This communication presents a novel linearly polarized pattern reconfigurable microstrip parasitic array. Specifically, this antenna uses four switches (currently copper strips for proof of concept) to reconfigure the radiation pattern into three variations over a shared 2:1 VSWR bandwidth, and has potential applications in mobile communication devices and large phased antenna arrays. Both measured and simulated results of a microstrip parasitic array are provided. The effects of changes in physical dimensions and directions for future work are also discussed.

This work describes the integration of commercially available packaged radio frequency microelectromechanical system (RF MEMS) switches with radiation pattern reconfigurable microstrip antennas. Most applications of RF MEMS switches consider the switches as only circuit elements. In contrast, the implementation of packaged switches in this particular antenna must address not only the simple open/closed behavior of the switches but also their impact on the radiation characteristics of the reconfigurable antenna. Here, two Radant MEMS single-pole single throw (SPST) SPST-RMSW100 (packaged RF MEMS) switches are used to reconfigure the radiation patterns of a resonant square spiral microstrip antenna between endfire and broadside over a common impedance bandwidth. Switch insertion, matching network design, and other issues are addressed. Results for both simulated and measured antennas, as well as recommendations for future work in this area, are provided.

This paper presents a novel pattern and frequency reconfigurable microstrip antenna that uses switched connections. The basic antenna operates with linear polarization around 3.7 GHz. One set of connections provides a re-directed radiation pattern while maintaining a common operating impedance bandwidth with the baseline configuration. The second set of connections results in operation at a higher frequency band at 6 GHz with broadside patterns. Measured results of the three antenna configurations are provided. Potential applications of this reconfigurability and directions for future work are discussed.

The use of liquid metal as a switching mechanism for a frequency‐reconfigurable edge‐fed microstrip patch antenna designed to operate in either the 2.4 GHz ISM band or the 1.6 GHz GPS band is illustrated. A partitioned fluidic manifold bonded to the top of the antenna enables the pressure‐driven displacement of a low‐loss dielectric fluid and the liquid metal from a reservoir atop the patch to switch between the two antenna states. Fabrication and measurement of the antenna illustrates the use of fluidics as an alternative to RF switches for reconfigurable antennas.

A nontoxic liquid metal, such as eutectic gallium-indium (EGaIn) alloy, has been used to develop tunable radio frequency (RF) components, such as antennas, inductors, or capacitors, for enabling large tunable range, better linearity, and low loss, using fluidic displacement of the liquid metal. However, EGaIn residue, due to its fast oxidation, limits multiple movement of the EGaIn in the reconfigurable RF components. This paper focuses on the use of surfactants, carrier liquids, and microchannel coating materials that minimize EGaIn fragmentation and EGaIn residues on poly(dimethylsiloxane) (PDMS)-based microfluidic channels during repeated actuation of an EGaIn plug. Using a combination of carrier liquids and microchannel coating materials to minimize EGaIn from leaving residues on the PDMS microfluidic channel, a microstrip transmission line switch as a proof-of-concept reconfigurable RF application using the EGaIn plug is demonstrated. It is switched ON<;4 dB and OFF with a loss of <;18 dB over the frequency range between 4 and 15 GHz.

The vertical displacement of a columnar fluidic colloidal dispersion is examined as a frequency reconfigurable dielectric resonator antenna (DRA). The coaxial probe-fed structure has tunable impedance properties that are reversibly controlled by adjusting the columnar height of the dispersion. Colloidal barium strontium titanate was dispersed in hydrotreated naphthenic oil and placed at several heights into a section of polycarbonate tubing over an aluminum ground plane to demonstrate the impedance properties of this structure. Measured, simulated, and calculated results for a range of heights that corresponded to single-mode operation are provided for a design operating between 2.5 and 4.5 GHz.