Characterization of a Reflectarray Gathered Element With Electronic Control Using Ohmic RF MEMS and Patches Aperture-Coupled to a Delay Line

Abstract

A reflectarray element with electronic phase control implemented by ohmic MEMS switches is characterized and validated in the X-band. The proposed element is based on two patches aperture-coupled to a microstrip network with a common delay line, forming a sub-array, in order to reduce both cost and manufacturing complexity in large reflectarrays. The electrical length of the line can be modified through the inclusion of a series switch between different segments of the microstrip line. The ohmic electrostatic switch has been designed for RF applications and manufactured on a coplanar line. The transition between the coplanar line of the MEMS and the microstrip delay line has been implemented using gold wires which have been bonded to the printed pads. This connection leads to a high impedance line. The MEMS switches have been characterized using reflection and transmission measurements on microstrip lines for deducing an equivalent circuit, which has been used in the validation of the gathered element with electronic phase control measured using waveguide simulator. The same approach has been applied to evaluate a 2-bit reflectarray element.

Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review

“…To manage the complexity of this system, the unit cell for this RRA consists of microstrip patch directly connected to a 1-bit reflective transmission line embedding a p-i-n diode. MEMS technology has also been also considered here, and a fully-operational monolithic MEMS RRA at 26 GHz was designed and fabricated [71], while cells using surface mount MEMS elements were also implemented [72]. In both cases thermal losses were several dB despite the use of MEMS technology, which is below the performance that can be achieved using MEMS technology and the tunable resonator approach [40].…”

Reflectarray Antennas for Dual Polarization and Broadband Telecom Satellite Applications

“…Fourth, reflectarrays offer an independent phase control on each polarization, which can be used to produce a different beam in each polarization [16]- [17]. Finally, reflectarrays could provide in-flight reconfigurability of the coverage [18], provided that electronically controllable phase-shifters are included at element or sub-array level [19].…”

Beam-Scanning Reflectarray Antennas: A technical overview and state of the art

“…Another reconfigurable reflectarray element consisting of a patch and variable length slots using MEMS switches was demonstrated in [82]. A 2-b X-band reflectarray element with electronic phase control implemented by ohmic MEMS switches was also demonstrated in [83]. The first functional MEMS reflectarray prototype operating at 26.5 GHz was recently demonstrated in [84] using aperture-coupled microstrip patch elements.…”