In this paper, two types of RF MEMS switches namely step structure and Normal beam structure are designed and analyzed using different meander techniques. Three techniques namely plus, zigzag and three-square meander were used to lower the pull-in voltage. The actuating beam is designed with the rectangular perforations affects the performance of a switch by lowering the pull-in voltage, switching speed and results in better isolation. In this paper a comparative analysis is done for all three meander techniques with and without perforations on the beam. Total six structures have been designed with the combination three meanders and two different beam structures. The proposed stepdown structure exhibits high performance characteristics with a very low pull-in voltage of 1.2 V having an airgap of 0.8 µm between the actuation electrodes. The gold is used as beam material and HfO2 as the dielectric material such that the upstate and downstate capacitance is seen as 1.02 fF and 49 fF. The FEM analysis is done to calculate the spring constant and thereby the pull-in voltage and behavior of the switch is studied with various parameters. The switch with a step structure and three-square meander configuration has shown best performance of all by requiring a pull-in voltage of 1.2 V and lower switching time of 0.2 µs. The proposed switch also exhibits good RF performance characteristics with an insertion loss below − 0.07 dB and return loss below − 60 dB over the frequency range of 1–40 GHz. At 28 GHz a high isolation of − 68 dB is exhibited.
相似文献This paper presents the design and simulation of RF MEMS switch using uniform U-Shaped meanders. High isolation and low insertion loss are the main performance parameters enhanced by considering the inductive sections on the design and developing high capacitance using HfO2 as a dielectric medium. The inductive sections in the design help maintain the device at resonance. The proposed uniform U-shaped meanders lower the spring constant and reduce the Pull-in-voltage of the switch. The performance characteristics are observed by simulating the proposed switch in the electromechanics environment using the COMSOL FEM tool. The switch exhibits a low Pull-in-voltage of 5.2 V with a very low switching time of 23.1 µs. Total capacitance of 42.19 fF is formed during upstate which provides a low insertion loss of less than 0.1 dB. Capacitance of 19.11 pF during downstate provides high isolation of − 42.11 dB.
相似文献A new radio frequency (RF) micro-electro-mechanical-system (MEMS) single cantilever series contact switch is designed as a low-insertion-loss and low-power electronic component that is intended to provide integrated control of the opening and closing signals of other MEMS devices operating over a wide frequency range (DC–60 GHz). The MEMS switching element consists of an A-type top electrode that is fixed onto coplanar waveguide lines through anchor points to reduce the insertion loss in the on-state of the device. The air gap between the top electrode and the actuation electrode of the designed MEMS switch is optimized to improve the isolation characteristics of the switch. In addition, the switching voltage required is approximately 24 V. The simulation results presented here show that the insertion loss of the switch in the on-state is less than 0.71 dB, while the minimum isolation is 20.69 dB in the off-state at 60 GHz. The proposed RF MEMS switch will be useful for communication devices and test instruments used in broadband applications.
相似文献RF-MEMS technology is indicated as a key enabling solution to realise the high-performance and highly-reconfigurable passive components that future 5G communication standards will demand for. In this work, a novel design concept of an 8-bit reconfigurable power attenuator manufactured in the RF-MEMS technology available at the CMM-FBK, in Italy, is tested and discussed. In the current Part 1 of the contribution, the RF-MEMS power attenuator design concept is discussed. The device features electrostatically controlled MEMS ohmic switches, in order to select/deselect resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. In Part 2 of the article, fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated in with a Finite Element Method software tool. Despite the attenuator complexity, the simulation approach leads to accurate prediction of the experimental behaviour. The device exhibits attenuation levels (S21) in the range from − 10 to − 60 dB, up to 110 GHz. In particular, the S21 shows flatness from 15 dB down to 3–5 dB, from 10 MHz to 50 GHz, while less linear traces up to 110 GHz. A comprehensive discussion is developed around the voltage standing wave ratio, employed as quality indicator for the attenuation levels. Finally, margins of improvement at design level are also discussed, in order to overcome the limitations of the presented RF-MEMS device.
相似文献RF-MEMS technology is indicated as a key enabling solution to realise the high-performance and highly-reconfigurable passive components that future 5G communication standards will demand for. In this work, divided in the previous Part 1 and the current Part 2, a novel design concept of an 8-bit reconfigurable power attenuator manufactured in the RF-MEMS technology available at the CMM-FBK, in Italy, is presented, tested and discussed. As reported in Part 1, the device features electrostatically controlled MEMS ohmic switches, in order to select/deselect resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. In the current Part 2, fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated in a full 3D Finite Element Method (FEM) environment. Despite the attenuator complexity, the simulation approach leads to accurate prediction of the experimental behaviour. The device exhibits attenuation levels (S21) in the range from − 10 to − 60 dB, up to 110 GHz. In particular, the S21 shows flatness from 15 down to 3–5 dB, from 10 MHz to 50 GHz, while less linear traces up to 110 GHz. A comprehensive discussion is developed around the voltage standing wave ratio (VSWR), employed as quality indicator for the attenuation levels. Finally, margins of improvement at design level are also discussed, in order to overcome the limitations of the presented RF-MEMS device.
相似文献In this paper, a novel merged LNA-mixer denoted as LNMA is proposed. The proposed LNMA consisting of a folded cascode LNA using improved derivative superposition technique and folded double-balanced subthreshold mixer using capacitor cross-coupled common-gate transconductor and it is integrated with on-chip LC voltage controlled oscillator (LC-VCO). In LNMA, a diode and power clamp based on-chip ESD protection circuit is used to tolerate ESD current of human-body-model specifications. To evaluate its performance, it is implemented in 0.18-µm MMRF CMOS process with 1-V supply, studied through post layout simulation and compared the results with other reported works. It achieves higher conversion gain of 27 dB, lower noise figure of 9.5 dB, lower input return loss (S11) of − 20 dB, higher third-order input intercept point (IIP3) of – 16 dBm and higher IIP2 of + 29.9 dBm compared to the works reported in the literature. The on-chip oscillator has the lower phase noise of – 114 dBc/Hz. The proposed LNMA and the LC-VCO achieves the power consumptions of 1.6 and 1.72 mW, respectively at 1-V power supply.
