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This paper presents the design of flexible parasitic element patch (FPEP) antenna with defects on ground plane at ISM band for biomedical application. The antenna resonates at 2.46 GHz frequency with reflection coefficient of −16.8 GHz in free space and at 2.45 GHz frequency when being placed on cotton and the single layer skin tissue of human body. The proposed parasitic element patch antenna is used to measure the body temperature, and the specific absorption rate (SAR) of the proposed antennas is 1.0 W/kg. The measurement data with respect to reflection coefficient, and radiation pattern are presented.

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This Paper Presents the design and simulation of RF MEMS switch taken on Microstrip patch antenna loaded with the circular type CSRR. The Tunability of the patch antenna is achieved when the two switches moves from upstate to down state arranged on the feeding line provided with the CPW. The actuation voltage required to move the switch downwards is 7.6 V. The switch operates at transition time of 0.8 lsec with the capacitance ratio 10. The return loss (S 11 ) of antenna -28.67 dB is observed at the frequency of 19 GHz when one switch is in on state and at 16 GHz frequency the S 11 of -29.31 dB is achieved by actuating the 2 switches at a time, which gives the reconfigurable property of the antenna. The antenna provides 2 GHz and 5 GHz frequency shift when single and both the switches are in on state. The antenna can be tuned for various applications in the range of 15-30 GHz frequency. The characteristics of switch has been observed by simulating the switch design in FEM tool and results have been compared with theoretical calculations. The tunable characteristics of antenna has been observed and presented by using HFSSV.13 tool.

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Movable suspended microstructures are common features of sensors and devices in the field of micro electro mechanical systems (MEMS). This paper addresses the study of approach to model the capacitance for the crab-type meander-based RF MEMS shunt switch with etching holes on the beam. The presented paper evaluates the parallel-plate capacitance and fringing-field capacitance caused by the etching holes on the beam and introduces empirical formulae. From the literature study, an accurate empirical formula is presented. The capacitance involves a parallel plate and a fringing field. The parallel-plate capacitance term is proposed by the authors of this work; the fringing-field capacitance term is adopted from previous work. The proposed accurate empirical capacitance formulae are derived by curve fitting the simulated values through the commercially available FEM solver. The two existing benchmark models of fringing-field capacitance are used to modify the perforated MEMS switch to obtain the proposed formula. With the existing models and presented formula, the capacitances are computed for a wide range of dimensions; the simulated results of the presented formula are validated with the calculated results. The deviation of the presented formula has an error estimation of ±0.1%. The variation of the capacitance with different deictic thicknesses and errors is estimated and analyzed for the presented formula. The Mejis model is found to be satisfactory for a lower air gap and a 1-µm-thick beam. The Yang's model is sufficient for a higher air gap and a large number of etching holes. The proposed formulae are good for the ligament efficiency µ ≤ 0.5, with thickness >1 µm, and the deviation of error estimation is within ±5%. INDEX TERMS Fixed-fixed beam, etching holes, ligament efficiency, RF MEMS, parallel-plate capacitance, fringing-field capacitance.

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