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In this work, broadband linear to cross and circular to circular polarization converter for K and Ka-band applications is proposed. The metasurface comprises a novel H-shaped unit cell printed on 1.2 mm thin FR-4 grounded dielectric substrate. It exhibits 90% polarization conversion ratio (PCR) over a bandwidth of 22.26 GHz (17.97-40.23 GHz) with 76.5% FBW maintaining a minimal PCR of 92.5%. The converter also maintains handedness for circularly polarized incident wave. Surface current distributions at different resonant frequencies are analyzed to illustrate the reason behind the broadband behavior.The converter design is simple with the cell periodicity of 0.209λ o and thickness of 0.071λ o , where λ o is the free-space wavelength corresponding to the lowest frequency of the band. Monostatic and Bistatic RCS analysis of the designed converter is performed, demonstrating greater than 10 dBsm RCS reduction over all the frequency range. It shows 16 to 30 dBsm at resonant

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This paper presents a radio frequency micro-electromechanical system (RF MEMS) based 3-bit phase shifter using MEMS single-pole-eight-throw (SP8T) switches. Devices are fabricated on 635 µm alumina substrate utilizing on the coplanar waveguide (CPW) transmission line. Single switch dimensions are 0.14  ×  0.23 mm2 which is much smaller than Si-on-insulator switches. The symmetric and compact SP8T switch is the primary building block of the 3-bit phase shifter. The SP8T switch results in isolation levels of 31–15 dB, return loss of 33–18 dB and insertion loss of 0.6–1.9 dB, respectively, at 26–40 GHz. Later, two SP8T switches are connected back to back to develop the 3-bit phase shifter using different delay lines at 35 GHz. Finally, the phase shifter provides average return loss of better than 14 dB and average insertion loss of 4.4 dB over the 34.75–35.25 GHz. Measured average phase error is less than 0.98° at 35 GHz. The total area of the fabricated 3-bit phase shifter is 5.95 mm2. SP8T switches are capable of handling 0.1–1 W of power up to 100 million cycles which is sufficient power handling capability for wireless communication systems. Reliability of the phase shifter is extensively characterized with different incident RF powers at room temperature (25°C) and discussed in detail. To the best of the authors’ knowledge, this is the first reported MEMS 3-bit phase shifter in the literature that has used a minimum number of switching elements per phase state.

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The design, development, and characterization of broadband (1-30 GHz) micro electromechanical systems (MEMS) based electrostatically driven lateral switching networks are presented in this paper. Initially, single switch performances are optimized, and later it is used to develop different switching networks like single-pole-double-throw (SPDT), single-pole-three-throw (SP3T), and single-pole-six-throw (SP6T). All switches are extensively characterized including reliability testing. Switching networks demonstrate measured return loss of better than 21 dB (11.4 dB) with worst case insertion loss of 0.67 dB (∼5 dB) and isolation of better than 31 dB (17.7 dB) at 3.5 GHz (28 GHz) for 5G communications. Switching networks tested for > 1 billion cycles with 1 W of RF power are found to be operational. Maximum fabricated switch (SP6T) area is ∼0.7 mm 2 including bias lines and pads.