposed antenna operates from 350–750 MHz and has a unique bi-layer design where the two antenna trace layers are disposed of on two separate fiberglass composite skin surfaces. The effects of the presence of a tubular structural member on the antenna performance are studied by considering various dielectric materials to mimic a structural support member, such as a spar. Measured VSWR results of the LPDA in the presence of Kevlar structural support member are presented.

Effect of bias traces and wires on a MEMS reconfigurable pixelated patch antenna

The simulated studies showing the effect of DC bias lines on an aperture coupled reconfigurable pixelated patch antenna for CLAS applications is presented. The simulations show significant deterioration in S11 and gain for all operating modes when copper bias wires are introduced. A solution utilizing very high sheet resistance bias lines in place of copper traces is proposed.