Parameter Analysis of Millimeter-Wave Waveguide Switch Based on a MEMS-Reconfigurable Surface

IEEE Trans. THz Sci. Technol.

et al. 2016

Self Cite

This paper presents a submillimeter-wave 500–550-GHz MEMS-reconfigurable phase shifter, which is based on loading a micromachined rectangular waveguide with 9 E-plane stubs. The phase shifter uses MEMS-reconfigurable surfaces to individually block/unblock the E-plane stubs from the micromachined waveguide. Each MEMS-reconfigurable surface is designed so that in the nonblocking state, it allows the electromagnetic wave to pass freely through it into the stub, while in the blocking state, it serves as the roof of the main waveguide and blocks the wave propagation into the stub. The phase-shifter design comprises three micromachined chips that are mounted in the H-plane cuts of the rectangular waveguide. Experimental results of the first device prototypes show that the microelectromechanical system (MEMS)-reconfigurable phase shifter has a linear phase shift of 20° in ten discrete steps (3.3 bits). The measured insertion loss is better than 3 dB, of which only 0.5–1.5 dB is attributed to the MEMS surfaces and switched stubs, and the measured return loss is better than 15 dB in the design frequency band of 500–550 GHz. It is also shown that the major part of the insertion loss is attributed to misalignment and assembly uncertainties of the micromachined chips and the waveguide flanges, shown by simulations and reproducibility measurements. The MEMS-reconfigurable phase shifter is also operated in an analog tuning mode for high phase resolution. Furthermore, a detailed study has been carried out identifying the reason for the discrepancy between the simulated (90°) and the measured (20°) phase shift. Comb-drive actuators with spring constant variations between 2.13 and 8.71 N/m are used in the phase shifter design. An actuation voltage of 21.94 V with a reproducibility better than σ=0.0503 V is measured for the actuator design with a spring constant of 2.13 N/m. Reliability measurement on this actuator was performed in an uncontrolled laboratory environment and showed no deterioration in the functioning of the actuator observed over one hundred million cycles.

QC 20170201

Section: Concept and Designmentioning

confidence: 99%

Submillimeter-Wave 3.3-bit RF MEMS Phase Shifter Integrated in Micromachined Waveguide

Shah

Decrossas

IEEE Trans. THz Sci. Technol.

et al. 2016

Self Cite

QC 20170201

“…This design requires a highly reduced "b"-dimension waveguide to achieve contact to the broadwall and will have higher losses as a result. An alternative approach utilizes a reconfigurable surface placed in the cross section of the waveguide [2]. At W-band this device showed low losses of 0.65 dB, but scaling to higher frequencies the presence of the comb in the waveguide could incur significant insertion loss and degrade the return loss of the switch [3].…”

Section: R F Microelectromechanical Systems (Rf-mems) Devicesmentioning

confidence: 99%

A 700-GHz MEMS Waveguide Switch

Reck

IEEE Trans. THz Sci. Technol.

Chattopadhyay

2016

A low-loss microelectromechanical systems (MEMS) waveguide reflect switch is demonstrated operating across the WM-380 (WR-1.5) waveguide band. The design uses a large deflection MEMS actuator to mechanically obstruct a reduced height waveguide to create the switch. The MEMS device exhibits 3 dB of insertion loss across the band in the open state, over 20 dB of isolation when closed, and better than 20 dB of return loss. Lifetime testing of this device demonstrates 5.07 million cycles before it failed in the closed state. Index Terms-Reflect switch, RF microelectromechanical systems (RF-MEMS), silicon micromachining.

“…MEMS-based RF devices are rare above 100 GHz and have so far been reported only up to a maximum frequency of 220 GHz [7]. This paper reports on the first ever MEMS reconfigurable sub-millimeter wave component: a RF MEMS switch able stub using a MEMS switched surface [8] operating in the frequency band between 500 to 600 GHz. It is the first MEMS microwave component operating above 220 GHz and the first MEMS waveguide component over 110 GHz.…”

Section: Introductionmentioning

confidence: 98%

500-600 GHz RF MEMS based tunable stub integrated in micromachined rectangular waveguide

Shah

Decrossas

2015 IEEE MTT-S International Microwave Symposium

et al. 2015

This paper presents a 500-600 GHz switchable E plane waveguide stub tuned MEMS device. It is the first ever RF MEMS component reported to be operating above 220 GHz. The micromachined E-plane stub can be blocked/unblocked from the micromachined waveguide by using a MEMS-reconfigurable surface. The surface is designed so that in the blocking state it is in the H-plane and comprises the roof of the main waveguide, whereas in the non-blocking state it comprises a transmissive E plane surface for the stub. The measurement results of the first prototypes show a return loss better than 15 dB from 500-600 GHz. The insertion loss is better than 3 dB up to 550 GHz, and better than 4 dB up to 600 GHz. The switchable stub can be utilized as a basic reconfigurable device for tuning/matching of waveguide components under operation; the implemented prototype switchable stub achieves a (measured) tuning of 2.50 at 500 GHz, with a change in S21 better than 0.15 dB for the whole band. The paper further shows that the reconfigurable stub can also be operated in analog tuning mode. This paper also demonstrates that MEMS-reconfigurable E-plane surfaces can be designed and operated deep into the submillimeter-wave frequency range.Index Terms -Micromachined rectangular waveguide, RF MEMS, submillimeter-wave, terahertz, THz, waveguide stub.