相似文献In this study, electronic properties of Manganese atom doped Graphene are studied using Atomistix Tool Kit-Virtual NanoLab (ATK-VNL), QuantumWise simulation package. All the calculations are done using density functional theory. The doping of Manganese atom creates a small band gap and this gap increases with increasing doping concentrations. Chemical potential measurements exhibit a rise in the values for pristine Graphene is − 10.48 to − 9.91 eV for single doped atom to − 9.87 eV for double doped Manganese atom to − 9.57 eV for triple atom doped Manganese. Total energy calculated for pristine, one, two and three Manganese atom doped Graphenes are as − 4506.6, − 4599.5, − 4691.97 and − 4789.31 eV, respectively. Optical spectrum plots also support the aforementioned characteristics deviation in the pristine Graphene. Transmission spectrum is also varied for pristine Graphene in comparison to one, two and three Manganese atom doped nanosheets. Density of states calculations also illustrates the rise in the values for the number of states occupied by electrons for pristine Graphene, one to three Manganese atom doped nanosheet, respectively. The flow of current reduces with increasing number of impure atoms. Understanding the effect of Manganese as dopant at different lattice sites of 2D-Graphene helps in designing conductivity tunable Graphene based electro-mechanical devices and sensors for myriad nanoelectronic applications.
相似文献This paper presents the design of a highly sensitive surface acoustic wave (SAW)-based sensor with novel structure for the longitudinal strain measurement. The sensor utilizes thin lithium niobate (LiNbO3) diaphragm as the sensing element rather than the bulk substrate. The application of the diaphragm effectively decreases the cross-sectional area of the strain sensitive element, and meanwhile reduces the resistance between the sensor and the specimen. The newly designed strain sensor is to operate around a frequency of 50 MHz. The insertion loss of − 12 dB and quality factor of 63 are obtained analytically from impulse-response model. The sensor performance with tensile testing of the steel beam is predicted by the finite element method. The prestressed eigenfrequency analysis is conducted with the COMSOL commercial software. The simulation shows the resonance frequency of the sensor shifts linearly with the strain induced in the testing beam. For the SAW sensor with traditional configuration applying 1 mm thick substrate, the strain sensitivity is obtained as 0.41 ppm/με. For the sensor with the novel design employing thin diaphragm with the thickness of 200 μm, the strain sensitivity is increased to 0.83 ppm/με. With the availability of the bulk micromachining of LiNbO3, the application of the piezoelectric diaphragm as sensing element in SAW strain sensor can be an alternative way to enhance the sensor sensitivity.
相似文献This research article presents and describes a novel design with improved performance low power consumption threshold voltage based CMOS thermal sensor for aerospace applications. The proposed temperature sensor utilizes the change in behavior of threshold voltage of MOSFET with variation in temperature. The challenge while designing the temperature sensor was to achieve the linearize output voltage with respect to change in temperature. Process corner analysis has been done to check the robustness of the circuit while performance analysis and sensitivity of the temperature sensor have been verified in the occurrence of parasitic. The proposed temperature sensor is featured with low power consumption, less power supply voltage utilization, high performance and sensitivity with inaccuracy as low as possible. The presented temperature sensor utilizes an active area of 18 µm × 9.85 µm with 117 nW power consumption. An improved linear performance with an inaccuracy of merely − 0.01 to + 0.47 °C over a wide temperature range of − 20 to + 120 °C is presented here. The sensitivity of proposed temperature sensor is found to be as high as 0.77 mV/°C. The proposed temperature sensor is realized and tested in Cadence virtuoso mixed signal design atmosphere using 0.18 µm CMOS technology and further investigated with support of tool from Mentor graphics. The engaged area of pad-limited chip is measured to be 0.96 mm2.
相似文献This paper presents a dielectric material selection methodology for RF-MEMS switch used for radio frequency applications. Here Ashby’s material selection approach is used to optimize the performance indices of RF-MEMS switch such as dielectric charging, stability, hold down voltage and RF performance. In this work, dielectric constant (ɛ r), electrical resistivity (ρ), thermal conductivity (λ), thermal expansion coefficient (α), Young’s Modulus (E) are chosen as material indices of dielectric layer in RF-MEMS switch to evaluate the various performance indices. The Ashby’s material selection charts shows that Al2O3 and SiN are the best suitable material for dielectric layer in RF-MEMS switches to exhibit improved performance for radio frequency applications.
相似文献A unique tiny wideband antenna with improvements in fundamental features is offered. The antenna consists of a crown-shaped patch and an incomplete ground plane. The proposed patch shape is constructed by introducing multiple truncated circular-shaped arcs, which help to enhance the performance of the designed antenna. A unique strategy of etching the substrate structure, is integrated which aims to provide a useful solution for the excitation of the surface waves within the microstrip antenna. The essential attributes including impedance bandwidth and radiation efficiency of the recommended antenna are strengthened after the removal of these portions. The recommended antenna can be used for X-band applications with a compact size of 30 × 30 mm2. The usable impedance bandwidth (S11 ≤ 10 dB) covered by the proposed antenna is 6.2 GHz and ranges from 5.8 to 12 GHz. The antenna is experimentally tested to confirm the outcomes of the simulation thus, a satisfactory agreement is reached between simulated and measured results that prove the antenna’s validity for wideband operations.
相似文献